Study On Working Performance Of Concrete Based On Modified Water Film Thickness Model

The design of concrete fit ratio is an important work in hydraulic and civil engineering.As there is no method to accurately predict the working performance of the concrete mix in the current concrete mix design,it is usually necessary to test the mix several times in the actual project to obtain the concrete material mix that meets the design specifications,which is less efficient;and it is sometimes difficult to obtain the material mix that meets both strength and working performance for aggregates that are not ideal grade such as mechanical sand.The prediction of the working performance of the mix is therefore critical to the design of the concrete mating ratio.The paper used wet measurement method to carry out the test of material accumulation densities under different aggregates and water reducing agents,and the test of cement net slurry expansion.The relationship between the particle accumulation densities and the amount of water added was studied,the mechanism of the effect of water reducing agents on the release of flocculating water was analyzed,and the effect of water reducing agents was determined.At the same time,the paper compares the results of stacking densities measurement by wet measurement with the theoretical calculation results of compressible stacking model,and summarizes the advantages and disadvantages of the current stacking densities measurement,providing a more concise and effective method for the calculation of water film thickness.The paper carried out the expansion degree and T200 test of cement mortar under different aggregate proportion and different water reducing agents,and analyzed the concrete multiphase mixture into different solid-liquid two-phase mixtures.The paper analyzes and simplifies the factors affecting the working performance of concrete on the basis of the working performance model of cement slurry and mortar,and proposes a design method for concrete mating ratio based on the modified water film thickness model,which provides a reasonable,efficient and simple solution for future concrete working performance prediction and control.