9713943 Riffle This project is an interdisciplinary plan for engineering carbon fiber reinforced vinyl ester composites to meet the rigorous environmental durability needs for infrastructure. Composite materials will be designed specifically to withstand long-term moisture and UV exposure based on both chemical constituents and composite construction, particularly fiber-matrix interface design. The project encompasses modified resin and composite development, hygrothermal and ultraviolet laboratory exposure, environmental field testing, and residual mechanical property analyses as a function of exposure. This is the first comprehensive study of an important class of candidate materials for infrastructural uses where the constituent chemistry, the environmental exposure, and the mechanics of degradation are linked. NIST will provide state-of-the-art ultraviolet testing facilities and expertise for both the laboratory and field experiments in collaboration with the project. The Tom's Creek Bridge project, a vinyl ester/carbon/glass vehicular bridge constructed in Blacksburg, VA during the summer of 1997, will be leveraged as a field-testing site. The work will also be done in close collaboration with major resin suppliers to insure that modifications under consideration have potential for large volume production, and to insure that technology is transferred to appropriate producers efficiently. The experimental plan is to design and fabricate composites, age materials, and characterize damage. ***
