Extrusion molding method for cement-based building materials

摘要

PURPOSE:To improve an extrusion molding method of a cement-based building material for which, while suppressing the using quantity of the salt of a naphthalene sulfonic acid.formaline high condensation product, a slurry concentration is maintained without reducing the using quantity of water and also the strength is improved without increasing the specific gravity of the product. CONSTITUTION:In the extrusion molding method of the cement-based building material composed by adding an extrusion auxiliary agent to the cement compound consisting of cement, silica powder of 0.7-1.3 times of the quantity of the cement, the necessary quantity of reinforcing fiber and lightweight aggregate, etc., 0.1-3wt.% of the salt of naphthalene sulfonic acid.formaline high condensation product and 3-15wt.% of magnesium hydroxide are added to the compound expressed in terms of solids in the prescribed compound, and further, water is added and mixed to prepare a kneaded product and then the kneaded product is molded by the extrusion molding process. By a synergistic effect of the salt of naphthalene sulfonic acid.formaline high condensation product and magnesium hydroxide, the strength of the slurry and the product strength is improved.