Design and Testing of LWSCC Bridge-Deck Slabs Reinforced with GFRP Bars
Mahdi Aflakisamani, Salaheldin Mousa, Hamdy M. Mohamed, Ehab A. Ahmed, Brahim Benmokrane
Appears on pages(s):
bridge deck slab; cracking patterns and strains; design codes; GFRP reinforcing bars, lightweight self-consolidating concrete; load-deflection; punching shear; ultimate capacity; wheel-load
Advances in new lightweight self-consolidating concrete (LWSCC) mix designs have led to the construction of new concrete structures with much lower weights and higher strengths. The integration of glass fiber-reinforced polymer (GFRP) bars with LWSCC can be used effectively to build durable bridges with smaller cross sections and extended service lives. This study aimed at evaluating the effectiveness of this type of concrete for building concrete bridge-deck slabs with GFRP reinforcement. Five full-scale edge-restrained concrete bridge-deck slabs were fabricated, simulating a slab-on-girder bridge deck commonly used in North America. The bridge-deck slabs were 3000 mm (118.1 in.) in length, 2500 mm (98.4 in.) in width, and 200 mm (7.9 in.) in thickness. The test parameters included reinforcement type (Sand coated GFRP or helically wrapped GFRP and steel) and reinforcement ratio (ranging from 0.44% to 1.15%). The bridge-deck slabs were designed according to the Canadian Highway Bridge Design Code. The specimens were exposed to a concentrated load over a contact area of 250 × 600 mm (9.8 × 23.6 in.), which simulates the footprint of a sustained truck wheel load (87.5 kN CL-625 truck), as specified in Canadian standards. The test results indicate that the failure mode of all deck slabs was punching shear. The recorded ultimate load capacities for all specimens exceeded the design factored load, which validates the use of GFRP-reinforced LWSCC for the construction of bridge-deck slabs. It was also concluded that the surface conditions of the GFRP bars (sand coated or helically wrapped) had a minor effect on the cracking, deflection, and behavior of the tested LWSCC deck slabs. In addition, increasing the axial-reinforcement stiffness in the GFRP-reinforced slabs signiﬁcantly increased the ultimate capacity and reduced maximum crack width, reinforcement strains, and mid-span deﬂection at ultimate load.