Study On Mechanical Properties Of Polymer Foam And Foam Impregnated With Water

Polymer grouting technology has achieved many results in disease repair.This technology has obvious advantages compared with traditional maintenance methods.This paper will focus on the mechanical properties of polymer foam and polymer foam impregnated with water.The main work is as follows :(1)By uniaxial compression test,the elastoplastic and atypical brittle compressive characteristics of polymer foam were observed and explained with different densities.By observation of scanning electron microscope,those two compressive characteristics were analyzed microscopically.To quantify the two characteristics,the prediction models of compressive stress-strain curve for polymer foam were derived.Moreover,the prediction models were simplified.The simplified models are easy for engineering applications.(2)By three-point bending test,the effects of density and loading rate on their bending strength were studied macroscopically.By observation of scanning electron microscope,the bending failure process of polymer foam was analyzed microscopically.To quantify the above effects,the prediction model of bending strength was obtained by using experimental data.(3)In the complete process of water absorption for polymer foam,two kinds of weakening and enhancement effect of water on compressive strength for foam impregnated with water were observed and explained,combining macroscopic and microcosmic experiment.To quantify the influence of the above effects on the compressive strength for foam impregnated with water,the prediction model of their compressive strength is proposed.(4)In the complete process of water absorption for polymer foam,two kinds of weakening effects of water on bending strength are analyzed by three-point bending test.By observation of scanning electron microscope,the changes of microstructural for foam before and after immersion were studied.Based on the data obtained from experiments,the prediction model for the bending strength of foams impregnated was proposed,which quantitatively describes the effect of weakening effect on the bending strength.