Strut-and-tie model and its applications in reinforced concrete deep beams: A comprehensive review

Strut-and-tie model (STM), with its truss analogy, is yet a powerful tool for analyzing and designing complex prestressed and reinforced concrete structures. Which represents a simplistic method that predominantly provides conservative strength predictions. This article aims to provide a comprehensive review on the STM and its applications in reinforced concrete (RC) deep beams that are available in the open literature. Accordingly, a review of the STM technique is presented with a particular focus on the basic concept of STM, associated B- and D-regions, fundamentals of STM, historical development of STM, and its applications in RC deep beams. The review also covers a wide range of STM aspects including: strut strength and its effectiveness factor, node strength and its effectiveness factor, tie strength and minimum reinforcement, the effect of tie anchorage, and strain energy minimization. Hence, essential formulas and parameters of STM proposed by various design codes and researchers are reviewed and then summarized in comprehensive tables. Consequently, from the reviewed literature, several challenges are highlighted. Findings and recommendations that are necessary to be considered in future works are addressed. With the provided information, this review article serves as a useful reference for structural engineers and researchers who are familiar with STM, as well as who wish to enter this research field.