Research On The Low Intensity Self-compacting Concrete Properties And Construction Technology

At present in all kinds of tunnel, the cracking, permeating, honeycomb were widespread, these problems impacted on the beautiful and durability of concrete seriously. And not divided the concrete quality and construction technology. In order to solve these problems, a free vibration, self-leveling concrete was presented at self-compacting concrete.Starting with the analysis of the relations between the composition materials and the workability, strength and shrinkage of the Self-compacting concrete, the thesis combined the characteristics of the second lining of Self-compacting concrete, and studied the effect of the mineral admixture content, water to binder ratio, aggregate volume content etc. Analysised the fly ash content, water to binder ratio, curing time on the influence of chloride diffusion coefficient. On this basis of the above resaerch,the mixing parameters of self-compacting concrete parameters were optimized.In this paper, the parameters of demand is less and the relative stability of a kind of mix design method——fixed sand method was choosed, respectively on the workability of self-compacting concrete and compressive strength and shrinkage to sex and anti-permeability of influence factors research. Research shows that:the mixed quantity of fly ash increased from20%to40%, the workability of self-compacting concrete has obvious change; The compressive strength of decreasing trends at60d, the fly ash content is25%, respectively, compared with the mixing content is30%,35%,40%increased14.9%,14.2%,21.8%; Dry shrinkage sex have significantly reduced at60d,40%fly ash content of self-compacting concrete’s shrinkage value than35%,30%,25%and20%respectively of the concrete was reduced by32.3%,34.7%,43.4%.44.3%; Chloride diffusion coefficient reducing, that of self-compacting concrete of impermeable level was.improved. Coarse aggregate volume content is0.30～0.34, and fine aggregate the volume fraction of mortar is0.42, the workability of self-compacting concrete is good, and satisfy the intensity the design requirements; The shrinkage performance also followed with W/B, water cement ratio were0.38,0.45,0.51, chloride diffusion coefficient with the water-binder ratio increases, that is, with the intensity of self-compacting concrete is decreased. And anti-chloride ion the diffusion coefficients as maintenance time growth and reduce.Research also pointed out that the construction technology was the important link about influencing the self-compacting concrete performance. From the raw material quality control, and the proportion of the production and construction will affect the Self-compacting concrete performance, so ensure the standardization of Self-compacting concrete production and construction was very important for project quality.