Experimental Study On The Lightweight Technology And Influence Factors Of Dredged Sludge

EPS beads mixed lightweight soil is a kind of lightweight soil, which is mainly mixed and cured of raw soil, EPS beads, curing agent and additives, etc. To research and develop not only can reduce the environmental pollution, but also can reuse the project discarded soil and waste, to convert it into renewable resources, which has important theoretical and practical significance.Based on previous researches, this dissertation carried out a series of research work on the curing agent, strength and deformation properties and microstructure of EPS beads mixed lightweight soil of Hangzhou canal dredged sludge by means of unconfined compression test, direct shear test and SEM test. The main contents and results are as follows.(1) The basic physical and mechanical properties of dredged sludge are obtained by means of laboratory soil test, and the main factor affecting the lightweight of EPS beads mixed lightweight soil is the volume fraction of EPS beads.(2) The effect of adding cement singly on the curing effect of lightweight soil of dredged sludge is determined using unconfined compression test. The value of compression strength of the lightweight soil increases with the increase of cement content for certain value of volume fraction of EPS beads, and the increase scope is obvious, while the value of compression strength of the lightweight soil decreases with the increase of EPS beads volume fraction for certain cement content.(3) The effect level and scope of main curing agent cement and additives, such as lime, gypsum, fly ash on the lightweight soil solidification effectiveness is studied by means of single doped experiment. The compression strength of sample reaches the maximum when the content of cement, lime, gypsum and fly ash is18%,5%,2%and12%, respectively for constant EPS beads volume fraction.(4) The optimal combination of the factors is determined by orthogonal experiment: cement content is18%, lime content is5%, gypsum content is2%and fly ash content is12%. The sequence of factors from the main influence factors to the secondary influence factors is:cement content, fly ash content, gypsum content and lime content in turn.(5) The direct shear test indexes of EPS beads mixed lightweight soil is obtained by direct shear test, and the effect of EPS beads volume fraction, cement content, additive optimal recipe and curing period on the shear strength indexes is analyzed.(6) The microstructure and pore characteristics of EPS beads lightweight soil of dredged sludge before and after adding additive recipe is investigated by means of SEM tests.