Submitted Conference Abstracts

Submitted Conference Abstracts

Below is the collection of Abstracts submitted for the 17th AAPA International Flexible Pavements Conference 2017.  Please note that these do not necessarily reflect the Conference Program.

AAPA will be awarding a Best Abstract Award, to the author of the best paper presented at the conference, as judged by the scientific committee.

Tehran Road Management System (TRMS)

Pedram Bagherian1Kayvan Aghabayk1, Tahmaz Ahmadpoor2 

  1. School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran
  2. CEO, Tehran Engineering & Technical Consultancy Organization, Tehran, Iran

Roads and in particular their Pavements are the fundamental components of road network that need continuous maintenance. A monitoring method and efficient pavement management system are needed for optimizing maintenance operations. Data pictorial record is one of the practical methods of urban streets monitoring which contains numerous benefits. This type of database gives a better description of existing conditions. The use of GIS to record locations of pavement damages results in full compliance of collections with no repetitive information recording. 

This paper presents a pavement management system (PMS) used in Tehran, Iran. The system is GIS-based and called TRMS (Tehran Road Management System). TRMS has a pictorial and very extensive database and applies a unique and special method to determine the road rehabilitation operations and pavement maintenances. The main objective of the system is to prioritize the pavement maintenance and rehabilitation operations. The paper explains the performance concepts, pavement deterioration and components of an efficient pavement management system through describing TRMS.  

High Modulus Asphalt to Prevent Rutting at Intersections

Greg Arnold1 

  1. Road Science, Mt Maunganui, TAURANGA, New Zealand

Local authority pavements at intersections often show shoved and rutted asphalt.  A main reason for this is the static and slow loading on the asphalt while heavy vehicles stop at limit lines.  Traditional asphalt becomes very soft under static loads and for this reason aircraft stopping areas are concrete slabs rather than asphalt.  A recent example of this was the Te Rapa/Wairere Drive intersection in Hamilton that had 50mm ruts in a 400mm thick asphalt pavement.  To repair the rutted areas a special High Modulus Asphalt that uses a very hard binder with a penetration grade of 15 was used.  This high modulus asphalt was proven to have a 100 times more rut resistance than other mixes trialled when tested in the Repeated Load Triaxial apparatus that simulates slow loading times.  The High Modulus Asphalt is also high in binder content to give improved fatigue/crack resistance.   This combination of high modulus and improved fatigue reduces the pavement depth by a third which is an ideal solution for Local Authority urban roads that are constrained by curb and channel while still being able to resist rutting especially as axle loads of buses are increasing.

An Assessment of the Asphalt Fatigue Equation for Foamed Bitumen Stabilised Materials

Ethan Dardras1Hossein Asadi2, Hamid Nikraz1 

  1. Civil Engineering, Curtin University, Perth, Western Australia, Australia
  2. GHD, Brisbane City, QUEENSLAND, Australia

The basis for the Austroads method for the design of in-situ foamed bitumen stabilised pavements is that the fatigue life of the pavement can be predicted using the same asphalt fatigue equation as applied in the Austroads Guide to Pavement Technology Part 2, Structural Design. The aim of this paper is to investigate the applicability of Austroads fatigue equation for the design of in-situ foamed bitumen stabilised materials. A new four-point bending device was utilised as a scaled up version of the standard four-point bending apparatus which allows testing of much larger beams by removing the constraint that the maximum width and thickness are dominated by maximum aggregate size. The large beam testing programme has shown some variables in the fatigue performance of the material.

The Upgrading of Provincial Main Road P255 in Durban, South Africa: An Initiative Towards Environmentally Sustainable Road Design and Construction Methodology

Shan Hansraj1, Tony Lewis1, Wynand Nortje2, Simon Tetley1, Kit Ducasse3, Yesh Balaram1 

  1. VNA Consulting, Westmead, KWAZULU-NATAL, South Africa
  2. Asphalt Supplier, National Asphalt, Durban, KwaZulu-Natal, South Africa
  3. Transport, KwaZulu-Natal Department of Transport, Pietermaritzburg, KwaZulu-Natal, South Africa

The upgrading of the six-kilometre urban arterial between Durban’s Hillcrest and Waterfall suburbs from a two-lane single carriageway to a four-lane dual carriageway was completed in August 2015. This paper covers the manufacture and paving of the asphalt base, which contained 25% reclaimed asphalt and was manufactured as a “Warm Mix” Asphalt using foamed bitumen technology.

 This was the first full-scale project in South Africa where Warm Mix Asphalt was manufactured using foamed bitumen, with mixing and paving temperatures being reduced by around 30 degrees centigrade below those of similar conventional asphalt mixes. This paper reports on the successful use of nearly 20 000 tons of this mix in the base layer.

 The paper also touches on the recycling of concrete waste. Altogether approximately 8 000 m3 of crushed concrete was used, both in the pavement layers as well as for the base in the sidewalks. This paper details the process and covers the benefits that were found in recycling this waste material.

 With almost two years having lapsed since the full length of the upgraded road was opened to traffic, the paper explores the short-term performance of the pavement.  

 Keywords: Warm mix asphalt, recycled asphalt, recycled waste concrete, pavement performance

Assessment system for thin asphalt surfacings in Queensland

Andrew Beecroft1, Jason Jones2, Joe Grobler1, Erik Denneman3 

  1. ARRB Group Ltd, Albion, QLD, Australia
  2. Queensland Department of Transport and Main Roads, Brisbane
  3. Australian Asphalt Pavement Association, Brisbane, Queensland, Australia

Australian road authorities presently resurface many asphalt roads across the network with overlays of thickness 40 mm or greater. An alternative approach is thin asphalt surfacing systems, which are comprised of a heavy tack coat followed by a coarse gap-graded aggregate, with a typical thickness range of 12-30 mm. Thin asphalt surfacing systems have been shown to have significant functional performance benefits, while leading to cost savings in materials, easier paving operation and the ability to re-open roads shortly after paving. Many jurisdictions around the world base their road surface renewal programs around the use of thin asphalt surfacing systems.

The two fundamental applications for thin asphalt surfacings in Queensland (and Australia in general) are as a functional layer to restore skid resistance and safety properties in higher traffic environments over existing structurally sound pavements, and as a rehabilitation treatment over existing spray-seal or thin asphalt layers with the primary consideration being to provide a surfacing treatment that delivers increased life in a high deflection environment.

Many propriety products have been used around the world, so a process of approval for these products is required before they can be applied in Australia. The mechanism for acceptance in the UK and South Africa are the product approval schemes HAPAS and Agrément respectively.

ARRB and the Queensland Department of Main Roads, through the NACOE research program, investigated prior experiences with thin asphalt surfacing systems and researched product approval schemes around the world. With the help of AAPA, a workshop was held with industry representatives to discuss the most appropriate path for assessment, and ultimately procurement, of thin asphalt products.

Following these discussions, a TIPES Supplement for thin asphalt surfacing systems was developed and is now published. Consultation with industry is ongoing with respect to possible product applications and future trials.

How Close is Too Close?

Craig Beyers1 

  1. Assured Monitoring Group, Tennyson, QLD, Australia

Planning policies across major cities in Australia actively encourage increased dwelling density, sustainable infill development and transit oriented development to maximise land use and minimise urban sprawl. For asphalt manufacturing facilities, this increased densification can often lead to conflict between lawfully operating, existing asphalt plants and new residences.

Asphalt production in Australia, as with most industries, strives for on-going improvements to both advance the performance of pavements and provide for cost-effective recycling of waste materials. The use of reclaimed asphalt pavement (RAP) and crumbed rubber (soured from recycled tyres) as inputs into road pavements are two environmentally sustainable improvements gaining traction in Australia.

This paper provides a comparison of odour emissions from traditional hot mix asphalt production with emissions from a range of RAP and crumbed rubber products and highlights how the use of these sustainable products could result in a worsening of land use planning conflicts moving forward. Through this analysis, the paper provides guidance for asphalt producers seeking to introduce these products into new or existing plants.

Effectiveness of rejuvenators on RAP binder long-term performance

Alessandro Borghi1, Filippo Giustozzi1 

  1. School of Engineering, Civil and Infrastructure Discipline, Royal Melbourne Institute of Technology (RMIT), Melbourne, Victoria, Australia

The increasing concern for the global warming, together with the rising awareness of the environmental sustainability, have been leading the modern society to reduce the carbon footprint by promoting eco-friendly materials. In this sense, the asphalt industry is striving to increase the percentage of reclaimed asphalt pavement (RAP) material and reduce the amount of virgin and non-renewable bituminous materials in new asphalt mixtures. Research has already demonstrated that high RAP content mixtures can be obtained by using bio-rejuvenators; this innovative solution take advantage of natural and organic bio-oil to restore some properties of the aged RAP binder.

This study aims to investigate the rheological properties of rejuvenated binders at four different laboratory-produced ageing stages (unaged, RTFO, PAV and PAVx2) to evaluate the long-term performance of rejuvenated RAP binder. For this purpose, binder recovered from RAP source was rejuvenated with a bio-oil derived from pine trees.

Results showed that the binder initial properties can be restored and, specifically, fatigue and rutting performance of rejuvenated RAP binder can be even improved if the proper dose of bio-rejuvenator is added.

Keywords: RAP, rejuvenated asphalt binder, rheology, linear amplitude sweep test, multiple stress creep recovery test

Optical Measurement of Deflection Bowls

Marko Cickovic1, Nicolas Diefenbach1, Andreas Eichhorn1 

  1. Technische Universität Darmstadt, Darmstadt, HESSEN, Germany

The following studies confirm that vertical deflections can be measured with optical measurement methods. For this purpose, a laser beam and a Position-Sensitive Device (PSD) were used to detect vertical displacements, caused by a Falling Weight Deflectometer (FWD).

This paper describes preliminary studies that confirm the basic suitability of optical measurement methods. With a variation of distances between the load-inducing FWD and the laser and a variation of impulse forces (achieved by varying falling heights of the FWD), a parameter study was established to see, whether the rather small deflections can be detected by the PSD or not.

At this stage of studies, the boundaries of the measurement method become clear: a higher temporal resolution is needed, in order to record the exact time history of the displacement. Additionally, rather stiff pavements are not suitable for this measurement method, as the small deflections cannot be clearly distinguished from data noise. As a positive result it can be stated that the deflection peaks, measured by the optical measurement system correspond to the ones measured by the FWD – in conclusion: the measurement method is capable of detecting deflections of pavements.

Non-Destructive Testing of Layer Bonding with the Falling Weight Deflectometer (FWD)

Marko Cickovic1 

  1. Technische Universität Darmstadt, Darmstadt, HESSEN, Germany

Missing or insufficient bonding between layers leads to stress redistributions and consequently to a higher loading of the remaining construction. Therefore the examination of layer bonding is highly crucial. Currently the testing methods require drilling cores, which are being destroyed during the testing procedure and are not available for further examinations and/or a repetition of the layer bonding testing procedure. A non-destructive testing procedure would eliminate these problems, as, ideally, there is no need for drilling cores to be taken out of the existing road construction and the specimens are not being destroyed during the testing procedure.

The following article therefore focuses on the non-destructive testing of layer bonding by using FWD measurements. After a brief introduction into the field of layer bonding, failure mechanisms and already known and described approaches on the non-destructive testing of layer bonding, the Darmstadt FWD interpretation method is being introduced, as well as its capability of giving insight into the quality of layer bonding of the examined road construction. The theoretical approach is then being verified with the help of an example measurement. The comparison between non-destructive testing of layer bonding with the FWD and the actual on-site layer bonding of the examined asphalt pavement shows good results concerning the accuracy of detecting areas of poor layer bonding without the necessity of excessive core extractions. 

