BEHAVIOUR AND ANALYSIS OF BOTTLE-SHAPED STRUTS

Abstract

The strut-and-tie method (STM) is gaining recognisation as a code worthy and consistent methodology for the design of D-(Dis continuity)regions in structural concrete. In this we study about identification of B&D regions in a beam. Bernoulli’s Bending theory is valid for B-regions. Strut-and-Tie models and some codal recommendations for the design of Bottle-shaped struts is available. Unfortunately, the development of code provisions for the STM has been hampered by uncertainity in defining the strength and dimensions of the idealised load-resisting struss(or Strut-and-Tie model). In addition, it has been encumbered by an iterative and time-consuming design procedure in which many geometric details need to be considered. Influence of some major geometric characteristics such as diameter of bar, development length and number of bars on the strut efficiency factor and reinforcement of a Bottle-Shaped Strut has been discussed. As Diameter of bar, Dispersion angle increases strut efficiency factor also increases. Whereas strut angle of inclination (Ɵ), grade of concrete increases strut efficiency factor decreases.