Airport Pavement Research Program

2020 Research Projects

The following student and staff projects were undertaken in 2020, either directly or in association with the APRP. Some of these projects are ongoing.

Reflection Cracking of Concrete Pavement Joints through Asphalt Overlays (ongoing)

Undertaken by Sahar Deilami (part‐time PhD student) under the supervision of Dr. Greg White and Associate Professor Christophe Gerber.

This project aims to develop a laboratory test machine and protocol for measuring the propagation rate of reflection cracks from concrete joints through asphalt overlays. Once developed, the test machine will enable the efficacy and cost‐effectiveness of different asphalt mixtures, strain alleviating membranes and geofabric interlayers to be objectively measured. Initial results are expected in 2021 and completion is expected in 2023.

Evaluation of marginal materials for foamed bitumen base course (ongoing)

Undertaken by Roberto Espinosa (Master of Science in Civil Engineering) under the supervision of Dr. Greg White and Dr. Adrian McCallum. The project considers the efficacy and efficiency of foamed bitumen stabilisation of marginal gravel materials. The general approach includes comparing marginal materials, improved by blending with RAP and other products, to a class A gravel. Improved performance associated with alternate foaming agents is also being considered. Outcomes will improve the understanding of this useful technology for regional and remote airports. Roberto completed his research in 2020 and some outcomes have been published. Well done Roberto.

university of the sunshine coast cricos provider number: 01595d

The University of the Sunshine Coast gratefully appreciates the support provided by:

Airport Pavement Research Program March 2021

Rise, and shine.

Introduction

Staffing In 2020, Finn Hall joined the

APRP as a part‐time research

student investigating waste

plastic modification of

bituminous binder for asphalt

production.

Finn is based in the UK and is completing

his work as an off‐campus international

student. Finn visited in early 2020 and

looks forward to returning in 2021.

Hudson Anstee also joined

the APRP in 2020, also as a

part‐time Masters research

student. Hudson’s research

is investigating proof rolling

and compacting granular

material in airport pavement construction.

Hudson is based in Melbourne and is also

researching in an off‐campus mode.

During 2020, both Tom Weir and Roberto

Espinosa completed their respective

Master of Science (Civil Engineering)

research. By coincidence, both Tom and

Roberto were research aspects of foamed

bitumen stabilisation technology. Both

officially graduated in March 2021.

Congratulations to both Tom and Roberto.

AIRPORT PAVEMENT RESEARCH PROGRAM | March 2021 university of the sunshine coast | cricos provider number: 01595d

Predicting age‐related asphalt erosion and ravelling for airport asphalt mixtures

Undertaken by Ahmed Abouelsaad (PhD student) on scholarship under the supervision of Dr. Greg White and Dr. Adrian McCallum.

This project will investigate theoretical modelling and laboratory testing of asphalt ravelling, the primary distress triggering runway resurfacing when major distresses (such as severe cracking and groove closure) are avoided. The outcome is expected to provide an objective basis for comparing different asphalt mixtures on the basis of relative erosion and ravelling resistance. Ahmed is full‐time and the findings of this project are expected to

become available from 2020 to 2022.

Load transfer and joint stiffness for rigid airport pavements

Undertaken by Sean Jamieson (part‐time PhD student) under the supervision of Dr. Greg White and Dr. Ali Jamshidi.

This project investigates jointing systems in rigid airport pavements

and the factors that affect joint stiffness and load transfer. This

will enable a better understanding of joint function and whether

current Australian jointing practices are as effective and efficient as

they can be. Outcomes are expected to be published from 2021

and completion is expected around 2025.

Recycled waste plastic modification of asphalt binder as a mature technology

Undertaken by Finn Hall (Master of Science in Civil Engineering) under the supervision of Dr. Greg White and Dr. Adrian McCallum.

Although significant work has been undertaken to show the

improvement in the engineering properties of binders and asphalt

mixtures modified with waste plastic, there remains questions

regarding the long‐term performance, whether wet mixing or dry

mixing is preferable, as well as a range of environmental and safety

questions. This project aims to address these issues as well as

demonstrating a micro‐circular economy via a real life case study

where this technology is being applied.

Compaction and proving granular layers in airfield pavement construction

Undertaken by Hudson Anstee (Master of Science in Civil Engineering) under the supervision of Dr. Greg White and Dr. Adrian McCallum.

This project aims to address the gaps in compacting and proving

granular layers for flexible airport pavement construction that

were created by the downgrading of the heavy roller fleet, as well

as by the ever‐increasing wheel loads and tyre pressures associated

with modern aircraft. The project will quantify the current size of

the compaction/proving gap, potential approaches to reducing or

closing the gap and will combine field trials with theoretical

modelling of roller compactive effort at depth, focusing on

vibrating and impact rollers that claim to have similar compactive

effort but with a much smaller roller. Outcomes are expected in

2021 and 2022.

