Autogenous shrinkage of high performance concrete containing mineral admixtures under different curing temperatures

The present study investigated experimentally autogenous shrinkage behaviors of high performance concrete (HPC) containing fly ash (FA) and blast-furnace slag (BS) exposed to different isothermal temperatures. The deformation of concrete specimen after initial setting was determined using a modified method which is based on non-contact measurement technique. The results indicated that the method can precisely monitor non-load induced deformations of HPC mixtures. The inclusions of BS and FA resulted in significant increase and decrease of autogenous shrinkage of HPC, respectively. While both the rate and the magnitude of autogenous shrinkage for almost all mixtures were increased with rise of curing temperature, extents of the influence were varied with water–binder ratio, composition of cementitious materials and age. It is noted that although the equivalent age equation was widely applied to evaluate temperature dependence of mechanical properties of cement-based materials, its applicability on autogenous shrinkage of HPC was questionable. In addition, on a trial and error basis, a modified autogenous shrinkage equation was performed in terms of numerical fitting of the measured data.