Rheological behavior and setting time of microfine cement-based grouts

In specific grouting applications, such as for fine soils and finely cracke d structures (rock or concrete), microfine cement-based grouts are often us ed instead of chemical grouts, which were frequently used in the past. Diff erent types of microfine cements are available, and their chemical and phys ical characteristics vary widely. Microfine cements are systematically used with a high range water reducer (HRWR) to obtain desirable workability. In this study, six different microfine cements (three portland-based and thre e slag-based), associated with four. different HRWRs, show the effect of gr out composition and grout formulation on the performance of grouts. Interac tion between cement and admixtures influences the rheological characteristi cs and the final setting time of fresh grouts. Changing cement type in art optimized grout formulation or HRWR type leads to changes in grout properti es. To obtain a good grout quality (fluid and stable), it is therefore impo rtant to control its behavior. in the laboratory with routine tests that ar e reproducible on the field. Grout formulations and components used in fiel d work have to be the same as those tested in the laboratory.