Effect of polymer water retaining agent on physical properties of silty clay

Abstract

Abstract Background Ecological protection of slope surfaces by vegetation is one of the effective methods to reduce soil erosion. However, the surface soil of slope often has the problems of poor structure and low water use efficiency, which is not conducive to plant growth. Super absorbent resin (SAR) as a new type of water retention agent can effectively improve the surface soil of slopes. The study was designed to evaluate the effect and mechanism of SAR on aggregate stability, soil water characteristics and mechanical strength by analyzing the aggregate characteristics, moisture characteristics, microstructure and mechanical properties of SAR-treated soil. Results The results show that (1) the volume expansion and shrinkage in the process of water absorption and release of SAR loosened the soil, which improved the microstructure of the soil and increased the aggregate content, while the change of soil pore distribution significantly affected the soil–water characteristics; (2) the fractal dimension and stability of aggregates, the cohesion and internal friction angle of soils all tend to decrease with increasing SAR; and (3) the strong water absorption and retention of SAR increases the water holding capacity of the soil, thus increasing the water availability. Conclusions The above research is conducive to further revealing the good role of SAR in improving the surface soil of slope, promoting plant growth and improving the environmental protection effect. It can provide experimental and data support for the application of polymer water retaining agents. Graphical Abstract