Effect of mixing procedure on injectability of cementitious grouts

Injection grouts made of cement and mineral additives, such as lime and nat ural or artificial pozzolans, coagulate in suspension; the use of a superpl asticizer is not sufficient to improve injectability when penetrability in very fine voids is required. The effect of two different mixing procedures, one with a mechanical and one with an ultrasonic mixer, has been studied. Ultrasonic mixing improves dispersion, especially when silica fume is added to the grout, and permits the use of a water content lower than that of hi gh turbulence mixing for the achievement of the same penetrability of the g rout. (C) 1999 Elsevier Science Ltd. All rights reserved.