GFRP Shear Studs for GFRP-RC Flat Slab-Column Connections

点击翻译按钮获取中文摘要

Pultrall is a leading Canadian manufacturer of composite materials for various applications including products related to transportation, medical, military and construction industry. One of these applications is the development of non-corrodible, fibre-reinforced polymer (FRP) reinforcing bars for concrete structures using the pultrusion process. These bars have proven to be an excellent alternative for steel reinforcement provided that steel corrosion is the main cause of deterioration of reinforced concrete (RC) structures especially those in harsh environments such as bridges and parking structures. A large number of parking structures in North America are constructed using flat plate structures in which flat slabs are directly supported on columns. In these structures, the transverse punching shear at the two-way slab-column connections usually governs the design. Besides, punching shear failure is usually brittle, sudden and catastrophic in nature and, therefore, it should be certainly avoided. Providing well-anchored transverse (shear) reinforcement results in significantly thinner slabs (much less cost) with significant deformation (ample warning) before failure. Pultrall is in the process of developing a new product, GFRP studs, to reinforce such connections in shear. The main issue is the small slab thickness (200-300 mm) in which the development of adequate bond or anchorage is a challenge. A short length (150-250 mm), double-headed GFRP bars are proposed to be used as shear studs. The current production method for headed bars requires a length of at least 60-70 mm per head for size 13 (12.7-mm diameter) bars; larger size bars require longer heads. To develop such a new product (bar diameter, corresponding head size and usable strain), it requires full-scale testing of RC slab-column connections using different GFRP shear stud patterns (size, extend and arrangement) in the vicinity of the column.