Study On The Constitutive Relationship Of Foam Concrete

Foamed concrete is a kind of new building material that is light in weight,cheaper in cost than concrete,energy-saving and energy-saving,and has convenient pouring and complete functions.Different kinds of admixtures,quantity,water-to-batch ratio and foaming agent type have mechanical properties.have a great impact.This paper improves and supplements the research on the constitutive relationship of foam concrete in the National Natural Science Foundation project "Research on the failure mechanism of light steel and foam concrete composite structure".It is a single admixed fly ash foam concrete,lime foam concrete,and sand foam.The experimental study and theoretical analysis of the mechanical properties of concrete were carried out to investigate the effects of two kinds of admixtures on the compressive strength and elastic modulus of foam concrete and its constitutive relationship.Firstly,the mechanical properties of foam concrete with single admixtures in Document 1 and Document 2 were analyzed.Through the test results and the constitutive curves obtained,the characteristics of the two kinds of admixtures may be compared with the characteristics of foam concrete.The influence of the relationship.Therefore,a total of 72 fly ash-sand foam concrete and lime-sand foam concrete specimens of 800kg/m3,1000kg/m3 and 1200kg/m3 were designed,and the two kinds of admixtures were designed in the same proportion.It is added in an amount of 5%,10%,15%,20%,25%,and 30%,and the corresponding compounding ratio calculation method is obtained.Secondly,the strain modulus of the test piece is measured by the computer to measure the elastic modulus and Poisson's ratio of the test piece,and then the strength is measured to obtain the corresponding stress-strain relationship curve,and the damage state of the test piece is observed.The variation of strength and density,strength and dosage,and elastic modulus and density of foam concrete were analyzed by experimental data.Finally,the existing mathematical model of constitutive relation is summarized and the geometric characteristics of the constitutive curve under uniaxial compression are summarized.The two parameters a1 and a2 of the ascending and descending segments are obtained through experimental analysis,and polynomial is used.And rational to determine the constitutive equation.Using the constitutive equation fitting method of this paper,the constitutive relation expression of the foam-concrete concrete is improved to meet the basic boundary conditions,which provides a theoretical basis for the foam concrete composite structure.