Validation of CSCT Strain-based Shear Failure Criteria for Prestressed Concrete Members without Shear Reinforcement

Abstract

The shear provision for members without shear reinforcement in the second generation of Eurocode has been changed to a new set of formulas based on the critical shear crack theory (CSCT). The formula is based on a shear failure criterion originally developed for reinforced concrete members without shear reinforcement. To allow its application as a design code type for formula, the original CSCT failure criterion undergoes several modifications, such that it can be used to verify the shear resistance of prestressed members as well. Since the new Eurocode shear provision will be applied to design and assess prestressed concrete members in Europe and many other countries in the world, it is important to extensively validate this model. This paper presents a validation study of three different variations of the CSCT strain-based failure criteria, including the one eventually employed in the second generation Eurocode shear provision, using the ACI-DAfStb shear database. The results are also compared with the current Eurocode shear provisions. The second generation Eurocode shear formula appears to be able to determine the shear resistance more accurately than the current one, even for prestressed concrete members without shear reinforcement while it was not actually developed for this. However, Annex I.8 shear formula may lead to an overestimation of the shear resistance for higher values of the effective span to depth ratio (acs/d).