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Milija N. Pavlović - One of the best experts on this subject based on the ideXlab platform.
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Size effects in beams with small Shear Span-to-depth ratios
Computers & Structures, 2004Co-Authors: Michael D. Kotsovos, Milija N. PavlovićAbstract:The work described in the paper complements previous work concerned with the investigation of the causes of size effects in structural-concrete members. It is based on the use of a finite-element model found to yield realistic predictions of structural-concrete behaviour in all cases investigated to date. In fact, the previous use of this model in investigations of size effects in reinforced-concrete beams with a Shear Span-to-depth ratio larger than 2 indicated that such effects reflect the dependence of load-carrying capacity on small unintended eccentricities of the applied load and/or load-induced anisotropy, rather than, as widely considered, on fracture-mechanics characteristics. The present work extends the scope of the above investigation so as to include the case of beams with a Shear Span-to-depth ratio smaller than 1.15, the behaviour of which is already established experimentally. It is found that, unlike the beams with a Shear Span-to-depth ratio larger than 2, the beams investigated in the present work, in contrast with the interpretation given to recently published experimental findings, are size-effect independent. (C) 2003 Elsevier Ltd. All rights reserved
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Size effects in beams with small Shear Span-to-depth ratios
Computers & Structures, 2003Co-Authors: Michael D. Kotsovos, Milija N. PavlovićAbstract:The work described in the paper complements previous work concerned with the investigation of the causes of size effects in structural-concrete members. It is based on the use of a finite-element model found to yield realistic predictions of structural-concrete behaviour in all cases investigated to date. In fact, the previous use of this model in investigations of size effects in reinforced-concrete beams with a Shear Span-to-depth ratio larger than 2 indicated that such effects reflect the dependence of load-carrying capacity on small unintended eccentricities of the applied load and/or load-induced anisotropy, rather than, as widely considered, on fracture-mechanics characteristics. The present work extends the scope of the above investigation so as to include the case of beams with a Shear Span-to-depth ratio smaller than 1.15, the behaviour of which is already established experimentally. It is found that, unlike the beams with a Shear Span-to-depth ratio larger than 2, the beams investigated in the present work, in contrast with the interpretation given to recently published experimental findings, are size-effect independent.
Michael D. Kotsovos - One of the best experts on this subject based on the ideXlab platform.
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Size effects in beams with small Shear Span-to-depth ratios
Computers & Structures, 2004Co-Authors: Michael D. Kotsovos, Milija N. PavlovićAbstract:The work described in the paper complements previous work concerned with the investigation of the causes of size effects in structural-concrete members. It is based on the use of a finite-element model found to yield realistic predictions of structural-concrete behaviour in all cases investigated to date. In fact, the previous use of this model in investigations of size effects in reinforced-concrete beams with a Shear Span-to-depth ratio larger than 2 indicated that such effects reflect the dependence of load-carrying capacity on small unintended eccentricities of the applied load and/or load-induced anisotropy, rather than, as widely considered, on fracture-mechanics characteristics. The present work extends the scope of the above investigation so as to include the case of beams with a Shear Span-to-depth ratio smaller than 1.15, the behaviour of which is already established experimentally. It is found that, unlike the beams with a Shear Span-to-depth ratio larger than 2, the beams investigated in the present work, in contrast with the interpretation given to recently published experimental findings, are size-effect independent. (C) 2003 Elsevier Ltd. All rights reserved
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Size effects in beams with small Shear Span-to-depth ratios
Computers & Structures, 2003Co-Authors: Michael D. Kotsovos, Milija N. PavlovićAbstract:The work described in the paper complements previous work concerned with the investigation of the causes of size effects in structural-concrete members. It is based on the use of a finite-element model found to yield realistic predictions of structural-concrete behaviour in all cases investigated to date. In fact, the previous use of this model in investigations of size effects in reinforced-concrete beams with a Shear Span-to-depth ratio larger than 2 indicated that such effects reflect the dependence of load-carrying capacity on small unintended eccentricities of the applied load and/or load-induced anisotropy, rather than, as widely considered, on fracture-mechanics characteristics. The present work extends the scope of the above investigation so as to include the case of beams with a Shear Span-to-depth ratio smaller than 1.15, the behaviour of which is already established experimentally. It is found that, unlike the beams with a Shear Span-to-depth ratio larger than 2, the beams investigated in the present work, in contrast with the interpretation given to recently published experimental findings, are size-effect independent.
