scholarly journals Shear strength in one- and two-way slabs according to the Critical Shear Crack Theory

2008 ◽  
pp. 131-131 ◽  
Author(s):  
M Fernández Ruiz ◽  
A Muttoni
Keyword(s):  
Shear Strength ◽  
Shear Crack ◽  
Crack Theory

Critical shear crack theory-based punching shear model for FRP-reinforced concrete slabs

2020 ◽  
pp. 136943322097814
Author(s):  
Xing-lang Fan ◽  
Sheng-jie Gu ◽  
Xi Wu ◽  
Jia-fei Jiang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Crack ◽  
Concrete Strength ◽  
Weight Ratio ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Crack Theory ◽  
Reinforced Concrete Slabs ◽  
Rc Slabs

Owing to their high strength-to-weight ratio, superior corrosion resistance, and convenience in manufacture, fiber-reinforced polymer (FRP) bars can be used as a good alternative to steel bars to solve the durability issue in reinforced concrete (RC) structures, especially for seawater sea-sand concrete. In this paper, a theoretical model for predicting the punching shear strength of FRP-RC slabs is developed. In this model, the punching shear strength is determined by the intersection of capacity and demanding curve of FRP-RC slabs. The capacity curve is employed based on critical shear crack theory, while the demand curve is derived with the help of a simplified tri-linear moment-curvature relationship. After the validity of the proposed model is verified with experimental data collected from the literature, the effects of concrete strength, loading area, FRP reinforcement ratio, and effective depth of concrete slabs are evaluated quantitatively.

Fibre-reinforced polymer composite shear reinforcement: performance evaluation in concrete beams and code prediction

2010 ◽  
Vol 37 (8) ◽  
pp. 1057-1070 ◽  
Author(s):  
Ehab A. Ahmed ◽  
Ehab F. El-Salakawy ◽  
Brahim Benmokrane
Keyword(s):  
Shear Strength ◽  
Glass Fibre ◽  
Large Scale ◽  
Shear Crack ◽  
Design Strength ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Composite Shear

This paper evaluates the performance of carbon and glass fibre-reinforced polymer (FRP) stirrups and the accuracy of the shear design provisions incorporated in the currently available design codes and guidelines. A total of seven large-scale T-beams were constructed and tested: three reinforced with carbon fibre-reinforced polymer (CFRP) stirrups, three reinforced with glass fibre-reinforced polymer (GFRP) stirrups, and one reinforced with a steel stirrup for comparison, when applicable. The test results revealed that the design strength of the tested beams is not affected by the reduced strength of FRP stirrups at bend locations. Also, the recent CAN/CSA-S6 update is capable of adequately predicting the shear strength of the beam specimens reinforced with FRP stirrups. The software, Response-2000, which is based on the modified compression field theory (MCFT), predicted well the shear strength and the average strain in the stirrups of the tested beams; however, it overestimated the shear crack width.

scholarly journals Comparison Crack Resistance of RC Beams with and without Transverse Reinforcement after Shear Testing

2019 ◽  
Vol 1 (1) ◽  
pp. 342-349
Author(s):  
Pavlo Vegera ◽  
Roman Khmil ◽  
Rostyslav Vashkevych ◽  
Zinoviy Blickharskyy
Keyword(s):  
Shear Strength ◽  
Crack Resistance ◽  
Shear Crack ◽  
Crack Opening ◽  
Shear Capacity ◽  
Rc Beams ◽  
Inclined Crack ◽  
Distribution Width ◽  
Shear Span ◽  
External Reinforcement

Abstract Main parameters, which characterize shear strength, are crack distribution, width of diagonal crack opening and angle of inclined crack. There are in this article, comparison crack resistant of testing reinforced concrete (RC) beams on the shear with such variable parameters like presence or absence internal reinforcement, different shear span, and presence or absence external composite reinforcement. Shear span (relative span to effective depth ratio) was acquired the following values: a/d=2, 1.5, 1. For internal reinforcement, rebar’s A240C with diameter 8 mm and steps 100 mm was chosen. The composite FRCM system was like external reinforcement with three stripe of composite fabric with width 70 mm and step 100 mm. Eight RC beams were tested. After testing, we discovered that the most influenced on the serviceability capacity was shear span. Internal transverse reinforcing increased shear strength on the same level and it was independent from shear span and other factors. Only quantity of reinforcing determine level of increasing shear capacity. FRCM system is efficient strengthening system, which significant increase shear crack resistant for RC beams. External FRCM reinforcing increase shear crack resistance on the same percentage and independent from presence or absence internal reinforcement.

scholarly journals Biaxial Shear Crack Propagation Modes of Rock-Like Specimens with Prefabricated Fissures and Their Strength Characteristics

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Nai-Zhong Xu ◽  
Chang-Qing Liu ◽  
You-Jian Wang ◽  
Hong-Bin Dang
Keyword(s):  
Shear Strength ◽  
Crack Propagation ◽  
Shear Crack ◽  
Crack Coalescence ◽  
Strength Characteristics ◽  
Propagation Mode ◽  
Peak Shear Strength ◽  
Shear Cracks ◽  
Tensile Shear ◽  
Dip Angle

