scholarly journals Recycled Asphalt Shingle Modified Asphalt Mixture Design and Performance Evaluation

2020 ◽  
Author(s):  
He Wang ◽  
Punyaslok Rath ◽  
William Buttlar
Keyword(s):  
Asphalt Mixture ◽  
Performance Testing ◽  
Compact Tension ◽  
Asphalt Mixtures ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Tension Tests ◽  
Field Investigations ◽  
And Performance ◽  
Wheel Tracking

The inclusion of recycled asphalt shingles (RAS) in asphalt mixtures has become increasingly common; however, the underlying design principles vary significantly by agency. The primary objectives of this study included: (1) evaluating the ‘binder availability’ concept for RAS mixtures through a carefully designed laboratory experiment; (2) demonstrating a balanced mixture performance testing approach for the design of RAS mixtures; and (3) evaluating the field data of RAS mixtures placed in the Midwest region of the U.S. Three asphalt mixture designs with RAS contents of 0.0, 2.5 and 5.0%, which were designed to have nearly identical volumetric characteristics, were investigated. The binder availability was determined to be approximately 100% in the two RAS mixtures considered. In addition, Hamburg wheel tracking and disk-shaped compact tension tests were conducted to evaluate the high- and low-temperature mixture performance. As expected, the addition of RAS significantly improved the rutting resistance. DC(T) test results demonstrated that a soft base binder effectively permitted the design of thermal-crack-resistant RAS mixtures. Field investigations indicated that the performance of pavement surfaces containing RAS was similar to that of surfaces containing only reclaimed asphalt pavement or virgin materials. This study also highlights a performance-engineered mix design approach, which is currently being adopted by several agencies in the Midwest (e.g. Illinois Tollway, Missouri DOT, etc.) and can provide mix designers a reliable approach for designing innovative asphalt mixtures with higher recycling levels and a modern, heterogeneous composition. Furthermore, the proposed approach may prove to be a simpler, more mixture-centric alternative to the primary method suggested in AASHTO PP78-17, which recommends arbitrary VMA bumping plus binder extraction, recovery, and advanced binder testing.

scholarly journals Performance Analysis of Asphalt Mixtures Modified with Ground Tire Rubber Modifiers and Recycled Materials

2019 ◽  
Vol 11 (6) ◽  
pp. 1792 ◽  
Author(s):  
Punyaslok Rath ◽  
Joshua Love ◽  
William Buttlar ◽  
Henrique Reis
Keyword(s):  
Compact Tension ◽  
Asphalt Mixtures ◽  
Asphalt Pavements ◽  
Tire Rubber ◽  
Ground Tire Rubber ◽  
Reclaimed Asphalt ◽  
Dry Process ◽  
Polymer Hybrid ◽  
And Performance ◽  
Wheel Tracking

The usage of Ground Tire Rubber (GTR) in asphalt pavements has gained renewed interest due to its potential sustainability, economic, and performance benefits. This study focuses on asphalt mixtures designed with three different rubber modifier products including (1) a terminal-blend GTR, (2) a dry-process, chemically processed rubber product, and (3) a terminal-blend rubber-polymer hybrid product. The modifications were incorporated into Illinois Tollway’s approved Stone Matrix Asphalt (SMA) designs using (1) a base binder (PG 58-28), (2) a softer binder (PG 46-34), and (3) a softer binder with higher recycled content. Disk-shaped Compact Tension (DC(T)) test, Hamburg Wheel Tracking Test (HWTT) and Acoustic Emission (AE) tests were performed to characterize the mixtures. The fracture energy for most mixtures met the stringent criteria of 690 J/m2 and the rut depths measured were less than 6 mm at 20,000 wheel passes. A Hamburg-DC(T) plot suggests that higher amounts of RAP/RAS (RAP: Reclaimed Asphalt Pavement; RAS: Reusable Asphalt Shingles) can be successfully used if a suitably soft base binder is employed.

scholarly journals Cost-benefit Analysis of RAP Incorporated Stone Matrix Asphalt Mixtures

2019 ◽  
Vol 8 (3) ◽  
pp. 6146-6149
Keyword(s):  
Production Cost ◽  
Cost Benefit Analysis ◽  
Asphalt Mixture ◽  
Cost Benefit ◽  
Asphalt Mixtures ◽  
Public Works ◽  
Reclaimed Asphalt ◽  
Cost Benefit Ratio ◽  
And Performance ◽  
The Cost

