Evaluation of corrosion-resistant basalt-fiber-reinforced polymer bars and carbon-fiber-reinforced polymer grid reinforcement to replace steel in precast concrete underground utility vaults.

Abstract

Underground utility vaults are widely used to house utilities and are conventionally designed using steel reinforcement. These structures are often designed with thicker cover concrete in an attempt to prevent the corrosion of steel that is exposed to corrosive environments. Replacing steel with corrosion-resistant fiberreinforced- polymer materials is beneficial both for production and maintenance. Ultimate and service load behaviors of panels reinforced with basalt-fiber-reinforced polymer (BFRP) and carbon-fiber-reinforcedpolymer (CFRP) grid are discussed in this paper. Failure load and failure mode were used to evaluate the ultimate load behavior; deflection and crack width were used to examine the service load behavior of the tested panels. Test results show that corrosion-resistant reinforcing materials, such as BFRP and CFRP grid, can replace steel in underground utility vaults. Test results are compared with test results from conventional steel-reinforced panels and unreinforced panels and verified against design code recommendations.