scholarly journals Preliminary Evaluation of Hot Mix Asphalt Containing Reclaimed Epoxy Asphalt Materials

2020 ◽  
Vol 12 (9) ◽  
pp. 3531
Author(s):  
Mohammed Alamri ◽  
Qing Lu ◽  
Chunfu Xin

Designing long-life pavements and pavement recycling with reclaimed asphalt pavement (RAP) are two important strategies for improving the sustainability of asphalt pavements. Epoxy asphalt, as a proven long-life pavement material, is attracting attention from the pavement community for its use in road pavements. The recyclability of epoxy asphalt mixtures, however, has never been studied and has now become one concern in promoting the use of epoxy asphalt in road pavements. This study attempts to explore the performance of hot mix asphalt (HMA) containing reclaimed epoxy asphalt materials. Reclaimed epoxy asphalt was fabricated in the laboratory and incorporated into regular asphalt mixtures at various contents. Specimens were prepared and tested for their performance in comparison with mixtures without RAP. It was found that replacing the coarse aggregates in HMA with epoxy RAP up to 80% did not negatively affect its Marshall stability, tensile strength, and moisture resistance. The plastic deformation at failure of HMA, however, may increase with the increase in epoxy RAP content. At the current stage, the results from this study do not provide evidence to invalidate the use of epoxy RAP in HMA, at least at a coarse aggregate replacement rate of less than 40%.

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7060
Author(s):  
Mohammad Alharthai ◽  
Qing Lu ◽  
Ahmed Elnihum ◽  
Asad Elmagarhe

This study investigates the substitution of conventional aggregate with a Florida washed shell in open-graded asphalt mixtures and evaluates the optimal substitution percentage in aggregate gradations of various nominal maximum aggregate sizes (NMASs) (i.e., 4.75, 9.5, and 12.5 mm). Laboratory experiments were performed on open-graded asphalt mixture specimens with the coarse aggregate of sizes between 2.36 and 12.5 mm being replaced by the Florida washed shell at various percentages (0, 15, 30, 45, and 100%). Specimen properties relevant to the performance of open-graded asphalt mixtures in the field were tested, evaluated, and compared. Specifically, a Marshall stability test, Cantabro test, indirect tensile strength test, air void content test, and permeability test were conducted to evaluate the strength, resistance to raveling, cracking resistance, void content, and permeability of open-graded asphalt mixtures. The results show that there is no significant difference in the Marshall stability and indirect tensile strength when the coarse aggregates are replaced with Florida washed shell. This study also found that the optimum percentages of Florida washed shell in open-graded asphalt mixture were 15, 30, and 45% for 12.5, 9.5, and 4.75 mm NMAS gradations, respectively.


2020 ◽  
Vol 46 (3) ◽  
pp. 394-408
Author(s):  
Kumari Monu ◽  
G.D. Ransinchung R.N. ◽  
Surender Singh ◽  
Gaurav Singh Raghav

Reclaimed Asphalt pavement (RAP) is a C&D waste originating from the reclamation of asphalt pavement which has completed its service life. Using RAP would potentially reduce reliance on primary aggregates and lowers the environmental impact of construction. The present study is an attempt made to utilize RAP judiciously as a bound base course of the flexible pavement. Natural coarse aggregates were replaced by RAP in proportions of 50% & 100% with & without Warm Mix Asphalt (WMA), for production of bound-base course mixes. To ensure the long run performance, the aging condition was simulated in the laboratory and mechanical properties such as Marshall Stability, Tensile Strengths, Marshall Stability Retained, Indirect Tensile Ratio, rutting resistance, Fatigue life, and abrasion resistance were considered. With the incorporation of 50-100% coarse RAP, the Marshall Stability, rutting resistance and abrasion were found to be improved by 30-32%, 43-104% and 11-17% respectively. Similarly, total cost saving is about 15-35%, which is quite significant. However, the addition of WMA enhanced the cost by 3-4%, which is insignificant when combined with RAP, furthermore, the reductions in fume emission enhance the sustainability aspect of the technology.


2011 ◽  
Vol 39 (1) ◽  
pp. 102699 ◽  
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
Feipeng Xiao ◽  
Serji N. Amirkhanian ◽  
Boli Wu

2008 ◽  
Vol 385-387 ◽  
pp. 297-300
Author(s):  
Tao Xie ◽  
Ze Zhong Jiang ◽  
Yan Jun Qiu ◽  
Bo Lan

The fracture resistance of asphalt materials significantly influences the service life of asphalt pavements and consequently affects the maintenance and rehabilitation costs of the pavement network. Therefore, there is significant interest in understanding the mechanism of fracture in asphalt pavements and in developing analysis tools that would lead to the selection of asphalt materials with increased fracture resistance. Study of cracking behavior of asphalt mixtures should be conducted in a micro-scale level to have a real simulation of crack propagation. Using SIEMENS SOMATOM plus X-ray CT (computerized tomography) and multi-functional testing rig, a dynamic observation of cracking propagation of hot mix asphalt was conducted in this research. Failure process under compressive pressure was recorded using CT images and CT numbers. The direct responses in density change of Marshall Samples under a CT-compressive process are change of CT numbers. Cracking propagation in the samples can be clearly observed and failure mode and stress-strain behavior can then be simulated. The tests reported provide important theoretical fundamentals to study the cracking behavior and failure mechanism of asphalt mixtures.


