Experimental Study On Mechanical Properties Of Big Fluidity Of Pavement Concrete

Large flow refers to the degree of concrete slump is not less than 160 mm,good construction workability,Slump after the loss is a kind of high performance concrete。Big fluidity concrete has good workability,excellent mechanical properties,got rapid development in our country。Will big fluidity of concrete used in road engineering is not only the construction speed is fast,but also reduce environmental pollution and noise,Has obvious social and economic benefits。At present our country big fluidity of pavement concrete research is relatively small,the lack of perfect technology and procedures,and big fluidity mechanics performance of pavement concrete research is scattered。As a result, the large fluidity mechanics performance of pavement concrete is of great significance。This article first of the great fluidity pavement concrete raw materials tested,each technical index requirements of raw materials is proposed;Then for bigger fluidity pavement concrete mixture ratio design,with water/cement ratio, the dosage of gelled material, sand ratio, dosage of fly ash as factors,By means of orthogonal experimental design method of the selected scheme,to slump value and under the age of 7d, 28 d compressive strength, flexural strength as evaluation indexes,using poor, variance analysis methods to analyze the various factors influence size,and according to the influence degree of various factors to optimize mixture ratio。On the basis of orthogonal test design, study different factors change on big fluidity pavement concrete compressive strength, splitting, bending, impact resistant, mechanical properties such as elastic modulus, and the influence of the early crack resistance,at the same time by using the finite element software MIDAS to big fluidity pavement concrete numerical simulation analysis of mechanical performance,big fluidity of pavement concrete is studied under different stress is the stress distribution and failure mechanism,and comparing the calculated value and measured value to the accuracy of the validation test。Finally using SEM images on the fluidity of the fly ash pavement concrete-hardened cement paste microstructure observation and analysis,It is found that the amount of fly ash can improve the mechanical properties of the pavement concrete,the best dosage is 20%。...