Early Intervention - Pay Less Get More in the Longer Term

Vincent Conserva1 

  1. Double Bond Polymers, EAST DONCASTER, VIC, Australia

   

For each conference theme a number of topics have been suggested. Authors are encouraged to put forward additional topics that address the main themes.

Next Generation Bituminous Surfacings

  • Advances in spray seal technology
  • High friction courses
  • Cold mix asphalt
  • Binder technology
  • Crumb rubber modified binder and seals

Rhinophalt is a natural asphalt fortified low cost preservation material. When utilised as a surface treatment it has been proven to extend the life of treated areas for a significant number of years. Applied to a reasonably sound surface over a solid structure Rhinophalt is ideally suited as part of a preventative maintenance regime. Optimum results will be achieved by applying Rhinophalt within the first few years after laying a surface. All classes of highways, airfield runways and other asphalt surfaces can be treated with Rhinophalt. Test results have shown that Rhinophalt will preserve the treated surface for between 5-7 years and repeated applications will extend this life further. 

In addition to growing environmental pressure, the financial and disruption costs associated with conventional resurfacing to bituminous bound pavements are becoming an ever increasing burden to owners and asset managers. Through its proven ability to halt the surface deterioration of these essential infrastructure assets, I will show how Rhinophalt can significantly extend the serviceable life of asphalt and macadam pavements thus delivering unparalleled social, financial and environmental benefits when compared to conventional methodologies and I will focus on some case studies to demonstrate how it can be applied in the Australian road context.  

Independent evaluation has demonstrated a reduction of over 94% in the carbon footprint, when comparing the use of RHiNOPHALT® with conventional maintenance methods. RHiNOPHALT® IS THE ONLY BBA HAPAS APPROVED AND CE MARKED ASPHALT PRESERVATION SOLUTION THAT EXTENDS ASPHALT SURFACE LIFE.

Improved characterisation of fatigue in asphalt at Queensland temperatures

Erik Denneman1, Peter Bryant2, Joe Grobler3 

  1. Australian Asphalt Pavement Association, Eight Mile Plains, QLD, Australia
  2. Queensland Department of Transport and Main Roads, Brisbane
  3. ARRB Group, Brisbane

Full depth asphalt pavements with thicknesses in excess of 400 mm have been designed for heavily-trafficked urban roads in Queensland. The high thickness is a consequence of the fact that the current pavement design models, including the Austroads Guide to Pavement Technology, predict an increased rate of fatigue damage accumulation at higher temperatures. This negative correlation between pavement temperature and fatigue performance of asphalt pavements however, does not agree with field observations. Available field data indicates that the majority of fatigue damage accumulation occurs at low temperatures rather than at elevated temperatures.

This paper presents the outcomes of a three-year study investigating whether improvements to pavement design models can be made to more accurately reflect the nature of fatigue damage accumulation in thick asphalt pavements in Queensland.

The fatigue behaviour of typical Queensland asphalt mixes was characterised over a range of temperatures. Changes to the asphalt pavement design method were proposed to allow the use of mix specific flexural modulus master curves and fatigue models in pavement design. The use of modulus master curves will result in a higher modulus at elevated temperatures, resulting in reduced pavement design thicknesses. The fatigue results presented in this study indicate that it is possible to design mixes for improved fatigue performance at elevated temperatures. Use of these mixes will also result in reduced thickness requirements. It is envisaged that the introduction of the option to use mix specific modulus master curves and fatigue models will encourage the use and development of asphalt mixes that have improved characteristics for use in the Queensland climate.

Development and validation of a crumb rubber modified open graded asphalt specification

Erik Denneman1Ian Clarke2, Jason Jones3, Andrew Beecroft4, Joe Grobler4 

  1. Australian Asphalt Pavement Association, Eight Mile Plains, QLD, Australia
  2. Downer Group, Bli Bli, Queensland
  3. Queensland Department of Transport and Main Roads, Brisbane
  4. ARRB Group, Brisbane

Millions of tyres reach their end-of-life every year in Australia. When expressed in equivalent passenger units (EPU) to correct for the weight difference in tyres used by different vehicle types, two EPUs are scrapped per Australian per year. Rubber and carbon black represent approximately 70% of the weight of a tyre. A high application destination for these materials when recycled is as crumb rubber modifier (CRM) in bitumen used in road construction. CRM binder can be used to increase the cracking resistance and durability of both asphalt and spray seals. CRM binder is ideally suited for use in open graded asphalt (OGA). The higher film thickness that can be achieved without binder drain down, on account of the high viscosity of the CRM binder, offers significant durability benefits for OGA. This paper presents the process followed in developing and validating an Australian CRM OGA specification. The specification introduces binder technology widely used in California and Arizona to Australia. Binders and an OGA mix design were produced locally to comply with the specification. A paper further describes the construction of the first trial section with the CRM OGA. In order to address any concerns with regards to harmful emissions related to CRM technology, emissions were monitored at the trial. The results are presented in the paper.

Towards more robust seals for high trafficked roads

Trevor Distin1, John Esnouf2 

  1. Colas Australia, Winston Hills, NSW, Australia
  2. VicRoads, Melbourne, Victoria, Australia

With the increase in the number of heavy vehicles using their roads, VicRoads is anticipating the need to place more robust, waterproof and durable seals in their periodic maintenance treatments to protect existing pavements. To gain insight into potentially more robust treatments, VicRoads has been considering incorporating trial sections with alternative treatments in the upcoming construction works on the Western Highway. The Western Highway has been chosen because of the high volumes of heavy vehicles using the route as a major connector between Melbourne and Adelaide. The proposed trials attracted the attention of Western Quarries who were in the process of constructing an access road to their new quarry. They decided to be early adopters of the principle of more robust seals and instigated trials of their own in anticipation of the high traffic volumes and loadings that are expected on the quarry access road. The seals types selected for the purposes of the Western Quarries trial were i) 20/7/7mm triple seal based on successful robust seals placed in South Africa ii) XSS 20/10mm double seal iii) 10mm emulsion seal placed under a XSS 14/7 mm double seal with geotextile incorporated into the seal and iv) XSS 14/7 mm double seal as a control. All seal trials are to be placed on a previously primed granular surface. 

The seals are to be constructed at the beginning of February 2017 and monitored under traffic for signs of embedment, flushing and cracking. Tests will be conducted to measure the water permeability and for any changes in surface texture. It is anticipated that the construction and evaluation of these trial seals will provide useful information that will benefit the further trials on the Western Highway and help with the development of more robust seals for very high trafficked roads.

Comparison of asphalt performance between full-scale accelerated pavement testing and two laboratory wheel-tracking tests

Peter Eady1Didier Bodin1 

  1. Australian Road Research Board, Vermont South, VICTORIA, Australia

The resistance of deformation of asphalt mixtures can be determined in a number of ways, including full-scale accelerated pavement testing as well as smaller-scale wheel-tracking laboratory tests. This paper describes a comparison of the performance of a Class 320 hot-mix dense graded asphalt mix using both accelerated pavement testing and laboratory tests.

The accelerated pavement testing examined the performance of a 150 mm thick asphalt layer, placed on top of a 300 mm thick cement treated crushed rock subbase. The material was subjected to over 100,000 cycles of a 50 kN load half-axle load. The pavement temperature was controlled via radiant heating, with a targeted mid-depth pavement temperature of 45°C.

Laboratory tests examined the deformation resistance of the same asphalt mix using wheel-tracking tests. Two sizes of test slabs were examined, the large size described in European standard EN12697-22 (500x180x100) as well as the size in the Austroads test method (300x300x75). Each size was tested at both 45°C (the same temperature as the accelerated pavement testing) and 60°C (the standard reference test conditions listed in Austroads test method AG:PT/T231).

The evaluation of the results examined the deformation performance of the three approaches, and the laboratory wheel-tracking tests to full-scale deformation performance were compared.

At a later stage, a similar process will be performed using foamed bitumen stabilised materials with varying percentages of recycled asphalt pavement.

Keywords

Accelerated loading, wheel-tracking, laboratory tests

Biographies

Peter Eady is a Senior Engineer at ARRB. His research has focused on projects dealing with improved understanding of the performance of foamed bitumen stabilised (FBS) pavements.

Dr Didier Bodin is a Principal Research Engineer at ARRB. His research has focused on the current Austroads projects dealing with rut-resistance characterisation, modelling and prediction of unbound granular materials response.

Successful Compaction using Vibratory Pneumatic Tire Roller

Hitoshi Fujita1 

  1. SAKAI HEAVY INDUSTRIES,LTD., Minato-ku, TOKYO, Japan

A vibratory pneumatic tire(VPT) roller has been developed in Japan. The effectiveness of this type roller has come to light through comparison test with conventional static pneumatic tire roller. It was found that that VPT roller could achieve the required level of density in a HMA mix using fewer rolling passes and uniform density distribution throughout the depth of HMA lift. The combination of the kneading action of the pneumatic tires and the vibratory force applied through the pneumatic tires provides “the best compaction of HMA mixture”. Recently VPT roller has been used not only thick lift HMA mixture but also thin layer HMA mixture or surface dressing like chip seal especially in Australia . In such cases VPT roller provides good aggregate bonding and protect crashing of the aggregates and fretting of the aggregates. Finally the usage of VPT roller results in good performance asphalt pavement construction.

Investigation of asphalt joint compaction using discrete element simulation

Ehsan Ghafoori Roozbahany1, Manfred Partl1, 2 

  1. Civil and Architectural Engineering, Royal Institute of Technology (KTH), Stockholm, STOCKHOLM, Sweden
  2. EMPA, Zurich

Constructing asphalt joints with high qualities plays a vital role on preventing premature failures on the pavements. Previous studies have suggested that many construction parameters directly and indirectly influence the quality of the asphalt joints. Since there are uncertainties about the significance of each of these parameters on the quality of the finalized joints, there is still need for closer and more detailed studies for providing a better ground for further improvements in this field. This study is an attempt towards analyzing the possible impacts of the thickness, surface roughness of the bottom layer, the joint interface shapes (geometries), and gradation as well as compaction techniques on the interlock between the hot and the cold sides of the joints using a commercially available discrete element software. Hence, discrete element asphalt mixtures were generated and their input parameters were qualitatively adjusted based on the results of an earlier study on the required loads and flow behaviors of asphalt mixtures under simulated compacting loads; then, the impact of each asphalt joint construction parameter was analyzed and compared for two different cases; the results of the analysis were then used to report the constructing parameters with highest potentials for improving the mechanical properties of asphalt joints. The results of this study also allowed to justify some of the previous recommendations mentioned the literature in a more comprehensive way.  

ARM 2500: The next Cold-in-place generation workshop by EIffage in France

Claude E GIORGI1, Yann LALLAIN2 

  1. EIFFAGE Infrastructures, Vélizy-Villacoublay, ILE DE FRANCE, France
  2. EIFFAGE Route, Sud-Ouest, Pessac, Aquitaine, France

   

Next Generation Bituminous Surfacings

  • Cold mix asphalt

 

In a context of global decrease of the road budgets of maintenance, construction firms are in search of technical solutions allowing to minimize the costs while protecting the objectives of eco-responsibility and sustainable development. In this context, the solutions of in place recycling roads are recognized to be particularly successful. Eiffage Travaux Publics has a long experience of reprocessing in place with hydraulic binders and mixed binder thanks to the ARC 700 and ARC 1000 reprocessing workshops which have already reinforced more than 11 million m2 of pavements in France and abroad. It is therefore from this long experience that EIFFAGE Travaux-Publics group decided in February 2014 to develop a new workshop specializing in emulsion or bitumen foam recycling and benefiting from the latest advances both in terms of “material” technology and in terms of the  “bitumen emulsion design” . Processing according an downcut process and using a specially designed emulsion, this workshop enables to recycle down to 15 cm of old surface and base layers all together with the addition of only 2.5 to 3.0 ppc bitumen emulsion. Thanks to these advantages, EIFFFAGE has become in three years the biggest player in France in that technique recycling more than 200 000 square meters of roads for the year 2016 only.

