Experimental Study Of Granulated Blast Furnace Slag As Fine Aggregate Concrete

In this experiment,the blast furnace slag is used to substitute the sand to prepare the concrete,The orthogonal design is adopted first,and the design factors are 3,and each factor corresponds to 3 levels.The factors and levels are: water binder ratio(0.36,0.41,0.46),sand rate(34%,32%,30%)and slag content(20%,40%,60%).The experimental study on mechanical and working properties of granulated blast furnace slag and sand substitute concrete is carried out.Then,on the basis of the orthogonal test results,we choose different slag content(0%,20%,40%,60%,80%)to make concrete.The influence of slag content on the workability,compressive strength and dry shrinkage property of concrete is studied through comparative tests.The test results show that for concrete mixture and ease of nature,the reasonable sand rate of concrete is 34%,and the optimum slag generation rate is 40%.The new generation of slag mix sand concrete fluidity with increasing slag sand rate increased after the first drop,the mixture of cohesiveness and water retention are better than ordinary concrete in the slag sand rate is less than 60%;slag sand concrete water cement ratio is the main factor affecting the compressive strength.The second is the sand ratio,finally slag sand rate.With the increase of slag replacement rate,the compressive strength of concrete increases first and then decreases.When the slag replacement rate is 60%,the strength reaches the maximum value.After drying shrinkage test,it is found that slag fine aggregate has a restraining effect on the drying shrinkage of concrete.Through the analysis of the above test results,while the slag sand rate is 60%,the slag concrete strength reached the maximum,workability and deformation performance of ordinary concrete can meet the performance requirements,using slag as fine aggregate concrete mixing concrete is feasible.