A biaxial shear test is performed on prefabricated, single-fissure type, cubic rock-like specimens by using the TZW-500 rock direct shear apparatus to study the shear strength characteristics, crack coalescence, and propagation modes of the specimens with different geometric parameters. Results show that the crack coalescence and propagation modes of the rock-like specimens with prefabricated fissures can be divided into four types, namely, single main shear crack coalescence mode, main shear crack coalescence and secondary tensile-shear crack propagation mode, main shear crack coalescence and secondary shear crack propagation mode, and main shear crack coalescence and secondary tensile crack propagation mode. All modes are affected by the dip angle α and length l of the prefabricated fissure. When the dip angle of the prefabricated fissure is α∈[0°, 20°) or (70°, 90°], the cracks center on shear failure, and most shear cracks propagate along one end of the prefabricated fissure. At α∈(30°, 50°), the cracks bear the tensile-shear combined action, and the shear cracks propagate along the two ends of the prefabricated fissure. The peak shear strength of the rock-like specimens with prefabricated fissures is also closely related to the dip angle α and length l of the fissure. With the increase in dip angle α of the prefabricated fissure, the peak shear strength of each rock-like specimen decreases initially then increases, and the peak shear strength curve presents a similar “U” shape. At α∈[30°, 60°], the peak shear strength is within the peak-valley interval. When the length l of the prefabricated fissure is increased, the peak shear strength experiences a gradual reduction. When l > 20 mm, the peak shear strength is greatly influenced by l, but the influence is minimal when l ≥ 20 mm. At the same dip angle α and fissure length of l ≥ 20 mm, the correlation between peak shear strength and fissure width b is low.

scholarly journals Modelling of the shear resistance of self-stressed beams reinforced with FRP applying the Critical Shear Crack Theory

2021 ◽  
Vol 350 ◽  
pp. 00016
Author(s):  
Viktar Tur ◽  
Aliaksandr Varabei
Keyword(s):  
Shear Crack ◽  
Crack Opening ◽  
Shear Resistance ◽  
Experimental Investigations ◽  
Inclined Crack ◽  
Ultimate State ◽  
Bond Slip ◽  
Crack Theory ◽  
Dowel Action ◽  
Frp Bars

This paper presents a mechanical model of the shear resistance based on Critical Shear Crack Theory (CSCT) and its application for the checking of the shear ultimate state of self-stressed elements reinforced with FRP bars. The shear force, which is transmitted through the inclined crack by aggregate interlock, residual tensile strength, dowel action and inclined chord of the compression concrete, is calculated depending on the value of the inclined crack opening, determined according to the modified law “bond-slip” for FRP bars. The reliability of the proposed approach is confirmed by comparison both with the results of our own experimental investigations and with numerous research results by various authors.

scholarly journals Shear Performance of Reinforced Concrete Beams Affected by Satisfactory Composite-Recycled Aggregates

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1711
Author(s):  
Changyong Li ◽  
Na Liang ◽  
Minglei Zhao ◽  
Kunqi Yao ◽  
Jie Li ◽  
...  
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Shear Crack ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Recycled Aggregates ◽  
Shear Span ◽  
Model Code ◽  
Model Code 2010

This paper is the outcome of experiments on the shear performance of reinforced concrete beams with approved composite-recycled aggregates. The strength grade of composite-recycled aggregate concrete (CRAC) was between 30 MPa and 60 MPa. The shear span-to-depth ratio varied from 1 to 3. The adaptability of HRB400 rebar, with critical yield strength of 400 MPa, used as stirrups was also verified. As the composite technology overcame the shortcomings of recycled coarse aggregate, CRAC had similar mechanical properties with those of conventional concrete. Details on the shear behaviors of test beams under a four-point loading test are presented. The results indicated that the changes of CRAC strain, stirrup strain, and shear-crack width depended on the failure patterns, which are controlled by the shear-span to depth ratio. The stirrups yield at the failure of reinforced CRAC beams. The shear cracking resistance and the shear capacity of reinforced CRAC beams can be predicted by the statistical equations. Based on the design codes GB50010, ACI318-19, Model Code 2010 and DIN-1045-1-2008 for conventional reinforced concrete beams, the shear strengths provided by CRAC and stirrups are statistical analyzed. The rationality of the design equations is examined by the utilization level of shear strength provided by CRAC. The maximum shear-crack widths are extracted from the test data of reinforced CRAC beams at normal service state. Comparatively, by specifying the lower limit of shear strength provided by the CRAC with various shear-span to depth ratios, China code GB50010 gives a rational method for utilizing CRAC. Under the premise that the design of shear capacity would give considerations to meet the normal serviceability, the factored strength of HRB400 rebar should be 360 MPa for the calculation of shear strength provided by stirrups. The design methods in codes of GB50010, ACI318-19 and Model Code 2010 are conservative for the shear capacity of reinforced CRAC beams.

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