Full definition
A flat piece cut or die-stamped from solid neoprene (CR) rubber sheet to specific dimensions, used as a load-bearing support, vibration isolator, or weather-resistant gasket. The most critical application is structural bridge bearing pads per AASHTO M 251 (formerly AASHTO M 251 Type A for unreinforced, Type B for laminated with steel plates): 50-60 Shore A hardness, minimum tensile 17 MPa, maximum compression set 25% (70h/100°C), ozone resistance per ASTM D1149. Bridge bearings accommodate thermal expansion, rotation, and horizontal movement of bridge girders while transferring vertical loads to substructure. Neoprene is preferred over NR for bridge bearings due to superior ozone and weather resistance. Other applications: machinery mounting pads (vibration isolation — natural frequency determined by pad stiffness, area, and thickness), shipping container anti-vibration pads, weatherproof equipment gaskets, electrical transformer pads, and HVAC equipment isolation. Sizes: from 25×25 mm equipment pads to 600×600 mm bridge bearings. Thicknesses: 6-150 mm (laminated bearings can be very thick with internal steel plates). Per AASHTO M 251, EN 1337-3 (European bridge bearing standard), and ASTM D2000 BE for compound.