Proceedings of the 9th International Conference on Maintenance and Rehabilitation of Pavements—Mairepav9

Table of Contents

1. Frontmatter

2. Advanced Trends in Design, Rehabilitation and Preservation

   1. Frontmatter

   2. Influence of the Aggregate Gradation on the Rutting Resistance of Bituminous Mixtures

      B. S. Abhijith, J. Murali Krishnan

      Abstract

      Rutting in bituminous pavements predominantly depends on the aggregate gradation. In particular, for fine graded mixtures, the aggregate gradation below 2.36 mm play a critical role since more than 60% of aggregates will pass through this sieve. The present work is focused on quantifying the rut resistance of three different fine aggregate gradations. The control gradation is the well-graded gradation used in India, and the other two gradations were obtained following Bailey method. The Bailey gradations were designed in such a way that the gradation below 2.36 mm sieve size was varied while the gradation above this sieve size was kept the same as that of the control gradation. The mixtures were fabricated using an unmodified binder (binder content kept constant at 5.4%) at 6% air voids using a shear box compactor. The influence of aggregate gradation on the creep and recovery response of bituminous mixtures was investigated at two temperatures by applying 10,000 repetitions of a repeated trapezoidal loading and recovery cycles. From the resulting residual strain curve, the Bailey mixture designed towards the coarser side below 2.36 mm sieve was found to have a higher resistance to rutting when compared to the conventional bituminous concrete-middle gradation.

   3. Experimental Investigation of Pothole Repair Materials

      Debaroti Ghosh, Mugur Turos, Mihai Marasteanu

      Abstract

      Pothole repairs represent a major maintenance item in the budget of many highway agencies. Currently, there are no required specifications for patching materials. Although the appearance of potholes every spring is a major public relations concern, limited experimental work has been performed on pothole repair materials to evaluate their mechanical properties. The focus of this study is to investigate relevant mechanical properties of current pothole materials. A total of six materials consisting of both summer and winter mixtures were used in this study. Several issues were encountered during the sample preparation of cold mixtures, such as the need of significant curing to gain strength and stiffness at low temperatures. For the cold mixtures, only Indirect Tensile creep and strength testing were performed, while for the other mixtures fracture energy and toughness were also determined. Experiments were also performed to evaluate if the addition of graphene nano-platelets (GNP) to patching materials improve their properties. Based on the results, several recommendations were made to improve the durability of pothole repair materials.

   4. A Durable Potholes Repair Method Using Polymer Modified Patching Material in Cold-Wet Weather

      Sen Han, Jinping Xia, Hui Xu, Hongwei Zhang

      Abstract

      There are two common deficiencies of the existing cold asphalt mixtures, one is the contradiction between workability or storage and strength, and the other is the problem of low initial strength after paving. In order to solve the problems, new polymer modified patching materials with dense gradation (PADG mixtures) are recommended for durable pothole repair in cold-wet weather, based on microcapsule technology and reinforcement action. In this paper, laboratory test and field investigation were performed to assess the performance of PADG mixtures, compared with dense graded cold mixtures (DG mixtures) and open graded cold mixtures (OG mixtures). It showed that the PADG mixtures solved the contradiction between workability, storability and strength of cold mixtures, and had better cohesion, stability, freeze-thaw resistance and durability in low temperature and wet conditions. Besides, the field survey over 13 months indicated that the pothole patches using PADG mixtures met the requirements of traffic safety and ride-ability. Therefore, combined with laboratory and field text results, it can be concluded that PADG mixtures are applicable to durable maintenance in adverse conditions of cold-wet weather.

