Method of stopping leakage of water in concrete structure and impregnating agent for use in said method

Abstract From the Canadian patent

A method of stopping leakage of water in a concrete structure comprising injecting a hydrophilic one component type polyurethane prepolymer or an impregnating agent which is prepared by adding cement to such polyurethane prepolymer into a hermetically sealed chamber formed in a leaking part of the concrete structure, whereby the polyurethane prepolymer foams and cures through reaction with water leaking in the concrete structure and the foamed prepolymer is forced to enter all cracks in the leaking part of the concrete structure by means of foaming pressure and volume expansion caused by the reaction, thereby caulking and hermetically sealing the cracks, and thus restoring the strength and …