Influence of extreme high-temperature environment and hydration time on the rheology of cement slurry

Abstract As a large number of projects are being constructed in deep rock masses, high ground temperatures and hot water disasters are inevitably encountered during construction. Considering the design of grouting parameters and the actual reinforcement effect, it is important to study rheology of grouting materials in high ground temperature environments. This study investigated the influences of temperature and hydration time on the rheology of Portland cement. The water-cement ratio (W/C) of Portland cement PO42.5 varied from 0.5 to 2.0. Through design experiments, the rheological models and parameters (yield stress, plastic viscosity) of cement slurry with different degrees of hydration were studied at different temperatures from 30°C to 80°C. The results show that cement slurries with different water-cement ratios (W/Cs) belong to three flow patterns in different temperature environments. The flow pattern hardly changed during grouting. The rheological model of slurry was controlled by W/C. In addition, the influence of temperature on shear stress varied with the change of W/C. The increase in hydration time increased the shear stress of the slurry for each W/C. The constitutive equation considering the effects of temperature and hydration time was established. This research can provide necessary guidance for the establishment of grouting diffusion theory and numerical model in high ground temperature environment.