Title:
Extended Strut-and-Tie Model for Punching-Shear Strength of Fiber-Reinforced Polymer-Reinforced Concrete Edge- Slab Column Connections
Author(s):
Ahmed E. Salama, Brahim Benmokrane, and Adel El-Safty
Publication:
Structural Journal
Volume:
119
Issue:
1
Appears on pages(s):
155-167
Keywords:
bottle-shaped strut; design codes; edge-slab column connections; extended strut-and-tie model; glass fiber-reinforced polymer bars; size effect
DOI:
10.14359/51733137
Date:
1/1/2022
Abstract:
Fiber-reinforced polymer (FRP) bars have emerged as a pioneering solution to eliminate the corrosion problems associated with conventional steel bars in aggressive environments. Glass fiber-reinforced polymer (GFRP) bars are now extensively used as internal reinforcing because they are more cost-effective than other types of FRP bars. This paper presents a new design model—namely, the extended strut-and-tie model (STM)—to predict the punching-shear strength of edge slab-column (ESC) connections entirely reinforced with FRP bars. The proposed model was developed based on the failure criteria of the strut-and-tie method for symmetric punching in conjunction with an interactive approach to describe asymmetric punching-shear behavior due to moment transfer in FRP-reinforced concrete ESC connections. The extended STM is appropriate for normal-strength concrete (NSC) and high-strength concrete (HSC) ESC connections reinforced with FRP bars. The connections tested by the authors and others found in the literature were used to evaluate the proposed model. The extended STM yielded safe predictions compared with the experimental ones, giving average experimental-to-predicted punching-shear strengths of 1.19 ± 0.13 and coefficient of variation of 10.86%. Furthermore, the proposed model achieved higher accuracy and narrower scatter for punching-shear strength predictions than the equations in ACI 440.1R-15, CSA S806-17, and JSCE-97.
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