   5. Maximising Stabilisation and Recycling Benefits for Sustainable Pavement Performance in New Zealand and Australia

      Allen Browne

      Abstract

      The stabilisation of granular pavement materials and/or underlying soils is accepted practice in Australasia (i.e. Australia and New Zealand). Stabilisation in this context involves the mechanical introduction of reactive agents, typically lime, cement and foamed bitumen. The reuse/recycling of aged existing pavement materials is imperative for sustainable management of finite resources. Reduction in aggregate availability has hastened the need for development of insitu stabilisation to rehabilitate the pavement alongside other performance gains. Hiway Group have commissioned laboratory research and undertaken extensive field trials in partnership with industry and academic partners to lead industry adoption and confidence in sustainable recycling. This paper will outline a variety of proven approaches ranging from hot in-place asphalt recycling through aggregate stabilisation treatments employing waste materials such as ground steel slag to innovative processes to mitigate and control deleterious subgrade soils and low ground pressure fill drying methodologies. Case studies such as exhuming 30+ year-old pavements to evaluate durability of lime stabilised layers will be outlined through to recent research and field trials that successfully incorporate substantial proportions of waste plastic, glass, steel slag and concrete blended recycled aggregates. Examples of structural benefits will be detailed that have been monitored to substantiate performance and calibrate design parameters.

   6. Evaluation of Warm Mix Asphalt Produced from Iraqi Materials

      Noor J. Mahdi, Duraid M. Abd, Taher M. Ahmed

      Abstract

      Warm mix asphalts (WMAs) have gained a widespread popularity as they have reduced emissions due to lower production temperature compared to that of traditional hot mix asphalt (HMA). In Iraq, such asphalt mixture is completely new while no project of WMA has constructed in the field so far although there is a huge demand to either re-construct or construct new highways. One of the considerations that should be taken into account in this regard is to get the advantages of installing WMA in Iraq. The aim of this study is to produce a warm mix asphalt using foaming additive, Zeolite, in both types natural and synthetic. The production temperatures of WMAs were at three levels 140, 130 and 120 °C while the traditional HMA was produced at 160 °C. This study includes producing HMA and WMAs from Iraqi materials, where one binder grade (40/50 pen) from one sources, it is Durah with one type of aggregate, limestone. Hydrated lime was also used as anti-stripping additive to study its effect on improving moisture damage of WMA produced at lower temperature. To study those properties, two techniques were used Marshall properties and Indirect Tensile test. The results showed there is no significant difference between the performances of WMAs compared to that of HMA taking in account level of reduction in the production temperature compared to that of traditional hot mix asphalt. Furthermore, the result of Indirect Tensile Strength ITS has shown the enhancement in moisture susceptibility of warm mix when hydrated lime was used.

   7. Influence of Curing on the Mechanical Properties of Cement-Bitumen Treated Materials Using Foamed Bitumen: An Interlaboratory Test Program

      Marco Pasetto, Emiliano Pasquini, Andrea Baliello, Simone Raschia, Amir Rahmanbeiki, Alan Carter, Daniel Perraton, Francesco Preti, Beatriz Chagas Silva Gouveia, Gabriele Tebaldi, Andrea Grilli, Eshan V. Dave

      Abstract

      The use of reclaimed asphalt (RA) in road pavements is continuously gaining interest thanks to the technical, economic and environmental advantages guaranteed by such sustainable practice. Cold recycling techniques compared to traditional asphalt mixes allow a significant reduction of energy, fume emissions, use of natural resources, etc. In this perspective, the Task Group 1 on “Cold Recycling” of the RILEM Technical Committee on “Asphalt Pavement Recycling” (TC 264-RAP) launched an interlaboratory test program (ITP) aimed at ensuring a better understanding for cold recycled mixtures. The paper presents the results collected by a restricted group of the participating laboratories testing cement-bitumen treated materials that included a single RA source and prepared with foamed bitumen. Gyratory compacted specimens were used to evaluate the influence of curing (free, partial or restricted-surface drying for 14 days at 40 °C at a relative humidity of 55 ± 5%). Stiffness was evaluated as a function of the curing stage and the corresponding water loss; strength was tested after 14 days of curing testing specimens in both dry and wet conditions to also determine the water sensitivity. As expected, the different curing conditions clearly influenced the rate of water loss of tested samples with clear effects on mechanical properties and durability.

