1.1 This specification covers the physical property requirements of elastomeric seals (gaskets) used to seal the joints of precast concrete structures conforming to Specifications C 14, C 14M, C 118, C 118M, C 361, C 361M, C 443, C 443M, C 505, or C 50 This specification covers the physical property requirements of elastomeric seals (gaskets) used to seal the joints of precast concrete structures used in gravity and low head pressure applications. The seals shall be classified as: Class A; Class B; C