Research on Moisture Susceptibility of Emulsion Treated Cold Reclaimed Asphalt Mixture

Author(s):  
Jie Xiao ◽  
Yongsheng Yu
Author(s):  
Amir Golalipour ◽  
Varun Veginati ◽  
David J. Mensching

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.


2011 ◽  
Vol 415-417 ◽  
pp. 1531-1536
Author(s):  
Fu Ming Liu ◽  
Duan Yi Wang

This paper presents the results of laboratory and performance tests for an asphalt treated base (ATB) and mixes developed in this study for perpetual asphalt pavements. Laboratory tests for the mixes included moisture susceptibility, wheel tracking and fatigue tests. The results of performance test indicated that the resistances of the high content binder ATB against moisture and fatigue damage were better than those of the lower one. It was also found from the full scale test sections that the tensile strain values at the bottom of the asphalt layer for the ATB sections were low when the asphalt layer thicknesses of the ATB sections were not thicker than those of the conventional sections. All the tensile strain values measured from the ATB sections were within the fatigue endurance limit of 70 microstrain which is the fatigue criterion of a perpetual asphalt pavement.


Author(s):  
Ekarizan Shaffie ◽  
◽  
H.A. Rashid ◽  
Fiona Shiong ◽  
Ahmad Kamil Arshad ◽  
...  

Stone Mastic Asphalt (SMA) is a gap-graded hot mixture designed to provide higher resistance towards permanent deformation and rutting potential by 30% to 40% more than dense-graded asphalt, due to its stable aggregate skeleton structure. However, compared to other types of hot mix asphalt, SMA unfortunately has some shortcomings in term of its susceptibility towards moisture-induced damage due to its structure and excessive bitumen content in the composition. This research aims to assess the performance of a SMA mixture with steel fiber by enhancing overall stability, abrasion resistance, and, most importantly, moisture susceptibility. This study involved the incorporation of various steel fiber proportions of 0%, 0.3%, 0.5% and 0.7% by the total weight of mixture. The steel fiber modified SMA was made up of 6.0% PEN 60/70 bitumen content. The performance of SMA were evaluated through Marshall stability and flow test, Cantabro loss test and indirect tensile strength test. The results obtained from the testing showed that the incorporation of steel fiber is significantly effective to enhance the resistance towards moisture damage, while increasing the stability and reducing the abrasion loss of SMA mixture, compared to conventional mixture. Overall, it can be concluded that the addition of steel fiber in asphalt mixture specifically SMA, has improved the mechanical performance in the application of asphalt pavement with the optimum steel fiber proportion of 0.3% by the weight of mixture. The developed models between the independent variables and responses demonstrated high levels of correlation. The study found that Response Surface Methodology (RSM) is an effective statistical method for providing an appropriate empirical model for relating parameters and predicting the optimum performance of an asphaltic mixture to reduce flexible pavement failure.


2019 ◽  
Vol 2 (2) ◽  
pp. 149-157
Author(s):  
Hendra Arianto ◽  
Sofyan M. Saleh ◽  
Renni Anggraini

Reuse of reclaimed asphalt pavement material (RAP) is an alternative which applicated for potential enough on the roughness of the road. RAP material can be reused by adding the asphalt and the new aggregate according of the mixture composition so that it is expected will be obtained the quality as planned. One of the efforts made in improving the quality of asphalt mixture RAP material is using a modified asphalt with additional material, such as styrofoam. The use of styrofoam into the asphalt is expected to improve the technical properties of a mixture. The purpose of this research is to know the comparative characteristics of hot mix asphalt (asphalt concrete) type AC-WC that uses RAP material with additional asphalt pen. 60/70 and asphalt pen. 60/70 substitution in the styrofoam by 8%, 10% and 12% against the weight of asphalt based on levels of asphalt left on the material. The initial stages of this study is to conduct an examination of the physical properties of RAP material, then manufacturing a specimen with variations of the addition of asphalt and aggregate new levels based on the job mix diesign (JMD) Bina Marga Aceh (2013). Based on research results, parameter values marshall on all types of asphalt mixture with new aggregate as well as RAP materials and the use of 100% asphalt pen. 60/70 additional or different types of asphalt on OAC has fulfilled the technical specifications defined by the Bina Marga (2014). Best stability values obtained on asphalt mixture using RAP material with additional asphalt pen. 60/70 with 12% styrofoam substitution on OAC JMD Bina Marga Aceh, that amounted to 3,308.72 kg, the lowest value stability retrieved on asphalt mixture using a new aggregate based on the results of Department of Bina Marga Aceh on OAC i.e. of 983.94 kg.


Author(s):  
Moses Akentuna ◽  
Louay N. Mohammad ◽  
Sanchit Sachdeva ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper

Moisture damage of asphalt mixtures is a major distress affecting the durability of asphalt pavements. The loaded wheel tracking (LWT) test is gaining popularity in determining moisture damage because of its ability to relate laboratory performance to field performance. However, the accuracy of LWT’s “pass/fail” criteria for screening mixtures is limited. The objective of this study was to evaluate the capability of the LWT test to identify moisture susceptibility of asphalt mixtures with different moisture conditioning protocols. Seven 12.5 mm asphalt mixtures with two asphalt binder types (unmodified PG 67-22 and modified PG 70-22), and three aggregate types (limestone, crushed gravel, and a semi-crushed gravel) were utilized. Asphalt binder and mixture samples were subjected to five conditioning levels, namely, a control; single freeze–thaw-; triple freeze–thaw-; MiST 3500 cycles; and MiST 7000 cycles. Frequency sweep at multiple temperatures and frequencies, and multiple stress creep recovery tests were performed to evaluate asphalt binders. LWT test was used to evaluate the asphalt mixture samples. Freeze–thaw and MiST conditioning resulted in an increase in stiffness in the asphalt binders as compared with the control. Further, freeze–thaw and MiST conditioning resulted in an increase in rut depth compared with the control asphalt mixture. The conditioning protocols evaluated were effective in exposing moisture-sensitive mixtures, which initially showed compliance with Louisiana asphalt mixture design specifications.


Author(s):  
Edith Arámbula-Mercado ◽  
Santiago J. Chavarro-Muñoz ◽  
Sheng Hu ◽  
Howie Moseley

Florida Department of Transportation yearly maintenance and rehabilitation activities include milling and resurfacing of approximately 2,000 lane miles of roadway, with an average resurfacing depth of about 2.1 in. (55 mm). These activities result in the generation and accumulation of roughly 1.8 million tons of reclaimed asphalt pavement (RAP) each year. The use of elevated quantities of RAP in asphalt pavement provides an environmentally responsible solution to the accumulated RAP surplus in some urban areas, while at the same time offering an economical pavement maintenance and rehabilitation option to local agencies facing budget constraints. The objective of this project was to compare the performance of mixtures with 60% RAP content to be used primarily on low volume roads (average daily traffic <750 vehicles) and suggest adequate test methods within the context of a balanced mix design approach. To accomplish this objective, three types of mixtures were considered: hot, cold with emulsion, and cold with foamed binder. Performance testing included intermediate temperature cracking, rutting, moisture susceptibility, and durability. The hot recycled mixtures showed good moisture susceptibility and cracking resistance, especially when rejuvenators were incorporated. The cold recycled mixtures showed poor moisture susceptibility and durability characteristics, which were alleviated when hydrated lime or Portland cement was incorporated in the emulsified and foamed mixtures, respectively. Most hot recycled mixtures, and all the cold recycled mixtures, exhibited poor rutting behavior, likely because of the harsh conditions of the test. A life-cycle cost analysis demonstrated more favorable savings when cold recycled mixtures were used.


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