This article will present the main technical specificities of the ARM 2500 workshop and the realization of the RD 117 project for the Ariège General Council in the southwest of France.

Other developments of this technology called “Recyclean” for treatment of polluted pavements with tar and/or abestos and “Recytal” using a bio-based binder will be evoked.

Flexible Pavements for Logistic Platforms Design Method & Case Study

XAVIER GUYOT1 

  1. COLAS ASIA PACIFIC, BANGKOK, -, Thailand

Pavement for logistics platforms for reception and handling of containers are generally designed using the British Port Authorities Manual, leading to thick structure with cement treated materials. However, flexible materials with specific modified asphalts can also be a cost effective solution easier to construct and maintain for this type of pavement.

Owing to their extreme loads, the handling equipment moving on these port or multi modal platforms apply very heavy loads to the pavements, in no way comparable to those produced by the heaviest road traffic; the strict application of the roadway structural design method to the case of logistics platforms most often leads to obvious over-designing.

However, research works have been recently carried out to adapt the French rational approach used for the structural design of road pavements with Alize software to apply it for these specific pavements. This new methodology based on mechanical analysis models for pavements, coupled with failure criteria for materials, leads to the development of innovative solutions and optimized structures.

This proposed design methodology has already been used for a couple of years on several projects (multi modal, port, industrial platforms) worldwide with success.

Specific Asphalts for Airport European Experience

XAVIER GUYOT1 

  1. COLAS ASIA PACIFIC, BANGKOK, -, Thailand

Due to the expected increase in air traffic movements around the world and its impact on the environment, the requirement to build more sustainable and low maintenance airfield infrastructures has become very important. One solution consists in using high performance asphalt materials in order to provide a better sustainable whole life cost solution.

The French “Norme” for asphalt concrete surfacing on airfields – Béton Bitumineux pour chaussées Aéronautiques (BBA) – represents an alternative solution to traditional Marshall Asphalt (MA). BBA was seen to be easier and quicker to manufacture and install than MA, without compromising performance. In particular, surface friction is achieved without the need for grooving. For many years now, this asphalt has been laid on major airport runways within Europe.

In France, BBA surfacing is generally used with EME2 base in the airfield pavement design. EME2, which was developed and has been widely used in France for nearly 30 years, represents a base course material with a relatively high content of low penetration bitumen and low air voids content, designed to provide good mechanical properties, durability and impermeability. EME2 showed on major airport projects his potential as a viable alternative to the traditional airfield pavement materials for base course such as Crushed Rocks or Dense Bitumen Macadam.

Permeability and Density in Thin Layer Asphalt wearing courses using PMB’s: Challenges Versus Workmanship - The South African Experience

Wim Hofsink1, Herman Marais2 

  1. Wim Hofsink Civil Engineering Services (Pty) Ltd, Pretoria, GAUTENG, South Africa
  2. Much Asphalt (Pty) Ltd, South Africa

The use of elastomeric Polymer Modified Binders (PMB) in thin layer asphalt mixes are very popular and have been widely used in South Africa over the last decade. The excellent rut resistant and flexibility properties made this the mix of choice. The fatigue properties at in service temperature are also known and much advocated. With best of both worlds covered using elastomeric PMB the question arises if this really implies to thin surfacing mixes as well (<40mm). Recent experience with PMB thin layer wearing courses highlighted the sensitivity on density and subsequent permeability properties especially with the rapid cooling rate of the mix.

This paper will also look at what influence the sensitivity in temperatures might have on workmanship in relation to compaction efforts and density as well as the type of mix designs needed to achieve specified properties as far as rut resistance and fatigue is concerned.
The influence of high variance in softening point and the relation to temperature and the cooling factor has also been widely discussed as possibilities of thin layer PMB mixes not performing to expectations and will from part of the discussions of this paper.

Epoxy Asphalt For Durability Of Open Graded mixes

Glynn Holleran1, Sean Bearsley 2, Doug Wilson 1, Charles J Dubois3 

  1. Transport Engineering, University Of Auckland , Auckland, New Zealand
  2. Higgins group, Palmerston North, New Zealand
  3. E. I. du Pont de Nemours and Company, Houston, TexaS, USA

Epoxy Modified Asphalt (Bitumen) has been used for decades on bridge decks. It has been used in New Zealand by the NZTA but as a diluted material (25%) with local bitumen  in Open Graded Porous Asphalt (OGPA) mixes. The specification developed for NZTA claims a life span of 44 years based on Cantabro testing and accelerated aging of OGPA blocks. Cantabro testing is empirical in nature and the abrasion losses are affected by a number of factors including sample geometry, sample preparation, binder content, binder type and aggregate gradation. More realistic tests using aging processes that are more simulative are developed and opportunities for improving OGPA specifications are discussed.

There are potential issues for the successful construction and long term performance of epoxy modified OGPA . Uncured epoxy resin is  a diluent and can  reduce modulus during early curing . This can be problematic when working under traffic in hot conditions. Early stiffness for traffic resistance can be achieved by enhancing interlock of aggregate and aggregate selection. It has also been observed that uncured epoxy resins are not water resistant and that epoxy resins are not stable to UV light.  In dense graded asphalt UV light penetrates only a limited way into the sample whereas in OGPA it can penetrate further where UV light can reduce the mechanical properties of mixes.

The mechanism of epoxy action with bitumen is known and the way in which epoxy can improve oven aging is discussed. Epoxy asphalt can create an improved ageing resistance (based on oven aging), but better, more simulative tests and due deference to bitumen and epoxide chemistry is required. Given the mechanism of epoxy modification of asphalt, it is possible that other binder systems, mix designs and specifications could be used to achieve the same results. This needs to be investigated.

Pavement Preservation and Rejuvenation

Glynn Holleran1, 2, Simon Everett3, Irina Holleran2, Douglas Wilson2 

  1. AAT Asphalt Ltd NZ, Golflands, AUCKLAND, New Zealand
  2. Civil and Environmental Engineering, University Of Auckland , Auckland , New Zealand
  3. Asco Asphalt Services , Auckland , New Zealand

   

Durability and sustainability of assets are a focus for many authorities, often called “Sweating the asset”. Methods of rejuvenation and preserving pavement surfaces have been used for many years. These have had various degrees of success. This paper examines the science of rejuvenation with respect to the chemistry and performance of binders and discusses what durability actually means. It discusses available rejuvenation agents as used in hot mix asphalt and their sustainability.

The common method of pavement preservation and timing are discussed and how sustainable these products are. A new product currently being trialled in New Zealand and developed in USA, where it has a ten year track record is discussed. This product is a bio oil based entirely on renewable resources and able to both rejuvenate and preserve asphaltic surfaces. A cost analysis is presented and some information from trials in NZ and projects in USA

For each conference theme a number of topics have been suggested. Authors are encouraged to put forward additional topics that address the main themes.

Next Generation Bituminous Surfacings

  • Advances in spray seal technology
  • High friction courses
  • Cold mix asphalt
  • Binder technology
  • Crumb rubber modified binder and seals
  • advances in asphalt surfacing preservation

Validation of a viscoelastic pavement model on a database of real loading signals and effect on the fatigue life of pavements

Farah Homsi1Didier Bodin2, Jean-Maurice Balay3, Armelle Chabot3, Olivier Chupin3 

  1. 3Concept France, Engineering Studies and Research Bureau, Tripoli, LEBANON, Lebanon
  2. ARRB Group Ltd, Vermont South, Australia
  3. IFSTTAR, Bouguenais, France

The repetition of loadings on asphalt pavements cause their fatigue damage. The fatigue performance of bituminous materials is a key issue for the structural design of asphalt pavements. The French asphalt pavements design method is based on the European standard laboratory fatigue test that consists of the application of continuous sinusoidal signals and the computation of the number of loading cycles before failure. Real loading signals, however, differ in shape from the sinusoidal signals, and, according to the bibliography, the shape of the loading signal has an effect on the fatigue life of bituminous mixtures. Moreover, new regulations allow longer trucks with multiple axle configurations to circulate on pavements and allow current trucks to carry heavier loads in order to reduce the environmental impact and to improve road transport efficiency. For road owners, there is a need to evaluate the effect of real loading signals on the fatigue life of asphalt pavements. Real scale experiments, which measure the loading signals under different loading conditions, take long time, are expensive and have limited capabilities in varying the loading conditions. A viscoelastic model that evaluates the loading signals in asphalt pavement under different loading conditions is presented and validated on a database of real signals measured in an experimental pavement. The effect on the fatigue life is evaluated using a multi-linear fatigue model that takes into account the shape of the loading signal.

KEYWORDS: Asphalt Pavements design, viscoelastic behavior, viscoelastic pavements model, fatigue, multiple axle loadings, multi-linear fatigue model

Use of RAP in Stone Mastic Asphalt

Petr Hyzl1, Iva Coufalikova1, Michal Varaus1, Ondrej Dasek1, Dusan Stehlik1, Pavel Coufalik1 

  1. Brno University of Technology, Brno, CZ, Czech Republic

SMA type mixtures are used as a surface layer on the most heavily loaded roads with flexible cover. As a result of increasing traffic in general, the overall percentage of roads using this mixture type also increases. Manufacturing of these mixtures uses high-quality and expensive raw materials and therefore it is desirable to consider using RAPs in these mixtures from both economic and ecological perspective, despite the fact most technical standards do not yet allow this.

The paper deals with the issue of using RAPs in SMA-type asphalt mixtures and it has been proven that adding up to 30% RAP does not have any negative effects on the mixture characteristics.

SMA-type asphalt mixtures with 0%, 10%, 20% and 30% RAP content were designed and prepared in a laboratory, all having the same sieve size distribution, air void content, and bitumen content. Due to the aging of the asphalt binder in RAP, a rejuvenator was applied to rejuvenate the aged binder.

The basic empirical and functional parameters of all the prepared asphalt mixtures were carefully analyzed, in particular stiffness modulus and low-temperature behavior, and resistance against permanent deformation.

Conclusion then includes a comparison of the parameters with reference mixture with no RAP added.

Asphalt Reinforcement with Polyester Grids, Practical Experience in Airfields

Zehra Kaya1, FABIANA LEITE-GEMBUS2 

  1. HUESKER Australia, NSW, Australia
  2. HUESKER Synthetic GmbH, Gescher, Germany

Installation of asphalt overlays is a conventional method used for rehabilitation of airfield pavements. However, existing cracks and/or the expansion joints can rapidly propagate into the new asphalt overlay as a result of dynamic forces from the aircraft and the inherent temperature changes. Widely known as reflective cracking, this phenomenon can be addressed by incorporating Polyester asphalt reinforcing grids that have shown significant results in delaying the process of crack propagation. The reinforcement occurs through a mechanism whereby the polymer grid captures the peak stresses at the tip of the crack, distributes them over a larger area and therefore achieves a retardation of the crack propagation into the newly installed asphalt overlay. Utilizing basic theory and practical experiences, this paper will demonstrate the success and extended pavement life that can be achieved by using Polyester asphalt reinforcing technology in airfield pavements. Evaluation of long-term performance on site and the key factors associated with the effectiveness of the reinforcing material (e.g. the loss of tensile strength due to the paving procedure, and the importance of the bond-strength) have been highlighted in particular. Furthermore, based on 40 years’ practical experience with asphalt reinforcement, this paper presents typical applications and also limitations associated with the use of asphalt reinforcement in rehabilitation of deteriorated runways and aprons at airports. The paper concludes that the extended pavement life achieved by the use of this technology reduces both the construction disruption to airfield traffic flow and the associated maintenance costs to asset owners.