It is desirable to incorporate Reclaimed Asphalt Pavement into the asphalt mixtures, which provides several benefits i.e. economic, environmental and performance. It is necessary to study, the economic analysis of the RAP since that incur several contingencies to the asphalt mixtures. In this study, a simple approach is used to evaluate the production cost of the asphalt and RAP incorporated asphalt mixtures. Apart from that Waste Vegetable Oil (WVO) is used as a rejuvenator to enhance the properties of the mixture. In this study, asphalt mixture production cost is evaluated and cost of each material is taken from the Public Works Department Standard Scheduled of Rates (PWD – SSR) and the market survey techniques are followed. From the cost-benefit ratio, it is observed that the reduction in the Optimum Binder Content (OBC) provides great economic savings to the production cost. The incorporation of the RAP reduced the asphalt content and reduced the production cost of the asphalt mixtures. The addition of the WVO further reduced the OBC but increased the production cost compared to the non-rejuvenated mixture. The increase in the production cost is due to the extra cost invested on the WVO and other contingencies.

scholarly journals The Effect of Aging on the Cracking Resistance of Recycled Asphalt

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Mojtaba Mohammadafzali ◽  
Hesham Ali ◽  
James A. Musselman ◽  
Gregory A. Sholar ◽  
Aidin Massahi
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Fatigue Cracking ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Reclaimed Asphalt Pavement ◽  
Cracking Resistance ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Important Concern

Fatigue cracking is an important concern when a high percentage of Reclaimed Asphalt Pavement (RAP) is used in an asphalt mixture. The aging of the asphalt binder reduces its ductility and makes the pavement more susceptible to cracking. Rejuvenators are often added to high-RAP mixtures to enhance their performance. The aging of a rejuvenated binder is different from virgin asphalt. Therefore, the effect of aging on a recycled asphalt mixture can be different from its effect on a new one. This study evaluated the cracking resistance of 100% recycled asphalt binders and mixtures and investigated the effect of aging on this performance parameter. The cracking resistance of the binder samples was tested by a Bending Beam Rheometer. An accelerated pavement weathering system was used to age the asphalt mixtures and their cracking resistance was evaluated by the Texas Overlay Test. The results from binder and mixture tests mutually indicated that rejuvenated asphalt has a significantly better cracking resistance than virgin asphalt. Rejuvenated mixtures generally aged more rapidly, and the rate of aging was different for different rejuvenators.

scholarly journals Fatigue Evaluation of Recycled Asphalt Mixture Based on Energy-Controlled Mode

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Tao Ma ◽  
Kai Cui ◽  
Yongli Zhao ◽  
Xiaoming Huang
Keyword(s):  
Fatigue Life ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Fatigue Performance ◽  
Fatigue Properties ◽  
Dissipated Energy ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Bending Fatigue Test ◽  
Fatigue Evaluation

The fatigue properties of asphalt mixtures are important inputs for mechanistic-empirical pavement design. To understand the fatigue properties of asphalt mixtures better and to predict the fatigue life of asphalt mixtures more precisely, the energy-controlled test mode was introduced. Based on the implementation theory, the laboratory practice for the energy-controlled mode was realized using a four-point-bending fatigue test with multiple-step loading. In this mode, the fatigue performance of typical AC-20 asphalt specimens with various reclaimed asphalt pavement (RAP) contents was tested and evaluated. Results show that the variation regulation of the dissipated energy and accumulative energy is compatible with the loading control principle, which proves the feasibility of the method. In addition, the fatigue life of the asphalt mixture in the energy-controlled mode was between that for the stress-controlled and strain-controlled modes. The specimen with a higher RAP content has a longer fatigue life and better fatigue performance.

