scholarly journals Experimental Investigation of the Shear Behavior of a Concrete Beam without Web Reinforcements Using External Vertical Prestressing Rebars

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Xingwei Xue ◽  
Xuan Wang ◽  
Xudong Hua ◽  
Meizhong Wu ◽  
Longqing Wu ◽  
...  
Keyword(s):  
Compressive Stress ◽  
Shear Failure ◽  
Concrete Beams ◽  
Shear Crack ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Shear Cracks ◽  
Web Reinforcement ◽  
Shear Performance

The shear performance of concrete beams is known to be an important mechanical feature; hence, enhanced shear resistance is critical for determining a beam’s performance in terms of security and service life. This paper presents a study on the shear behavior of concrete beams without web reinforcement strengthened by external vertical prestressing rebars (EVPRs). Experimental data were obtained from seven test beams with varying influencing factors (stirrup ratio ρsEP, arrangement spacing s, prestressing force Fp, and compressive stress degree γp of the EVPRs) to determine their effects on the shear behavior. The results reveal that the EVPRs can significantly improve the shear capacity and ductility of concrete beams without web reinforcement. Furthermore, the failure mode is changed from brittle diagonal tension to relatively ductile shear compression, and the flexural cracks and shear cracks are more fully developed. The shear capacity becomes enhanced as the ρsEP and γp are increased; vertical compressive stress provided by the EVPRs can reduce the principal tensile stress of the concrete structure to prevent the shear cracking and enhance the shear resistance of the concrete. Meanwhile, in the stage from the formation of the critical shear crack (CSC) to the shear failure, the EVPRs can be used as stirrups to share the shear load. It can be concluded that EVPRs can effectively improve the shear performance of concrete beams.

scholarly journals Analytical study on creep shear failures of RC slender beams without web reinforcement

2018 ◽  
Vol 195 ◽  
pp. 02010
Author(s):  
Halwan Alfisa Saifullah ◽  
Kenichiro Nakarai ◽  
Nobuhiro Chijiwa ◽  
Koichi Maekawa
Keyword(s):  
Shear Failure ◽  
Concrete Structures ◽  
Reduction Factor ◽  
Shear Capacity ◽  
Sustained Load ◽  
Shear Cracks ◽  
Shear Design ◽  
Web Reinforcement ◽  
Slender Beams ◽  
Shear Failures

Sustained load problems, which can cause excessive deformation and severe damage to concrete structures, have been considered in current worldwide design codes by applying reduction factors on the compressive and tensile strength of concrete. A reduction factor in the shear design may also be required due to the decrease of shear-transfer action corresponding to the increases of the shear cracks opening. However, only a few studies are examining the effect of creep on shear performance of concrete structures, and the results are still inconclusive. As a complement to the previous experimental works, this study aims to investigate the effect of loading rate on the shear capacity of RC slender beams by non-linear finite element (FE) analysis. A spaceaveraged constitutive model with fixed multi-directional cracks was employed in the simulation of diagonal shear failure. The present study analytically examines the time-dependent effects on the beams under different loading rates until the delayed failure and compares the results with the previous experimental ones.

Shear Behavior of CFRP Prestressed Concrete Beams without Stirrups

2011 ◽  
Vol 266 ◽  
pp. 126-129 ◽  
Author(s):  
Zuo Hu Wang ◽  
Xiu Li Du ◽  
Jing Bo Liu
Keyword(s):  
Prestressed Concrete ◽  
Failure Modes ◽  
Shear Failure ◽  
Concrete Beams ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Shear Span ◽  
Compression Failure ◽  
Concrete Members ◽  
Prestressed Beams

Five beams were tested up to failure to study the shear behavior of concrete beams prestressed with fiber reinforced polymer (FRP). Different factors were taken into consideration: the type of prestressing tendons and the shear span ratio. The shear failure modes and the influence of different factors on shear behavior were investigated in details. The test results showed that FRP prestressed beams without stirrups had two shear failure modes: diagonal compression failure and shear compression failure; the shear span ratio was the most important factor to determine the failure mode and shear capacity of the prestressed beams. The shear capacity of concrete members prestressed with FRP tendons was lower than that of concrete beams prestressed with steel cables.

scholarly journals Influence of flange on the shear capacity of reinforced concrete beams

