Title: Deflection of Two-Way Slabs Subjected to Restrained Volume Change and Transverse Loads

Author(s): K. S. Stephen Tam and Andrew Scanlon

Publication: Journal Proceedings

Volume: 83

Issue: 5

Appears on pages(s): 737-744

Keywords: concrete slabs; cracking (fracturing); creep properties; deflection;reinforced concrete; shrinkage; two-way slabs.

DOI: 10.14359/10665

Date: 9/1/1986

Abstract:
Effects of shrinkage-induced cracking are included in an analytical model for computing immediate deflections of two-way slabs. A simple model for estimating reduction of stiffness in the vicinity of a shrinkage-induced crack is combined with Branson’s effective moment of inertia procedure for slabs subjected to transverse loads to account for the net effect of both restraint cracking and flexural cracking. Results for an example slab illustrate the sensitivity of slab deflections to shrinkage cracking. Calculated deflections are compared with field-measured deflections for a 28-story office building. Recommendations are made to account for shrinkage restraint in slab deflection calculations.