consolidation of single-component grouting mortars in the course of dewatering: redistribution of particles

Two contradictory requirements are basically demanded on single-component grouting mortars. on the one hand, a sufficient workability lasting for several hours; on the other hand, a rapid development of shear strength immediately after grouting. the latter is normally achieved through dewatering of the mortar into the surrounding soil. during dewatering also particles are transported to the soil and lead to a clogging in the interface, which can have a significant influence on the further dewatering process and thus on the consolidation behavior of the grout. in this research study, the dewatering behavior and redistribution of the particles of single-component grouting mortars have been systematically investigated under variation of the relevant material-specific parameters, such as the granulometry of the fines and aggregates. for the determination of the filtrate water, a filter press test was developed, simulating the conditions within the annular gap. for the evaluation of the redistribution of the particles, the particle size distribution, density and water content of individual layers of the dewatered grout were determined over the specimen height. the investigations revealed a significant influence of the granulometry of the particles on the grout properties. at early mortar ages, the amounts of filtrate water were at the same level independent of the granulometry and specific surface of the binder. however, the shear strengths increased steadily with increasing specific surface of the binder and age. with regard to the granulometry broken particles with a rough surface provided an essential contribution to the development of shear strength.