Structural Behavior of High Strength Reinforced Concrete Slabs Strengthened with CFRP

Structural behavior of ten RC slabs with dimensions of (900x900 mm), strengthened with CFRP and non-strengthened were evaluated experimentally, under concentrated load at the top fibers of their centers. All slabs were a simply supported of clear span (820x820 mm), which were made by normal and high strength self-compacting concrete; NSSCC, HSSCC. It was found that the tested slabs of HSSCC, e.g. from 30 to 60 MPa provide more resistance capacity of 18-23% than their counterparts made of NSSCC. Also, the latter increase is related to the decrease in the corresponding deflection under ultimate loads by (11-18%). In similar manner to the effect of HSSCC, the increase of reinforcement ratio results in the increase of resistance capacity by (21-27%). This leads to decrease in the corresponding deflection under the ultimate loads by (15-22%). In terms of the strengthened specimens with CFRP sheet, they also provide more resistance capacity by (25-33%) and a decrease in the corresponding deflection under ultimate loads by about (20-26%) as compared with non-strengthened specimens. Moreover, the obtained results indicated that the strengthened slabs along 50% of span length have a higher load capacity than those strengthened slabs along 25% of span length by (25%-33%). Further, the failure type of specimens was found to be in punching shear in all cases. However, the CFRP failures were found to be demolition, debonding, CFRP fracturing and peeling off.