Study On Self-Compating Performance And Engineering Application

This article analysis on the applicability of mix design method about self-compacting concrete, the mineral admixture and VMA affections on the properties of self-compacting concrete; preparation the ordinary concrete had same label, same mixed method and the proportion of mineral admixture with self- compacting, study on the ordinary concrete and self-compacting concrete with porous structure, durability, shrinkage pilot and analysis their comparative. Finally, self-compacting concrete is applied in segment shield of subway and reinforced concrete component had complex shapes. The results are:Due to its unique performance, self-compacting concrete is considered as an inevitable trend by national scholars and it could be applied in all kinds of concrete structures and construction conditions. However, its technology is not mature; and has not been widely applied from in and abroad. The main restrictions in the use of self-compacting concrete is: that the work of fresh concrete is very sensitive to be affected by raw material quality, the accuracy of ingredients and other factors the impact of fluctuations in substantial changes; so far there has not a widely accepted method in the mix design.Compared with ordinary concrete, self-compacting concrete mix design has more cementations material and higher sand rate. Whether its performance is different with ordinary concrete is another question. All that reasons make this technique still is considered as a special concrete and be careful used.(1) The fixed volumes content of aggregate method had a good theoretical basis and engineering practicability in self-compacting concrete's mix design methods.(2) Different mineral admixtures have different affections in the performance of self-compacting concrete. The fly ash can improve the performance of concrete and reduce the concrete mixture liquid and the loss rate. The slag had poor resistance to segregation and water demand is small, but it can improve the workability of fresh concrete. Silica fume concrete mixture can improve the cohesion and rheological greatly of self-compacting, improve the self-compacting concrete mix stability. VMA can improve the cohesive nature of the mixture, has a certain influence of strength and pore structure.(3) Self-compacting concrete has higher density in the porous structure compaction than ordinary concrete, and its pore size distribution is different with ordinary concrete. (4) In concrete's durability and shrinkage, the self-compacting concrete's frost resistance is better than the ordinary concrete. Although the self-compacting concrete resistance to chloride ion penetration is less than ordinary concrete, its good resistance to chloride ion penetration. Self-compacting concrete and ordinary concrete have the same carbonation resistance compared with the ordinary concrete. Self-compacting concrete had large shrinkage coefficient, but it is not harmful to the stability of the volume of concrete construction.(5) In engineering used self-compacting concrete, it should be more strengthen in the quality control of raw materials. In construction, the pouring rate must be controlled, and the vertical drop is not more than 5m.