A composite of expansive materials for crack prevention of cementitious materials by using of waste fly ash

摘要

PURPOSE: An expanding agent composition of cement group using waste fly ash which is byproduct of desulfurization process is provided to prevent the cracking of cement materials and to control dry shrinkage of cement mortar by using deposal of queen scatter, aluminum potassium sulfate, aluminum hydroxide, polyethylene oxide, and zinc stearate. CONSTITUTION: An expanding agent composition of cement group using waste fly ash which is byproduct of desulfurization process comprises deposal of queen scatter 40-65 weight%, normal Portland cement 20-30 weight%, aluminum potassium sulfate 9-14 weight%, aluminum hydroxide 3-7 weight%, polyethylene oxide 1-3 weight %, zinc stearate 1-3 weight%, and league scull sulfate group dispersing agent 1-3 weight %. The league scull sulfate group dispersing agent is used to uniformly disperse composition of expansion material. In the distribution of particle size of disposal of queen scatter, particles which size is less than 20 micrometer is 90% or greater. The aluminum potassium sulfate plays a role of an assistant for producing ettringite. The ethylene oxide compound controls initial plastic shrinkage of cement mortar.