scholarly journals Fire Resistance Investigation of Simple Supported RC Beams with Varying Reinforcement Configurations

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yamin Song ◽  
Chuanguo Fu ◽  
Shuting Liang ◽  
Ankang Yin ◽  
Longji Dang
Keyword(s):  
High Temperature ◽  
Fire Resistance ◽  
Room Temperature ◽  
Shear Failure ◽  
Failure Time ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Longitudinal Reinforcement ◽  
Rc Beams ◽  
Vertical Deflection

To investigate fire-resistance behaviors of simple supported reinforced concrete (RC) beams with three faces exposed to fire, six full-scale specimens were designed in accordance with the principle of “strong bending and weak shearing.” One beam was treated as the control case of room temperature while the other five beams were exposed to high temperature. Parameters related to shear capacity were discussed, such as longitudinal reinforcement ratio and stirrup ratio. The experimental results show that brittle shear failure under room temperature may transfer to shear-bend failure at high temperature due to thermal expansion and strength degradation of concrete and steel. The greater the longitudinal reinforcement ratio, the longer the failure time of specimens. It indicates that the pinning action of longitudinal reinforcement can significantly improve the shear capacity of beams under high temperature. In addition, the configuration of stirrup reinforcement can effectively reduce the brittle change of vertical deflection when the beam enters the failure stage.

Parametric Analysis of Shear Behavior of Concrete Beams Reinforced with Continuous FRP Rectangular Spirals

2012 ◽  
Vol 217-219 ◽  
pp. 2435-2439
Author(s):  
Ying Tao Li ◽  
Shi Yong Jiang ◽  
Bing Hong Li ◽  
Qian Hua Shi ◽  
Xian Qi Hu
Keyword(s):  
Parametric Analysis ◽  
Failure Modes ◽  
Shear Failure ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Experimental Program ◽  
Longitudinal Reinforcement ◽  
Shear Span ◽  
Depth Ratio

An experimental program was carried out by the author to investigate the shear behavior of concrete beams reinforced with continuous FRP rectangular spirals, the main variables considered in the test were the shear reinforcement ratio and the shear span to depth ratio and the longitudinal reinforcement ratio. However, the experimental program is inadequate to gain insight into the shear behavior of the members. First, the quantities of test specimens were too small, only six beams were made and tested, the experimental database was so limited that the resultant analytical results and conclusions may not be sound enough. Second, not all the main factors that have influences on the shear behavior of the members have been treated as variables in the experimental program, such as the effective transverse compression stress and the concrete compression strength, the influences of these two factor on the shear behavior of the members were not clear yet through the experimental study. Considering the insufficient information provided by the experimental investigation, the parametric analysis of the shear behavior of the members was carried out, and a revised rotating-angle softened truss model for the shear analysis of the members was proposed as the analytical tool. Based on the proposed model, the influences of various factors on the shear capacity and shear failure modes of the members were discussed, related nonlinear analysis was carried out using the arithmetic of iteration and step approximation, and several FORTRAN codes were written accordingly. Through the experimental study and the parametric analysis, it is indicated that the shear capacity and the shear failure modes of the members are greatly influenced by three major factors, including the shear reinforcement ratio and the shear span to depth ratio and the effective transverse compression stress. The influences of the concrete compression strength and the longitudinal reinforcement ratio on the shear capacity are not noticeable comparatively. The shear capacity is little affected by the shear span to depth ratio in the case of the shear-tension failure, there is no noticeable correlation between longitudinal reinforcement ratio and the shear failure modes.

scholarly journals Experimental Study on Shear Capacity of High Strength Reinforcement Concrete Deep Beams with Small Shear Span–Depth Ratio

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1218 ◽  
Author(s):  
Jun-Hong Zhang ◽  
Shu-Shan Li ◽  
Wei Xie ◽  
Yang-Dong Guo
Keyword(s):  
High Strength ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Longitudinal Reinforcement ◽  
Deep Beams ◽  
Shear Span ◽  
Depth Ratio ◽  
Diagonal Compression ◽  
Web Reinforcement ◽  
Small Shear

This study aimed to investigate the shear capacity performance for eight deep beams with HTRB600 reinforced high strength concrete under concentrated load to enable a better understanding of the effects of shear span–depth ratio, longitudinal reinforcement ratio, vertical stirrup ratio and in order to improve design procedures. The dimension of eight test specimens is 1600 mm × 200 mm × 600 mm. The effective span to height ratio l0/h is 2.0, the shear span–depth ratio λ is 0.3, 0.6 and 0.9, respectively. In addition, the longitudinal reinforcement ratio ρs is set to 0.67%, 1.05%, 1.27%, and the vertical stirrup ratio is taken to be 0%, 0.25%, 0.33%, 0.5%. Through measuring the strain of steel bar, the strain of concrete and the deflection of mid-span, the characteristics of the full process of shear capacity, the failure mode and the load deflection deformation curve were examined. The test results showed that the failure mode of deep beams with small shear span–depth ratio is diagonal compression failure, which is influenced by the layout and quantity of web reinforcement. The diagonal compression failure could be classified into two forms: crushing-strut and diagonal splitting. With decreasing of shear span–depth ratio and increasing longitudinal reinforcement ratio, the shear capacity of deep beams increases obviously, while the influence of vertical web reinforcement ratio on shear capacity is negligible. Finally, the shear capacity of eight deep beams based on GB 50010-2010 is calculated and compared with the calculation results of ACI 318-14, EN 1992-1-1:2004 and CSA A23.3-04, which are based on strut-and-tie model. The obtained results in this paper show a very good agreement with GB50010-2010 and ACI 318-14, while the results of EN 1992-1-1:2004 and CSA A23.3-04 are approved to be conservative.