Estimating the replacement value and maintenance cost of Australian airport pavements

Undertaken by Jacob Farrelly (undergraduate civil engineering student) under the supervision of Dr. Greg White. This project quantifies the physical area of rigid and flexible aircraft

pavement assets across Australia’s 350 (or so) paved and registered

airfields, ranging in size from Sydney to Bourke, using GIS‐based

tools. Based on typical using aircraft and subgrade conditions, the

thickness and cost of the airport pavement asset base will be

estimated. Finally, the depreciation cost and maintenance burden

associated with Australia’s airport pavements will be estimated. The

output will assist engineers and assets owners to seek support for

research, development and maintenance funding.

Using construction records to estimate the real strength of aircraft pavements

Undertaken by Rodrigo Lourenco (undergraduate civil engineering student) under the supervision of Dr. Greg White. This project will determine the realistic post‐construction strength of

the new Sunshine Coast airport runway pavement based on actual

construction data. This will be compared to the designed strength of

the pavement using stochastic inputs and Monte Carlo simulations.

The output will show that pavements are designed conservatively

and are often built with significantly greater strength than was

intended by the design.

Modelling the mid term friction evolution of runways

Undertaken by Jonard Erro (undergraduate civil engineering student) under the supervision of Dr. Greg White. This project develops a generic evolution of runway friction over the medium term of the 10‐12 year expected life of an asphalt runway surface. Friction survey data was obtained from various airports, where it has been collected multiple times per year over many years, and trends within airports and across airports are investigated. The output helps airports to better understand and manage runway friction over the life cycle of their asphalt runway surfaces.


Pilot project verification of stone mastic asphalt as an ungrooved runway surface

Undertaken by Dr. Greg White. Following the development of a specification for stone mastic as an

ungrooved runway surface material, this project aims to verify the

performance of stone mastic from the pilot project at Emerald

airport which was resurfaced in late 2019. The construction quality

records, visual condition evaluation and ongoing surface

texture/friction testing will allow the efficacy of ungrooved stone

mastic to be compared to grooved dense graded asphalt as a

runway surface for the future. Comparative costs, risks and

construction limitations will also be considered.

Comparing different measures of asphalt modulus

Undertaken by Dr. Ali Jamshidi. This project aims to mine the data from various previous projects

where different measures of modulus have been measured in

order to develop general relationships between the different test

methods. The developed relationships will be compared to

theoretical and published conversions to determine their efficacy.

A reliable conversion would allow designers to characterise asphalt

modulus by the most convenient test method, rather than one that

best replicates in‐service loading conditions.

Theoretical comparison of more sustainable airport asphalt mixtures

Undertake by Demi Van Den Heuvel, a CPEE Master of Pavements student completing an industry research project under the supervision of Dr. Greg White. This project compared the theoretical financial, social and

environment cost/benefit associated with the incorporation of

recycled plastic, recycled asphalt, crumb tyre rubber and crushed

recycled glass in asphalt mixtures. The triple bottom line was used

to combine the costs, resulting in a weighted combined or total

cost. The outcome will be published in 2021.

Synthetic and epoxy modified binders for airport asphalt production

Undertaken by Dr. Ali Jamshidi

A detailed desk‐top review as a first‐cut screen of the potential to

modify or replace bitumen in asphalt production with a synthetic or

epoxy‐type material. The potential is a surface that lasts 40 years

and it not affected by fuel or high temperatures. The challenges

include the high cost of the epoxy materials, as well as the logistics

and construction risks associated with products that chemically cure

and can’t be softened by reheating.

Industry support and representation In additional to APRP research and projects, USC APRP staff and students also supported and represented the

Australian airport industry through a range of initiatives during 2020, including:

Prepared draft Pavement Strength and Runway Skid Resistance Advisory Circulars for CASA, associated with the release of the new MOS 139.

Member and Secretary of the AAA PWG throughout 2020, including telecons and meetings.

Attended the online ICAO Airport Pavement Expert Group meeting in, October 2020.

AAA Webinar Stone Mastic Asphalt as an Ungrooved Runway Surface, June 2020.

Revised Airport Practice Note 12: Airfield Pavement Essentials, to address the new MOS 139 and to incorporate the Supplemental chapter on rural, regional and remote airfields.

Facilitated an Airport Sprayed Sealing Specification, published by AAPA in September 2020.

2021 research underway In additional to the continuation of 2020 research

projects, new projects for 2021 include:

Sustainable airport pavements. Completed as a PhD under scholarship, providing an app‐based calculator of the social, financial and environmental cost of options.

Crumbed rubber modified bitumen for asphalt surface anti‐ageing. A Masters research project undertaken by Andy Kidd.

Comparison of bituminous pavement surfaces for regional airports. Undertaken by Dr. Greg White and considering thin asphalt, sprayed seals and microsurfacing.

Asphalt preservation trials. Undertaken by Dr. Greg White, with the assistance of the Department of Defence, considering various product types.

Simulating arctic snow sintering in a freezer trailer. A final year engineering project to replicate arctic snow in a trailer mounted freezer on the Sunshine Coast.

Better waste plastic modified bitumen storage stability. Undertaken by Dr. Ali Jamshidi, considering chemicals called RET and PPA to reduce segregation risk during hot transportation.


