Latex as an asphalt modifier has gained popularity in the asphalt industry as it improves the durability of asphalt pavement.However,the elastomeric properties of latex stiffen the asphalt binders,resulting in additio...Latex as an asphalt modifier has gained popularity in the asphalt industry as it improves the durability of asphalt pavement.However,the elastomeric properties of latex stiffen the asphalt binders,resulting in additional energy consumption during the production of asphalt mixtures,which may cause a higher emission of greenhouse gases.This is undesirable for sustainable development and the environment.In this study,the applicability of diluted methanol and water was comparatively evaluated as foaming agents in the production of warm mix asphalt(WMA)mixtures incorporating latex.Diluted methanol was used because it has a lower boiling point and latent heat than water,allowing the asphalt mixture to be produced at a lower temperature and thus consuming less energy.The performance of the foamed asphalt mixture was investigated through service characteristics,mechanical performance,and moisture susceptibility of mixtures.The service characteristics,on the other hand,were measured in a laboratory while preparing and compacting the asphalt mixture,which refers to the amount of energy required during the production and construction stages in the asphalt plant and on the construction site,respectively.The degree of energy required was assessed based on the workability index,coatability index,and the compaction energy index.The mechanical performance of asphalt mixtures was characterized by indirect tensile strength,resilient modulus,and dynamic creep tests.The resistance to moisture damage was evaluated based on the common parameter,indirect tensile strength ratio.The findings revealed that the use of diluted methanol foaming agent helped improve the workability of latex modified asphalt mixtures.The foamed latex-modified WMA demonstrated better performance compared to asphalt mixtures prepared using water as the foaming agent.展开更多
The consistency of the ethanol foamed binders and mixtures prepared using asphalt binders foamed by the manual injection technique and laboratory foaming device were evaluated and compared in this study. The asphalt b...The consistency of the ethanol foamed binders and mixtures prepared using asphalt binders foamed by the manual injection technique and laboratory foaming device were evaluated and compared in this study. The asphalt binders foamed using both methods was prepared at 120℃, 130℃ and 140℃. The performance of ethanol-foamed binders was evaluated in terms of rotational viscosity, expansion ratio, and low temperature cracking.Meanwhile, the performance of foamed WMA mixtures was tested using semi-circular bending(SCB), disk-shaped compact tension(DCT), and tensile strength ratio(TSR) tests. In order to conduct the TSR test, the samples were conditioned using the Moisture Induced Stress Tester(MIST) to simulate the pore pressure and scouring effects due to a tire passing over wet pavement. The foamed WMA mixtures were produced using pre-heated aggregates at 80℃ and 100℃ and foamed asphalt binders produced at 130℃. The nano-hydrated lime was used as the filler and anti-stripping agent. Overall, the properties of ethanol-foamed binders and WMA mixtures produced via both methods are significantly comparable, except the resistance to moisture damage test result. However, the findings indicate that the ethanol-foamed WMA mixtures prepared using both techniques are having good resistance to moisture damage, based on the TSR values more than 0.8. The foamed WMA mixtures also exhibited a better resistance to cracking, as indicated by a higher tensile strength compared to the control HMA. Additionally, the WMA specimen prepared at 100℃ was less susceptible to rutting than the samples produced at 80℃.展开更多
基金The authors express their appreciation to the National Natural Science Foundation of China(NSFC)for providing financial assistance via the Research Fund for the International Young Scientist(Grant No.51750110491)Additionally,acknowledgements are due to Universiti Sains Malaysia for providing financial support via Research University Individual(RUI)Grant 1001.PAWAM.8014140.Authors also would like to recognize supports from Chang'an University,China.Last but not least,special thanks to all technical staff of the Highway Engineering Laboratory,Universiti Sains Malaysia(USM),for their valuable help and support.
文摘Latex as an asphalt modifier has gained popularity in the asphalt industry as it improves the durability of asphalt pavement.However,the elastomeric properties of latex stiffen the asphalt binders,resulting in additional energy consumption during the production of asphalt mixtures,which may cause a higher emission of greenhouse gases.This is undesirable for sustainable development and the environment.In this study,the applicability of diluted methanol and water was comparatively evaluated as foaming agents in the production of warm mix asphalt(WMA)mixtures incorporating latex.Diluted methanol was used because it has a lower boiling point and latent heat than water,allowing the asphalt mixture to be produced at a lower temperature and thus consuming less energy.The performance of the foamed asphalt mixture was investigated through service characteristics,mechanical performance,and moisture susceptibility of mixtures.The service characteristics,on the other hand,were measured in a laboratory while preparing and compacting the asphalt mixture,which refers to the amount of energy required during the production and construction stages in the asphalt plant and on the construction site,respectively.The degree of energy required was assessed based on the workability index,coatability index,and the compaction energy index.The mechanical performance of asphalt mixtures was characterized by indirect tensile strength,resilient modulus,and dynamic creep tests.The resistance to moisture damage was evaluated based on the common parameter,indirect tensile strength ratio.The findings revealed that the use of diluted methanol foaming agent helped improve the workability of latex modified asphalt mixtures.The foamed latex-modified WMA demonstrated better performance compared to asphalt mixtures prepared using water as the foaming agent.
基金the U.S. National Science Foundation which funded a research grant through SusChEM/Collaborative Research program (Award Number: 1300286) and enabled this study to be completed
文摘The consistency of the ethanol foamed binders and mixtures prepared using asphalt binders foamed by the manual injection technique and laboratory foaming device were evaluated and compared in this study. The asphalt binders foamed using both methods was prepared at 120℃, 130℃ and 140℃. The performance of ethanol-foamed binders was evaluated in terms of rotational viscosity, expansion ratio, and low temperature cracking.Meanwhile, the performance of foamed WMA mixtures was tested using semi-circular bending(SCB), disk-shaped compact tension(DCT), and tensile strength ratio(TSR) tests. In order to conduct the TSR test, the samples were conditioned using the Moisture Induced Stress Tester(MIST) to simulate the pore pressure and scouring effects due to a tire passing over wet pavement. The foamed WMA mixtures were produced using pre-heated aggregates at 80℃ and 100℃ and foamed asphalt binders produced at 130℃. The nano-hydrated lime was used as the filler and anti-stripping agent. Overall, the properties of ethanol-foamed binders and WMA mixtures produced via both methods are significantly comparable, except the resistance to moisture damage test result. However, the findings indicate that the ethanol-foamed WMA mixtures prepared using both techniques are having good resistance to moisture damage, based on the TSR values more than 0.8. The foamed WMA mixtures also exhibited a better resistance to cracking, as indicated by a higher tensile strength compared to the control HMA. Additionally, the WMA specimen prepared at 100℃ was less susceptible to rutting than the samples produced at 80℃.
