Title:
Modified Shear Design Model for Steel- and Fiber- Reinforced Polymer-Reinforced Concrete Beams
Author(s):
A. N. Tarawneh, E. F. Saleh, A. M Alghossoon, G. S. Almasabha, O. S. Alajarmeh, A. Manalo, and B. Benmokrane
Publication:
Structural Journal
Volume:
121
Issue:
1
Appears on pages(s):
147-158
Keywords:
ACI 440; axial stiffness; code evaluation; fiber-reinforced polymer (FRP)-reinforced concrete (RC) beams; fiber-reinforced polymer (FRP) reinforcement; reliability analysis; shear strength; steel-reinforced concrete beams; steel reinforcement
DOI:
10.14359/51739191
Date:
1/1/2024
Abstract:
This study proposes a unified shear design provision for slender
steel- and fiber-reinforced polymer (FRP)-reinforced concrete (RC)
members. The proposed model is a modification of the ACI 318-19
model to include the axial stiffness of the longitudinal reinforcement
by introducing a new modification term, nc, representing the elastic
modular ratio of the longitudinal reinforcement to the concrete.
The new relation is Vc = (0.4 [nc ρfl]1/3 λ s√fcꞌ + Nu/[6Ag])bwd.
The unified shear model was assessed with five experimental data
sets: FRP-RC beams without shear reinforcement (288 beams),
steel-RC beams without shear reinforcement (759 beams), FRP-RC
beams with shear reinforcement (56 beams), steel-RC beams with
shear reinforcement (157 beams), and steel-RC beams with axial
force (prestressed) but without shear reinforcement (209 beams).
The unified shear model provided better performance than the ACI
318-19 and ACI CODE-440.11-22 provisions in terms of mean,
coefficient of variation, standard deviation (SD), and absolute
average error (AAE). The unified model also showed improved
performance over a wider range of material properties. In addition,
reliability analysis using Monte Carlo simulation indicated
that the unified shear model provides a consistent satisfactory
safety level with a reliability index between 3.5 and 4.0 for both
steel- and FRP-RC members. The reliability index provided by the
unified model is similar to the reliability index provided by the ACI
318-19 shear provision. In contrast, the ACI CODE-440.11-22
results in highly conservative estimates with a reliability index
between 4.5 and 5.0.