Title: Testing and Analysis of Two Deep Beams Designed Using Strut-and-Tie Method

Author(s): G. A. Martinez, K. S. Beiter, A. R. Ghiami Azad, G. E. Polo, R. L. Shinn, T. D. Hrynyk, and O. Bayrak

Publication: Structural Journal

Volume: 114

Issue: 6

Appears on pages(s): 1531-1542

Keywords: deep beam; finite element analysis of reinforced concrete; strut-and-tie

DOI: 10.14359/51689504

Date: 11/1/2017

Abstract:
The seventh edition of the AASHTO LRFD Bridge Design Specifications (2016 interim) includes revised provisions for the design of deep beams using the strut-and-tie method. The validity and accuracy of these provisions as applied to simply supported deep beams loaded in a manner that generates an inflection point between the supports was investigated in this research. As part of a course-related laboratory investigation, graduate students at the University of Texas at Austin used these provisions to design two reduced-scale deep beams. The specimens were subsequently constructed and tested. The experimental behaviors of the specimens including governing failure modes, load-displacement curves, and their ultimate capacities were investigated and compared with estimates developed from the strutand-tie method. The results obtained validated the suitability of the revised provisions for the design of deep beams with inflection points located between supports. Additionally, the students developed pre-test estimates for the behaviors and strengths of the two deep beam specimens using the finite element software program VecTor2. While there was some variation among the computed responses, the blind predictions accurately captured governing failure modes and provided reasonable capacity estimates.