   8. Laboratory Tests for the Characterization of Cold Asphalt Patching Mixtures

      Pier Paolo Riviera, Davide Dalmazzo, Ezio Santagata

      Abstract

      Cold asphalt patching mixtures are widely employed in pavement maintenance operations due to their technical and economical effectiveness. However, their selection is seldom based on the results of laboratory characterization tests, since there are no standard procedures which are recognized by the international community for such a purpose. The investigation described in this paper focused on the evaluation of the strength and stiffness properties of several cold asphalt patching products which were subjected to analysis in two characteristic compaction states: low compaction, as achieved after placement in the field, and high compaction, as reached under the action of traffic loads. Mechanical characteristics evaluated in the laboratory included indirect tensile strength, California Bearing Ratio, resilient modulus and quick shear strength. Analysis of the obtained results highlighted the existence of significant differences between the various products which were explained by referring to their composition and curing behavior.

   9. Performance Evaluation of Long-Life Pavements Using the Mechanistic-Empirical Asphalt Pavement Analysis (MEAPA) Web Application

      M. Ghazavi, A. Seitllari, M. E. Kutay

      Abstract

      The long-life pavements that last longer than 50 years without major structural rehabilitation and require only periodic surface renewal due to surficial distresses are known to have relatively low life cycle cost. The enhanced performances of such pavements (also known as perpetual pavements) are due to many factors such as improved structural design, better materials and construction practices. In Michigan, several long-life pavement sections were constructed in response to the Public Act 175 (2015) and the Roads Innovation Task Force (RITF) Report. The objective of this study was to evaluate the fatigue performance of one of the long-life pilot projects sections (US-131) and compare it with a standard design in Michigan. A new mechanistic-empirical analysis software (MEAPA) was used to predict the long-term performance of the pavements included in the study. The critical strains for bottom-up and top-down cracking, fatigue life (i.e., number of cycles to failure (Nf)) and predicted magnitudes of bottom-up and top-down cracking were compared. Even though it was observed that the long-life structure is expected to perform better than the standard section in terms of fatigue cracking, both sections are expected to perform well over 30-year design life.

3. Management Systems and Life Cycle Analysis

   1. Frontmatter

   2. The Challenges of Warm Mix Asphalt as a Mature Technology

      Ali Jamshidi, Greg White

      Abstract

      Laboratory tests and field investigations show promising results of structural performance of warm mix asphalt (WMA). Also, the lower environmental burdens and fuel requirement in WMA production increase sustainability in the asphalt industry. However, there are challenges that significantly affect WMA performance and marketing in the future. In this paper, all these challenges are discussed, and the trend of WMA technology is evaluated. The statistics indicate that the energy market plays a pivotal role in enthusiasm for WMA. Lastly, WMA requires further investigations to meet requirements of post-modern pavement, as a new concept of pavement design in the 21st century.

   3. A Framework for Network Level Pavement Maintenance Planning for Low Volume Roads

      H. R. Pasindu, R. M. K. Sandamal, M. Y. I. Perera

      Abstract

      Low volume roads (LVRs) play a pivotal role in the economic development of rural areas especially by providing connectivity for the communities to access markets, education and social needs in an efficient manner. They serve as the link between the local road network to the arterial and collector road network designed at providing accessibility to residential, agricultural or industrial areas. Lack of funding, subjective and ad hoc decision making has resulted in an inefficent utilization of resources  in the local road agencies. Lack of a sound analytical process is a major impediment to maintain these roads in cost effective manner under the resource constraints prevalent. Existing pavement management systems (PMS) require extensive data collection and complex analysis processes, which makes them impractical to be deployed in local agencies. The core attributes of the proposed system are, reduced the data requirements, simplified the analytical tools and allowing users to customize considering the resource constraints. In this study, a relationship between International Roughness Index (IRI) and relevant distresses for LVR is established and based on that cost estimation model is developed for distress repair. Furthermore, the strategy which provide maximum condition for preventive maintenance is found by using decision tree approach in the network level optimization. A case study illustrated that the use of proposed PMS provides better overall network condition with compare to conventional decision making for same budget level.

