Rotational Stiffness of Concrete Slabs


  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal


Title: Rotational Stiffness of Concrete Slabs

Author(s): Mehrdad Mehrain and Bijan Aalami

Publication: Journal Proceedings

Volume: 71

Issue: 9

Appears on pages(s): 429-435

Keywords: bending moments; building codes; columns (supports); elastic analysis; finite difference theory; finite element method; fiat concrete plates;

Date: 9/1/1974

Using a finite element elastic plate analysis, lower and upper limits to the rotational stiffness of a flat slab at the column-slab junction are evaluated for a number of typical square slabs on a central column. The slabs represent unit panels of multiple-slab floors. The stiffnesses determined are presented in a graphical form and may be used in the equivalent-frame method in design of multiple square slabs. The results are comprehensive and effectively serve to clarify the picture of slab stiffness behavior. They also provide a useful basis for the accuracy assessment of the current approximate methods of stiffness evaluation. A comparison with the related recommendations of ACI 318-71 shows that the Code underestimates the slab stiffness for certain column-slab geometrics. The resulting lower bound solutions for slab stiffness and maximum moment coefficients closely agree with those previously available. A numerical example is given to illustrate the use of the data offered.