Over the years, a variety of the design code expressions for non-slender beams (a/d < 2.4) have been proposed and calibrated by using different data sets. In order to unify research efforts that are taking place in Europe and USA, this research aims at combining a variety of different databases for evaluating the performance of American and European provisions for such beams. Principal investigator: Leonardo Todisco
2018
|
Todisco, L; Bayrak, O; Reineck, K -H ACI-DAfStb database for tests on deep beams and comparisons with code provisions Artículo de revista Structural Concrete, 19 (1), 2018, ISSN: 17517648. Resumen | Enlaces | BibTeX @article{Todisco2018a,
title = {ACI-DAfStb database for tests on deep beams and comparisons with code provisions},
author = {L Todisco and O Bayrak and K -H Reineck},
doi = {10.1002/suco.201700061},
issn = {17517648},
year = {2018},
date = {2018-01-01},
journal = {Structural Concrete},
volume = {19},
number = {1},
abstract = {textcopyright 2017 fib. International Federation for Structural Concrete In an effort to calibrate design methods and code provisions, an ACI-DAfStb database was assembled for deep beams and non-slender beams with vertical stirrups and horizontal web/skin reinforcement subjected to point loads. This collection database includes 218 tests, and with the exception of a few, all tests have a shear span to effective beam depth ratios less than 2.4, that is, $kappa$ = a/d textless 2.4. For the purposes of evaluating the accuracy and conservativeness of design provisions, several control and filtering criteria were applied, and after this process, 89 beams remained in the evaluation database. In light of this database, the performance of shear design provisions of ACI 318-14 and Eurocode 2, as well as strut-and-tie models (STMs) of the FIP Recommendations were examined. The analyses conducted using this database indicated that the application of STMs of ACI 318-14 is conservative, that is, the database analyses yielded less unsafe tests than the desired 5% fractile. Furthermore, statistical evaluations showed that shear design expressions of Eurocode 2 and FIP Recommendations for non-slender beams and deep beams are conservative too.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
textcopyright 2017 fib. International Federation for Structural Concrete In an effort to calibrate design methods and code provisions, an ACI-DAfStb database was assembled for deep beams and non-slender beams with vertical stirrups and horizontal web/skin reinforcement subjected to point loads. This collection database includes 218 tests, and with the exception of a few, all tests have a shear span to effective beam depth ratios less than 2.4, that is, $kappa$ = a/d textless 2.4. For the purposes of evaluating the accuracy and conservativeness of design provisions, several control and filtering criteria were applied, and after this process, 89 beams remained in the evaluation database. In light of this database, the performance of shear design provisions of ACI 318-14 and Eurocode 2, as well as strut-and-tie models (STMs) of the FIP Recommendations were examined. The analyses conducted using this database indicated that the application of STMs of ACI 318-14 is conservative, that is, the database analyses yielded less unsafe tests than the desired 5% fractile. Furthermore, statistical evaluations showed that shear design expressions of Eurocode 2 and FIP Recommendations for non-slender beams and deep beams are conservative too. |
2016
|
Todisco, Leonardo; Reineck, Karl-Heinz; Bayrak, Oguzhan European design rules for point loads near supports evaluated with data from shear tests on non-slender beams with vertical stirrups Artículo de revista Structural Concrete, 17 (2), pp. 135–144, 2016, ISSN: 14644177. Enlaces | BibTeX @article{Todisco2016d,
title = {European design rules for point loads near supports evaluated with data from shear tests on non-slender beams with vertical stirrups},
author = {Leonardo Todisco and Karl-Heinz Reineck and Oguzhan Bayrak},
url = {http://doi.wiley.com/10.1002/suco.201500089},
doi = {10.1002/suco.201500089},
issn = {14644177},
year = {2016},
date = {2016-01-01},
journal = {Structural Concrete},
volume = {17},
number = {2},
pages = {135--144},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
2015
|
Todisco, Leonardo; Reineck, Karl-Heinz; Bayrak, Oguzhan Database with Shear Tests on Non-slender Reinforced Concrete Beams with Vertical Stirrups Artículo de revista ACI Structural Journal, 112 (6), pp. 761–770, 2015, ISSN: 0889-3241. Resumen | Enlaces | BibTeX @article{Todisco2015d,
title = {Database with Shear Tests on Non-slender Reinforced Concrete Beams with Vertical Stirrups},
author = {Leonardo Todisco and Karl-Heinz Reineck and Oguzhan Bayrak},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84948457022&partnerID=tZOtx3y1},
doi = {10.14359/51688055},
issn = {0889-3241},
year = {2015},
date = {2015-01-01},
journal = {ACI Structural Journal},
volume = {112},
number = {6},
pages = {761--770},
publisher = {American Concrete Institute},