Keywords: Asphalt Reinforcement, Polyester polymer grid, Pavement Rehabilitation, Airfields, Resurfacing, Case Study.

 

The evaluation of an optimal amount of rejuvenator

Tomas Koudelka1Michal Varaus1 

  1. Brno University of Technology, Brno, CZECH REPUBLIC, Czech Republic

Asphalt binder hardens over time, therefore, its chemical and rheological properties are altered considerably. The change of properties starts already during the production process and continues throughout the pavement’s lifecycle mostly in the pavement wearing course.

When incorporating such aged material in the form of reclaimed asphalt pavement (RAP) during the mix design of asphalt mixtures in greater amounts, the addition of rejuvenating agents is a vital option which enables to restore the original properties of aged binder.  However, an evaluation of an optimal amount of rejuvenator might be a difficult task.

Three various dosages of different rejuvenators and their impacts on artificially aged binder were evaluated. An optimal amount was assessed by an empirical approach as well as by rheological measurements using dynamic shear rheometer (DSR).  

Perpetual Pavement Design over Conventional Proposed Ring Road for Pune City

Saurabh S Kulkarni1Mahadeo S Ranadive1 

  1. College of Engineering Pune, Pune, Maharashtra, India

Pune is one of the most populous city in India and the second largest in the state of Maharashtra. Vehicular traffic around Pune city has been increasing at high rate due to industrial and economical development, thus necessitating capacity expansion of the existing radial routes emanating from the city. Also traffic exiting Pune is passing through central part of the City thus overloading the inter city network and creating traffic congestion. Considering necessity of decongestion of traffic, Government has proposed a new circular outer six lane rigid road with a design life of 30 years for Pune. This paper focuses on suggesting alternative perpetual flexible pavement design using Indian road congress guidelines and analysis with software like IITPAVE, KENPAVE, PerRoad etc. After repeated iterations the pavement is designed for the calculated cumulative million standard axles and with the calculated values of the strain, it is then checked for the fatigue and rutting type of failure for a desired design life. After proposed design of the pavement, the same is analysed using various software. It is found that the perpetual flexible pavement becomes a better choice considering the factors like design of pavement, expected design life and economy . There is also a need to spread awareness about perpetual pavements in a country like India where rigid pavements are generally favoured for important highways.

An Evaluation of The Whole of Life Benefits Obtained From The Use of Cement Stabilised Granitic Sand as a Pavement Sub-base.

Robert J Ladd1 

  1. Pyrenees Shire Council, Beaufort, VICTORIA, Australia

The Pyrenees Shire Council municipal road network has a substantial volume of granitic sand pavements within in the southern precinct of the municipality. These pavements were constructed typically from locally sourced granitic sand from a former Council operated quarry at Mount Emu.

The granitic sand was utilised as cheap and locally abundant material, as it had a high California Bearing Ratio (CBR), low shrink swell properties and had minimal cartage lead from pit to placement. Since the year 2000 the Pyrenees Shire Council has adopted the process of cement stabilising there granitic sand pavements and applying a plant mix crush rock overlay in the order of 150 mm compacted depth, as part of their annual capital investment program for pavement rehabilitation and renewal.

The process has been adopted from intuitive sallies or off- the-cuff analyses, founded by the internal works group, with very little to no engineering basis for the process and treatment adopted. The purpose of the research is to establish does the treatment of sub-base granitic sand with cement stabilisation offer any structural improvement within the pavement, or is improved pavement structural capacity simply derived from a plant mix crushed rock overlay increasing the cover to the sub-grade.

The paper look at wheather the adopted pavement intervention levels and forecst asset lifes are achieveable, whith comparision of whole of life costs compared against 4 other simular regional Councils within Western Victoria

Comparing the use of long-life Pavement Concepts with the current Austroads Design Procedures in South-East Queensland.

JEFFREY L LEE1 

  1. ARRB GROUP, Albion, QUEENSLAND, Australia

ABSTRACT

As part of the National Asset Centre of Excellence (NACOE) research program , a two-year project focused on the implementation of long-life pavement concepts for Queensland has been completed in 2016. Based on the outcomes of this study, the design traffic at 200 million ESA has been proposed as an interim approach for use on Queensland Department of Transport and Main Roads (TMR) projects.

There are two parts in this paper. First, an overview of the long-life pavement concepts and the major research conducted to-date in Australia will be presented. In the second part, analysis of the pavement thicknesses obtained from different long-life pavement concepts will be compared with the current and proposed Austroads design procedures. The analysis will be focused on the hot weather climate in the South East Queensland.

THEME

Perpetual pavement designs

BIOGRAPHY 

Dr. Jeffrey Lee is a Principal Pavements Engineer in the Pavement Technology Section of ARRB Group.  He has over 18 years experience in the design and assessment of pavements for urban and rural highways, industrial, and airfield environments. Recently, Jeffrey has been responsible for delivering a range of NACOE research projects in Queensland (in cooperation with TMR).  He has written over 20 refereed papers and presented at different international conferences.

KEYWORDS

Long-life pavements, pavement designs, full-depth asphalt

Ground Instrumentation and Frequency Domain Analysis of Non-Destructive Deflection Testing.

JEFFREY L LEE1 

  1. ARRB GROUP, Albion, QUEENSLAND, Australia

As part of the National Asset Centre of Excellence (NACOE) research program, a multiple-year project focused on improving the understanding of the Traffic Speed Deflectometer (TSD) has been conducted by the ARRB Group. The TSD is a continuous deflection testing equipment that operates at traffic speeds. This has quickly become a valuable pavement assessment tool for road authorities around the world. When compared with traditional discrete deflection testing, for example, falling weight deflectometer (FWD), the TSD can measure hundreds of kilometer of road networks each day.

The objective of this paper is to present a ground instrumentation methodology for use to improve the understanding of the deflection basin under a semi-trailer and a FWD. In this case, a semi-trailer was used to simulate the dynamic loading of a TSD. The ground instrumentation involves measuring the ground motion using accelerometers embedded in the surface of an asphalt pavement. The surface motions generated by a semi-trailer and a FWD has been analysed and compared in the time and frequency domains.

The study concluded that the ground instrumentation methodology developed as part of this project is robust and can be deployed for future study. It is anticipated that such ground instrumentation is an important step to allow using the TSD measurements in the routine decision making for road authorities.

Paving in the rain: When is it too wet?

Jaco Lienbenberg1 

  1. GHD, Brisbane, QLD, Australia

Asphalt resurfacing works on airports are usually performed at night and subject to extreme restrictions.  The schedules of airlines and the number of long haul international flights expected shortly after completion of a work shift eliminates any opportunity for re-opening a runway late.

Runway resurfacing works are planned to the finest detail well before the commencement of a work shift and adherence to these schedules are vital in order to prevent disruptions to normal airport operations. Although a fair amount of consideration is given to expected weather conditions during a resurfacing shift, it sometimes happens that inclement weather is experienced during a work shift.  Current specifications are very strict on the acceptance of work placed during inclement weather and affected works are generally rejected and replaced.

This paper looks at paving in inclement weather, international practice and specifications, as well as testing conducted on weather affected mixes during the recent Brisbane Airport Runway overlay project.

Asphalt surfacing mixes for airport applications: Challenges and developments

Jaco Lienbenberg1 

  1. GHD, Brisbane, QLD, Australia

During the 1970’s the Australian Department of Works developed an asphalt mix specifically for airport applications.  This mix was extensively used in Australia and has performed well during the last 40 years.  The continuous development of larger and heavier aircraft, with increased wheel loads and tyre pressures, is pushing the performance expectations of asphalt to its limit.

This paper take a brief look back into the development and early performance of the Australian airport asphalt mix, existing challenges and performance issues being experienced as well as future developments in order to keep up with the challenges high wheel loads and tyre pressures presents.

Asphalt mixes are a complex combination of various constituent materials and each of these ingredients can have a significant impact on the overall mix performance, particularly of a high-performance mix.  The paper looks at various mix ingredients, the challenges being experienced and developments in bitumen and aggregate properties and selection.  The paper outlines the current state of knowledge as well as future research requirements.

Maintaining Asphalt Mix Quality in a Variable Bitumen Source

John Lysenko1 

  1. Fulton Hogan, McGraths Hill, NSW, Australia

Over the past decade bitumen supply in Australia has progressively shifted from local manufacture to direct importation with local production now occurring at only two refineries. This has been accompanied by the increasing presence of international trading companies and an exit or reduced participation by the oil majors. The direct consequence has been the emergence of a wider range of bitumen sources on the market and more frequent changes between import sources. While this does not necessarily reflect on the general suitability of the imported product the associated molecular changes can pose a challenge in the production of polymer modified binders (PMBs) and emulsions from some of these bitumens.
This paper examines some of these challenges with regards to PMB manufacture and use in asphalt production. Two examples of major paving works are described where transport and storage of PMBs have been successfully managed to achieve high quality results under variable bitumen source conditions.

SAMIPrime ECO - An environmentally friendly prime coat

Kanjana Yindee1, Azeem Remtulla1, Stuart Nugent2 

  1. SAMI Bitumen Technologies, Camellia, NSW, Australia
  2. Colas WA, Guildford, WA, Australia

Please see category overview below and remove when submitting abstract.

For each conference theme a number of topics have been suggested. Authors are encouraged to put forward additional topics that address the main themes.

Keywords: Environment, Prime coat, Penetration power

 

SAMIPrime ECO is formulated and designed as a prime coat cationic emulsion. SAMIPrime ECO is a penetrating prime coat emulsion specifically formulated for use on compacted stabilised or bound base course surfaces (lime or cement), or on unbound compacted surfaces. It contains no petroleum solvents that have flammable vapours, are hazardous to workers and release harmful VOC’s into the environment. It is made from sustainable, natural resources that do not pollute groundwater. It is water-based, safe for workers and easy to use.

SAMIPrime ECO is engineered to give superior penetration into the base, binding surface fines and superior bonding between the underlying surface and overlays.

The paper focuses on the performance of the environmentally friendly SAMIPrime ECO in terms of its base course penetration, waterproofing and its ability to create a strong and stable bond with the subsequent bituminous application.

SAMITac - Non-tracking tack coat emulsion

Kanjana Yindee1, Azeem Remtulla1, Jarryd King2 

  1. SAMI Bitumen Technologies, Camellia, NSW, Australia
  2. SRS Roads, Camellia, NSW, Australia

Tracking, the pick-up of bituminous material by vehicle tires, can occur as a result of the tack coating operation. The critical consequence of tracking is the removal of the tack coat from the existing asphalt, which may prevent adequate bond with the subsequently applied asphalt layer.

 

SAMITac is an advanced cationic bitumen emulsion specially formulated to dry very quickly into a hard and driveable coating, often in less than 30 minutes after application. SAMITac greatly reduces tracking to surrounding surfaces and also delivers a substantially stronger bond between layers. SAMITac also provides waterproofing which safeguards the substrate and base layers, while ensuring good adhesion with the overlay.

Laboratory evaluation of bitumen stabilised base course mixes

Iulian Man1, Kanjana Yindee, Trevor Distin 

  1. SAMI Bitumen Technologies, Camellia, NSW, Australia

The treatment of unheated crushed rock with lower percentages of bitumen present a great opportunity to improve the sustainability of our scarce materials for building durable road bases. However in terms of bitumen stabilisation, bitumen emulsions have been seldom used for base course stabilisation in Australia compared with foam bitumen stabilisation.

