Title: Investigation of Dispersion of Compression in Bottle-Shaped Struts

Author(s): Dipak Kumar Sahoo, Bhupinder Singh, and Pradeep Bhargava

Publication: Structural Journal

Volume: 106

Issue: 2

Appears on pages(s): 178-186

Keywords: bottle-shaped strut; compression; strut-and-tie model; transverse tension.

DOI: 10.14359/56356

Date: 3/1/2009

Abstract:
Struts are used in strut-and-tie models to represent the flow of compression within a concrete member. A bottle-shaped strut can form when load is applied to a relatively small area, and the resulting stresses disperse as they flow through the strut. The directional changes of the dispersing stresses give rise to transverse tensile forces that have an important influence on the behavior of bottle-shaped struts. In this investigation, the dispersion of compression in a bottle-shaped strut has been examined from first principles and compared with experimental results, and the ACI 318-05 recommendations for modeling of the dispersion of compression in a bottle-shaped strut have been critically reviewed. The results indicate that the dispersion of compression is significantly influenced by the bearing area of the applied load. The proposed expression for the dispersion of compression enables the structural designer to estimate the magnitude of the transverse tensile force for different loading conditions, which in turn is essential for design and detailing of transverse reinforcement in bottle-shaped struts.