Shear Strength Prediction Model of FRP Bar-Reinforced Concrete Beams without Stirrups

Abstract

The shear strength prediction model for fiber-reinforced polymer (FRP) bar-reinforced concrete beams without stirrups in ACI440.1R-2015 does not consider the “size effect” and the effect of shear span-to-depth ratio and predicts the zero-shear strength for concrete members without longitudinal reinforcement. A modified shear strength prediction model for FRP bar-reinforced concrete beams without stirrups was presented in this paper. The proposed model takes into account the effect of concrete strength, size of the beam, shear span-to-depth ratio, reinforcement ratio, and modulus of elasticity of the longitudinal reinforcement and the “size effect.” The superiority of the proposed model has been evaluated by comparing the calculated shear strength of FRP bar-reinforced concrete beams without stirrups by the proposed model with the experimental results and calculated values by the models in design codes, respectively. It confirmed that the shear strength of FRP bar-reinforced concrete beams without stirrups by the proposed model was in better agreement with the experimental results.

Prediction about Effect of Span-to-Depth Ratio on Shear Capacity for FRP Bar Reinforced Concrete Beams without Web Reinforcement

“…e current researches [8,9] have confirmed that the shear capacity of FRP bar reinforced concrete beams without web reinforcement, as shown in Figure 1, is influenced by several factors, such as concrete compressive strength (f c ′ ), shear span-to-depth ratio (a/d), elastic modulus of FRP bars (E f ), reinforcement ratio of longitudinal FRP bars (ρ f ), width of the beam (b) and effective depth of the beam (d). However, the influence of span-to-depth ratio (L/d) on the shear capacity of FRP bar reinforced concrete beams without web reinforcement is rarely involved, which represents the ratio of two sizes of the specimen, including effective span (L) and effective depth of the beam (d), respectively.…”

“…In recent years, Uday Naik has proved that the change of L/d has an effect on the shear capacity of steel bar reinforced concrete beams by the artificial neural network technology [17], which has been widely used in civil engineering because of its excellent performance in the development of accurate and reliable prediction models for the shear capacity of reinforced concrete beams without web reinforcement [18][19][20][21][22][23]. e previous experimental study indicated that although FRP bars and steel bars have the great differences in elastic modulus and some mechanical properties, FRP bar reinforced concrete beams and steel bar reinforced concrete beams are still similar in shear-carrying mechanism [1,9,24]. us, the L/d also plays a certain role in the structural analysis of shear capacity of FRP bar reinforced concrete beams.…”

“…e calculation models of the shear capacity of FRP bar reinforced concrete beams without web reinforcement in codes, such as CSA/CAN-S806-12, ACI440.1R-15, CNR-DT203-2006, GB50608-2020, and a modified model by Gao and Zhang are summarized in Table 1 [9,[25][26][27][28]. e factors that have been considered are listed in Table 2.…”

Experimental Study on Mechanical Properties of Novel FRP Bars with Hoop Winding Layer

“…ereafter, studies on FRP-reinforced concrete structures were carried out in Japan, Canada, China, and many other countries [9][10][11]. Up to present, the related studies of FRP-reinforced concrete structures mainly includes the mechanical properties and durability of FRP bars [12][13][14][15], the bonding properties between FRP bars and concrete [16][17][18], the failure mode and design theory of FRP reinforced concrete beams [19][20][21][22], columns [23][24][25][26][27], joints [28][29][30][31], and fire resistance [32,33].…”

A Model for Shear Strength of FRP Bar Reinforced Concrete Beams without Stirrups

“…). e shear strength calculation models provided by ACI 440.1R-15, JSCE-97, GB50608, and BISE-99 were reported to be conservative for the FRP bar reinforced concrete slender beams without stirrups, whilst the CAN/CSA S806-12 model did not well consider the effects of ρ f nor E f [10], and thus led to excessive reinforcement and also increasing the overall cost of construction [11].…”