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

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.

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1218 ◽  
Author(s):  
Jun-Hong Zhang ◽  
Shu-Shan Li ◽  
Wei Xie ◽  
Yang-Dong Guo

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.


2012 ◽  
Vol 217-219 ◽  
pp. 2435-2439
Author(s):  
Ying Tao Li ◽  
Shi Yong Jiang ◽  
Bing Hong Li ◽  
Qian Hua Shi ◽  
Xian Qi Hu

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.


2020 ◽  
pp. 136943322098165
Author(s):  
Jianyang Xue ◽  
Xin Zhang ◽  
Xiaojun Ke

This paper mainly focused on the seismic performance and shear calculation method of steel reinforced high-strength concrete (SRHC) columns with rectangular helical hoops. An experimental investigation was performed in this paper. Eleven SRHC columns with rectangular helical hoops and one with ordinary hoops were constructed at the laboratory of Guangxi university. The failure modes, hysteresis loops, envelope curves, characteristic loads and displacements and cumulative damage analysis are presented and investigated. It can be seen from the test results that the failure modes of SRHC columns can be divided into three types with the shear span ratio increased, namely, shear baroclinic failure mode, flexure-shear failure mode and flexure failure mode. In addition, the specimens with rectangular helical hoops have plumper hysteretic loops. Shear span ratio is the main influencing factor of characteristic load; the axial compression ratio and concrete strength have less influence on characteristic load, while stirrup ratio has little effect on the characteristic load. Finally, a calculation method for shear capacity of SRHC columns under shear baroclinic failure and flexure-shear failure mode is proposed.


2020 ◽  
Vol 23 (11) ◽  
pp. 2388-2398
Author(s):  
Bo Da ◽  
Hongfa Yu ◽  
Haiyan Ma ◽  
Bo Yu ◽  
Zhangyu Wu ◽  
...  

Reinforced coral aggregate concrete beam and reinforced ordinary aggregate concrete beam with different concrete type, concrete strength, and steel type were designed in this study to investigate their shear behavior. The shear behavior of reinforced coral aggregate concrete beam was tested, the failure mode and deflection behavior were studied, and the calculating model for the ultimate shear capacity ( Vcs) of reinforced coral aggregate concrete beam was proposed. Results showed that the failure mode of reinforced ordinary aggregate concrete beam and reinforced coral aggregate concrete beam were basically the same. As the concrete strength increases, the normal section cracking load ( Vcr), inclined section Vcr, and Vcs of reinforced coral aggregate concrete beam increased gradually. Furthermore, Vcr and Vcs of reinforced coral aggregate concrete beam were as follows: 316 stainless steel > common steel > zinc-chromium coated steel > new organic coated steel. For the coral aggregate concrete structure in ocean engineering, in order to prolong its service life, the use of new organic coated steel was suggested. At the same time, the influence of high-strength coral aggregate concrete and stirrup corrosion was comprehensively considered and the calculation model for the Vcs of reinforced coral aggregate concrete beam was presented and was then verified.


2021 ◽  
Author(s):  
Chun-song Jiang ◽  
Gui-Qin Liang

Abstract This paper presents a data-driven machine learning approach of support vector regression (SVR) with genetic algorithm (GA) optimization approach called SVR-GA for predicting the shear strength capacity of medium-to ultra-high strength concrete beams with longitudinal reinforcement and vertical stirrups. 148 experimental samples collected with different geometric, material and physical factors from literature were utilized for SVR-GA with 5-fold cross validation. Shear influence factors such as the stirrup spacing, the beam width, the shear span-to-depth ratio, the effective depth of the beam, the concrete compressive and tensile strength, the longitudinal reinforcement ratio, the product of stirrup ratio and stirrup yield strength were served as input variables. The simulation results show that the predicted shear strength of SVR-GA model can achieve high accuracy based on testing set with a coefficient of determination (R2) of 0.9642, root mean squared error (RMSE) of 1.4685 and mean absolute error (MAE) of 1.0216 superior to that for traditional SVR model with 0.9379, 2.0375 and 1.4917. The sensitivity analysis reveals that the most important variables affecting the prediction of the shear strength are shear span-to-depth ratio, concrete compressive strength, reinforcement ratio and the product of stirrup ratio and stirrup yield strength. Three-dimensional input/output maps can vividly reflect the nonlinear variation of the shear strength with the two coupling variables. All in all, the proposed SVR-GA model presents an effective and accurate artificial intelligence technology for modeling the shear strength of ultra-high strength concrete beams with stirrups.


