Experimental investigation of the shear behaviour of concrete beams with CFRP strip stirrups under static and fatigue loading

Abstract

Existing reinforced concrete (RC) structures often decrease in safety and service life owing to reinforcement corrosion or fatigue. Therefore, there are urgent requirements to propose new structures for engineering applications. This study investigates the static and fatigue shear behaviours of concrete beams using carbon fibre reinforced polymer (CFRP) strips instead of steel stirrups. The study mainly conducted the shear tests on nine statically loaded beams and six cyclically loaded beams with varied shear span ratios (a /d = 1.0, 2.5 and 3.5) and configurations of CFRP strip stirrups. The results reveal that concrete beams with CFRP strip stirrups have similar static shear behaviour to RC beams. Nevertheless, the CFRP strip stirrup beams exhibit superior fatigue life compared to that of RC beams, which significantly restrain the development of deflection, concrete cracks, and stirrup strain. Using CFRP strip stirrups instead of steel stirrups can effectively improve the shear resistance of the concrete beams under static and fatigue loading.