Strengthening reinforced concrete column-slab connection using CFRP sheets.

摘要

Due to the high cost of new construction and the increasing inventory of otherwise adequate structure, the need for repair, strengthening, or reinforced-concrete structures is growing significantly in Canada and worldwide. Fiber reinforced polymer technology has emerged during the past decade as a particular tool to upgrade existing structures. These materials are an excellent option for use as external reinforcing because of their light weight, resistance to corrosion, and high strength. This thesis introduces a strengthening technique of slab-column connection in flat-slab structures to enhance its flexural strength. Six flat-slab column connections were fabricated and then tested under increasing gravity loading up-to-complete collapse to investigate the effectiveness of using carbon fiber reinforced polymer (CFRP) sheets in enhancing their flexural capacity. Each specimen comprised 2000 x 1000 x 150 mm slab, with a 200 x 200 mm column stub extending below and above the slab. The tested specimens consisted of two groups. The first group provided control specimens, on which three specimens had central column, edge column, and eccentric column, respectively. The second group was similar to the first group but with CFRP sheets installed around the column on the tension side of the slab. Different structural quantities were used to examine the contribution of CFRP sheets slab. Different structural quantities were used to examine the contribution of CFRP sheets to the flexural strength of the tested specimens. These structural quantities included deflections, concrete and steel strains, ultimate load carrying capacities and crack patterns. Results from testing showed that the ultimate load carrying capacity increased by 32, 38 and 65% for the tested specimens with central, eccentric, and edge column, respectively, when strengthened using CFRP sheets.