   4. P-F Curves in Modelling of Pavement Performance

      Adam Zofka

      Abstract

      Road asset management (RAM) is a systematic approach to maintain road network at sufficient functionality level in order to provide desirable level of services. Various strategies can be implemented within RAM but only proactive strategy ensures sustainable, optimal, and cost-effective decisions. One of the variations of the proactive strategy is reliability-centered maintenance (RCM). Integral part of the RCM framework are so called P-F curves that allow to knowingly consider the potential failure and loss of functionality of road asset. While this is not entirely new concept as comparing to models used for pavement performance, P-F curves emphasize critical stages of the development of pavement damage and concurrent continuous increase in probability of functional failure. This paper discusses several aspects of different strategies in maintenance management and associated deterioration models together with P-F curves highlighting the need for continuous improvement of processes involved in decision-making as well as verification of effectiveness and efficiency of actions applied onto road network.

   5. Combined Life Cycle Cost Analysis and Life Cycle Assessment of Road Pavements

      Egemen Okte, Imad L. Al-Qadi

      Abstract

      Life cycle assessment (LCA) and life cycle cost analysis (LCCA) are the main pillars of pavement sustainability. LCA addresses environmental impacts of a pavement structure, and LCCA addresses life cycle costs. While both techniques go hand in hand with transportation agencies’ decision making, they are usually used separately because there are no tools or methodologies that consider both under the same framework. This study introduces a LCCA add-on to a LCA tool developed by the Illinois Center for Transportation (ICT). The tool analyzes all pavement life stages, namely, construction and materials, maintenance, use and end of life. With the new add-on, the tool can calculate agency costs and user costs associated with both work zone and normal operating conditions as well as global warming potential and energy consumption. The developed tool makes the pay item framework easier to use for agencies and contractors. At the end, a case study is presented to illustrate the tool’s capabilities.

   6. Decision Support for New Holistic Uri Road Asset Management Process

      Frank Schiffmann, Rade Hajdin, Alfredo Serioli

      Abstract

      By maintaining Uri road infrastructure, the cantonal road agency is ensuring safety, reliability and driving comfort on the roads for passengers and freight transport and thus, contributes to economic and social added value. The canton Uri has one of the first road agencies with an infrastructure division responsible for all road infrastructure objects. This includes inventory, condition inspections, maintenance planning and necessary data management. Uri maintenance and rehabilitation processes for pavements are embedded in a holistic road asset management process supported by an essential IT infrastructure.

      One of the key applications is a flexible decision support tool “infFaros Uri” which was customized and developed together with the infrastructure division of canton Uri to meet their needs. infFaros can handle road sections and bridge together allowing synergy effects and corridor planning. It supports various methodologies including probabilistic and deterministic deterioration, cost/benefit and cost/effectiveness decision-making as well as consideration of four-year maintenance and rehabilitation plan and evaluation of its impact. By linking short- and long-term maintenance and rehabilitation planning using existing cantonal transportation data complex questions can be answered and decision making can be efficiently supported by scenario comparisons. infFaros is a modern web-based application. The paper presents both the technical background of the software and use of it to support four-year maintenance and rehabilitation planning within new Uri road asset management process.

   7. Life Cycle CO2 Analysis of Low Rolling Resistance Asphalt Pavements

      A. Kawakami, M. Yabu, H. Nitta

      Abstract

      Reducing rolling resistance of pavement surfaces contributes to improved fuel efficiency for automobiles and reduced CO₂ emissions in exhaust gases. The authors have developed actual low-rolling-resistance asphalt pavements and shown that such pavements can reduce CO₂ emissions from automobiles by 1.3–6.6% through a driving test. In contrast, in order to evaluate the CO₂ emissions of pavement technologies, which will contribute to the realizing of a sustainable society in the future, it is important to conduct the life cycle assessment of these pavement technologies, including CO₂ emissions, due to the production and transportation of pavement materials, pavement construction work, and the recycling as well as the reconstruction of pavements. Thus, for the purpose of clarifying the environmental improvement effect of low-rolling-resistance asphalt pavements, this research paper reports on the life cycle CO₂ emissions assessment conducted for studying not only CO₂ emissions due to the production and transportation of pavement materials, pavement construction work, reconstruction but also reductions in CO₂ emissions through the improvement in fuel efficiency of automobiles by the low-rolling-resistance asphalt pavements. As a result of the life cycle CO₂ emissions assessment, it is clarified that the low-rolling-resistance asphalt pavements can reduce CO₂ emissions by 70% compared to conventional pavement (porous asphalt pavement).

