AWAM International Conference on Civil Engineering 2019 (AICCE'19) - Nibong Tebal - Malaysia (2019-08-21)

Proposed Procedures for Analysis and Design of RC Wide Corbels

What is meant by the wide corbel here is the corbel whose width (b) is more than two times its height (h). Wide Corbels are short cantilevers that stand out from inner face of wide columns or shear walls to support uniformly distributed loading that comes from wide beam. ACI 318-14 provisions allow the structural design of shear-controlled corbels through either shear friction (SF) method or the Strut-and-Tie modeling (STM). The current study presents analysis and design procedures using both SF and STM. Numerical examples for analyzing and designing one meter wide corbel are presented here in detail. It is concluded that the calculated load capacity using SF is 21% greater than that of STM. In other words, SF requires less reinforcement than STM by about 25%. That can be attributed to the difference in the safety factors that adopted by both approaches. More specifically, SF considers the main reinforcement as the reinforcement that resists moments, while STM considers it as the reinforcement that resists the direct tension of the formed tie. On the other hand, SF considers that the concrete and the horizontal stirrups resist shear, while STM considers that the shear is resisted by the formed inclined struts. The wide reinforced concrete corbel is designed here in the same way of the narrow one, but with some important differences. The main differences that were adopted in wide corbels are the applied load is a uniformly distributed load through the corbel width, repeating the frame reinforcement through the corbel width in order to hold the secondary reinforcement, and distributing the secondary reinforcement in a repetitive, overlapping and interchangeable way in order to ensure that the stirrups exist inside the entire corbel core.
Professor Khattab Abdul-Razzaq