Ultra High Performance Strain Hardening Cementitious Composites (UHP-SHCC) is a compos- ite material comprising a cement-based matrix and short reinforcing fibers with outstanding mechanical and protective performance. Besides using a thin layer of UHP-SHCC as a protective coating to extend…
Ultra High Performance Strain Hardening Cementitious Composites (UHP-SHCC) is a compos- ite material comprising a cement-based matrix and short reinforcing fibers with outstanding mechanical and protective performance. Besides using a thin layer of UHP-SHCC as a protective coating to extend the service life of concrete structures, strengthening of existing reinforced concrete beams with UHP-SHCC layer casted to their soffit may be very successful at restoring or increasing their strength. This type of strengthening no- ticeably increases both the ultimate load-carrying capacity and the serviceability of reinforced concrete beams. Nevertheless, observed brittle mode of failure of UHP-SHCC-strengthened RC beams and inability of the UHP-SHCC strengthening layer to exhibit a strain hardening behavior is still a concern. Experimental works presented in this paper examine the ability of proposed steel reinforcement to preclude the localized fracture and consequently to improve the post-cracking behavior of UHP-SHCC under axial tension. The dimensions of the practical size test specimens (200 x 50mm) were selected similar to the average value of those used for beams' strengthening applications (thickness = 30 ~ 70 mm).Test results on ten average practical size speci- mens under axial tension with different reinforcement ratio are reported. Different reinforcement ratios (0.3%, 0.6%, 0.9% and 1.2%) were used to evaluate the reinforcement ratio needed to achieve a target value of duc- tility.