An inverted asphalt pavement is created by reversing the sequence of the lower and middle layers in a conventional asphalt pavement. The lower layer is composed of material with larger particle size and lower asphalt ...An inverted asphalt pavement is created by reversing the sequence of the lower and middle layers in a conventional asphalt pavement. The lower layer is composed of material with larger particle size and lower asphalt content, which improves its ability to withstand deformation caused by rutting. On the other hand, the middle surface has a higher asphalt content, specifically designed to resist fatigue cracking. This paper examines the mechanical response of two pavement structures and investigates the potential of two measures, inverted asphalt pavement and asphalt mixture design by vertical vibration compaction method(VVCM), in reducing stresses and stress levels in asphalt pavements. Additionally, a large thickness rutting and fatigue test method was developed to study the rutting resistance and fatigue life of the pavement structures, and to construct rutting deformation and fatigue life prediction models. Finally, test sections were paved to verify the feasibility of the inverted pavement and VVCM materials. The findings show that inverted pavement and VVCM materials have a minimal impact on pavement stress, but can reduce pavement shear and tensile stress levels by up to 18%–25%.Furthermore, inverted pavement and VVCM materials have positive effects on improving the rutting resistance and fatigue life of asphalt pavements.展开更多
To investigate the deformation properties of remolded loess subgrade under long-term cyclic dynamic loading,remolded loess specimens compacted via vertical vibration compaction method were produced and some factors in...To investigate the deformation properties of remolded loess subgrade under long-term cyclic dynamic loading,remolded loess specimens compacted via vertical vibration compaction method were produced and some factors influencing elastic strain and cumulative plastic strain,which include the number of vibration cycles,depth,and water content,have been investigated.A prediction model for cumulative plastic deformation was established.In addition,the collapsible deformation properties of remolded loess were investigated.Results indicate that the elastic strain and plastic strain are decreased with increasing vibration cycles and depth and finally tend to be stable when the number of vibration cycles is more than 2000 and the depth exceeds 2.5 m.The elastic strain and cumulative plastic strain of compacted loess are increased by 7.2%and 13.0%,respectively,when the water content increases by 1.0%.The cumulative plastic deformation of remolded loess follows a logarithmic distribution.The elastic deformation and cumulative plastic deformation of loess subgrade are far less than the demands for elastic deformation and post-construction settlement of subgrade.As the compaction coefficient and water content are increased by 1.0%,the collapsibility coefficient of compacted loess is decreased by an average of 13.7%and 14.5%.Such investigations can prevent subgrade diseases and ensure the safety of subgrade filled with loess soils.展开更多
基金supported by Shaanxi Province Innovation Capacity Support Program (2022TD-06)Transportation Industry Key Science and Technology Projects (2021-MS1-011)+1 种基金the Science and Technology Project of the Shaanxi Provincial Department of Transportation (20-02K)the Scientific Project from Henan Provincial Communication (2021-2-8)。
文摘An inverted asphalt pavement is created by reversing the sequence of the lower and middle layers in a conventional asphalt pavement. The lower layer is composed of material with larger particle size and lower asphalt content, which improves its ability to withstand deformation caused by rutting. On the other hand, the middle surface has a higher asphalt content, specifically designed to resist fatigue cracking. This paper examines the mechanical response of two pavement structures and investigates the potential of two measures, inverted asphalt pavement and asphalt mixture design by vertical vibration compaction method(VVCM), in reducing stresses and stress levels in asphalt pavements. Additionally, a large thickness rutting and fatigue test method was developed to study the rutting resistance and fatigue life of the pavement structures, and to construct rutting deformation and fatigue life prediction models. Finally, test sections were paved to verify the feasibility of the inverted pavement and VVCM materials. The findings show that inverted pavement and VVCM materials have a minimal impact on pavement stress, but can reduce pavement shear and tensile stress levels by up to 18%–25%.Furthermore, inverted pavement and VVCM materials have positive effects on improving the rutting resistance and fatigue life of asphalt pavements.
基金the funding received from the Science and Technology Project from Shaanxi Provincial Department of Transportation(Grant Nos.:18-02K,19-27K)the Scientific Research of Central Colleges of China for Chang'an University(Grant No.300102218212)。
文摘To investigate the deformation properties of remolded loess subgrade under long-term cyclic dynamic loading,remolded loess specimens compacted via vertical vibration compaction method were produced and some factors influencing elastic strain and cumulative plastic strain,which include the number of vibration cycles,depth,and water content,have been investigated.A prediction model for cumulative plastic deformation was established.In addition,the collapsible deformation properties of remolded loess were investigated.Results indicate that the elastic strain and plastic strain are decreased with increasing vibration cycles and depth and finally tend to be stable when the number of vibration cycles is more than 2000 and the depth exceeds 2.5 m.The elastic strain and cumulative plastic strain of compacted loess are increased by 7.2%and 13.0%,respectively,when the water content increases by 1.0%.The cumulative plastic deformation of remolded loess follows a logarithmic distribution.The elastic deformation and cumulative plastic deformation of loess subgrade are far less than the demands for elastic deformation and post-construction settlement of subgrade.As the compaction coefficient and water content are increased by 1.0%,the collapsibility coefficient of compacted loess is decreased by an average of 13.7%and 14.5%.Such investigations can prevent subgrade diseases and ensure the safety of subgrade filled with loess soils.
