Efficiency Factors for Reinforced Concrete Deep Beams: Part 1 - Improved Models

Abstract:

A strut-and-tie model (STM) has been used as a rational and simple method for analysis and design of reinforced concrete deep beams. The STM idealizes the discontinuity regions in such members as a truss-like structure consisting of compression struts and tension ties. The strength of a deep beam is usually controlled by the capacity of the diagonal concrete struts which is generally proposed in terms of the concrete strength and the efficiency factor. The efficiency factor accounts for the variation of the concrete material and the compression softening effect. One has been used in many STMs and often exhibit biases and uncertain errors in prediction of the shear strengths of deep beams. This uncertainty is due to the imperfection of formulation, missing parameters, and insufficient experimental data. Based on a database of 406 test results and six state-of-the-art formulations of the efficiency factors found in the international building codes and literature, this paper proposes improved STMs for accurate prediction of shear strength of simply supported reinforced concrete deep beams by correcting the bias and quantifying the scatter using a Bayesian parameter estimation method.

• Periodical: Advanced Materials Research (Volumes 931-932)
• Pages: 506-513
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.931-932.506
• Online since: May 2014
• Authors: Panatchai Chetchotisak*, Jaruek Teerawong, Danaipong Chetchotsak, Sukit Yindeesuk
• Keywords: Bayesian Parameter Estimation, Deep Beam, Efficiency Factor, Probabilistic Model, Strut-and-Tie Model

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