Minimum shear reinforcement ratio of steel plate concrete beams

Steel plate Concrete (SC) has been used for the shield building in nuclear power plant AP1000 recently. However, the minimum shear reinforcement ratio for SC beams is unknown. This paper reports that six steel plate concrete beams were tested to determine the minimum shear reinforcement ratio (ρ_t,min) to ensure a certain shear ductility. The main parameters of the experimental program include shear reinforcement ratio (ρ_t,test) and shear span-to-depth ratio (a/d). Currently no minimum shear reinforcement ratio of SC beams is proposed in any technical document. Designers quite often use the provision of reinforced concrete (RC) structures specified by ACI 349 code (2006) for SC structure design. Based on the test results, a minimum shear reinforcement ratio of SC beams is proposed, which is greater than a minimum shear reinforcement ratio specified by ACI 349 code. Existing approaches to predict shear strength of RC members, ACI method (2006) and Kuo et al. method (2014), were evaluated and were found to overestimate the shear strength of SC beams because bond slip between steel plate and concrete weakens the shear capacity. In addition, the Model Code (2010) was compared with the test results and was found very conservative. A method is recommended to estimate shear strength of SC beams with a reasonable accuracy.