Web-shear capacity of prestressed composite inverted multi-tee slabs

Prestressed inverted multi-tee (IMT) slabs have been widely used in recent precast construction as a fast-built composite flooring system. However, there is a critical issue about its vulnerability in shear. To this end, a total of six IMT slabs were tested in this study, where the magnitude of prestress, and presences of shear reinforcement and cast-in-place (CIP) topping concrete were considered as key experimental variables. An analytical method capable of estimating the shear strengths of IMT slabs with topping concrete as a composite prestressed member was suggested by using the transformed section approach combined with the dual potential capacity concept. The proposed model can identify the shear strength and failure mode, and a simplified model was also developed and verified for its better applicability to be easily used in practice.