scholarly journals Shear capacity of reinforced concrete beams strengthened with web side bonded CFRP sheets

2019 ◽  
Vol 258 ◽  
pp. 04010
Author(s):  
Rendy Thamrin ◽  
Zaidir ◽  
Sabril Haris
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Cover ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Longitudinal Reinforcement ◽  
Flexural Mode ◽  
Cfrp Sheets ◽  
Reinforced Polymer

The shear capacity of reinforced concrete beams strengthened with web side bonded carbon fiber-reinforced polymer (CFRP) sheets was measured experimentally. Nine reinforced concrete beams without stirrups; three control beams and six beams strengthened with minimal application of web side bonded CFRP sheets, were tested. The test variables were ratio of longitudinal reinforcement (1%, 1.4%, and 2.4%) and angle of application of CFRP sheets (450 and 900). The test results show that reinforced concrete beams strengthened with web side bonded CFRP sheets have higher shear capacity compared to the control beams. Shear capacity of strengthened beams with 450 angle of application of CFRP sheets is similar to that of beams strengthened with 900 angles. Beams with 1% of longitudinal reinforcement ratio failed in flexural mode indicated by concrete crushing in compression zone while beams with higher longitudinal reinforcement ratio (1.4% and 2.4%) failed in brittle mode as indicated by delamination of the concrete cover.

Influence of Longitudinal Reinforcement Ratio on Shear Strength of RC Slender Beam Under Different Loading Rates

2020 ◽  
Vol 897 ◽  
pp. 91-97
Author(s):  
Halwan Alfisa Saifullah ◽  
Kenichiro Nakarai ◽  
Nobuhiro Chijiwa ◽  
Koichi Maekawa ◽  
Stefanus Kristiawan
Keyword(s):  
Shear Strength ◽  
Loading Rate ◽  
Concrete Structures ◽  
Shear Resistance ◽  
Reinforcement Ratio ◽  
Sustained Load ◽  
Longitudinal Reinforcement ◽  
Rc Beams ◽  
Shear Cracks ◽  
Loading Rates

. A primary current focus in concrete shear design is how to ensure the shear resistance of the concrete structures to withstand the possible adverse creep effects during the service life. All shear-carrying actions are supposed to depreciate due to the enhanced critical shear cracks under sustained loads. However, only a few studies that evaluated the performance of concrete structures failing in shear due to long-term loading. As the longitudinal tensile reinforcement strain influences the shear strength of RC beam, the shear resistance of the beam under sustained load may also be affected by the amount of longitudinal reinforcement. The present study aims at investigating the influence of flexural reinforcement ratio on the shear creep failures of reinforced concrete (RC) beams without stirrups by non-linear finite element analysis. In this study, the numerical model of RC beams with reinforcement ratios varying from 0.4% to 3.2% was evaluated under different loading rates. A loading rate of 1000 and 10000 times slower than the static loading rate were adopted to reveal the creep effects of RC beams.

scholarly journals Experimental Study on Shear Behavior of Reactive Powder Concrete Beam

2022 ◽  
Vol 2148 (1) ◽  
pp. 012032
Author(s):  
Yuexia Li ◽  
Huijun Yang ◽  
Chao Liu
Keyword(s):  
Failure Mode ◽  
High Strength ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Reactive Powder Concrete ◽  
Deformation Capacity ◽  
Longitudinal Reinforcement ◽  
Shear Span ◽  
Reactive Powder

Abstract In order to study the shear behavior of high-strength reinforced Reactive Powder Concrete (RPC) beams, eight test beams were designed and fabricated for the shear test under symmetrical concentrated load. By observing the development and failure mode of diagonal cracks, the influence of shear span ratio, stirrup ratio, and longitudinal reinforcement ratio on the cracking load, shear capacity, and deflection of the test beam is analyzed. The results show that: in a specific range, the shear capacity increases with the increase of stirrup ratio and longitudinal reinforcement ratio and decreases with the increase of shear span ratio. The shear span ratio has the most significant influence on the component’s failure mode and deformation capacity. The increase of the stirrup ratio can improve the deformation capacity of the component in a specific range. It is conservative to use the code to design concrete structures to calculate the shear capacity of high-strength reinforced reactive powder concrete beams. It is suggested that the shear calculation formula suitable for high-strength reinforced reactive powder concrete should be adopted to make the theoretical calculation results closer to the measured values.

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