Research On Static Mechanical Properties And Constitutive Model Of EPS Concrete

EPS concrete is a new environment-friendly building materials which has been widely used in civil engineering owing to its properties of good features of light weight and thermal insulation.Therefore,the mechanical behavior and constitutive model of EPS concrete become the hotspot of concrete materials science.Firstly,the quasi-static compression,splitting and bending experiments of EPS concrete with different particle sizes and different replacement rates were carried out.The compressive stress-strain curves of EPS concrete under different replacement rates were analyzed.The effects of replacement rate on compressive,splitting and flexural properties were analyzed.The influence of EPS particle size on the static mechanical properties of concrete was studied.The relationship between relative compressive strength,relative tensile strength and relative density was established.The influence of particle size on the mechanical properties of concrete was studied by single hole test.The theoretical expression of the effect of particle size on concrete strength was deduced and the validity of it was verified by using the experimental data.The EPS concrete with particle size of 0.5-1mm and replacement rate of 50% was selected as reference test.The polypropylene fiber incorporation of 0.8kg / m3,1.3 kg / m3 and 1.8 kg / m3 was introduced to mixed to study the effect of fiber content on static mechanical properties of EPS concrete.In addition,the mechanism of fiber on the mechanical properties of EPS concrete was analyzed.The two groups of EPS concrete with particle size of 0.5-1mm,EPS replacement rate of 50% and 75% were selected as reference test.The natural river sand in EPS concrete was replaced with the mechanism sand,and the replacement rate was 0,20%,40%,60%,80%.The relationship between compression strength、 tensile strength and mechanism sand replacement rates was established and the mechanism of manufactured sand on the mechanical properties of EPS concrete was analyzed.Based on the elastic damage and the classical plastic mechanics,the constitutive model of the concrete under pressure was used to describe the stress-strain relationship of the EPS concrete.The characteristic parameters of the constitutive model were determined by the test data.The damage constitutive curve and the stress-strain curve obtained from the experiment are compared with each other,and the results are in good agreement with each other.This article provided the foundation for studying the constitutive model of EPS concrete under complex loads.