The purpose of this paper is to compare and evaluate the laboratory performance of bitumen emulsion and foamed bitumen treated crushed materials.

The paper will investigate and develop a laboratory protocol for testing the suitability of crushed rock materials in order to compare the performance of the bitumen emulsion treated materials against foamed bitumen.

The use of emulsions in stabilising crushed rock is likely to be more beneficial in terms of improving workability and performance in the presence of moisture due to the better coating of the aggregate particles. Additionally, emulsions are easier and safer to handle then hot bitumen during transport, storage and mixing with cold aggregates.

 

Iulian Man Biography:

In 1999 Iulian Man joined SAMI Bitumen Technologies as Product Development Engineer being responsible for research work in hot and cold asphalt mixes and the application of new engineering technologies of bitumen modification with polymers.

He is currently Technical Support Manager with SAMI Bitumen Technologies, member of Colas Australia Group.

Apart from hot mix technologies, his research interests include warm and cold asphalt mixes.

Iulian holds a Bachelor degree in Chemical Engineering and a Master of Pavement Engineering degree.

Latest developments in Crumb Rubber modified bitumen for use in Asphalt and Seals - The South African experience

Herman Marais1, Christi Botha2, Wim Hofsink3, Jacques van Heerden4 

  1. Much Asphalt, Doornpoort, GAUTENG, South Africa
  2. SMEC, Pretoria, Gauteng, South Africa
  3. Wim Hofsink Civil Engineering Services (Pty) Ltd, Pretoria, Gauteng, South Africa
  4. Tosas, Wadeville, Gauteng, South Africa

The advantages of using Crumb Rubber modified bitumen are well documented throughout the world as well as South Africa, with increased fatigue resistance and reduction in ageing of the binder being the major drivers for its use.  The increased focus on the influance of the construction industry on the environment and ways of reduction and re-use of waste material has also been influential in motivating the use of Crumb Rubber modified bitumen. The manufacture and placing of the product do require special measures and care to ensure the envisaged advantages are materialised.

Although the technology is well entrenched in South Africa, with robust specifications and Guidelines in place, the need arose to compare the South African technology with what is being done in the USA, where the technology originated from.  Two study tours were undertaken with the fist being focussed on the conventional Crumb Rubber modified bitumen and the latter being focussed on Hybrid and Terminal blend technology.  This paper will discuss the findings from the study tours and how the learnings were incorporated in the South African Specifications.  There has also been very exiting developments in Low Temperature Crumb Rubber modified bitumen technology that is aimed at reducing the risks associated with the use of the premium product, and findings of trial projects using this technology will be discussed.

Binder Recovery from RAP & Asphalt to allow for binder characterisation.

Roderick L McArthur1 

  1. Topcoat Asphalt, Wingfield, SA, Australia

 

In South Australia we have an allowance in DPTI specifications to use up to 50% RAP in our mixes; one of the major issues is the assessment of the quality of the binder. The prevailing methodology for recovering the binder to allow for assessment involves highly specialised equipment, large lead times, yields results that are not accurate and has large amounts of clean up after recovery of the binder, as such cannot be considered a process test. An alternative method was sought. The validation methodology was to use a tested binder(viscosity), apply solvent, recover binder, retest (viscosity) and compare to original results. As a result of this investigation a modified Abson method was developed and is being used to assess the quality of the binder.

Sustainable Pavement Design - Delivering Sustainable Options Considering Existing Materials and Pavement Lifecycle.

Trent McDoanld1, Ernesto Urbaez1, Scott McIntyre2 

  1. Pavement Management Services, Sippy Downs, QLD, Australia
  2. Project Management and Construction, Moreton Bay Regional Council, Strathpine, QLD, Australia

With a drive toward sustainability and pavement longevity, there is an ever growing evolution in pavement materials and design concepts. In this paper, Pavement Management Services has proposed four mechanistic-empirical design options for a failing road in Moreton Bay Regional Council (MBRC) in Queensland, Australia in 2016.  Of the four pavement designs, two consisted of conventional asphalt and granular pavements, whilst the others consisted of foamed bitumen and a perpetual pavement design.

 An extensive pavement investigation was carried out including Falling Weight Deflectometer, boreholes, and geotechnical testing; which was used in assessing the in-situ conditions of the pavement and material properties. The investigation allowed the formulation of the foamed bitumen and a perpetual pavement design alternatives. The foamed bitumen option considered the utilisation of existing materials to incorporate into the rehabilitation, whilst the perpetual pavement considered a three layered asphalt pavement for an extended lifecycle. The three layered asphalt course (applied to the perpetual pavement), utilised the characteristics of three different mixes to limit strain at critical locations within the pavement, to control the mode of failure.  By doing so, the pavement was set to last in excess of 100 years without structural improvement and minimising pavement life cycle cost.

 Furthermore, a financial analysis has been conducted incorporating a preliminary cost comparison between convention asphalt design (deep lift asphalt) and perpetual pavement design. A 100 year analysis period was considered for a better comparison with the perpetual long life pavement. 

 This paper outlines the investigation and pavement design options and methodologies used in the design process. The pavement designs have been proposed and accepted by council, and are awaiting a final decision in the design option for tendering process.

Asphalt Surfaces for Motor Racing Circuits

Ivan Mr Mihaljevic1, John Mr Howe2 

  1. Kamen Engineering Pty Ltd, KINGSGROVE, NSW, Australia
  2. iEDM, Giold Coast, QLD, Australia

   

For each conference theme a number of topics have been suggested. Authors are encouraged to put forward additional topics that address the main themes.

Next Generation Bituminous Surfacings

  • Advances in spray seal technology
  • High friction courses
  • Cold mix asphalt
  • Binder technology
  • Crumb rubber modified binder and seals
  • Asphalt surfaces for motor racing ciruits 

 

Asphalt Surfaces for Motor Racing Circuits   

Motor racing has evolved in recent times into a dynamic industry that has introduced a number of street circuits in Australi. Advances in race tyre technology, vehicle dynamics and circuit design ensures that the stress applied to asphalt surfaces can at times far exceed that which is experienced over the remaining 51 weeks of the year under urban type conditions for these tracks. This paper details the development of asphalt materials which are specifically suited for motor racing circuits in Australia. 

 

Planning the asphalt construction process - towards more consistent paving and compaction operations

Chiristiaan Arbeider1, 2, Seirgei Miller1, André Dorée1, Marco Oosterveld2 

  1. Construction Management & Engineering, University of Twente, Enschede, the Netherlands
  2. BAM Infra, Gouda, the Netherlands

This research addresses the challenge of linking paving and compaction given that they are mostly treated as detached activities, leading to a decrease in the quality of the compacted asphalt layer. The objective was to develop a Decision Support Tool (DST) that can assist decision-making related to equipment allocation and compaction strategies to be followed, such that an asphalt layer – given the prevailing conditions at the construction site – can be compacted efficiently and uniformly within a limited time interval. A basic planning protocol, serving as the DST, was then developed based on variables such as asphalt cooling, paver characteristics, roller characteristics and road geometry. 12 road construction projects were monitored over a 3-month period. Empirical data on paver speed, roller speed and the number of roller passes served as input for tool. The monitored projects were evaluated by calculating actual paver output and theoretical and actual roller output on an interval scale and checking whether the output rates were aligned to each other during the whole construction process. The results show that in most cases, paver output, roller output and the available time for compaction were not aligned. The theoretical concepts applied in this research and the developed Decision Support Tool appear to be useful for planning and monitoring paving and compaction and for steering it towards a more uniform process. This may lead to an improvement in the quality of the final compacted asphalt layer.

Estimation of Dynamic Modulus values of Bituminous Mixes from Repeated Indirect Tensile Test

Amaranatha Reddy Muppireddy1, Bhrath Gottimukkala2 

  1. Indian Institute of Technology, KHARAGPUR, WEST BENGAL, India
  2. Flexible Pavement Division, Central Road Research Institute, New Delhi-110 020, New Delhi, Delhi, India

Aggregate gradation and bitumen are two key factors that influence the engineering properties of bituminous mixes. It is important to understand the behavior of bituminous mixes that consists of bitumen and aggregate for improving pavement performance. Bitumen is a viscoelastic material and its quality and quantity plays a significant role in both elastic and viscous properties of the bituminous mix. With the current trend towards developing mechanistic–empirical and more reliable pavement design procedures, accurate characterization of bituminous mix properties is always important. In India, Indian Road Congress guidelines have been used for design of flexible pavements and this method uses resilient modulus of mix as input to the pavement design (IRC:37-2012). Repeated indirect tensile test (IDT) is performed to evaluate resilient modulus value of the bituminous mix at a given temperature under standard loading time and rest period.  However a number of studies claim that use of dynamic modulus value from dynamic modulus test (DMT) data in pavement design has the ability to simulate real traffic conditions to a greater extent and thereby pavement performance can be predicted more accurately. Mechanistic-empirical pavement design (MEPDG 2002) is one of the examples of such designs that use dynamic modulus value of the mix as input parameter.  Adoption of such pavement designs requires Asphalt Mixture Performance Tester (AMPT) facilities that are generally costly. To overcome this, development of correlation from IDT data with DMT data would facilitate to estimate dynamic modulus of the mix.  Therefore an attempt has been made in the present study to establish a correlation between resilient modulus and dynamic modulus of bituminous mix so as to estimate dynamic modulus from the resilient modulus of the mix.

Risk management of high RAP content asphalt mixes by using statistical tools

Laszlo Petho1 

  1. ARRB Group Ltd, ALBION, QLD, Australia

The use of reclaimed asphalt pavement (RAP) in asphalt mixes provides a vital basis for sustainable development.  The re-use of RAP in its highest value application, i.e. as new asphalt product, has significant economic and environmental benefits.

Improved material characterisation, design methodology, production and construction practices promote appropriate use of a high percentages of RAP in asphalt mixes without compromising the performance.  In a recent Austroads study, which delivered better material characterisation and design methodology, it was found that the viscosity based binder blend calculation is valid for a wide range of asphalt mixes and therefore it can be used with confidence for designing the binder blend in mixes containing RAP.

Since variation of RAP stockpiles in terms of RAP binder viscosity is anticipated over time there is a need to assess the extent of the binder blend variability and its impact on asphalt performance.  A comprehensive sensitivity analysis, using the Monte Carlo simulation (MCS), was performed to provide insight into the variability, impact and risk assessment for asphalt mixes containing RAP.

When using RAP in an asphalt mix, there are many variables which influence the final properties of the binder blend; the MSC provides a powerful tool for such cases, especially when the analysed property can be described by a closed form equation.  The MSC utilises the probability distribution of each stochastic variable and such as provides a probability based risk assessment tool.  The parameters investigated included virgin binder type and viscosity, RAP binder source and viscosity, design mix binder content and RAP binder content.

The assessment methodology discussed in this paper provides a sound risk assessment tool for both asphalt manufacturers and the road agency.

Asphalt resurfacing of the V8 Supercars racetrack on the Gold Coast – the comprehensive way for achieving high performance

Laszlo Petho1, Ossi Mood2, Chris Lange3, Kevin Embleton4, Bart Bartley2 

  1. ARRB Group Ltd, ALBION, QLD, Australia
  2. City Infrastructure, City of Gold Coast, City of Gold Coast , QLD, Australia
  3. Fulton Hogan, Stapylton, QLD, Australia
  4. Fulton Hogan, Dandenong, VIC, Australia

The City of Gold Coast (the City) embarked on a research and development project with the ARRB Group (ARRB) with regard to the performance assessment and improvement of the asphalt surfacing along the V8 street circuit in Surfers Paradise in Queensland.  In 2014 there were a number of sections of the race track exhibiting distress in the form of ravelling under high shear stress racing conditions.  Findings and learning of the pavement condition and existing asphalt performance assessment were used for the development of alternative asphalt mix design options.  The historical development of specification requirements for racing conditions are also briefly discussed.

