Study of the viscosity-temperature characteristics of cement-sodium silicate grout considering the time-varying behaviour of viscosity

Grouting is the main method of water damage treatment in underground engineering. Viscosity is a key parameter affecting grouting. However, the viscosity is significantly affected by temperature. The grouting scheme at normal temperatures is not suitable for grouting at high temperatures. Therefore, it is important to study the viscosity-temperature characteristics of grout in high-temperature grouting engineering. This study investigated the effect of temperature on the gelation time of cement-sodium silicate (C-S) slurries. The standard test method and inverted cup method were used to test the gelation time of the C-S slurries. Through the viscosity test, the viscosity-temperature characteristics of C-S grouts were analysed, considering the time-varying behaviour of viscosity. The results show that there are optimal proportions of w/c ratio, retarder, and sodium silicate for gelation time development. The gelation time of the C-S slurries was negatively correlated with temperature. The variation in the stable viscosity value of C-S slurries with temperature can be divided into three stages: the viscosity declining stage, viscosity steady stage, and viscosity rising stage. The fitted viscosity-temperature equation can accurately reflect the viscosity-temperature characteristics. This study can provide effective guidance for the establishment of dynamic water grouting theories, numerical calculations, and grouting parameter design in high-temperature environments.