The characteristics of soil treated with cationic polyacrylamide(CPAM)mass content of 0%,0.2%,0.4%,0.6%,0.8%,and 1%were investigated through a series of laboratory tests to explore the practical engineering effect of ...The characteristics of soil treated with cationic polyacrylamide(CPAM)mass content of 0%,0.2%,0.4%,0.6%,0.8%,and 1%were investigated through a series of laboratory tests to explore the practical engineering effect of an expansive soil amended with environmental protection material CPAM.The results indicate that with the increasing CPAM content,the liquid limit and plasticity index of soil decrease,the plastic limit increases,and the free swelling ratio and loaded swelling ratio decrease.Besides,the improved soil has less disintegrating property and better water stability.The shear strength increases as the content increases,and the optimal content is 0.6%.Meanwhile,the cohesion of the soil first increases and then decreases,and the internal friction angle increases.Additionally,the unconfined compressive strength first increases and then decreases.The improved soil presents the characteristics of brittle failure and reaches the peak value(410.1 kPa)at the content of 0.8%after curing for 14 days.Scanning electron microscope(SEM)exhibits that the number of curved and wrinkled sections of the expansive soil is reduced after CPAM improvement.Simultaneously,the arrangement of the superimposed polymer changes from face-face to side-angle or side-face-angle,and the reticular structure formed improves the strength and spatial stability of the soil.Therefore,adding appropriate cationic polyacrylamide could improve expansive soil in engineering.展开更多
基金funded by the National Natural Science Foundation of China(41977236,41672278,41271071)the Science and Technology Planning Project of Housing and Urban-Rural Development of Anhui Province(2019-YF023)+1 种基金the Major Universities Natural Science Research Project in Anhui Province(KJ2016SD19)the Natural Science Foundation of Jiangxi Province(2019ACBL20002).
文摘The characteristics of soil treated with cationic polyacrylamide(CPAM)mass content of 0%,0.2%,0.4%,0.6%,0.8%,and 1%were investigated through a series of laboratory tests to explore the practical engineering effect of an expansive soil amended with environmental protection material CPAM.The results indicate that with the increasing CPAM content,the liquid limit and plasticity index of soil decrease,the plastic limit increases,and the free swelling ratio and loaded swelling ratio decrease.Besides,the improved soil has less disintegrating property and better water stability.The shear strength increases as the content increases,and the optimal content is 0.6%.Meanwhile,the cohesion of the soil first increases and then decreases,and the internal friction angle increases.Additionally,the unconfined compressive strength first increases and then decreases.The improved soil presents the characteristics of brittle failure and reaches the peak value(410.1 kPa)at the content of 0.8%after curing for 14 days.Scanning electron microscope(SEM)exhibits that the number of curved and wrinkled sections of the expansive soil is reduced after CPAM improvement.Simultaneously,the arrangement of the superimposed polymer changes from face-face to side-angle or side-face-angle,and the reticular structure formed improves the strength and spatial stability of the soil.Therefore,adding appropriate cationic polyacrylamide could improve expansive soil in engineering.
