The Synergistic Effect Of Coarse Aggregate And Cement Mortar On Concrete Performance Was Studied

Concrete is a composite material composed of coarse aggregate and cement mortar matrix,in order to study the synergistic effect of coarse aggregate and cement mortar on the mechanical properties of concrete,and then optimize the selection and dosage of coarse aggregate and cement mortar,while ensuring the quality of the project,reduce the project cost.In order to solve the above problems,this paper mainly conducted concrete mechanics tests by changing several parameters such as coarse aggregate particle size,coarse aggregate volume fraction,cement mortar strength,light aggregate volume fraction and light aggregate substitution rate,and explored the influence of the synergistic effect of the two on the mechanical properties of concrete.At the same time,the concept of cement mortar thickness is proposed to supplement the concept of sand rate in the concrete design specification,so as to provide reference for the determination of concrete mix ratio more accurately.In this paper,the study of this problem is based on the synergistic effect of coarse aggregate and cement mortar,and then explores the influence of cement mortar thickness on the mechanical properties of concrete,so as to provide data reference for solving this kind of problem in the future.The above experimental results are summarized and summarized.The following conclusions are drawn:(1)When a relatively low water cement,with the increasing size of coarse aggregate,the compressive strength and splitting tensile strength of concrete tend to reduce the change after the first increases,the tensile splitting strength of concrete,with the continuous increase of coarse aggregate volume fraction,with the strength of the cement mortar matrix increases continuously;With the increase of water-cement ratio,the effect of coarse aggregate with small particle size on the compressive strength of concrete is obvious,while the effect of the increase of coarse aggregate particle size and coarse aggregate volume fraction on the increase of concrete strength is decreasing.(2)When water cement is relatively low,the filling degree of coarse aggregate is 57.9%,and the elastic modulus of concrete reaches the maximum value.With the increase of coarse aggregate size,the elastic modulus of concrete increases first and then decreases.When the size of coarse aggregate remains the same,the elastic modulus of concrete increases with the increase of the volume fraction of coarse aggregate.(3)When the volume fraction of coarse aggregate remains unchanged,the compressive strength,splitting tensile strength and elastic modulus of concrete all show a trend ofincreasing first and then decreasing with the increase of the thickness of cement mortar.The compressive strength of concrete increases with the increase of the thickness of cement mortar when the particle size of coarse aggregate remains unchanged.(4)When the water cement is relatively low,the compressive strength,splitting tensile strength and elastic modulus of the lightweight aggregate concrete gradually decrease with the increase of the volume fraction of the lightweight aggregate;The elastic modulus of the lightweight aggregate concrete decreases with the increasing of the replacement rate of the lightweight aggregate.