| Title |
A Characteristic Study on Shear Strength of High Strength Reinforced Concrete Beams according to Shear Reinforcement Ratio and Beam Section Size |
| Authors |
박나정(Park, Na-Jeong) ; 노형진(Noh, Hyung-Jin) ; 유인근(Yu, In-Geun) ; 백승민(Baek, Seung-Min) ; 김우석(Kim, Woo-Suk) ; 곽윤근(Kwak, Yoon-Keun) |
| DOI |
https://doi.org/10.5659/JAIK.2020.36.8.181 |
| Keywords |
Shear Reinforcement Ratio; Size Effect; Shear Strength |
| Abstract |
The purpose of this study is to investigate the shear strength of high strength reinforced concrete beams according to shear reinforcement
ratio and beam section size. A total of twelve specimens were tested and designed concrete compressive strength is 50 MPa. The main
variables are shear reinforcement ratio and beam section size fixed with shear span to depth ratio (a/d = 2.5), the tensile reinforcement ratio
(ρ = 0.013) and width to depth ratio (h/b = 1.5). The test specimens were divided into three series of H1 (225×338 mm), H2 (270×405
mm) and H3 (315×473mm) respectively. The experimental results show that specimens represent various failure modes such as diagonal
tensile failure (DTF), bond failure (BF), shear compression failure (SCF) and flexural compression failure (FCF). In the H1 series, the shear
strength increased by 92.0%, 94.1% and 128.4% respectively as the shear reinforcement ratio increased, 103.8%, 138% and 143% respectively
in the H2 series, 131.1%, 168.7% and 151.7% respectively in the H3 series. The decreasing rate of shear strength increased as the beam’s
effective width increased, which is considered to be due to the size effect. Then, it is shown that the decreasing rate of shear strength
increases as d/s increases, and it can be seen that the effect of the size effect increases as the spacing between shear reinforcing bars
decreases. As compared to the standard and the proposed equations, theoretical values by proposed equation of Zsutty, Bazant, and Lee has
compared relatively well with experimental values. |