Determination of strut efficiency factor for concrete deep beams with and without fibre

• Published in: Advances in computational design Vol. 1; no. 3; pp. 253 - 264
• Main Authors: Sandeep, M.S, Nagarajan, Praveen, Shashikala, A.P, Habeeb, Shehin A
• Format: Journal Article
• Language: Korean
• Published: 2016
• Subjects: fibre reinforced concrete; SFRC; ANSYS; strut; STM; nonlinear analysis of concrete; strut-and-tie; efficiency factor; nonlinear finite element analysis of reinforced concrete
• ISSN: 2383-8477; 2466-0523

Based on the variation of strain along the cross section, any region in a structural member can be classified into two regions namely, Bernoulli's region (B-region) and Disturbed region (D-region). Since the variation of strain along the cross section for a B-region is linear, well-developed theories are available for their analysis and design. On the other hand, the design of D-region is carried out based on thumb rules and past experience due to the presence of nonlinear strain distribution. Strut-and-Tie method is a novel approach that can be used for the analysis and design of both B-region as well as D-region with equal importance. The strut efficiency factor (${\beta}_s$) is needed for the design and analysis of concrete members using Strut and Tie method. In this paper, equations for finding ${\beta}_s$ for bottle shaped struts in concrete deep beams (a D-region) with and without steel fibres are developed. The effects of transverse reinforcement on ${\beta}_s$ are also considered. Numerical studies using commercially available finite element software along with limited amount of experimental studies were used to find ${\beta}_s$.