In-line rheological measurements of cement grouts: Effects of water/cement ratio and hydration

The rheological properties of cement based grouts change with water/cement ratio and time, during the course of hydration. For this reason, it is desirable to be able to measure this change continuously, in-line, with a robust instrument during the entire grouting operation in the field. The rheological properties of commonly used cement grouts were determined using the Ultrasound Velocity Profiling combined with the Pressure Difference (UVP + PD) method. A non-model approach was used that directly provides the properties, and the results were compared with the properties obtained using the Bingham and Herschel-Bulkley rheological models. The results show that it is possible to determine the rheological properties, as well as variations with concentration and time, with this method. The UVP + PD method has been found to be an effective measuring device for velocity profile visualization, volumetric flow determination and the characteristics of the grout pump used. (C) 2014 Elsevier Ltd. All rights reserved.