2018 ◽  
Vol 162 ◽  
pp. 04003
Author(s):  
Kaiss Sarsam ◽  
Raid Khalel ◽  
Nisreen Mohammed
Keyword(s):  
Structural Engineering ◽  
Shear Failure ◽  
Concrete Beams ◽  
Design Method ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Test Results ◽  
Web Reinforcement ◽  
The Web

In structural engineering (RC, steel, etc.) it is usual to base the shear strength of members on the web only- e.g. in RC the stirrups used are usually called “web reinforcement”. Presently all codes, and several researches, base the strength of members on the capacity of the web alone. 93 tests of T-beams failing in shear available from the literature are studied in this work to estimate the influence of flanges on the shear capacity of RC beams. These include 32 ones without web reinforcement and 61 with stirrups. Comparison between test results and theoretical shear capacity show that all available equations conservatively estimate the occurrence of shear failure. In this work an equation for predicting the contribution of the flange to shear capacity in T-beams is presented. The best available design method obtained from the literature leads to a coefficient of variation (COV) of 17.58% compared to 13.46% for the proposed design method in this work.

Experimental Study on Shear Failure of High-Strength Concrete Beams with High-Strength Stirrups

2008 ◽  
Vol 400-402 ◽  
pp. 857-863
Author(s):  
Wei Jian Yi ◽  
Yan Mei Lv
Keyword(s):  
High Strength Concrete ◽  
Shear Failure ◽  
Concrete Beams ◽  
Concrete Strength ◽  
High Strength ◽  
Shear Capacity ◽  
Longitudinal Reinforcement ◽  
Test Results ◽  
Strength Concrete ◽  
Web Reinforcement

19 RC beams with shear span-to-depth equal to 3 were tested under a stiff testing facility, and complete load-deflection curves including the post-peak branch were obtained. Based on the test results the effects of concrete strength, stirrups strength, inclined stirrup angle, the amount of longitudinal reinforcement on failure mode, shear ductility index and shear capacity were analyzed. The test results were compared with the shear design approaches of Chinese Code and American Code. The results indicate that the shear failure of beam with appropriate web reinforcement has finite ductility. High-strength concrete beams with high-strength stirrups can increase not only the shear capacity, but also the shear ductility. The shear capacity of beams with high-strength concrete and stirrup can be designed with Chinese Code, but shear capacity of high-strength concrete beams without stirrups, or with the smaller amount of longitudinal reinforcement, and normal strength concrete beams with high-strength stirrups may be over-estimated by the Code.

Influence of Stirrup Corrosion on Shear Strength of RC Beams

2012 ◽  
Vol 204-208 ◽  
pp. 3287-3293
Author(s):  
Xin Xue ◽  
Hiroshi Seki ◽  
Yu Song
Keyword(s):  
Shear Strength ◽  
Mass Loss ◽  
Local Maximum ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Maximum Mass ◽  
Rc Beams ◽  
Load Carrying ◽  
Maximum Mass Loss

There have been few reports on shear behavior of reinforced concrete (RC) beams with corroded stirrups, and the influence of stirrup corrosion has yet to be identified. Given this background, experience was carried out to investigate the shear behavior of RC beams containing corroded stirrups. Investigation results indicate that if the percentage local maximum mass loss is below 35%, there is little influence on the load-carrying mechanism. The concrete shear resistance seems to change little and the shear capacity can be calculated by just taking into consideration the reduction in stirrup shear resistance. It is also found that the anchorage conditions of the stirrups have a predominant influence on the shears of RC beams.

Study on Shear Behaviour of Concrete Beams Prestressed with External CFRP Tendons

2013 ◽  
Vol 275-277 ◽  
pp. 1167-1171
Author(s):  
Xin Ding Wang ◽  
Hang Dai ◽  
Yong Chao Zhang
Keyword(s):  
Shear Failure ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Shear Behaviour ◽  
Similar Process ◽  
Shear Span ◽  
External Tendons ◽  
Straight Line ◽  
Steel Bars

