STRENGTHENING OF RC BEAMS SUBJECTED TO CYCLIC LOAD USING ULTRA HIGH-PERFORMANCE STRAIN HARDENING CEMENTITIOUS COMPOSITES

Abstract

Ultra High-Performance Strain Hardening Cementitious Composites (UHP-SHCC) is a composite material comprising a cement-based matrix and short fibers with outstanding mechanical and protective performance having advantages as large strain capacity as well as high compressive and tensile strength, which is useful for strengthening or repair concrete members. In the present study, five specimens were tested experimentally, one as a control and four strengthened with 40 mm thickness of UHP-SHCC layer attached from tension side with variable reinforcement ratios embedded in strengthening layer. Cyclic loading was applied to all specimens. The test results showed the importance of reinforcing the UHP-SHCC to eliminate the observed early strain localization and to gain adequate dissipated energy under cyclic loading. It is also proved that using an unreinforced UHP-SHCC layer for strengthening may lead to a brittle failure especially in case of cyclic load.