Coefficients for Calculation of Deformation-Strength Characteristic of Concrete for Injection with Two-Stage Expansion

摘要

Strength of concrete is a function of several variables, such as: water / cement ratio, Portland cement activity, filler quality, etc., adjusting which you can achieve the required strength. However, the introduction of the concrete admixtures, changing holding conditions of the samples, the volume restriction can affect the strength of the due to exposure impacts both the kinetics of hydration processes and on the structure formation of cement paste. The article presents the results of investigation the influence of the amount of gas-forming admixture, the presence, type and amount of superplasticizer, the ratio sand / cement, aggregate size and water-cement ratio on gassing and expansion of the mixture in the first stage and propose coefficient of effectiveness of gassing and of expansion. The authors proposed a formula to describe the dependence of the relative deformations of expansion of the concentration of aggregate. In order to assess the conditions in which there is a mixture, it is proposed to use the indicator - coefficient of congestion of expansion, to account for the influence of hardening conditions on the strength of the concrete -coefficient hardening conditions. The authors proposed to consider the impact of prescription and technological factors by introducing system of correction coefficients.