Yang-dong Guo - One of the best experts on this subject based on the ideXlab platform.
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Experimental Study on Shear Capacity of High Strength Reinforcement Concrete Deep Beams with Small Shear Span–Depth Ratio
Materials (Basel Switzerland), 2020Co-Authors: Jun-hong Zhang, Wei Xie, Yang-dong GuoAbstract: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.
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experimental study on Shear capacity of high strength reinforcement concrete deep beams with small Shear Span depth ratio
Materials, 2020Co-Authors: Jun-hong Zhang, Wei Xie, Yang-dong GuoAbstract: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.
Fung-kew Kong - One of the best experts on this subject based on the ideXlab platform.
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high strength concrete continuous deep beams with web reinforcement and Shear Span variations
Advances in Structural Engineering, 2004Co-Authors: Mohamed Chemrouk, Fung-kew KongAbstract:Tests under two-point loads were carried out to destruction on 12 reinforced concrete two-Span continuous deep beams. The beams were tested for two ShearSpan/depth ratios of 0.45 and 0.24 giving clear Shear-Span/depth ratio of 0.21 and 0.00 respectively. Various arrangements of web reinforcement were used such as minimum and maximum vertical bars, minimum and maximum horizontal bars and minimum and maximum inclined bars. Sagging and hogging tensile steel was used in accordance with the shallow beam bending moment distribution and was kept constant for all the beams. The results of the present tests are compared with those of the moderately deep beams reported in the litterature by Rogowsky et al. and with the two-beam tests of Leonhardth and Walther. The present tests show that the current codes and design manuals covering continuous deep beams could lead to severe cracking and may be unsafe for this type of structural members. The actual bending moment distribution is completely different from that recom...
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- With web reinforcement and Shear-Span variations
2004Co-Authors: Mohamed Chemrouk, Fung-kew KongAbstract:Tests under two-point loads were carried out to destruction on 12 reinforced concrete two-Span continuous deep beams. The beams were tested for two Shear- Span/depth ratios of 0.45 and 0.24 giving clear Shear-Span/depth ratio of 0.21 and 0.00 respectively. Various arrangements of web reinforcement were used such as minimum and maximum vertical bars, minimum and maximum horizontal bars and minimum and maximum inclined bars. Sagging and hogging tensile steel was used in accordance with the shallow beam bending moment distribution and was kept constant for all the beams. The results of the present tests are compared with those of the moderately deep beams reported in the litterature by Rogowsky et al. and with the two-beam tests of Leonhardth and Walther. The present tests show that the current codes and design manuals covering continuous deep beams could lead to severe cracking and may be unsafe for this type of structural members. The actual bending moment distribution is completely different from that recommended by these documents, with moments at Spans higher and those at internal supports lower. The tests also showed that the CIRIA guide may be too tolerant and hence unsafe towards bearing failure which, in the presence of an effective pattern of web reinforcement, is the dominant type of failure of reinforced concrete continuous deep beams.
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High Strength Concrete Continuous Deep Beams — With Web Reinforcement and Shear-Span Variations:
Advances in Structural Engineering, 2004Co-Authors: Mohamed Chemrouk, Fung-kew KongAbstract:Tests under two-point loads were carried out to destruction on 12 reinforced concrete two-Span continuous deep beams. The beams were tested for two ShearSpan/depth ratios of 0.45 and 0.24 giving clear Shear-Span/depth ratio of 0.21 and 0.00 respectively. Various arrangements of web reinforcement were used such as minimum and maximum vertical bars, minimum and maximum horizontal bars and minimum and maximum inclined bars. Sagging and hogging tensile steel was used in accordance with the shallow beam bending moment distribution and was kept constant for all the beams. The results of the present tests are compared with those of the moderately deep beams reported in the litterature by Rogowsky et al. and with the two-beam tests of Leonhardth and Walther. The present tests show that the current codes and design manuals covering continuous deep beams could lead to severe cracking and may be unsafe for this type of structural members. The actual bending moment distribution is completely different from that recom...
