Experimental and numerical investigation of large-scale reinforced concrete deep beams designed with the Generative Tie Method

Abstract

This study presents a comprehensive evaluation of the behavior of two large-scale reinforced concrete deep beams designed using the Generative Tie Method (GTM). Different admissible values of the loss of compressive strength in the concrete (ηadm) were considered, and the results were compared to a deep beam designed with the help of the Strut-and-Tie Method (STM). The study highlights the importance of selecting an appropriate ηadm value for designing reinforced concrete deep beams capable of exhibiting ductile behavior using the GTM. The results show that specimen SIIIa, designed using the GTM with a ηadm of 0.5, demonstrated a highly optimized reinforcement layout with the most pronounced reinforcement yielding, indicating ductile behavior. Among the studied specimens, the one designed using GTM with an ηadm of 0.7 exhibited the lowest maximum crack width and the highest ultimate load despite demonstrating brittle failure. Both GTM-designed specimens demonstrated maximized material efficiency and higher ductility ratios than the deep beam designed using STM. By integrating the bond-slip model proposed in the fib Model Code 2010 into the finite element analysis framework, the numerical simulations produced highly accurate predictions of the behavior of the deep beams. The authors suggest further investigations to enhance the proposed numerical strategy and apply the GTM for designing reinforced concrete deep beams with organic or optimized shapes.