Title:
Shear Capacity of Composite Precast Prestressed Hollow-Core Slabs (Prepublished)
Author(s):
Deuckhang Lee, Min-Kook Park, Yuguang Yang, and Kang Su Kim
Publication:
Structural Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
composite action, continuous member, core-filling, flexure-shear, hollow-core slab, negative moment, shear strength, topping concrete, web-shear
DOI:
10.14359/51748928
Date:
6/18/2025
Abstract:
No practically viable method exists yet to provide minimum shear reinforcements into pretensioned precast hollow-core slab (PHCS) units produced through the automated extrusion method. Subsequently, web-shear strength of PHCS units with untopped depth greater than 315 mm (12.5 in) should be reduced by half according to the current ACI 318 shear design provision. Meanwhile, continuous precast floor construction has been commonly adopted in current practices by utilizing cast-in-place (CIP) topping and/or core-filling concrete. However, shear test results on continuous composite PHCS members subjected to combined shear and negative bending moment are very limited in the literature. To this end, this study conducts shear tests of thick composite PHCS members with untopped depths greater than 315 mm (12.5 in) and various span-depth ratios, subjected to negative bending moments, where noncomposite and composite PHCS units subjected to shear combined with positive bending were also tested for comparison purposes. Test results showed that the flexure-shear strength can dominate the failure mode of continuous PHCS members rather than the web-shear failure, depending on the presence of CIP topping concrete and shear span-depth ratio. In addition, it was also confirmed that the shear strength of composite PHCS members is marginally improved by using the core-filling method under negative bending moment at continuous support, and thus its shear contribution seems not fully code-compliant and satisfactory to that estimated by using ACI 318 shear design equations.