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High-strength concrete deep beams with effective Span and Shear Span variations
ACI Structural Journal, 1995Co-Authors: Kang Hai Tan, Fung-kew Kong, Susanto Teng, Lingweii GuanAbstract:Nineteen reinforced concrete deep beams with compressive strengths in the range of 41 MPa ≤ f' c ≤ 59 MPa (6000 psi ≤ f' c ≤ 8600 psi) were tested under two-point top loading. All the beams were singly reinforced with main steel percentage p = 1.23 percent and with nominal percentage of Shear reinforcement ρ v = 0.48 percent. The beams were tested for seven Shear Span-depth ratios a/d, ranging from 0.27 to 2. 70, and four effective Span-depth ratios l e /d, ranging from 2.15 to 5.38. Test results indicate that l e /d has little influence on the magnitude of the failure load. But for beams with a/d ≥ 1.00, the flexural failure mode becomes dominant with increasing l e /d. The test results are compared with predictions based on the current ACI Building Code. The comparisons reported in this paper will provide an added assurance to designers that the deep-beam provisions in the ACI code, though essentially based on concrete strengths of less than 41 MPa (6000 psi) will insure safe designs for higher strength deep beams. However, the ACI code tends to be rather conservative, as shown by comparison to the Deep-Beam Design Guide issued by the Construction Industry Research and Information Association, London. Nevertheless, the ACI code has the important advantage of being easy to use.
Brahim Benmokrane - One of the best experts on this subject based on the ideXlab platform.
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Shear behavior of circular concrete members reinforced with gfrp bars and spirals at Shear Span to depth ratios between 1 5 and 3 0
Journal of Composites for Construction, 2016Co-Authors: Ahmed H. Ali, Hamdy M. Mohamed, Brahim BenmokraneAbstract:AbstractIn the last decade, the Shear strength of concrete members with rectangular cross sections reinforced with fiber-reinforced polymers (FRPs) has received considerable attention. Yet no research seems to have investigated circular concrete members reinforced with FRP reinforcement under Shear loads. This paper presents the results of an investigation of the Shear strength and behavior of six circular concrete specimens reinforced with glass-FRP (GFRP) bars and spirals. The specimens, which measured 3,000 mm in length by 500 mm in diameter, were tested under four-point bending. The test parameters included the Shear Span-to-depth ratio (a/d) ranging from 1.5 to 3.0 and the GFRP spiral reinforcement ratio with different spiral spacings (100, 150, and 200 mm) and spiral diameters (13 and 15 mm). As designed, the specimens failed in Shear due to GFRP spiral rupture or flexural-Shear failure for the specimens with a/d>2.5 and strut crushing combined with spiral rupture for the specimens with a/d<2.5. The...
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Shear Behavior of Circular Concrete Members Reinforced with GFRP Bars and Spirals at Shear Span-to-Depth Ratios between 1.5 and 3.0
Journal of Composites for Construction, 2016Co-Authors: Ahmed H. Ali, Hamdy M. Mohamed, Brahim BenmokraneAbstract:AbstractIn the last decade, the Shear strength of concrete members with rectangular cross sections reinforced with fiber-reinforced polymers (FRPs) has received considerable attention. Yet no research seems to have investigated circular concrete members reinforced with FRP reinforcement under Shear loads. This paper presents the results of an investigation of the Shear strength and behavior of six circular concrete specimens reinforced with glass-FRP (GFRP) bars and spirals. The specimens, which measured 3,000 mm in length by 500 mm in diameter, were tested under four-point bending. The test parameters included the Shear Span-to-depth ratio (a/d) ranging from 1.5 to 3.0 and the GFRP spiral reinforcement ratio with different spiral spacings (100, 150, and 200 mm) and spiral diameters (13 and 15 mm). As designed, the specimens failed in Shear due to GFRP spiral rupture or flexural-Shear failure for the specimens with a/d>2.5 and strut crushing combined with spiral rupture for the specimens with a/d