Research publications

The following papers and articles were published in 2020. All publications and associated student theses are

available from the USC APRP output repository, access here.

Research Theses Jamieson, S. 2019, Stone Mastic Asphalt for Australian Airport Pavements, a thesis for the award of Master of Science (Civil Engineering), School of Science and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia. Weir, T. 2020, Experimental Investigation of the Influence of Production Processes and Curing on Foamed Bitumen Stabilised Base Course Materials, a thesis for the award of Master of Science (Civil Engineering), School of Science and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia. Espinosa, R. 2020, Laboratory Evaluation of Marginal Materials for Foamed Bitumen Stabilsiation, a thesis for the award of Master of Science (Civil Engineering), School of Science and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia.

Journal articles White, G. 2020, ‘A synthesis of the effects of two commercial recycled plastics on the properties of bitumen and asphalt’, Sustainability, vol. 12, no. 8594, pp. 1‐20. White, G & Espinosa, R 2020, ‘Laboratory Evaluation of Gradation Improvement of Marginal Materials for Foamed Bitumen Stabilization’, Applied Sciences, vol. 10, no. 4224, pp. 1‐13.

White, G & Almutairi, H 2020 ‘Laboratory and field performance comparison of dense graded and stone mastic asphalt as a runway surface’, International Journal of Pavement Engineering, article‐in‐press. Deilami, S & White, G 2020, ‘Review of reflective cracking in composite pavements’, International Journal of Pavement Research and Technology, no. 13, pp. 524–535. White, G 2020, ‘Stochastic strength rating of flexible airport pavements using construction data’, International Journal of Pavement Engineering, vol. 21, no. 4, pp. 537‐548. Jamieson, S & White, G 2020, ‘Review of stone mastic asphalt as a high performance ungrooved runway surfacing’, Road Materials and Pavement Design, vol. 21, no. 4, pp. 886‐905. Jamshidi, A & White, G 2020, ‘Evaluation of performance of challenges of use of waste materials in pavement construction: a critical review’, Applied Sciences, vol. 10, no. 226, pp. 1‐13. White, G 2020, ‘Incorporating binder type into fatigue life characterisation of airport pavement surfaces’, International Journal of Pavement Research and Technology, no. 13, pp. 40‐47.

Conference papers

White, G & Jamshidi, A, 2020, ‘Extending the use of RAP in airport asphalt resurfacing’, RILEM International Symposium on Bituminous Materials, Lyon France, 14‐16 December. Weir, T & White, G 2020, ‘Comparing laboratory curing and in‐pavement curing of a foamed bitumen stabilized base course material’, RILEM International Symposium on Bituminous Materials, Lyon France, 14‐16 December. Weir, T & White, G 2020, ‘Laboratory comparison of in‐situ, ex‐situ and laboratory produced foamed bitumen stabilized base’, RILEM International Symposium on Bituminous Materials, Lyon France, 14‐16 December. Jamshidi, A & White, G 2020, ‘Comparing compressive and flexural dynamic asphalt modulus by statistical and neural network modelling’, RILEM International Symposium on Bituminous Materials, Lyon France, 14‐16 December.


White, G & Hall, F 2020, ‘Comparing wet mixed and dry mixed binder modification with recycled waste plastic’, RILEM International Symposium on Bituminous Materials, Lyon France, 14‐16 December. Jamshidi, A & White, G 2020, ‘The challenges of warm mix asphalt as a nature technology’, 9th International Conference on Maintennce and Rehabilitation of Pavements, Zurich, Switzerland, 1‐3 July. Abouelsaad, A & White, G 2020, ‘Fretting and ravelling of asphalt surfaces for airport pavements: a load or environmental distress?’, Nineteenth Annual International Conference on Highways and Airport Pavement Engineering, Asphalt Technology, and Infrastructure, Liverpool, England, United Kingdom, 11‐12 March. White, G, Kelly, G, Fairweather, H & Jamshidi, A 2020, ‘Theoretical socio‐enviro‐financial cost analysis of equivalent flexible aircraft pavement structures’, 99th Annual Meeting of the Transportation Research Board, Washington, District of Columbia, USA, 12‐16 January.

More information The next USC APRP update will include the first half of 2021 and will be available in September 2021. For more information regarding the Airport Pavement Research Program, or to enquire about completing a post‐graduate research degree, please contact: Dr. Greg White Director, Airport Pavement Research Program, University of the Sunshine Coast [email protected] | +61 400 218 048

Future research initiatives Other research projects available in the future, as undergraduate projects, Masters by Research or PhD thesis include:

Analysis of different fine crushed rock base course materials using repeated load triaxial testing.

Asphalt construction joint density, testing, compliance and improvement.

The effect of different asset management strategies on a network of airfield pavements.

Developing a universal long term trend in runway friction for aircraft skid resistance.

Sustainable airport concrete mixtures by recycling existing concrete and other waste materials.

If you are interested in these projects, please contact Dr. Greg White on the details below.

Documents

Airport Pavement Research Program