Research On The Self-compacting Mortar Filling Rock-fill Concrete

Self-compacting rock-filled concrete is a new type of concrete and it is applied inmass concrete project. The concrete can reduce the hydration heat and the project costeffectively and has good technical and economic benefits. There are fewer researchesabout the correlation of rock-filled concrete’s strength, the uniformity of rock-filledconcrete, and the nondestructive testing methods of rock-filled concrete’s strength. Andthe particle size of the coarse aggregate in concrete is more than100mm, which limits itsapplication in special projects. The self-compacting mortar is used to fill the rock-filledconcrete of which the particle size is less than100mm, and the performances about theintensity correlation, etc are studied in this paper.Combining results of current researches at home and abroad, the workability ofself-compacting mortar is tested by standard funnel which is used to test bulk density offine aggregate in this paper. According to the results of prophase research, the flow timeof self-compacting mortar are controlled in60s and120s and the extension degree arecontrolled in400mm and520mm. Considering the influence on the strength of concreteby water-binder ratio, fly ash, sand/cement ratio and the pebble grain size, throughorthogonal design, a series of concrete mix proportion rock-fill concrete of are designed.According to the results of the experiment process and the analysis of the effect of variousfactors on the pile of concrete, it is concluded that the best concrete mixture ratio, alsoanalyzes the concrete construction technology, as well as the strength of concrete.Results showed that the optimal ratio of self-compacting mortar were pebble grainsize of63～90mm, water-cement ratio of0.35, ash content of20%, sand-cement ratio of1.4from the view of strength and cost performance. There was no significant correlationbetween the strength of rock-fill concrete and self-compacting mortar. Therefore theexcessive increase of the strength of self-compacting mortar not only failed to improve thestrength of concrete, but also increased the production cost significantly. Rebound methodcould not detect the strength of concrete effectively because of the special process.