scholarly journals Shear Strength of Members without Transverse Reinforcement as Function of Critical Shear Crack Width

2008 ◽  
Vol 105 (2) ◽  
2020 ◽  
Vol 117 (1) ◽  
Author(s):  
Francesco Cavagnis ◽  
João T. Simões ◽  
Miguel Fernández Ruiz ◽  
Aurelio Muttoni

2020 ◽  
pp. 136943322097814
Author(s):  
Xing-lang Fan ◽  
Sheng-jie Gu ◽  
Xi Wu ◽  
Jia-fei Jiang

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.


2021 ◽  
Author(s):  
Kokilan Sathiyamoorthy

Shear and flexural behaviour of lightweight self-consolidating concrete (LWSCC) beams made of slag aggregates were investigated. Shear reinforced LWSCC beams showed similar shear behaviour compared to their non-shear reinforced counterparts until the formation of diagonal cracks but higher ultimate shear resistance and ductility. Compared to normal weight self-consolidating concrete (SCC) ones, non-shear reinforced LWSCC beams showed lower post-cracking shear resistance. Shear strength of LWSCC/SCC beams increased with the decrease of shear span to depth ratio. LWSCC beams showed higher number of cracks and wider crack width at failure than their SCC counterparts. LWSCC beams developed higher number of cracks with wider crack width at failure compared with their SCC counterparts. American, Canadian and British Codes were conservative in predicting shear strength of shear/non-shear reinforced LWSCC beams. LWSCC beams (with slag aggregate) showed good shear resistance compared with those made of other types of aggregates besides satisfactory flexural performance.


2019 ◽  
Vol 12 (3) ◽  
pp. 658-693
Author(s):  
A. M. D. SOUSA ◽  
M. K. EL DEBS

Abstract Concentrated loads in slabs without transverse reinforcement, usual in highway bridges, result in the horizontal spreading of the shear force towards the supports, situation in which not all the slab width contributes in the shear strength. Based on this, the analytical models of shear strength and punching capacity in slabs may not be suitable to deal with this loading. Since this topic is not widely discussed in the national technical literature, the paper aims to present contributions to these analyses with a focus on the accuracy level of the shear strength analytical models recommended by ABNT NBR 6118:2014. Therefore, the models available in the Brazilian code were applied to an experimental database with 118 test results and the results obtained by the Brazilian and European codes were compared. The results demonstrated that, as presented in the Brazilian code, shear strength model in one-way slabs can lead to unsafe resistance predictions while the punching capacity model can lead to very conservative predictions. From the analysis, it is concluded that considering the reduction of the shear force, in the case of loads distributed in small areas close to the support in slabs, and the use of more suitable procedures to define the effective width, it is possible to improve the level of accuracy of relations between experimental and theoretical values, but this still leads to high percentages of unsafe predictions of resistance (> 40%).


Author(s):  
Robert J. Peterman ◽  
Julio A. Ramirez ◽  
Jan Olek

In a recent study, 25 development-length tests were conducted on rectangular and T-shaped semilightweight beams having design compressive strengths of 48 MPa (7,000 psi) and 69 MPa (10,000 psi). In the rectangular beam tests, the design moment capacity was exceeded in every case. However, in the tests on T-shaped beams, bond failure occurred in some specimens immediately after the formation of a flexure-shear crack. Additional tests were then conducted on similar T-shaped beams having varying amounts of transverse reinforcement near the point load. These tests showed that bond failure could be prevented by increasing the transverse reinforcement near the point of maximum moment. The study showed that the shift in the tension force that occurs when flexural cracks turn diagonally may lead to bond failure if sufficient anchorage of the strand is not provided. Therefore, the investigators recommend that the current AASHTO requirements for strand development be enforced at a “critical section” located at a distance dp from the point of maximum moment toward the free end of the strand, where dp is the distance from the extreme compression fiber to the centroid of the prestressed reinforcement.


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