Strengthening concrete slab-column system using CFRP

Date of Award


Degree Type



Civil and Environmental Engineering




Six interior flat slab-column connections were constructed and tested to investigate the feasibility of using CFRP sheets as a strengthening technique for flat slab-column connections against flexural failure. Each specimen is made of 2000 * 1000 * 150 mm slab and a 250 * 250 mm column stub extending above and below the slab. Three of the tested specimens were strengthened by bonding to the tension side of the slabs carbon fiber reinforced polymer (CFRP) sheets using two-part epoxy resin, and three specimens were used as control specimens. All specimens' slabs were reinforced with the same internal steel reinforcement ratio and two different external reinforcement (CFRP) configurations were used. The specimens were tested by applying monotonic load up to failure. The load was applied through the central column-stub either concentrically or eccentrically. Tests results revealed the effectiveness of CFRP sheets in significantly increasing the stiffness of the slabs, yield and ultimate capacity of the slabs upto 65% and 80% respectively. Ductile behavior of strengthened specimens was observed, but with less deformation than control specimens at the same load levels. Ductility was achieved by having conventional reinforcement yielded; secured by limiting the maximum percentage of CFRP sheets. Finally, flexural ultimate carrying capacity for strengthened specimens can be predicted using CSA A23.3-94 standard and the recommendations of ISIS (Design manual No. 4, 2001).