Strengthening of Reinforced Concrete One-Way Slabs with Opening using CFRP Strip in Flexural

The purpose of this study is to investigate the flexural behavior of reinforced concrete one way slab with opening and applying strengthening to them by using CFRP strip. Size, shape of the opening, length, and width of CFRP strip are the main parameters that are investigated in this experimental research. Three different squares opening of (150 mm, 200 mm and 250 mm) side and three different shape of opening with constant opening area (square, rectangle and circle), two length of CFRP strip of (500mm and 700mm), and two width of CFRP strip of (50mm and 100mm) are tested. These openings are situated in the maximum bending zone. Two series of test are done during experimental program. First set of experiments are done without strengthening and second set of test are done after strengthening with CFRP strips. Totally, nine test specimens are tested, including one reference specimen, five specimens without strengthening and three specimens with strengthening. CFRP strips are located along the openings and fixed using anchor bolts. Finally some evaluations of test results are done for determining the performance of strengthening techniques. Crack load, ultimate load, service deflection, ultimate deflection, concrete compressive strain, crack width, crack pattern, and failure mode are calculated and compared. By all these evaluations, the strengthening technique that can be applied easily, faster and required less workmanship is developed