Abstract: An encapsulating and patching elastomer for concrete repairs including a two component urethane system including a polyol reacted with a diisocyanate or a mixture of diisocyanates and a hindered amine, and an aggregate filler. The elastomer polyester filler has a hardness of over 50 on the Shore A scale. The subject invention further provides a method of making an encapsulating and patching elastomer for concrete repairs, the method including the steps of dissolving the two component urethane system with the hindered amine. The mixture is applied as a film or patch to a concrete surface. The mixture is cured at ambient temperature for 48 to 72 hours to an elastomer having a hardness of over 50 on the Shore A scale.

Abstract: A roadway sealed expansion joint between roadway sections spaced by an expansion slot, the roadway sections having recesses adjacent and extending longitudinally of the slot. A metal plate bridges the slot and is secured to the bottom of the recess in one of the sections and is movable relative to the bottom of the recess in the other of the sections. Overlying the metal plate is a unitary elastomeric slab with its upper surface aligned with the upper surfaces of the concrete sections and with its edges bonded to the sides of the recesses, this elastomeric slab having a center premolded portion of relatively high elasticity and edge portions which are molded in situ and which are of relatively low elasticity.