Asphalt pavement rtting is a major safety concem and is one of the main distress modes of asphalt pavement.Research into asphalt pavement mixes that provide strong resistance for nutting is considered of great signifi...Asphalt pavement rtting is a major safety concem and is one of the main distress modes of asphalt pavement.Research into asphalt pavement mixes that provide strong resistance for nutting is considered of great significance as it can help provide extended pavement life and significant cost savings in pavement maintenance and rehabilitation.The objectives of this study are to develop numernical models to investigate the ntting of asphalt concrete pavements and to find optimal design of asphalt pave-ment mix for nutting resistance.Three-dimensional Finite Element mod-els were first developed to simulate both the axial compression and wheel track testing in which a visco elastic-plastic material model was used to predict the ntting of the asphalt concrete pavements.A strain hardening creep model with the material parameters developed from experimental testing was employed to model the time-dependent characteristics of the asphalt concrete pavements.The results were validated against the pre-vious experimental wheel track test results of different pavement mixes.Finally,optimisation techniques using the Design Of Experiments method were applied to the simulation rutting results by varying creep parameters to identify their effects on rutting resistance in order to obtain an optimal asphalt pavements mixes.The results of this paper clearly demonstrate an efficient and effective experimental-numerical method and tool set towards optimal design for asphalt concrete pavements for rutting resis-tance.展开更多
In this study,mechanical characteristics of tensile strength ratio(TSR)were evaluated by comparing it to other methods in evaluating moisture sensitivity of asphalt mixtures.Twenty types of asphalt mixtures with and w...In this study,mechanical characteristics of tensile strength ratio(TSR)were evaluated by comparing it to other methods in evaluating moisture sensitivity of asphalt mixtures.Twenty types of asphalt mixtures with and without anti-stripping additives were prepared and tested in the laboratory.Uniaxial compressive strength(UCS)and indirect tensile(IDT)testing were conducted to determine the mixture’s tensile strength ratio and cohesion ratio(CR).Determining TSR alone was found to be insufficient when evaluating moisture resistance.There is a need to consider both TSR and wet IDT strength to properly evaluate moisture behavior of asphalt mixtures.Moreover,it was found that the cohesion and the IDT strength have a good relation in which the minimum condition of the slope,must be met.However,it was observed thatβvalues change depending on material type and temperature.Hence,there is a need to evaluate theseβvalues for varying material and testing temperature.In addition,it was found that the TSR and CR results are highly correlated with an average difference of 1.5%.Furthermore,other tests such as Marshall stability and dynamic immersion were also conducted.It was found that Marshall stability ratio(MSR)and Marshall stability to flow ratio(MSFR)values are less sensitive to moisture effect when measuring moisture resistance compared to TSR values.Finally,the 48 h testing result of the dynamic immersion test showed better correlation with TSR values.展开更多
基金This study is part of the FIRST project‘The development of numerical simulation and optimization technologies for optimal performance of concrete asphalt pavements taking into account the traffic and climate conditions of Vietnam’(35/FIRST/1a/UTC).We acknowledge FIRST Project,Ministry of Science and Technology,Vietnam,for sponsoring this project。
文摘Asphalt pavement rtting is a major safety concem and is one of the main distress modes of asphalt pavement.Research into asphalt pavement mixes that provide strong resistance for nutting is considered of great significance as it can help provide extended pavement life and significant cost savings in pavement maintenance and rehabilitation.The objectives of this study are to develop numernical models to investigate the ntting of asphalt concrete pavements and to find optimal design of asphalt pave-ment mix for nutting resistance.Three-dimensional Finite Element mod-els were first developed to simulate both the axial compression and wheel track testing in which a visco elastic-plastic material model was used to predict the ntting of the asphalt concrete pavements.A strain hardening creep model with the material parameters developed from experimental testing was employed to model the time-dependent characteristics of the asphalt concrete pavements.The results were validated against the pre-vious experimental wheel track test results of different pavement mixes.Finally,optimisation techniques using the Design Of Experiments method were applied to the simulation rutting results by varying creep parameters to identify their effects on rutting resistance in order to obtain an optimal asphalt pavements mixes.The results of this paper clearly demonstrate an efficient and effective experimental-numerical method and tool set towards optimal design for asphalt concrete pavements for rutting resis-tance.
基金the partial support of Sejong University,BK21,and research project(Developmentof Eco-Friendly Pavements to Minimize Greenhouse Gas Emissions)funded by the Ministry of Land,Infrastructure and Transport and the Korea Agency for Infrastructure Technology Advancement,South Korea.
文摘In this study,mechanical characteristics of tensile strength ratio(TSR)were evaluated by comparing it to other methods in evaluating moisture sensitivity of asphalt mixtures.Twenty types of asphalt mixtures with and without anti-stripping additives were prepared and tested in the laboratory.Uniaxial compressive strength(UCS)and indirect tensile(IDT)testing were conducted to determine the mixture’s tensile strength ratio and cohesion ratio(CR).Determining TSR alone was found to be insufficient when evaluating moisture resistance.There is a need to consider both TSR and wet IDT strength to properly evaluate moisture behavior of asphalt mixtures.Moreover,it was found that the cohesion and the IDT strength have a good relation in which the minimum condition of the slope,must be met.However,it was observed thatβvalues change depending on material type and temperature.Hence,there is a need to evaluate theseβvalues for varying material and testing temperature.In addition,it was found that the TSR and CR results are highly correlated with an average difference of 1.5%.Furthermore,other tests such as Marshall stability and dynamic immersion were also conducted.It was found that Marshall stability ratio(MSR)and Marshall stability to flow ratio(MSFR)values are less sensitive to moisture effect when measuring moisture resistance compared to TSR values.Finally,the 48 h testing result of the dynamic immersion test showed better correlation with TSR values.
