Restraint degree concept in analysis of self-induced stress of massive RC structures

摘要

In this paper, the effect of reinforcement on the concrete self-induced stress before the concrete crack is analyzed. Based on a uniaxial restraint model, the effect of reinforcement on the concrete self-induced stress is investigated by taking into consideration such factors, as concrete shrinkage, concrete creep and thermal expansion, respectively. A numerical analysis on the self-induced stress of massive RC structures is then conducted using a finite element method. The effect of reinforcement on the concrete self-induced stress under the coupling effect of concrete shrinkage, creep and thermal expansion is studied. It is found that the external restraint plays an important role on evaluation of the effect of reinforcement on the concrete self-induced stress. A simplified relationship between the external restraint and the reinforcement influence coefficient is developed. The elastic and viscoelastic approach give a consistent description of the effect of reinforcement on concrete self-induced stress.