abstract = {A database is presented with 278 tests on non-slender reinforced concrete beams with vertical stirrups. These beams are commonly referred to as non-slender beams because they have shear spandepth ratios (a/d) less than 2.4. In keeping with European terminology, the term "deep beams" is not used for these beams, because in Europe, deep beams are often defined only for ratios of a/d textless 1 and always contain vertical as well as horizontal reinforcement in their web. After having applied several control/filtering criteria, 178 beams remained in the evaluation database that can be used to check conservativeness and accuracy of relevant design provisions. For example, the application of strut-and-tie models of ACI 318-14 to non-slender beams with stirrups (and without any horizontal skin reinforcement) was unconservative-that is, it yielded database analysis results that were above the desired 5% fractile. Almost all unconservative estimations were obtained for test specimens with very low amounts of stirrups. This problem can be solved either by increasing the required amount of minimum reinforcement in the vertical direction or by placing a minimum amount of reinforcement in both the horizontal and vertical direction. It is also important to note that a comparison with Kani's shear valley showed that for a/d textless 1, the valley was not filled up to the full flexural capacity, despite the presence of vertical stirrups in test specimens.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A database is presented with 278 tests on non-slender reinforced concrete beams with vertical stirrups. These beams are commonly referred to as non-slender beams because they have shear spandepth ratios (a/d) less than 2.4. In keeping with European terminology, the term "deep beams" is not used for these beams, because in Europe, deep beams are often defined only for ratios of a/d textless 1 and always contain vertical as well as horizontal reinforcement in their web. After having applied several control/filtering criteria, 178 beams remained in the evaluation database that can be used to check conservativeness and accuracy of relevant design provisions. For example, the application of strut-and-tie models of ACI 318-14 to non-slender beams with stirrups (and without any horizontal skin reinforcement) was unconservative-that is, it yielded database analysis results that were above the desired 5% fractile. Almost all unconservative estimations were obtained for test specimens with very low amounts of stirrups. This problem can be solved either by increasing the required amount of minimum reinforcement in the vertical direction or by placing a minimum amount of reinforcement in both the horizontal and vertical direction. It is also important to note that a comparison with Kani's shear valley showed that for a/d textless 1, the valley was not filled up to the full flexural capacity, despite the presence of vertical stirrups in test specimens. |
2014
|
Reineck, K -H; Todisco, L Database of shear tests for non-slender reinforced concrete beams without stirrups Artículo de revista ACI Structural Journal, 111 (6), pp. 1363–1371, 2014, ISSN: 08893241. Resumen | BibTeX @article{Reineck2014,
title = {Database of shear tests for non-slender reinforced concrete beams without stirrups},
author = {K -H Reineck and L Todisco},
issn = {08893241},
year = {2014},
date = {2014-01-01},
journal = {ACI Structural Journal},
volume = {111},
number = {6},
pages = {1363--1371},
abstract = {textcopyright 2014, American Concrete Institute. A database is presented with shear tests on non-slender beams without stirrups subjected to point loads with shear span to effective depth ratios (a/d) textless 2.4. From the 338 collected shear tests, 222 tests remained for the evaluations after several selection criteria were applied. The tests were compared with the left part of the shear valley by Kani and did not confirm the strength increase up to the flexural strength in the range from a/d = 2.4 to approximately 1.0. The test results were compared to the strut-And-tie model according to ACI 318-11. The model overestimated the test results. The reduction factor for the strength of the unreinforced struts should be reduced to ß s = 0.42 instead of 0.60 for a strut without reinforcement, such as the inclined strut transferring the load to the support for a point load near an end support.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
textcopyright 2014, American Concrete Institute. A database is presented with shear tests on non-slender beams without stirrups subjected to point loads with shear span to effective depth ratios (a/d) textless 2.4. From the 338 collected shear tests, 222 tests remained for the evaluations after several selection criteria were applied. The tests were compared with the left part of the shear valley by Kani and did not confirm the strength increase up to the flexural strength in the range from a/d = 2.4 to approximately 1.0. The test results were compared to the strut-And-tie model according to ACI 318-11. The model overestimated the test results. The reduction factor for the strength of the unreinforced struts should be reduced to ß s = 0.42 instead of 0.60 for a strut without reinforcement, such as the inclined strut transferring the load to the support for a point load near an end support. |