Glass Concrete Thin Sheets Prestressed with Aramid Fiber Mesh

Concrete has been prestressed traditionally with high-strength steel. The vulnerability of such material to corrosion calls for alternate materials, if thin-sheet products are to be prestressed. A research project at Columbia University is investigating the feasibility of using aramid fiber mesh for such purpose. This paper explores the chemical and mechanical properties of aramid in the form of both individual fibers and rovings. Although the material is inherently brittle, its high strength and stiffness appear to make it a suitable medium for prestress applications. Appropriate pre-stretching of the mesh can minimize prestress losses due to relaxation. The low bond strength requires special measures for both stressing and anchoring of the mesh. Also the chemical interaction between the fibers and the cement matrix calls for attention. Because of the potential of crushed glass aggregate for decorative and architectural thin-sheet applications, pilot studies have been performed using glass concrete matrices.