2020 ◽  
Vol 103 (2) ◽  
pp. 003685042092864
Author(s):  
Jiahui Feng ◽  
Weibin Liang ◽  
Haibo Jiang ◽  
Chengwang Huang ◽  
Jingyuan Zhang

Shear key joints are commonly used in constructions of precast concrete segmental bridges. Most researches focused on shear performance of the dry joints with the identical-strength concrete, leaving a research gap on that of composite joints between different concrete segments. This research aims to investigate shear behavior of shear key joint between reactive powder concrete and high strength concrete. Totally 12 specimens of single-keyed dry joint were tested, with the parameters of concrete compressive strength, steel fibers, and confining stress. The experimental results indicated that shear failure was observed, but crushing phenomenon occasionally occurred in composite joints in testing, which was confirmed by stress distribution from numerical simulation. In terms of shear capacity of composite joint, peak shear loads of reactive powder concrete specimens without steel fibers were enhanced by 10%–12% as increasing of concrete compressive strength, while those with steel fibers achieved 22%–25% enhancement. Nevertheless, a slight reduction of normalized shear strength was obtained because of its lower volume fraction of coarse aggregate. In numerical simulation, as increasing the concrete compressive strength of convex part, peak shear load was enhanced, but the increment rate of peak shear load decreased. Shear design formulae underestimated shear capacity of reactive powder concrete specimens with steel fibers, but the models proposed by Buyukozturk and Rombach gave accurate predictions on those without steel fibers.


2014 ◽  
Vol 578-579 ◽  
pp. 164-167 ◽  
Author(s):  
Peng Li ◽  
Xian Tang Zhang ◽  
Ming Ping Wang

To investigate the influence of shear span ratio for the shear behavior of reinforced concrete beam with HRBF500 high strength rebars as stirrups, an experiment was carried out, which included 8 simply supported beams with HRBF500 rebars as stirrups. Under concentrated loads, the crack, deflection, strain of rebars, bearing capacity and failure mode are observed under different shear span ratios. Some comparisons are made between test results and calculated outcome. It shows that the shear span ratio has very important influent on the shear behavior of reinforced concrete beam with HRBF500 high strength bars as stirrups. Formula in code for design of concrete structures can be used to calculate its shear capacity with enough safety.


Author(s):  
Muhammad K. Kayani ◽  
Wasim Khaliq ◽  
Muhammad K. Shehzad

Major factors contributing to the shear behavior in reinforced concrete (RC) beams have been identified as compressive strength of concrete, shear span to effective depth ratio, and longitudinal reinforcement. Though significant, few of these factors are not fully incorporated in ACI code provisions for design of minimum shear reinforcement. To investigate the effect of these parameters, an analytical and experimental study was undertaken on the shear behavior of ordinary strength RC slender beams with moderate longitudinal reinforcement. The experimental program consisted of testing of eight simply supported RC slender beams subjected to two concentrated loads at a shear span to depth ratio (a/d) of 2.5 and equipped with varying shear reinforcement according to four different criteria. Ultimate shear strengths obtained in this experimental program are compared to the analytical shear strengths calculated according to existing as well as proposed equations. Test results exhibit that, the modified equation proposed in this work gives more accurate prediction of shear capacity of RC beams.


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