Study On Equivalent Powder Slurry Volume Of Large Flowing Concrete

With the height of modern buildings increasing,large flowing concrete has been favored because of its large fluidity and excellent working performance.But with the increase of fluidity,risk of segregation and poor stability of the mixture increases at the same time.How to maintain the fluidity and the good performance of large flow concrete has become an important research topic.However,the parameters proposed in order to solve the problem such as powder and water powder ratio hardly be widely used.This paper puts forward the concept of equivalent powder slurry volume and extends out the mix design method of large flowing concrete.The feasibility of the concept is also verified by experiments.The main content of the thesis is as follows:(1)Because of the lack of uniform and accurate definition of large flowing concrete and in order to clarify the research object,this paper gives the definition of large flow concrete.The difference between the theory of large flowing concrete and ordinary concrete is pointed out in the paper,which points out the main point and the direction of mix design method of large flowing concrete;(2)The equivalent coefficient of each powder are determined by water demand ratio test.Equivalent powder slurry volume is proposed in this paper.linear relationship between the fluidity of cement colloidal mortar and the equivalent powder slurry volume is discovered through equivalent powder slurry volume test of cement colloidal mortar,which provides an idea for mix design method of large flowing concrete;(3)The paper puts forward mix design method of large flowing concrete with the equivalent powder slurry volume added.Reasonable equivalent powder slurry volume of different fluidity is determined by analyzing the experimental data through pure cement and mineral admixture concrete experiments;(4)The influence of the maximum particle size and grade of coarse aggregate on the working performance,strength and durability of large flow concrete is discussed under the condition of definitive equivalent powder slurry volume.