Hollow-core slabs with cast-in-place concrete toppings: A study of interfacial shear strength

Abstract

In this paper, the authors report tests on two types of hollow-core units (dry mix and wet mix) to determine interfacial shear strength between the units and their cast-in-place concrete toppings. Twenty-four specimens were tested, with hollow-core units fabricated with different surface conditions to determine the influence of surface roughness of interface shear strength. Test results indicated that interfacial shear strength correlates with surface roughness, sandblasting to remove laitance (from wet-mix specimens), and grouting.