Effects of Reheating Procedure and Oven Type on Performance Testing Results of Asphalt Mixtures

2018 ◽  
Vol 2672 (26) ◽  
pp. 124-133 ◽  
Author(s):  
Zachary Lemke ◽  
Husam Sadek ◽  
Daniel Swiertz ◽  
Signe Reichelt ◽  
Hussain U. Bahia
Keyword(s):  
Performance Testing ◽  
Substantial Effect ◽  
Asphalt Mixtures ◽  
Volumetric Properties ◽  
Performance Tests ◽  
Laboratory Equipment ◽  
Standard Procedures ◽  
And Performance ◽  
Time Required ◽  
Wheel Tracking

Reheating and oven-aging procedures of plant-produced asphalt mixtures in laboratories are important topics to consider as performance testing of mixtures becomes more popular among agencies. Differences between laboratory equipment and procedure could significantly affect performance properties. The objective of this study is to investigate the influence of sample size, oven type, and variation in reheating/aging temperatures on the results of two performance tests on plant-produced mixtures. A selected mixture was tested for volumetric properties and performance using Hamburg wheel-tracking (HWT) and semi-circular bending (SCB-IFIT) tests. Results show that reheating mixtures uncovered and in smaller containers could significantly reduce the time to achieve aging temperature, and could make the process more efficient and consistent. In addition, aging using three different oven types showed that temperature within ovens can vary significantly depending on the location of the sample inside the oven, which affects the time required to reach the target temperature, and thus may also influence the aging of the sample. The mixture volumetric properties show that the effect of various heating conditions is marginal. Using the developed reheating/aging procedure of this study, the results of the HWT and SCB-IFIT tests showed no substantial effect of oven type on rutting and cracking resistance. The overall results indicate that there is a need to standardize the conditions of reheating, sample geometry, and to verify uniformity of temperature in ovens. Such standardization can further reduce variability and thus should be part of the AASHTO/ASTM standard procedures for quality control, or of laboratory equipment calibration procedures.

scholarly journals Laboratory comparative assessment of warm and hot mixes Asphalt containing reclaimed Asphalt pavement

2020 ◽  
Vol 8 (2) ◽  
pp. 15-26
Author(s):  
Hasan H Joni ◽  
Aqeel Y M Alkhafaji
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Asphalt Mixtures ◽  
Reclaimed Asphalt Pavement ◽  
Moisture Resistance ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Marshall Stability ◽  
The Impact

Warm mix Asphalt (WMA) could be mixed and used in paving at low temperatures to minimize the consumption of energy and the emissions of greenhouse gas. Recycled Asphalt pavement (RAP) could save Asphaltic cement and aggregate, which could achieve the better effects of recycling. However, both of the two WMA and RAP technologies have some deficiencies. Warm mix Asphalt and Reclaimed Asphalt pavement (WMA-RAP) technique may solve these issues and deficiencies when they are utilized together. This study investigated the implementations of WMA-RAP and its impacts on the performance of the Asphalt mixture. Under the framework of this study, four percentages of RAP (0%, 20%, 30%, and 40%) were added to the hot mix Asphalt (HMA) and WMA containing 4% Sasobit to study the impact of increasing RAP content on Marshall stability and moisture resistance of Asphalt mixtures. In summary, the Marshall stability of HMA and WMA mixtures is higher than the control mixtures. A small decrease in moisture resistance of both (HMA and WMA) containing RAP comparing to control mixtures Asphalt was observed, as shown by reduced the tensile strength ratios (TSR), but it is still much higher than the minimum of 80%.

scholarly journals Development of a 4.75 mm asphalt mixture design for Implementation in Louisiana DOTD Specifications

2020 ◽  
Vol 13 (6) ◽  
pp. 637-644
Author(s):  
Saman Salari ◽  
Samuel Cooper ◽  
Louay N. Mohammad ◽  
Peyman Barghabany
Keyword(s):  
Comprehensive Evaluation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Performance Testing ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Construction Costs ◽  
The Cost ◽  
Wheel Tracking

AbstractThe Louisiana Department of Transportation and Development (DOTD) and other state agencies are continuously looking for techniques to reduce roadway maintenance and construction costs. A common consideration is to introduce asphalt mixtures with a smaller nominal maximum aggregate size (NMAS) for utilization in roadways. In a previous study, DOTD concluded that mixtures with a 4.75 mm NMAS provided acceptable performance as a surface layer. Excessive stockpiles of unused smaller aggregates can result in an economically competitive source to be consi dered for asphalt mixtures. The DOTD developed mixtures with four aggregate types and two binder types. A comprehensive evaluation of performance was conducted through volumetric and mechanistic testing. Performance testing consisted of the Loaded Wheel Tracking (LWT) test to determine rutting resistance, Semi-Circular Bend (SCB) test to evaluate intermediate temperature cracking resistance, and dynamic modulus (E*) to ascertain the stiffness at intermediate temperatures. As expected, asphalt binder grade, aggregate type and mixture composition affected the performance of mixtures evaluated. Gravel mixtures were susceptible to cracking, while limestone mixtures were susceptible to rutting. An economic analysis was conducted to determine the viability of 4.75 mm mixtures. The cost per ton of 4.75 mm mixtures in Louisiana was higher than conventional 12.5 mm mixtures. However, when considering the lift thickness of potential overlays, the 4.75 mm aggregate mixtures became more viable. Further, a life-cycle analysis of a designed pavement using AASHTO Pavement-ME was performed to compare the lifetime durability of the 4.75 mm NMAS mixtures to a conventional 12.5 mm mixture.

