Abstract: There is disclosed a method of cutting off water flow by grouting characterized by injecting a water flow cutoff agent (grout) comprising colloidal silica as the main component, a water flow cutoff agent comprising a water-soluble urethane diluted with water, or a water flow cutoff agent comprising a mixture of the above two kinds of water flow cutoff agents into a water-leaking part or a cavity. Also disclosed is a method of cutting off water flow by grouting characterized by injecting a water flow cutoff agent comprising colloidal silica as the main component into a water-leaking part or a cavity and then injecting thereinto a water flow cutoff agent comprising a water-soluble urethane diluted with water or a water flow cutoff agent comprising a mixture of a water flow cutoff agent comprising colloidal silica as the main component with a water flow cutoff agent comprising a water-soluble urethane diluted with water.

Abstract: A washer system comprising: an annular washer having a central opening and an annular packing member which is coaxially arranged with the annular washer, at least a portion of the annular packing member being arranged within the central opening of the annular washer; at least a portion of the outer surface of the annular washer being rust-proofed treated. A substantial portion of a contacting surface between the annular washer and the annular packing member is not rust-proofed treated. The annular packing member is made of an elastic water-swellable rubber. The annular packing member has a portion which extends radially outwardly from a portion of the annular washer defining the central opening, and contacts a portion of a lower substantially flat surface of the annular washer radially outwardly of the annular opening. The annular packing member has a portion extending below a lower substantially flat surface of the annular washer.

Abstract: An expansion joint for use in constructing concrete material structures of the present invention has a plurality of sandwich type composite plates each comprising a sheet-like elastic body sandwiched by a pair of hard plates with a rib at both surfaces thereof are connected with each other through a water-swelling rubber.

Abstract: The present invention relates to a device for filling up a recess left in a concrete wall after removal of a separator terminal, the device comprising a main body including a circumferential step formed around its outer periphery at a longitudinal intermediate location so that the circumferential step defines a diameter-reduced portion and a diameter-enlarged portion of the main body, a threaded hole centrally formed and axially extending in an end surface of the diameter-reduced portion to be engaged with a threaded end of the separator, tool receiving apertures formed in an end surface of the diameter-enlarged portion and in elastic water-swollen rubber cylinder put around the diameter-reduced portion so that an outer periphery of said cylinder is tapered towards the end surface of the diameter-reduced portion and an end surface of the cylinder looking towards the end surface of the diameter-enlarged portion bears against the step of the main body while the end surface of the cylinder looking towards the en

Abstract: The present invention relates to a device for prevention of rainwater or like from penetrating into a concrete structure around each separator left embedded therein, the device comprising a hollow cylinder of synthetic resin, the latter including a female threaded cylinder made of metal or other material embedded in the interior at one end thereof and water-swollen damming-up outer rings fixed on the outer periphery so as to serve together as terminals, a threaded cylindrical portion formed at one end of each of the terminals being engaged with a male threaded portion formed around the corresponding end of the separator, and the cylinder of synthetic resin further including a plug provided with a water-swollen damming-up inner ring fixed into the interior at the other end thereof.

Abstract: Water-swellable moisture-curing one-package polyurethane sealant which includes (1) a water-swellable polyurethane prepolymer having 1.5-10% terminal NCO group content obtained by reacting polyisocyanate with polyoxyalkylenepolyol having 50-90% of oxyethylene units based on polyalkylene chain molecular weight (2) non water-swellable polyurethane prepolymer having terminal NCO groups obtained by reacting polyisocyanate with polyoxyalkylenepolyol having 3-4 carbon atom oxyalkylene units, and (3) a filler. The sealant exhibits has been improved storage stability.