Study On The Mix-Design Method And Mechanical Properties Of Self-Compacting Concrete

Self-compacting concrete is one of the most innonative high performance concrete in the current time in that it has good workality and low permeability.It can fill every nook of the formwork depending on SCC’s weight on casting without concrete vibration.In the meantime,it can also avoid the emergence of aggregate segregation and bleeding phenomenon.Therefore,SCC is excellent in its working performance, mechanical properties and durability in comparasion with ordinary normal-strength concrete.In order to promote the application of self-compacting concrete,this paper conducted related experimental study on the mix-design method and fundamental mechanical properties of self-compacting concrete.The main results of this thesis are as follows:1. By the aggregate clearance volume packing mix-design method,three different ordinary natrual gravel aggregate gradation’s SCCs are produced,which are called “DNC”,“MNC”and“UNC”.Through repeated tests,a optimization aggregate gradation is choosed based on the workality and strength requirements whose compressive strength is 60 MPa. Then on the basis of the mix-design of self-compacting concrete with natural aggregate, self-compacting full lightweight aggregate concrete called “AL”,self-compacting gravel lightweight aggregate concrete called “CL” and self-compacting sand lightweight aggregate concrete called “FL” were manufactured with good flowability from a number of trial tests.2.By the tests on 27 self-compacting concrete cube specimens with the sizes of 100×100×100mm, 9 cube specimens of 150×150×150mm, 9 prism speciments of 150×150×300mm and 9 self-compacting concrete beams of 100×100×400mm, the influence of different coarse and fine aggregate volume fractions on cubic compressive strength, axial compressive strength and flexural strength of self-compacting concrete was studied.The size conversion coefficient of cubic compressive speciments with different sizes was calculated.In addition, the relationships of different strengths were analyzed.3.Through the experimental study on 9 self-compacting lightweight aggregate concrete specimens with the sizes of 150×150×150mm, 9 of 150×150×300mm and 9 of 100×100×400mm, the effects of different aggregate types on cubic compressive strength, axial compressive strength and flexural strength of self-compacting concrete were researched.Besides, the relationships between dry apparent density of selfcompacting lightweight aggregate concrete, aggregate loose bulk density and cubic compressive strength were put out as well as the relationships of different strengths.4.By the experimental research of 3 steel fibre reinforced self-compacting full lightweight aggregate concrete specimens with the sizes of 150×150×150mm, 3 of 150×150×300mm and 3 of 100×100×400mm, this paper analyzed the effect of steel fiber on cubic compressive strength, axial compressive strength and flexural strength and the relationships of different strengths.