Title: Influence of Construction Loading on Long-Term Slab Deflections

Author(s): Robert L. Vollum

Publication: Symposium Paper

Volume: 284

Issue:

Appears on pages(s): 1-22

Keywords: reinforced concrete slabs, deflections, construction loading

DOI: 10.14359/51683814

Date: 3/1/2012

Abstract:
The thickness of reinforced concrete slabs is usually governed by the need to limit deflections in service to avoid damage to finishes and partition walls. Deflection control has become more important over recent years due to requirements for longer spans and more economic use of materials as well as design method developments. It is well established that long-term slab deflections can be increased by early age construction loading and cracking induced by restrained shrinkage. The author has previously shown that long-term slab deflections in the European Concrete Building at Cardington were governed by construction loading. This paper examines the influence of short term peaks in loading on long term curvatures in slabs subject to sustained loading. A simplified method is proposed for taking account of the effects of construction loading in deflection calculations with Eurocode 2. The method is validated using laboratory data from tests on simply supported slabs carried out at Imperial College London.