2020 ◽  
Vol 8 (2) ◽  
pp. 57-63
Author(s):  
Omar T. Mahmood ◽  
Sheelan A. Ahmed

Cracking in the flexible pavement is a serious problem that reduces the service life of the roads pavement unless they are treated with great care. Since flexible pavement is very weaker in tension than in compression, it is usually necessary to consider the tensile stresses and some type of additives to improve asphaltpavement performance, and one of the most effective ways of improving asphalt pavement performance is to reinforce asphalt mixtures by incorporating natural fibers. The main objective of this study is to use palm fiber, which is locally available, in hot mix asphalt mixtures. To achieve this objective, the Marshall test and indirect tensile strength test were conducted on four asphalt mixtures with different types of natural fibers (Coconut, Corn, Palm, and Sisal), added in varying percentages 0.1, 0.2, 0.3, 0.4, and 0.5% and different lengths of fiber 0.5, 1, 1.5, and 2 cm. Based on the analyzed results, it can be concluded that the use of palm fiber increased the Marshall stability by 20% as compared with the conventional mixture and raised up the retained tensile strength ratio up to 92%. Finally, the use of 0.2% content of natural fiber at 1.5 cm length gave a better performance for the mixtures.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4704
Author(s):  
Waqas Rafiq ◽  
Madzlan Bin Napiah ◽  
Muslich Hartadi Sutanto ◽  
Wesam Salah Alaloul ◽  
Zarisha Nadia Binti Zabri ◽  
...  

Moisture damage in hot mix asphalt pavements is a periodic but persistent problem nowadays, even though laboratory testing is performed to identify different moisture-susceptible mixtures. In this study, a Hamburg Wheel Tracking device (HWTD) was used for rutting tests which were conducted on control and a high percentage of recycled asphalt pavement (RAP), i.e., 30%, 50% and 100% of virgin mixtures, under air dry and water-immersed conditions. Similarly, the extracted bitumen from RAP was tested for binder physical properties. Results showed that the asphalt mixtures containing RAP have less rut depth as compared to the control mix both in air dry and immersion conditions and hence showed better anti-rutting properties and moisture stability. Stripping performance of control and RAP containing mixtures was also checked, concluding that the RAP mixture was greatly dependent on the interaction between the binder (virgin plus aged) and aggregates.


2018 ◽  
Vol 7 (4.20) ◽  
pp. 338
Author(s):  
Gholamali Shafabakhsh ◽  
Hassan Divandari ◽  
Seyed Reza Sajadi

Durability of asphalt pavements is related to choosing proper materials. Fillers as the smallest particles of stone materials, and one of the most important parts of asphalt mixtures, exert pivotal effects on the performance of asphalt mixtures, by filling empty spaces and because of their softness, surface features and chemical compounds. Rice husk ash is one of the waste products of burning rice husk in powerhouses that is accounted as biomass. Recently, a good many of investigations have shown that rice husk ash, as a high quality pozzolan, can be properly replaced of common aggregates. In this study rice husk ash was used as filler in hot mix asphalt, and the result mixtures’ mechanical properties was compared with ordinary mixtures whose filler was stone powder. Asphalt mixture samples with two different aggregate graded, and 0, 25, 50, 75 and 100 percent of rice husk ash which were the substitution of stone powder content, were made and the effects of using rice husk ash on the moisture sensitivity, resilience modulus, rutting and dynamic creep of asphalt mixtures were investigated. The results demonstrated that increase of using rice husk ash as the replacement of prevalent fillers in hot mix asphalts, noticeably improves their performance; however, because of excessive stiffness created by rice husk ash, it's better to use it in optimized percentage. Accordingly, statistical analysis of the tests’ results leads to presenting an optimized model for the content of Rice Husk Ash to be used in hot mix asphalt. Finally, Rice Husk Ash content were suggested 26% for graded number 4 and 48% for graded number 5 as replacements for stone powder filler. 


2007 ◽  
Vol 35 (6) ◽  
pp. 100903
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
Shuo Li ◽  
Karen Zhu ◽  
Samy Noureldin

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