Expedient Structural Sandwich Soil Surfacing of Fiberglass Reinforced Polyester and Polyurethane Foam.

摘要

A structural soil surfacing (FOMAT), consisting of a rigid polyurethane foam core sandwiched between two fiberglass reinforced plastic (FRP) layers, is being developed to fulfill a need for a designable, heavy-duty, expedient surfacing for Marine Corps amphibious landing applications. In analytical and laboratory investigations, FOMAT showed very good potential for meeting expedient surfacing requirements. The FOMAT constructed of 15- and 20-pcf-density foams will adequately carry F4 aircraft wheel loadings as determined from finite element computer analyses and plate loading tests in a mechanical simulated subgrade. Tests performed on FOMAT with 20-pcf foam core showed that it meets or exceeds F4 aircraft arresting gear hook/impact and jet engine heat/blast performance specifications for a heavy-duty matting. Construction of FOMAT under field conditions indicated a problem with bonding of the polyurethane foam core and the bottom FRP layer, causing premature termination of simulated F4 aircraft wheel traffic tests on eight FOMAT panels located on heavy clay, lean clay, and sand soils. FOMAT panels consisting of 15- and 20-pcf density and 1- and 2-inch-thick foam cores were subjected to the traffic loadings. At a maximum of 40 passes on two panels of 2-inch-thick 15-pcf and 2-inch-thick 20-pcf foam core, a wheel deflection of 1 inch on the FOMAT surface was experienced. Development of field construction techniques to insure positive bond between the foam core and bottom FRP layer is recommended. (Author)