The asphalt mix for race conditions should be durable and stable while withstanding extreme horizontal shear forces.  Also, tightly controlled in situ air voids and a relatively high bitumen content ensures durability.  The adopted methodology for achieving these objectives in the mix design are discussed in details.  The bitumen selection for this particular application was based on the benchmarking of the rheological properties of different bitumen types by means of the dynamic shear rheometer (DSR).  The complex modulus and the phase angle of the different binders, related to race car loading frequency and pavement temperature conditions, were considered as key input parameters.

Fulton Hogan in collaboration with ARRB and the City developed the asphalt mix and supplied and laid the asphalt on the resurfacing works.  The complex system of asphalt mix production control, paving process control and workmanship were key items for delivering a successful resurfacing works of the racetracks.

Innovation for bituminous pavement recycling with bio-materials

Simon Pouget1François Olard1, Emmanuel Chailleux2, Pierre Hornych2, Davide Lo Presti3, Ana Del Barco Carrion3, Laurent Porot4, Troy Pauli5, Jean-Pascal Planche5, Chris Williams6, Eric Cochran6, Ka Lai Ng Puga6 

  1. EIFFAGE, Corbas, FRANCE, France
  2. IFSTTAR, Nantes, France
  3. NTEC, University of Nottingham, Nottingham, UK
  4. Arizona Chemical, Almere, The Nederlands
  5. WRI, Laramie, WY, US
  6. Iowa State University, Ames, IA, US

The proposed project is to investigate the merits of application of bio-materials from bio-mass in reuse of asphalt pavements. The project aims to demonstrate that reuse of asphaltic materials from pavements can be facilitated using bio-materials. To do so, this BioRePavation consortium will assess three technical solutions aiming to reduce the use of virgin aggregates and petroleum bitumen for road maintenance and construction. Successful technical solutions will not only have the advantage of using organic viscoelastic binder but it will also  provide equivalent performance in comparison to conventional asphaltic materials. The overall goal is to provide the opportunity for road authorities, or more generally for countries with mature networks, to be self-sufficient in materials via “BioRePavation” using bio-products locally produced and used along with asphalt pavement recycling.

The main scientific and technical objective is to prove that alternative binders can be used to recycle asphaltic pavement with the same level of performance in comparison to conventional solutions with petroleum bitumen. To do so, the research team proposes to build a demonstration where three innovative pavement solutions using bio-materials will be tested using an accelerated pavement testing facility. Performances will be evaluated by both measuring the time (or traffic level) needed for the pavement solution to reach a distress failure mechanism (cracking, rutting, etc.) and investigating the binder physico-chemical evolution using an innovative non-destructive method. Biorepavation will also assess the environmental impacts of the combined use of bio-binders and high-content of reclaimed asphalt (RA) in asphalt mixes. Special attention will be given to airborne emissions that will be directly measured at the laboratory scale. Obtained data will be used to perform a risk assessment, as well as a Life Cycle Assessment (LCA) for the aforementioned Biorepavation technologies.

GB5® : eco-friendly and long-lasting HiMA alternative to EME2

Simon Pouget1François Olard1 

  1. EIFFAGE, Corbas, FRANCE, France

Aggregate packing concepts developed in the field of high-performance cement concretes, initially by Caquot (1937) then by contemporary researchers since the 1970’s, were transposed to the field of asphalt concretes. These concepts, associated with the use of Polymer-modified Bitumen (PmB), enabled the development of a new generation of dense high-modulus asphalt concretes. The single or double gap-graded grading curves  of these mixes, lead to a great interlock between coarse aggregates. Consequently there is no need for low penetration grade bitumen to fulfill the European EME2 specification requirements, in particular the 14,000 MPa stiffness modulus value at 15°C.

Besides, the use of PmB, at a content of about 4.5%, combined with such an optimized aggregate packing leads to the design of the so-called High-Modulus Asphalt concretes (HiMA) characterized by great compactability, very high stiffness modulus and high fatigue resistance in a single formulation, which allow reduced pavement thickness and increased longevity. Moreover, the proposed mix design and the 4.5% binder content makes PMB’s use affordable in base courses.

Aggregates packing principles and mechanical performances measured in the lab are presented in the paper. Correlation between internal skeleton and mechanical performances are briefly treated. The paper also addresses the successful application of this new material on different job sites, located mainly in France and in South-Africa.

The proposed GB5® HiMA may be considered as a relevant solution for sustainable long-life and cost-effective pavements as an eco-friendly alternative to EME2.

Stone Mastic Asphalt (SMA); A durable and reliable asphalt mix for Extended road life cycle and maintenance cost savings; New developments based on the SMA principle

Stefan Schulz1 

  1. CFF GmbH & Co.KG, Gehren, THURINGIA, Germany

Abstract:

Due to the continuously increasing vehicle loads and the tremendous increase in freight traffic the demands on road surface courses have raised considerably. The necessity for a durable, long lasting, rut resistant asphalt surface is uncontroversial. Stone Mastic Asphalt (SMA) has been widely introduced in many countries for important main roads. Its improved stability is a result of the aggregate grain distribution, which must be in accordance with the “gap grading” principle. Its flexibility results from the relatively high binder content, which requires the application of stabilizing additives (e.g. cellulose fibres) which are used as bitumen carrier during the production, transportation and paving process in order to prevent bitumen drainage.

This presentation shows the principal characteristics of Stone Mastic Asphalt (SMA) for heavy traffic wearing courses, the innovative asphalt mix-design, the improved performance of SMA with regard to how its durability results in lower maintenance costs and extended life cycle of the road. Finally there will be an outlook to new developments based on the SMA concept, such as noise reduced SMA LA as well as SMA binder courses. And furthermore information about the new deformation resistant surface course PMA – Porous Mastic Asphalt.

It will cover following main aspects:

  • SMA’s high resistance to permanent deformation
  • SMA mix design and production process
  • longer lifetime, less maintenance costs
  • new asphalt developments based on SMA principle; SMA LA (low noise) and SMA binder courses
  • PMA – Porous Mastic Asphalt
  • different types of stabilizing additives

Adopting smart technology to supplement road asset performance monitoring and post construction evaluation

Ashish Shah1, Jinjiang Zhong1, Jessica Ly2 

  1. Logan City Council, Logan Central, QLD, Australia
  2. Student, QUT, Brisbane

Road roughness is one of the key indices employed by road agencies to evaluate the condition and performance of their road network. The majority of the road agencies in Australia rely on Laser Profilometer (LSR) to collect the roughness information. The LSR is often fixed to a survey vehicle which is also equipped with other survey devices such as GPS, gyroscope, high definition cameras and etc. to capture a range of road asset management related information. However, it is envisaged that the time and cost associated with transporting the survey vehicle to areas especially those in the outback region is high and this has inevitably limited its application in those areas.

 

With the evolvement of smart phones, apps have been developed to utilise the accelerometer and gyroscope sensor to measure road network roughness levels. Although these apps provide great flexibility for road agencies to collect roughness data, not many studies were done to examine the suitability of such apps on Local government road network.  Logan City Council (LCC) through the Industry Experience Program (IEP) initiated a study on three of these apps and validated their correlation level with LSR produced results, repeatability and other aspects of these apps.  “

International Experience on the Geogrid Reinforcement as a Sustainable Solution for Flexible Pavements

Amir Shahkolahi1, Jorg Klompmaker2 

  1. Global Synthetics, Virginia, QLD, Australia
  2. Geosynthetics, BBG Bauberatung Geokunststoffe GmbH & Co. KG, Espelkamp, Germany

The use of geosynthetic materials has become and acceptable practice in road construction including flexible pavements as a sustainable environmentally friendly solution. Geosynthetic reinforcement provides a wide range of benefits including reduction in the pavement thickness, improvement in the pavement serviceability and design life/design traffic, reducing maintenance costs, providing a working platform to start the construction, and many more. The use of geosynthetics has led to more efficient pavements and considerable reduction in the carbon footprint. These benefits have been proven though various laboratory and filed studies in the last decades. This paper reviews the research works on geogrid reinforced paved roads and focuses on the mechanisms of geogrid reinforcement in flexible pavements. Some test results on the verification of the geogrid reinforcement mechanisms and benefits are provided and some of the important parameters for the performance of a geogrid reinforced pavement is presented. It also reviews the behaviour of geogrid reinforced pavements and presents the results of some of the recent studies and monitoring of geogrid reinforced flexible pavements. Finally, a suggestion is provided about how to adopt geogrid reinforcement in flexible pavements in Australia based on the international experience and best practice and available test results.

Project Yellow

Ray Simpson1Louise Haining 1 

  1. Colas Australia Group Pty Ltd, Winston Hills, NSW, Australia

Please see category overview below and remove when submitting abstract.

For each conference theme a number of topics have been suggested. Authors are encouraged to put forward additional topics that address the main themes.

Constructing the Roads of the Future

  • Safety at roadworks

Working on highways presents a significant risk to workers. There is a too frequent history of incidents where road-user vehicles have collided with roadworkers or vehicles, with fatal injuries sadly resulting. 

The Colas Group are forward thinking in technological advancement, investing in R&D at their extensive Paris R&D facility. Considerable advances have been made to lower the risk of road worker collisions already through initiatives championing Zero harm, but engineering and new technologies now provide an opportunity to significantly reduce and/or eliminate these types of collision.

Colas Ltd., Aximum Electronic Products (both from Colas Group) and software experts Foxstream have developed The Project Yellow system. The system uses thermal imaging and video analytics to detect, classify approaching vehicles into ‘threat categories’ and alarm workers to evacuate from programmed zones. The thermal camera is mounted at height on the rear of a works or emergency vehicle and provides audible and visible alarms to road workers. 

Project YELLOW has the potential across the highways industry, emergency vehicles and roadside recovery services. In 2015 the prevention of a road death was priced £2 Million  per fatal incident (Department for Transport UK 2016). The Project YELLOW system minimises the risk of collision and injury in the incidents at which it is targeted, saving not only these quantifiable costs, but more so the immeasurable emotional and life changing impacts.

Autonomous IPV

Ray Simpson1Louise Haining 1 

  1. Colas Australia Group Pty Ltd, Winston Hills, NSW, Australia

 

Constructing the Roads of the Future

  • Next generation plant and equipment

Colas have used its expertise and experience to look at new technologies in autonomous vehicles to eliminate high risk activities on the road or in constructing the roads.

Colas sees collaboration with specialists as the key to innovation. Together with our partners Royal Truck and Equipment US leaders in Incident Protection Vehicle (IPV) manufacturing; and Micro Systems Inc. (Kratos Group), a large defence organisation with expert experience in military autonomy; we have developed a semi-autonomous IPV which removes the at-risk driver.

Our Auto IPV system uses the leader/follower technology designed for military applications developed from battle scenarios and where there is an IED risk. The vehicles have a system that precisely and securely transmits the location of the leader to the follower allowing it to follow the same path. 

The vehicle requires high precision military GPS sensors, and a vision based lane keeping system to improve accuracy of steering.  Forward and rear collision radars are also fitted and LIDAR builds a ‘point cloud’ map of the road environment.

Trials in the US and UK will begin in early 2017. The auto IPV system can be used for hard shoulder IPV work, traffic management, maintenance activities and incident response. Our autonomous system also has the potential for other working vehicles and scenarios.

