Prepacked grouting process in concrete construction

Abstract

Prediction of the prepacked grouting process provides useful information for site engineers to decide a proper spacing of injection point and foresee the injection pressure and flow rate to achieve a better quality control of concrete. Prediction methods based on both experimental and analytical work are proposed in this study to analyze the flow of cement grout through single-size aggregate media during the prepacked grouting process. Radial flow is employed to present a basic description of common cases in practice. Darcy's law modified for Bingham fluid (Darcy approach) and Buckingham-Reiner equation modified for porous media (capillary approach) are developed to determine and analyze the flow. Evaluations of the viscosity of cement grout and permeability of the aggregate media are carefully designed and relevant parameters established for prediction analysis. Validation of the proposed analyses is confirmed by comparing the predicted results with monitored values from grouting tests.