GCP Applied Technologies' ("GCP") ADCOR 500S waterstop is a conformable, butyl rubber-based hydrophilic waterstop strip that expands in contact with water. When fully encapsulated by poured concrete, the expansive forces form a seal against concrete faces. This seal resists hydrostatic pressure, and is specifically engineered to stop water from entering sub-structures. The ADCOR 500S waterstop is a unique product that has been specifically developed to provide superior performance compared to conventional bentonite and swellable rubber waterstops.