Colas Enterprise Asset Management

Ray Simpson1, Paul Middleton 

  1. Colas Australia Group Pty Ltd, Winston Hills, NSW, Australia

The Colas Enterprise Asset Management approach is centered on the needs and objectives of the asset owner. There are three levels of asset management decision making for the delivery of asset improvements, maintenance and operations; these are strategic, tactical and operational. Traditionally, although there are many synergies, they are rarely managed together. 

Colas’ approach is to integrate the three elements and develop a collaborative strategy that enables the assets to be managed in a more efficient and dynamic way.  This approach can scrutinise for example routine defect data and public enquiries through to high level corporate goals, risks and objectives. 

Our collaborative and strategic approach to Asset Management enables informed decisions across the levels based on many layers of data and through the incorporation of industry best practice in the form of treatments or products, innovation and data governance. Simply, this joined up approach allows asset management visibility, scenario asset analysis and continual improvement; for instance the consideration of the impacts of reactive routine activities or operational risk events to long term investment and vice versa.

This way of working enables the asset owner / manager to be fully informed and supported to effectively communicate to customers whilst remaining strategically objective centric especially where budgets and political demands are constraining.

“Effective use of warm asphalt mixes in the UK to reduce traffic disruption and improve environmental and working conditions”.

Carlos Solis-Navarro1 

  1. AECOM, Redfern, NSW, Australia

The problem of climate change at a global level and the pursuit of more environmentally friendly solutions have all meant that engineers involved in different aspects of the construction and maintenance of roads are now taking measures to ensure that the industry has as little negative impact as possible on the environment. At the same time, the vision of road agencies to support economic growth by relieving congestion and minimising delays while maintaining lane availability and improving the environment requires new technologies to address these challenges.

This paper explores some of the available methods to produce low and warm asphalt mixes and presents project experience of two of these technologies applied in the UK. An ex-situ cold recycled bound material “ULTIFOAM” was used as the base layer on the Morpeth Northern Bypass (4 km bypass, £35 M construction cost). Warm asphalt mixes were widely applied on the Highways England Strategic Network as part of maintenance schemes.

These technologies are designed to provide the same final properties as hot mix asphalt (HMA) while providing other benefits such as reduced fuel consumption and CO2 emissions, lower fume emissions, improved working conditions and earlier opening to traffic.

These examples demonstrate the successful application certainty of these techniques and their capability to offer what society, administrations and international bodies are seeking, namely a sustainable and efficient method of constructing and maintaining roads. As the Massai proverb says “We do not inherit the Earth from our ancestors; we borrow it from our children.”

  1. Carlos Solis-Navarro is a Pavement Engineer working for AECOM Australia within the Ground Engineering and Asset Management team. He was transferred from AECOM UK, where he gained significant experience in pavement maintenance schemes and sustainable warm mixes after his involvement in a number of projects, for local authorities and Highways England.

Polymer Modified Bitumen Emulsion (PMBE) Surface Treatments in Brisbane

Greg Stephenson1, Nihal Palipane1 

  1. Asset Management Branch, Brisbane Infrastructure Division, Brisbane City Council, Brisbane, QLD, Australia

Brisbane City Council, Australia’s largest local government authority, maintains a road network of 5,700 km, ranging from residential access streets to major arterial roads.  Pavement configurations include granular and cement stabilised granular with thin asphalt surface, concrete and deep strength asphalt.  Traffic loadings range from local residential streets through industrial access roads to arterial roads.  Nearly three quarters of the network is local residential streets providing direct property access.  These lightly trafficked streets are predominantly asphalt surfaced and the main deterioration mechanism is environmental ageing, typically oxidization of the bitumen leading to surface ravelling.

 

Since 2007, Council has been investigating Polymer Modified Bitumen Emulsion (PMBE) Surface Treatments as a method to extend the life of ageing asphalt surfacing on the residential streets.  A regular testing and monitoring program has been in-place and some streets have received a second cycle of treatment. 

 

The results from the testing of pre- and post-treated surfaces and monitoring program were used to assess the anticipated life of treatment.  This paper highlights how detailed assessment of existing surface texture was used to identify optimum application rates of PMBE and intervention standards for pavement condition suitable for the treatment.

Experimental Investigation of the Effect of Asphalt Healing under Rest Period on Stiffness Developement and Damage Characteristic Curves

Yang Mr. Su1, Hossein Dr. Asadi2, Hamid Prof. Nikraz1 

  1. Curtin University, Bentley, WESTERN AUSTRALIA, Australia
  2. ARRB Group Ltd, Perth, Western Australia, Australia

The researches on performance of asphalt mixtures which have been carried out during the last 20 years made it clear that asphalt mixtures possess healing characteristic which means the generated micro-cracks can heal themselves and this results in stiffness recovery of the mix. However, there is still a lack of insight into the qualification and quantification of asphalt healing. A model that takes into account asphalt healing could provide an improved tool to the performance evaluation, fatigue evaluation and crack damage characterization for flexible pavement and thus can lead into enhanced product and systems for design/maintenance and innovation of pavement products. In this study, Asphalt Mixture Performance Tester (AMPT) was utilised to carry out testing on AC10 C320 as one of the typical Western Australian asphalt mixes to investigate its healing capability under different rest period and currently at 20 Celsius degrees. Rest periods were applied between each load cycle and Visco Elastic Continuum Damage (VECD) theory was used to model the healing behavior of tested samples. Based on the damage characteristic curves, a trend was identified between rest periods and damage characteristic curve parameters. The current results including pseudo-stiffness change with load cycles and damage characteristic curves are presented and further discussed.

Flexible pavement design guideline for ports

Bevan Sullivan1 

  1. Futton Hogan, McGrath Hills, NSW, Australia

Please see category overview below and remove when submitting abstract.

For each conference theme a number of topics have been suggested. Authors are encouraged to put forward additional topics that address the main themes.

Flexible Pavement Technology for (Air)Ports

  • Improved specifications for airports
  • Intermodal pavement design

Innovations in Road Asset Management in the Age of Disruption - a Steward’s challenge

Giles Lewer1, Richard Trinder2 

  1. Ventia Boral Amey Joint Venture, Beenleigh, Queensland, Australia
  2. Ventia Boral Amey Joint Venture, Rockdale, NSW, Australia

Giles Lewer is the Stewardship Asset Manager for the Ventia Boral Amey Joint Venture on the Queensland Transport and Main Roads South Coast Region Road Asset Management Contract. He has 30 years’ experience with private industry and the public sector in road asset management, construction and maintenance, with a special interest in pavement management systems. He holds a Masters Degree in Pavement Engineering, is a Chartered Professional Engineer and RPEQ.

Keywords: Asset Management, Stewardship, Innovation, Safety

The Ventia Boral Amey Joint Venture was awarded the Queensland Transport and Main Roads (TMR) Road Asset Management Contract (RAMC) for the South Coast Region in October 2013. In April 2014 the Joint Venture commenced work on the NSW Roads and Maritime Services (RMS) Sydney South Stewardship Maintenance Contract (SMC). The general scope of the services performed includes Asset Management, Routine Maintenance, Improvement Works, Incident Response & Event Management. The JV has focused on innovative ways to promote safety and efficiency in service delivery; these have centred on road worker and road user safety. The innovations include enhanced traffic management and signage, improved communication with heavy vehicles and mechanical litter removal. In this age of disruption, innovation is understood to be the “game breaker” required in addressing these challenges. Asset and transport modelling and management is being used to pre-empt maintenance activities and deliver safer operations on our road networks. Equally important is the successful achievement of whole of life value for money solutions. Innovative asset management of flexible pavements within the network has included the use of Stone Mastic Asphalt for thinner surfacing, Hot-In-Place Asphalt Recycling of existing wearing surfaces, micro-surfacing and placement of EME2 high modulus base course asphalt. This paper further describes how the JV are addressing the challenges of Road Asset Management in this age of disruption.

Improved Asphalt Characterisation at Western Australian Temperatures

Ester Tseng1 

  1. Australian Road Research Board, Leederville, WA, Australia

In Western Australia the weighted mean annual pavement temperatures vary from 24°C in Albany, to 42°C in Kununurra. At higher temperatures and lower traffic speeds, asphalt presents lower modulus values. According to the current design methodology, lower modulus values result in increased pavement design thicknesses. However, empirical observations of pavements in-service indicate that most of the asphalt fatigue damage accumulates at low temperatures.

The ARRB, engaged by Main Roads WA, is conducting a study that aims at characterising the stiffness and fatigue performance of typical Western Australian asphalt mixes in order to evaluate opportunities for improving current asphalt mix and structural design practices. This will be achieved by the development of modulus master curves in accordance with AGPT/T274 and the preparation of asphalt fatigue performance models from four-point bending testing in accordance with AG:PT/T274. Additionally, it is proposed to investigate the effect of healing in asphalt fatigue performance by incorporating rest periods between load applications.

The project includes investigation of four Western Australian typical mixes: 20 mm, C320; 14 mm, C320; 20 mm, A35P; and 14 mm, A35P. Characterisation of asphalt flexural modulus and fatigue performance (excluding rest period tests) for the 20 mm, C320 mix has been completed. Test results for the 14 mm, C320 mix are expected to be available by early 2017, and therefore, expected to be presented in this paper.  

Preliminary results indicate that for the mix investigated the asphalt modulus at high temperatures and low load frequencies is lower than the modulus that would be assigned using the current design methodology and that the Shell fatigue model over-predicts the laboratory performance of the asphalt mix. This has also been observed in other recent studies and suggests that the Shell laboratory fatigue model may not be representative of the performance of current Australian asphalt mixes.

Nondestructive Testing, Airport Pavement Evaluation Technologies – Cases of Study

Ernesto Urbaez1, Pedro Yarza1 

  1. Pavement Management Services, Sippy Downs, QLD, Australia

 Nondestructive testing known as ‘NDT’ has become as excellent and preferred tool for pavement evaluation and design on Airport facilities. The Advisory Circular (AC 150/5370-11B) stated that ‘…Recent advances in hardware and software technology have significantly improved NDT equipment, data collection, and analysis software…’

Pavement Management Services (PMS), based in Australia has extensive background and experience (around 35 years) using nondestructive testing for pavement condition data collection on roads and airports. We have successfully used the Automated Road Analyser (ARAN) system for collecting surface pavement distresses for assessing Pavement Condition Index (PCI), Video Imagery and roughness in term of Boeing Bump Index (BBI), especially on the runways. Condition assessment has also included taxiway and apron. In addition, PMS has implemented structural evaluation using a Falling (Heavy) Weight Deflectometer (FWD) testing. FWD testing allowed to assess the structural capacity of the pavement structure based on the back analysis of the layer elastic modulus. This information is then used for ACN/PCN calculation using mechanistic-empirical approach. PMS has also performed data collection using a GSSI SIR Ssyetm-30, Ground Penetrating Radar (GPR), which combined with targeted borehole is an excellent toll for recording layer thickness of existing pavement.

This paper summarises the methodology and results of the nondestructive testing campaign undertaken in Rarotonga International Airport in Cook Islands and Moranbah Airport in Moranbah, QLD Australia. Results have been successfully used for pavement design and to upload Airport Pavement Management Systems in operation by different airport authorities.

Development of a binder test to rank the low temperature cracking performance of PMBs

Robert Urquhart1, Young Choi1 

  1. Australian Road Research Board, Vermont South, VIC, Australia

Polymer modified binders (PMBs) are increasingly used in road construction as they exhibit enhanced performance properties (e.g. rutting and crack resistance) compared to conventional bitumen. This study investigated whether binder tests conducted using an Australian piece of test equipment (i.e. the ARRB extensiometer) and an internationally used piece of test equipment (i.e. the dynamic shear rheometer (DSR)) could be used to rank the low temperature cracking performance of PMBs.

