Strengthening of reinforced concrete two-way slabs

The experimental phase of this research work includes testing of three groups of specimens. The first and second groups are composed of specimens strengthened using steel plates and steel bolts. The specimens of the first group are loaded centrally only. The second group of specimens is loaded centrally combined with lateral static or cyclic moment. The specimens of the third group are loaded centrally and strengthened with either Carbon Fibre Reinforced Polymer (CFRP) strips or Glass Fibre Reinforced Polymer (GFRP) laminates.;The first group of specimens is used to develop and optimize a strengthening technique using the integration of steel plates and steel bolts. The effectiveness of four different configurations of steel plates and steel bolts are evaluated. The steel plates are assumed to act as horizontal flexural reinforcement representing an equivalent concrete drop panel. Moreover, the steel bolts are designed to act as vertical shear reinforcement, to transfer the horizontal forces between steel plates and concrete slab, and to confine the concrete between the steel plates. An average increase in the load capacity of 50% is achieved over that of the unstrengthened specimens.;The second group of specimens is intended to evaluate the performance of recommended steel strengthening technique for specimens subjected to static or cyclic moments. The ultimate load capacity is increased by an average of 122% for specimens subjected to static moment compared to the unstrengthened specimens. For the specimens subjected to cyclic moment, the lateral drift is increased by 76% compared to the unstrengthened specimens.;The third group includes specimens strengthened using CFRP strips and GFRP laminates for flexural-strengthening. In addition, This group includes specimens strengthened with CFRP strips and steel bolts for punching-shear strengthening. Utilizing CFRP strips and GFRP laminates contribute to an average increase of the flexural capacity of two-way slabs by an average of 36% compared to that of the unstrengthened specimens. However, a small average increase within 9% is achieved for the CFRP punching shear-strengthening. (Abstract shortened by UMI.)...