   8. Accuracy Comparisons Between ASTM 1318-09 and COST-323 (European) WIM Standards Using LTPP WIM Data

      Syed W. Haider, Muhammad Munum Masud

      Abstract

      Weigh-in-Motion (WIM) is a primary technology used for monitoring and collecting vehicle weights and axle loads on roadways. Highway agencies collect WIM data for many reasons, including highway planning, pavement and bridge design, freight movement studies, motor vehicle enforcement, and regulatory studies. The process of weighing vehicles in motion estimates static truck weight by the wheel [single or tandem axles] or gross vehicle weight (GVW) as vehicles drive over sensors installed in a roadway or under a bridge. Two primary protocols are currently used across the globe to assess the accuracy of a WIM system, (a) ASTM E1318-09 and (b) European WIM accuracy protocols. The quality and accuracy of the data largely depend on the characteristics of the WIM equipment, calibration/validation, site characteristics, and data reporting. This paper compares the WIM sensor accuracies in the LTPP data for both protocols. The results show that there are minor differences in calculated accuracies.

   9. Detecting Significant Changes in Traffic Patterns for Pavement Design

      Gopi K. Musunuru, Syed W. Haider, Neeraj Buch

      Abstract

      The mechanistic-empirical pavement design guide (AASHTOWARE Pavement-ME) incorporates mechanistic models to estimate stresses, strains, and deformations in pavement layers using site-specific climatic, material, and traffic characteristics. These traffic characteristics include monthly adjustment factors (MAF), hourly distribution factors (HDF), vehicle class distributions (VCD), axle groups per vehicle (AGPV), and axle load distributions for different axle configurations. Site-specific traffic inputs (Level 1) were generated for each of the 41 WIM sites after extensive QC checks. The averages from nearby sites (regional) with similar traffic characteristics (groups or clusters) can be used as Level 2 data or Level 3 data when Level 1 data are unavailable. Multiple approaches were used to develop Level 2 and Level 3 traffic input levels. These developed traffic inputs at different levels need to be updated every few years due to several reasons, including the change in land use nearby the WIM locations, economic conditions resulting in the change in traffic patterns. Equations were developed to identify these changes in traffic patterns that would cause significant changes in design lives. Once these patterns are identified, the traffic inputs can be updated so that the pavement sections would not be over-designed or under-designed.

   10. Development of Road Maintenance Management System for India’s National Highway Network Using HDM-4 and Genetic Programming

       Abhishek Sharma, Tanuj Chopra

       Abstract

       With the increasing traffic loads on National highways of India, pavements are deteriorating at a faster rate leading to premature failure. In addition to this lack of scientific road management system leads to lower levels of serviceability and unreliable road network in the long term. Therefore, in order to maintain the highway network in good condition the road administration should focus on long lasting and economical road maintenance solutions. The research study focuses on the development of road management system for high volume roads using calibrated Highway Development & Management (HDM-4) model. Long-term pavement performance under various maintenance strategies has been measured in terms of roughness progression using HDM model. Genetic Programming (GP) system has been configured to develop four distress prediction models i.e., roughness, ravelling, cracking and rutting. Adequacy of GP models has been measured using simple linear regression analysis. Statistical significance of roughness model has been evaluated using student’s t-test. Variability in the output results of the two deterministic models i.e., HDM and GP has been computed by comparing the difference between predicted and observed roughness behaviour. Prediction models play a crucial role in development of Road Maintenance and Management System (RMMS) for systematic technical as well as economic appraisal of road projects. Future modelling of pavement behaviour related to various maintenance activities will assist the highway planners and road agencies in timely monitoring and conditioning of roads by adopting suitable management framework.