A range of binder samples which included bitumen samples and PMBs modified with polybutadiene (PBD), styrene butadiene styrene (SBS) and ethylene vinyl acetate (EVA) polymers, and crumb rubber, were subjected to force ratio tests using the extensiometer and stress ratio tests using the DSR. Very reasonable correlations were found between the results of both tests and the fatigue life results obtained for each of the binders after they were incorporated into a single type of 10 mm dense graded asphalt mix.  DSR tests appeared to be the most versatile for ranking the low temperature cracking performance of PMBs as all binders studied could be effectively tested.  Some of the harder binders studied and one C170 bitumen sample could be not effectively tested using the extensiometer as these materials either physically broke or detached from the testing apparatus during testing.

Performance based delivery for local government asphalt in Queensland

Performance based delivery for local government asphalt in Queensland

Robert Vos1, Chris Lange2 

  1. Australian Asphlat Pavement Association (AAPA), Eight Mile Plains, QUEENSLAND, Australia
  2. Fulton Hogan, Brisbane, QLD, Australia

“Queensland has embarked on the introduction of asphalt specifications which can be harmonised across neighbouring States and possibly Australia.  This was lead through the Strategic Alliance between the Australian Asphalt Pavement Association (AAPA) and the Queensland Department of Transport & Main Roads (TMR) and has resulted in a heavy & medium duty asphalt specification similar to that or New South Wales including a contractor pre-qualification system and a warranty for asphalt performance.  

The intention behind the harmonisation process was to transfer increased asphalt performance expectations onto the asphalt producer and concentrate on the harmonising the delivery of asphalt.  The goal was to remove local variations on standard tests, remove unjustified material property criteria and to use International or Australian Standard Test Methods, national pre-qualification systems and standardised performance criteria and assessment.  

Queensland was tasked by the AAPA National Technology and Leadership Committee to extend this system to accommodate the needs of Local Government.  

The process and outcomes of this project are detailed, covering the review of available specifications from leading local government authorities and major city users and producers of asphalt, and covering the engagement with industry associations representing local government asset owners and technical advisors and other jurisdictions in Australia.  The outcome is planned to be a specification and purchasing framework which can form the basis of both an AAPA National Guideline / Specification as well as an additional TMR specification for light duty asphalt.”

Recycling Behaviour of Rejuvenating Agent on Aged SBS Modified Asphalt

Jie Wang2, 1Yong-chun Qin2, 1, Song-chang Huang2, 1, Jian Xu2, 1, Xiao-pei Shi2, 1 

  1. Key Laboratory of Road Structure & Material(Beijing), Beijing, China
  2. Research Institute of Highway Ministry of Transport, Beijing, China

For each conference theme a number of topics have been suggested. Authors are encouraged to put forward additional topics that address the main themes.

Perpetual and Heavy Duty Pavement Technology

  • Sustainability
  • Performance based design
  • Perpetual pavement design
  • Innovative asphalt mix technology
  • Best practice use of RAP
  • Warm mix asphalt
  • Different types and blending proportions of rejuvenating agents were added to aged modified asphalt in order to evaluate the effect of rejuvenating agent on the properties of aged SBS modified asphalt and the recycling mechanism. The improvement effect of rejuvenating agents on the aged modified asphalt was analysed on the basis of experimental results involving penetration, softening point, ductility, Brookfield viscosity and toughness and tenacity. The relationship between the blending proportion of rejuvenating agent and each modified asphalt blend index is summarized. In addition, the role of rejuvenating agent on the aged modified asphalt was analysed by fluorescence microscope method. A relationship between the microscopic phase characteristic and the macroscopic property could be established. The results indicate that rejuvenating agent can recycle the properties of aged modified asphalt effectively, including its rheological property. However, the low-temperature property of modified asphalt blends is poor after thin film oven test (TFOT). The sensitivity of penetration and viscosity of modified asphalt blends is different for the various blending proportion of rejuvenating agents. The recovery degree of viscosity and ductility of modified asphalt blends is poorly synchronized. At the microscopic level, the initial phase of the aged modified asphalt is not changed by the addition of rejuvenating agents. After significant analysis, SBS particles area ratio of modified asphalt blends is significantly correlated with tenacity as the proportion of rejuvenating agent increases. Based on this, a novel approach to determine the blending proportion of rejuvenating agent in aged modified asphalt is proposed.

 

Validation of a New Generation Bitumen for Airport Asphalt

Greg White, Kevin Embleton

Airport asphalt surfaces are generally 14 mm maximum sized, dense-graded and Marshall-designed mixtures containing a premium bituminous binder. Reports of an increased frequency of early-life airport asphalt surface distress, anecdotally linked to binder variability, has prompted the airport industry to question the current range of binders for airport asphalt production. As a result, a number of bituminous surfacing companies have developed proprietary binders intended for airport asphalt production. One new elasto-plastomeric binder for airport asphalt production was assessed and validated. Assessment included comparison of new binder properties to those of other common binders and comparison of Marshall properties and performance properties of five different airport asphalt mixtures. Binder production data variability was also reviewed for the new binder produced in both high- and low-shear mills, before and after cold transportation and on-site re-heating. Based on results from the laboratory investigations and production data, the new binder was deemed to perform consistently and favourably compared to other binders commonly specified for airport asphalt production in Australia. This conclusion was supported by in-service performance of three different runway surfaces constructed in 2015 and 2016. Further evaluation is required to confirm the long-term performance of the new binder.

Developing a Performance Specification for Airport Asphalt

Greg White

A performance-based specification for airport asphalt surfacing was developed in collaboration with asphalt producers, design consultants and airport company representatives. The aim is to allow asphalt producers to innovate for reduced risk and to provided performance guarantees on the asphalt surface layer(s). The specification retains the general volumetric basis of traditional 14 mm dense graded Marshall-design airport asphalt. However, mixture design and binder selection is based on laboratory performance testing of the mixture and the traditional Marshall properties are only to be reported. Subsequent production acceptance testing is based on the volumetric composition and the Marshall properties. The specification is now in ‘provisional’ status and is ready for project validation. Future work must focus on the development of additional laboratory tests resistance to ravelling, to allow alternate aggregate gradings to be incorporated in the future.

Characterisation of Brisbane Asphalt Mixtures for Dynamic Modulus

Naomi Laws1, Kade Westaway1John Yeaman1, Greg White1 

  1. University of the Sunshine Coast, YANDINA CREEK, QLD, Australia

Modulus master curves were developed for Brisbane’s Type 3 asphalt mixtures prepared by different compactive efforts and thermal gradient testing was performed for the same mixtures. A more realistic pavement analysis was also performed in CIRCLY, using dynamic modulus values based on the temperature with depth based on the hottest day of 2015. When compared the constant modulus approach currently used by Brisbane City Council, the dynamic modulus approach required 35 mm greater asphalt thickness, for a typical pavement structure and typical traffic loading. This reflected the adoption of the hottest day for thermal gradient modelling, rather than the weighted mean temperature approach used for constant modulus design. Adoption of a dynamic modulus model will require consideration of the day to be adopted as the representative day for thickness design purposes.

Binder for Airport Asphalt Surfacing

Greg White1 

  1. University of the Sunshine Coast, YANDINA CREEK, QLD, Australia

Selection of bituminous binder is currently the most challenging element of airport asphalt mixture design. The traditional C320 and M1000 products have largely been discontinued and the elastomeric A10E has also been associated with variable asphalt field performance. To reduce performance-risk, industry has developed proprietary plastomeric and elasto-plastomeric binders, but some airports and designers remain cautious and have resisted their use. Assessing binder as part of a performance-specified asphalt mixture is essential to overcoming this challenge. Future efforts should also consider performance-indicative test methods for objective comparison of binders and the standardisation of handling and on-site re-testing requirements, which currently vary between project-level specifications.

High Speed Data Collection and Automatic Crack Mapping at the Network Level on the Bundaberg Region

Pedro Yarza1, Ernesto Urbaez1, Hennie Roux2, Peter Jensen2 

  1. Pavement Management Services, Sippy Downs, QUEENSLAND, Australia
  2. Roads & Drainage Service, Bundaberg Regional Council, Bundaberg, QLD, Australia

Bundaberg Regional Council (BRC) and Pavement Management Services (PMS) have worked together in the collection of multiple surface pavement parameters and asset identification of the BRC sealed (over 1,900 km) and unsealed (over 1,100 km) networks. This document shows how integrated collection of data from multiple sources (laser profiling sensors, 3D pavement cameras, right of way cameras for asset identification and a navigation system for georeferencing all the information) and integrated management of the derived results, can benefit in the best use of the available resources for the management of a local road network.

 

In order to visualise all this data, BRC and PMS use a custom tool for synchronised presentation of the information. The data can be visualised at different levels of aggregation depending on the task to accomplish: from road level for the network level decisions, to distress level in order to define the details of maintenance tasks. The information is shown by using not only images, charts and tables, but also specific tools to show the information through a web map interface with the network level condition, or to zoom in at the crack (mostly automatically detected) level on the pavement images.

 

The document shows how the above tools help BRC staff to better manage their road network by assisting in the decision making process. It also shows the advantages of visualising the results in an integrated environment to better understand the interrelations between the different elements (and associated parameters) that coexist in a local road network.

 

Keywords: GIS, laser data, distresses, cracking, automatic crack detection, integrated management, asset inventory

Validation of Fatigue Endurance Limit-Asphalt Stiffness Relationship for In-Service Perpetual Pavements

Saeed Yousefdoost1, JEFFREY LEE2, Robert Evans3, Binh Vuong4 

  1. ARRB Group, CLAYFIELD, QLD, Australia
  2. ARRB Group, Australia
  3. Swinburne University of Technology, Australia
  4. Binh Vuong Services, Oakleigh East, VIC, Australia

Australian Asphalt Pavement Association (AAPA) set out the Asphalt Pavement Solution for Life national project (APS-fL) in 2011, to introduce the perpetual pavement concept into the current pavement design practice in Australia. One of the major outcomes of the APF-fL project was the introduction of an asphalt stiffness based Fatigue Endurance Limit (FEL) design criteria which defines the capping strain level under which no bottom-up fatigue cracking will occur. This paper presents the findings of a comprehensive research to validate the proposed strain-stiffness design criteria against field data on 31 in-service heavily trafficked UK motorways. The CIRCLY-based back-calculation model EfromD3 was used to determine field pavement properties of the trial sections at various pavement temperatures over the time. For each pavement structure, the trend in changes of the field pavement properties over time was examined to confirm its perpetual status. In addition, the field pavement properties at three selected operating temperatures were used as inputs into the Austroads CIRCLY-based pavement response model to determine the field critical strains under the design axle loads. Since all the studied sites were reported to be un-cracked and in good service conditions, perpetual and non-perpetual pavements were identified by examining the variation in the back-calculated moduli of the pavements over time. It was also found that the identified relationship developed based on the analysis of UK sites, was different to the proposed AAPA FEL-asphalt stiffness relationship, therefore a revised design criteria was established. This effort was accomplished by developing a series of design chart nomograms based on the revised perpetual pavement design criteria.

The program includes sessions on:

  • Constructing the Roads of the Future
  • Perpetual and Heavy Duty Pavement Technology
  • Next Generation Bituminous Surfacings
  • Flexible Pavement Technology for (Air) Ports

Other useful links

  • Resilient Regional and Local Government Roads
  • Managing Road Networks in a Digitally Connected World
  • Delivering the Smart, Safe and Sustainable Roads of the Future