Laboratory Observation and Evaluation of Asphalt Blends of Reclaimed Asphalt Pavement Binder with Virgin Binder using SEM/EDS

2018 ◽  
Vol 2672 (28) ◽  
pp. 69-78 ◽  
Author(s):  
Yanxu Jiang ◽  
Xingyu Gu ◽  
Zhou Zhou ◽  
Fujian Ni ◽  
Qiao Dong
Keyword(s):  
Asphalt Pavement ◽  
Energy Dispersive Spectrometer ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Reclaimed Asphalt Pavement ◽  
Recycled Asphalt ◽  
Laboratory Observation ◽  
Reclaimed Asphalt ◽  
Recycling Agent ◽  
Aged Binder

In this paper, microscopic technique tests were carried out to observe and evaluate the degree of blending between reclaimed asphalt pavement (RAP) binder and virgin binder in hot mixed asphalt mixture. To this end, titanium dioxide (TiO2) was selected as a tracer to tag virgin binder. Scanning electron microscope/energy dispersive spectrometer (SEM/EDS) experiments were conducted on compacted recycled asphalt mixtures and virgin asphalt mixtures. The element mass ratio of titanium over sulfur (Ti:S) was proposed as an quantitative indicator of blending ratio to accurately evaluate the degree of partial blending between RAP and virgin binders. The SEM/EDS images visually displayed the partial blending in high RAP mixtures. Different partial blending patterns were observed under different handling processes. The results of EDS tests indicated that with the increase of the RAP content, the blending degree of virgin and aged binder decreased rapidly, and the homogeneity of blended binder became weakened. In addition, aging process and recycling agent could improve the efficiency of RAP binder as it is blended with virgin one, and it should be noted that the inter-diffusion of old and new binders need enough time. This methodology provides a systemic approach to determine the degree of binder blending in RAP mixture.

Evaluation of Asphalt Mixture Performance Using Cracking and Durability Tests at a Full-Scale Pavement Facility

2021 ◽  
pp. 036119812110218
Author(s):  
Amir Golalipour ◽  
Varun Veginati ◽  
David J. Mensching
Keyword(s):  
Performance Test ◽  
Asphalt Mixture ◽  
Performance Testing ◽  
Field Performance ◽  
Optimization Procedure ◽  
Cyclic Fatigue ◽  
Intermediate Temperature ◽  
Index Test ◽  
Reclaimed Asphalt ◽  
Indirect Tensile

In the asphalt materials community, the most critical research need is centered around a paradigm shift in mixture design from the volumetric process of the previous 20-plus years to an optimization procedure based on laboratory-measured mechanical properties that should lead to an increase in long-term pavement performance. This study is focused on advancing the state of understanding with respect to the value of intermediate temperature cracking tests, which may be included in a balanced mix design. The materials included are plant-mixed, laboratory-compacted specimens reheated from the 2013 Federal Highway Administration’s (FHWA’s) Accelerated Loading Facility (ALF) study on reclaimed asphalt pavement/reclaimed asphalt shingle (RAP/RAS) materials. Six commonly discussed intermediate temperature (cracking and durability) performance testing (i.e., Asphalt Mixture Performance Tester [AMPT] Cyclic Fatigue, Cantabro, Illinois Flexibility Index Test [I-FIT], Indirect Tensile Cracking [ITC, also known as IDEAL-CT], Indirect Tensile Nflex, and Texas Overlay Test) were selected for use in this study based on input from stakeholders. Test results were analyzed to compare differences between the cracking tests. In addition, statistical analyses were conducted to assess the separation among materials (lanes) for each performance test. Cyclic fatigue and IDEAL-CT tests showed the most promising results. The ranking from these two tests’ index parameters matched closely with ALF field performance. Furthermore, both showed reasonable variability of test data and they were successful in differentiating between different materials.

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