Based on independent research and development of a CFRP tendons wedge-type anchorage, the shear tests of six CFRP external prestressing concrete beams were done. Among them, CFRP external tendons of three pieces were installed in straight line while other pieces were installed in curved line. The results of experimental research show that shear behaviour of concrete beams prestressed with CFRP external tendons are the similar process to the traditional prestressed reinforced concrete beams. They go through the elastic stage, the stage of crack extension, the yield stage of internal hoop reinforcements at the intersection of inclined cracks and the failure stage. When external CFRP tendons are arranged in the same situation, the cracking load and the shear capacity of concrete beams prestressed with CFRP external tendons reduce gradually along with the increase of shear-span ratio,.When shear-span ratio is equal, the cracking load and the shear capacity of concrete beams prestressed with curved arrangement of CFRP external tendons are larger than those of concrete beams prestressed with straight arrangement of CFRP external tendons. Compared with traditional concrete beams prestressed with external steel bars, due to elasticity modulus and shear modulus of CFRP tendons are both smaller than those of steel bars, the mid-span deflection of concrete beams prestressed with CFRP external tendons at the time of shear failure is bigger than that of traditional concrete beams prestressed with external steel bars under the same circumstance.

Experimental Study on Shear Behavior of Combined Aggregate Concrete Beams

2012 ◽  
Vol 166-169 ◽  
pp. 1422-1425
Author(s):  
Yan Kun Zhang ◽  
Hui Liu ◽  
Ze Zao Song
Keyword(s):  
Experimental Study ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Lightweight Aggregate ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Aggregate Concrete ◽  
Design Formula ◽  
Ordinary Concrete

Based on the test，the shear behavior of combined aggregate concrete beams is studied. The results show that combined aggregate concrete beam have similar behavior with ordinary concrete beams, and the shear capacity reduces with the increase of lightweight aggregate. And design formula of the combined aggregate concrete shear capacity is suggested.

scholarly journals Shear Behavior of Single Cast-in Anchor Simulating Characteristics of Bridge Bearing Anchor

2021 ◽  
Author(s):  
Jin-Seok Choi ◽  
Won Jong Chin ◽  
Tian-Feng Yuan ◽  
Young-Soo Yoon
Keyword(s):  
High Strain ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Embedment Depth ◽  
Design Equation ◽  
Edge Distance ◽  
Negative Effect ◽  
Compressive Strength Of Concrete ◽  
Bridge Bearing

Abstract A bridge bearing anchor transmits various loads of a superstructure to a substructure. However, most anchors are generally designed without consideration of characteristics such as concrete pedestal, grout bedding, and anchor socket. Therefore, this study investigated the shear behavior of anchors in accordance with the edge distance, embedment depth, compressive strength of concrete, and height of the concrete pedestal in order to simulate the practical characteristics of the bridge bearing anchors. The actual shear capacity of the anchor differs from the shear strength calculated by the ACI 318 Code; especially, the importance of the embedment depth is underestimated in the code. An increase in the height of the concrete pedestal has a negative effect on the shear capacity because of the stress concentration. The grout is fractured prior to the occurrence of local damages in concrete, resulting in a secondary moment. As a result, the effect of the level arm is observed. An equation, which can predict the relative cracking degree of concrete, is proposed by analyzing the displacement of grout and concrete. High strain occurs in the stirrups close to the anchor, and the behavior of the strain is more influenced by the embedment depth than the edge distance. Finally, the design equation of concrete breakout strength is modified to predict the more precise shear resistance of a bridge bearing anchor.

scholarly journals Behaviour of Reinforced Concrete Beams with Wire Mesh As Shear Reinforcement

2019 ◽  
Vol 8 (12) ◽  
pp. 781-784
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Wire Mesh ◽  
Shear Behaviour ◽  
Experimental Program ◽  
Shear Reinforcement ◽  
Loading System ◽  
Shear Performance

This paper presents a study of shear behaviour of reinforced concrete beams. The major parameters used were type of shear reinforcement, namely stirrups alone, wire mesh alone and combination of both wire mesh and stirrups as shear reinforcement. The replacement of wire mesh was done on the basis of weight with stirrups. The experimental program includes four beams. All the beams were tested using two point loading system. It is evident from the result that the use of wire mesh enhanced improved shear performance and bearing capacity in the examined beams. Beams with wire mesh as shear reinforcement and combination of both wire mesh and stirrups exhibited some amount of increase in shear capacity with respect to the beams with stirrups alone as shear reinforcement. Furthermore beams with wire mesh and combination of wire mesh and stirrups as reinforcement exhibited less number of crack patterns compared beams with stirrups.

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