This study aims to reveal the macroscopic permanent deformation(PD)behavior and the internal structural evolution of construction and demolition waste(CDW)under loading.Firstly,the initial matric suction of CDW was me...This study aims to reveal the macroscopic permanent deformation(PD)behavior and the internal structural evolution of construction and demolition waste(CDW)under loading.Firstly,the initial matric suction of CDW was measured by the filter paper method.Secondly,the PD of CDW with different humidity and stress states was investigated by repeated load triaxial tests,and a comprehensive prediction model was established.Finally,the discrete element method was performed to analyze the internal structural evolution of CDW during deformation.These results showed that the VAN-GENUCHTEN model could describe the soil-water characteristic curve of CDW well.The PD increases with the increase of the deviator stress and the number of cyclic loading,but the opposite trend was observed when the initial matric suction and confining pressure increased.The proposed model in this study provides a satisfactory prediction of PD.The discrete element method could accurately simulate the macroscopic PD of CDW,and the shear force,interlock force and sliding content increase with the increase of deviator stress during the deformation.The research could provide useful reference for the deformation stability analysis of CDW under cyclic loading.展开更多
One of the big problems of the urban centres of the cities in Brazil is the growth of the generation of the Civil Construction Waste （CCW）. A disturbing concern for the public and private sectors is to find proper d...One of the big problems of the urban centres of the cities in Brazil is the growth of the generation of the Civil Construction Waste （CCW）. A disturbing concern for the public and private sectors is to find proper disposal of Urban Solid Waste （USW） in large cities, since suitable dumping sites for this waste are increasingly scarce due to the spread and development of large urban centres. In general, recycling is currently one of the procedures most studied by researchers for disposal of such waste. In this context and aiming a new application for recycled CCW aggregates, the research characterized the physical properties of the material to use in fill compaction piles in soil improvement. The analysis shows results from laboratorial tests executed in CCW recycled samples, which came from works in different construction stages from Recife-PE, and natural aggregate, adopted as a reference. Characterization tests were performed with samples CCW recycled CLue aggregates and samples of natural fine aggregate （stone powder）. The results of characterization tests showed similarities between the CCW samples tested and the reference samples, indicating that the civil construction wastes has potcntial use as material for consolidation piles in foundation works.展开更多
基金Project(52025085)supported by the National Science Fund for Distinguished Young Scholars,ChinaProjects(51927814,51878078)supported by the National Natural Science Foundation of China+3 种基金Project(2018-025)supported by the Training Program for High-level Technical Personnel in Transportation Industry,ChinaProject(CTKY-PTRC 2018-003)supported by the Design Theory,Method and Demonstration of Durability Asphalt Pavement Based on Heavy-duty Traffic Conditions in Shanghai Area,ChinaProject(2020RC4048)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(SJCX202001)supported by the Construction Project for Graduate Students of Changsha University of Science&Technology,China。
文摘This study aims to reveal the macroscopic permanent deformation(PD)behavior and the internal structural evolution of construction and demolition waste(CDW)under loading.Firstly,the initial matric suction of CDW was measured by the filter paper method.Secondly,the PD of CDW with different humidity and stress states was investigated by repeated load triaxial tests,and a comprehensive prediction model was established.Finally,the discrete element method was performed to analyze the internal structural evolution of CDW during deformation.These results showed that the VAN-GENUCHTEN model could describe the soil-water characteristic curve of CDW well.The PD increases with the increase of the deviator stress and the number of cyclic loading,but the opposite trend was observed when the initial matric suction and confining pressure increased.The proposed model in this study provides a satisfactory prediction of PD.The discrete element method could accurately simulate the macroscopic PD of CDW,and the shear force,interlock force and sliding content increase with the increase of deviator stress during the deformation.The research could provide useful reference for the deformation stability analysis of CDW under cyclic loading.
文摘One of the big problems of the urban centres of the cities in Brazil is the growth of the generation of the Civil Construction Waste （CCW）. A disturbing concern for the public and private sectors is to find proper disposal of Urban Solid Waste （USW） in large cities, since suitable dumping sites for this waste are increasingly scarce due to the spread and development of large urban centres. In general, recycling is currently one of the procedures most studied by researchers for disposal of such waste. In this context and aiming a new application for recycled CCW aggregates, the research characterized the physical properties of the material to use in fill compaction piles in soil improvement. The analysis shows results from laboratorial tests executed in CCW recycled samples, which came from works in different construction stages from Recife-PE, and natural aggregate, adopted as a reference. Characterization tests were performed with samples CCW recycled CLue aggregates and samples of natural fine aggregate （stone powder）. The results of characterization tests showed similarities between the CCW samples tested and the reference samples, indicating that the civil construction wastes has potcntial use as material for consolidation piles in foundation works.
