ВЛИЯНИЕ УРОВНЯ НАГРУЖЕНИЯ НА КОЭФФИЦИЕНТ ПОЛЗУЧЕСТИ БЕТОНА

Abstract

Reinforced concrete structures subjected to long-term load subsequently deform over time. This is due to the creep of concrete. Nonlinear creep appears at stresses (45...50)% of the prismatic strength of concrete under long-term loading. This leads to the fact that when calculating reinforced concrete structures, it is necessary to take into account the effect of the stress level in the compressed concrete on the creep coefficient, which is used to determine the concrete deformation modulus under conditions of long-term loading. The aim of this paper was an experimental study of the effect of the loading level on the creep coefficient of water-saturated concrete. In this regard, the experimental studies of the creep of heavy modified concrete were carried out. Concrete prisms 101040 cm in size were taken as prototypes. The loading level of concrete prisms varied from 0.35 to 0.9 in the experiments. The results of the research proved that at loading levels of 0.8 ... 0.9, the creep coefficient practically does not change. Based on experimental data and the analysis of data from various authors, domestic and European standards, the paper proposed the dependencies that reflect the influence of the loading level, concrete compressive strength class and relative humidity of the environment on the limiting value of the creep coefficient of compressed concrete.