The temperature investigated was controlled between 12 ☌ and 45 ☌ to simulate the true ground temperature in rock masses with a maximum depth of 1500 m below the surface. This paper aims to propose a simplified method to approximately estimate the initial yield stress and viscosity of cement grouts for rock grouting under elevated ground temperature that actually exists in deep rock masses, on the basis of the flow spread test. Reasonable understanding and control of the rheological behavior of cement grouts at true ground temperatures is very important to the quality of grouting. More importantly, the ground temperature in deep rock masses is elevated higher than that on the surface or under room conditions, which has been demonstrated to strongly influence the rheological properties of grouts. However, obtaining the magnitude of rheological parameters is not easy to achieve under site conditions. In practice, the rheological parameters should be timely adjusted according to the evolution of grouting pressure, flow rate and injection time. The rheology of cement grouts often plays a crucial role in the success of rock grouting.
