SHRINKAGE EFFECT ON CRACKING RESISTANCE OF FLEXURAL REINFORCED CONCRETE MEMBERS
Keywords: reinforced concrete, concrete creep, ageing coefficient, time-dependent stress strain state, uncracked cross-sections.
AbstractA time-dependent stress-strain state of reinforced elements induced by gradually developing shrinkage of concrete is analysed. Depending on environmental conditions the early age concrete shrinkage can produce a significant tensile stress in concrete that reduces the cracking resistance of the cross-section. To analyse this phenomenon a numerical model is proposed. For the exact analytical prediction of the time-dependent stress-strain state induced by restrained shrinkage, the key parameter is the coefficient of aging which is strongly dependent on the time-evolution of tensile stress of concrete and modulus of elasticity. The values of this coefficient obtained in the current analysis are suitable for the proper evaluation of the reduction of cracking resistance of the cross-section induced by restrained shrinkage evolving during concrete hardening process in a period prior to element loading.
MECHANICS OF SOLID BODIES