Study On Mix Design And Performance Of Self-compacting Concrete

Self-compacting concrete has captured enormous attention because it could consolidate without any vibration, show good mechanical performance and durability after the consolidation. Altuough the self-compacting concrete showed attractive performance, there is still no standard mix design and around the globe.In this paper, mix parameters of self-compacting concrete using dense packing method and improved method of specific surface area were discussed, and the mix parameters were analysized with optimization and regression using the orthogonal design method. Finally, the mechanical properties, durability and microstructure of interface structure of self-compacting concrete were studied and analyzed. Comparison between the convebtional absolute volume method designed concrete and the modified self-compacting concrete.Experiment results showed that slurry surplus coefficient could significantly affect the performance of the self-compacting concrete produced by the dense stacking mix design. When the value of n was set at 1.9, concrete showed the highest compressive strength and mechanical properties.The regression equation was obtained by the regression analysis of the slurry surplus coefficient and the expansion degrees. The average wrap thickness of sand parcel and paste palyed an important role in the performance of the self-compacting concrete, when the mix was calucated by the modified specific surface area method.The strength, compressive strength and expansion degree of each grade self-compacting concretes reached their peaks, when the values of d and t ?were set at 0.12 mm and 0.9 mm, respectively. The as-prepared concrete showed its highest performace, which could reache the first grade of the requirement. The fitting equation between the expansion degree and the average wrap thickness of sand parcel and paste of the self-compacting concrete by the regression analysis.The microhardness analysis showed that better morphologies were formed in the interface transition zone of the self-compacting concrete, comapred with that of conventioan concrete. This result well explained the reason why the self-compacting concrete showed better durability to some extent than the ordinary concrete.