New preparation of super-early-strength grouting materials by ternary complex system

An innovative preparation of super-early-strength grouting material made from a ternary complex system combined with a variety of admixtures is described. The ternary complex system comprised sulfoaluminate cement, aluminate cement and gypsum at respective contents of 67, 23 and 10 wt%. The effects of different retarders, the early-strength component (lithium carbonate) and superplasticisers (SP) on the setting time and strength of the ternary complex system were studied. It was found that borax had the best retarding effect and the optimum dosage was 0·4 wt%. When the dosage of the early-strength component was 0·02 wt%, the setting time and early-strength performance of the composite system conformed to requirements. In addition, the appropriate dosage of naphthalene SP for this system was determined to be 1·2 wt%. With added naphthalene SP, the initial fluidity of the composite system was increased and the 20 min fluidity loss was reduced.