Optimization of self-compacting filling grout mixtures for repair purposes

Today self-compacting filling grouts (SCFG) are preferred for rapid repair purposes due to the application easiness, in addition to physical and mechanical advantages. However for self-compactability, the paste phase must meet some certain criterion at fresh state. To reach the optimum mix design for SCFG, it is important to find out the right combination of cement and filler material, both amount and type. The successful utilization of quarry dust in self-levelling cement pastes could turn this waste material into a valuable resource. In this research, the effect of cement replacements with three types of limestone powders produced from different quarries on the rheology of the fresh SCFGs has been studied. Also the mechanical and drying shrinkage properties of SCFGs have been investigated. A 10% replacement of cement with a special type of quarry dust was found to lead the best performance at fresh state rheological properties and at hardened state compressive strengths and drying shrinkage. All filler additions decreased the drying shrinkage of cement pastes at different orders when compared with pure cement paste specimens. The positive effects of quarry dust on fresh and hardened properties of self-levelling binders make this material a feasible additive besides its economical and environmental advantages. (c) 2006 Elsevier Ltd. All rights reserved.