Title:
Flat Slab Thickness Required to Satisfy Serviceability
Including Early Age Construction Loads
Author(s):
K. Ofosu-Asamoah and N. J. Gardner
Publication:
Structural Journal
Volume:
94
Issue:
6
Appears on pages(s):
700-707
Keywords:
construction loads; design aids; flat slabs; long term deflec-tions;
serviceability.
DOI:
10.14359/9730
Date:
11/1/1997
Abstract:
The use of higher strength concretes and steel yield strengths allows designers to design thinner slab systems which satisfy all the requirements of strength. However; the use of thinner slabs leads to increased deflections and the possibility of violating deflection serviceability criteria. The shore-reshore method of construction applies significant construction loads to the immature supporting slabs. The span/thickness provisions of ACI 318-89 do not consider the sensitivity of slab deflections to early-age construction loads or rate of construction. A parametric study showed the current code requirements for minimum slab thickness to be over conservative in some cases and insufficiently conservative in others. A span-thickness criterion, which includes the effect of early-age construction loads, concrete strength, and panel aspect ratio, was developed from the results of the parametric s t u d y .