Mix Proportion Design And Study On Mechanical Properties Of C90 High Strength And High Performance Concrete

Compared with ordinary concrete,high-strength and high-performance concrete has certain advantages in working performance,mechanical properties,durability,long term and economy.The use of high strength and high performance concrete can make the structure smaller,which can save the cost and make reasonable use of resources,and can meet the needs of more specific shape which can be bearing,so It is very important to study the high strength and high performance concrete.This paper takes the C90 high-strength and high-performance concrete as the research object,including six aspects of the selection of raw material,the design of mix proportion,the workability,mechanical properties,durability,Micro-mechanism analysis.Firstly,Raw materials are preferred and the initial mixing ratio can be determined by calculating the mixing ratio test.On the basis of this,the orthogonal test method can be used to select the appropriate dosage of the three kinds of materials,and the reference ratio of the laboratory can be obtained.Secondly,under the laboratory benchmark mix,through the contrast test,the paper studies three factors-the amount of cementitious material,water binder ratio,sand ratio-at three different levels to affect concrete cube compressive strength,prism compressive strength,flexural strength,splitting tensile strength and compressive elastic modulus.The total amount of cementitious materials is 550 kg/m~3?600 kg/m~3? 650kg/m~3,the water-cement ratio is 0.20?0.22?0.24,the sand rate is 38%,?40%? 42%.The strength grade of high strength concrete is based on the compressive strength of standard specimen cube.When studying the variation of five mechanical properties,the scale conversion coefficient between standard specimen and nonstandard specimen is proposed.The configuration of the C90 compressive strength will meet the requirements.According to the test data,the author put forward the regression curve and regression equation of other four mechanical properties about compressive strength.In this paper,impermeability and anti-cracking performance of C90 high strength and high performance concrete are researched by anti-chloride ion permeation test and early crack test.The electric flux and the impermeability coefficient of the C90 high-strength and high-performance concrete in 28 days were measured by the electric ion method.The long-term shrinkage were measured in using contact method after the hardening of concrete and 3 days standard maintenance.Early crack test is researched by sliding method on cracking resistance of C90 high strength and high performance concrete.The morphological characteristics and phase difference between C90 high-strength and high-strength concrete and ordinary strength concrete will be analyzed by scanning electron microscopy(SEM)and X-ray diffraction(XRD).The performance of C90 high-strength and high-performance concrete will be analyzed from microscopic superior reason.