The effect of curing temperature on autogenous deformation of fly ash concretes

Abstract

For concrete subjected to restrained conditions, autogenous deformation (AD) and thermal dilation (TD) are the main driving forces behind stress development in the hardening phase. Generally, AD in concrete is modelled by model codes or measured in the laboratory under 20 °C isothermal conditions, and then used as basis for stress calculations under realistic temperature conditions. To evaluate this common simplification, the current study investigated the effect of curing temperature on the AD of a series of fly ash concretes. A comprehensive test program was performed for fly ash concretes subjected to various temperature curing conditions. The model codes and measurements under 20 °C isothermal conditions provided AD developments in the same order of magnitude. However, when subjected to a realistic temperature history during curing, major changes in the AD developments were observed, emphasising that AD must be determined under relevant temperature conditions.