Performance of Concrete Beams Reinforced with Basalt FRP for Flexure and Shear

The flexural and shear performances are evaluated for concrete beams reinforced with basalt fiber-reinforced polymer (BFRP) rebar and stirrups. Nine 150× 300× 3, 100-mm beams were tested in four-point bending to examine the effect of BFRP flexural reinforcement ratios varying from 0.28 to 1.60 the balanced ratio on the structural performance. The beams were reinforced by either BFRP or steel stirrups, and some had no shear reinforcement. It was shown that ultimate and service loads increased with flexural reinforcement ratio for all shear reinforcement types while the service load levels were not affected by stirrup type. Beams without stirrups and those with BFRP stirrups failed in shear, with the former reaching 55–58% of ultimate flexural capacity and the latter failing by stirrup rupture at 90–96% of flexural capacity. Beams with steel stirrups failed in flexure. Deformability values show that methods that combine strength and curvature digress more from those based on midspan strain energy as shear-related deformation increases. Standard provisions predicted well the capacity of beams failing in flexure. For beams failing in shear, standards were both conservative and nonconservative. The modified compression field theory predicted well the shear capacity for members with and without stirrups. Designated methods gave reasonable predictions for service loads at deflections of span/360 and span/180.