Effects of super absorbent polymer on scouring resistance and water retention performance of soil for growing plants in ecological concrete

摘要

Ecological concrete could protect the slopes along a motorway or on a river bank and prevent water/soil loss and beautify and built the environment compared to ordinary concrete. Overlaying soil, as a key component of ecological concrete, plays an important role in greening rate of ecological concrete. However, natural soil used as overlaying soil cannot meet plants growing demand due to its unsatisfying scouring resistance and water retention properties. In this paper natural super absorbent polymer (SAP) was utilized to modify the natural soil for the preparation of a material with enhanced scouring resistance and water retention performance which are indispensable for growing plants in ecological concrete. Experimental results suggested that 1.5 wt% SAP content in the soil was the most suitable option. At this natural soil replacement level, the scouring resistance increased by 68.9% while its water retention performance improved by 11.1% at the age of 160 h. In addition, other performance improvements of the soil were determined including increasing of the water absorption rate which was tested increasing by up to 69.4% and the cone index of up to 0.39 MPa, and the advancements of perennial ryegrass were measured increasing of the survival ratio which was found increasing by up to 97.9% and the dry weight of up to 2.16 kg/m(2).