MiniBarsTM is a kind of high-performance composite macrofibre made of BFRP. It is designed to improve the flexural tensile strength and post-cracking (residual) strength of the concrete. Moreover, it has a reputation for corrosion-free and zero conductivity. This thesis focused on the influence of the MiniBarsTM fiber volume fraction on the behavior of the concrete under compressive and tensile stress. A compression test and 3-point bending test were conducted on the specimens containing 0%, 0.5%, and 1% of fiber by volume.
MiniBarsTM fiber volume fraction had a minor effect on the compressive strength of the concrete. In comparison with the plain concrete, the compressive strength decreased by 0.1% and 5.6% respectively for MiniBarsTM dosage of 0.5% and 1% after curing for 28 days. However, the MiniBarsTM fiber did improve the failure of the concrete. Fewer spalling and narrower cracks occurred in the cubes reinforced by MiniBarsTM fiber. No remarkable change was observed in the flexural tensile strength of the concrete due to the fiber addition. But the test results showed that the addition of MiniBarsTM fiber significantly improved the behavior of the concrete after flexural cracking. The specimens revealed a ductile response to the tensile stress. The residual tensile strength of the MiniBarsTM reinforced concrete in ULS and SLS went up by 110% and 150% respectively after when the added fiber volume fraction increased from 0.5% to 1.0%. It was mainly due to the bridging action and the pulling-out resistance of the MiniBarsTM.