Shrinkage-induced strains on cross-sections of reinforced concrete prisms

Abstract

This paper describes experimental testing to investigate the effects of steel reinforcement on the distribution of shrinkage strains over cross-sections of reinforced concrete (RC) prisms. Measurements were taken in a harsh environment (50°C and 5% relative humidity (RH) and a moderate environment (28°C and 50% RH) on prisms of dimensions (80 × 150 × 500 mm). The research provides experimental measurements that supplement the scarce database for the distribution of induced drying shrinkage strains over RC cross-sections. As expected, the presence of steel restrains the development of shrinkage strains and the degree of restraint depends on the amount of steel. The effect of reinforcing steel on induced strains at the upper levels of the cross-sections increases as the steel ratio increases, particularly for specimens cured in the harsh environment. Over time, the distributions of total strains over cross-sections were found to approach linearity, with a higher rate towards linearity as the steel ratio was increased.