Ductility and internal forces redistribution in lightweight aggregate concrete beams
Tomasz Waśniewski
tomasz.wasniewski@p.lodz.plDepartment of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Lodz University of Technology; 6 Politechniki Avenue, 90-924 Łódź, Poland (Poland)
https://orcid.org/0000-0001-7303-4920
Ewelina Kołodziejczyk
Department of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Lodz University of Technology; 6 Politechniki Avenue, 90-924 Lodz; (Poland)
https://orcid.org/0000-0002-3533-4145
Abstract
Lightweight Aggregate Concrete (LWAC) is typically defined as concrete having a density smaller than or equal to 2200kg/m3 and can be obtained by mixing natural or artificial lightweight aggregates. There is a general scepticism regarding the use of lightweight aggregate concrete (LWAC) for structural applications. This concern is attached to the more brittle material behaviour which leads to lower ductility.
This article presents a numerical parametric analysis of the behaviour of the reinforced LWAC cross-sections under the immediate load taking into account the density of the LWAC concrete, concrete strength and tensile reinforcement ratio.
Numerical analysis of the beams was conducted in OpenSees, an open–source nonlinear finite element method framework. One-dimensional elements, with three degrees of freedom at each end, were used. Bending stiffness in the integration points was calculated based on the sectional moment – curvature relationship.
The analysis showed that there is a relationship between the ductility of the cross-sections made of lightweight concrete and its density class. It is associated with limited compressive strains and the brittle behavior of LWAC. The limited rotation capacity of the reinforced concrete sections made of LWAC also affects the ability of redistribution of internal forces in statically indeterminate beams
Keywords:
lightweight concrete, ductility, redistribution, beamsReferences
European Committee for Standardization. EN 1992-1-1 Eurocode 2: Design of concrete structures Part 1-1: General rules and rules for buildings. CEN, Brussels, 2004.
Google Scholar
Øverli J. A., Jensen T. M., “Increasing ductility in heavily reinforced LWAC structures”, Engineering Structures, vol. 62-63, (15 March 2014), pp. 11-22.
DOI: https://doi.org/10.1016/j.engstruct.2014.01.017
Google Scholar
Carmo N.F., Costa H., Simões T., Lourenço C., Andrade D., “Influence of both concrete strength and transverse confinement on bending behavior of reinforced LWAC beams”, Engineering Structures, vol. 48, (March 2013), pp. 329-341.
DOI: https://doi.org/10.1016/j.engstruct.2012.09.030
Google Scholar
Dias-da-Costa D., Carmo R. N. F., Graça-e-Costa R., Valença J., Alfaiate J., “Longitudinal reinforcement ratio in lightweight aggregate concrete beams”, Engineering Structures, vol. 81, (15 December 2014), pp. 219-229.
DOI: https://doi.org/10.1016/j.engstruct.2014.09.016
Google Scholar
Øverli Jan A., “Towards a better understanding of the ultimate behaviour of LWAC in compression and bending”, Engineering Structures, vol. 151, (15 November 2017), pp. 821-838. https://doi.org/10.1016/j.engstruct.2017.08.063
DOI: https://doi.org/10.1016/j.engstruct.2017.08.063
Google Scholar
Liu, X., Wu, T., & Liu, Y., „Stress-strain relationship for plain and fibre-reinforced lightweight aggregate concrete”, Construction and Building Materials, vol. 225, 2019, pp. 256-272. https://doi.org/10.1016/j.conbuildmat.2019.07.135
DOI: https://doi.org/10.1016/j.conbuildmat.2019.07.135
Google Scholar
Naaman A.E., Jeong S.M., “Structural ductility of concrete beams prestressed with FRP tendons”, in 2nd Int. RILEM Symp. (FRPRXS-2), Non-Metric (FRP) Reinforcement for Concrete Structures. RILEM, Bagneux, France, 1995, pp. 379-386.
Google Scholar
Czkwianianc A., Kamińska M. E., „Metoda nieliniowej analizy żelbetowych elementów prętowych”, Studia z zakresu inżynierii, nr 36 (Institute of Fundamental Technological Research Polish Academy of Sciences, Warsaw, Poland, 1993).
Google Scholar
Mander J. B., Chang G., “Seismic energy based fatigue damage analysis of bridge columns: Part I – evaluation of seismic capacity”, Technical Report 94-0006, NCEER, 1994.
Google Scholar
Maekawa K., Dhakal P. R., “Path-dependent cyclic stress-strain relationship of reinforcing bar including buckling”, Engineering Structures, vol. 24, 2002, pp. 1383-1396. https://doi.org/10.1016/S0141-0296(02)00080-9
DOI: https://doi.org/10.1016/S0141-0296(02)00080-9
Google Scholar
The Open System for Earthquake Engineering Simulation Manual, Berkeley University of California, Available: https://opensees.berkeley.edu/wiki/index.php/OpenSees_User [Accessed: 01 February 2020]
Google Scholar
Authors
Tomasz Waśniewskitomasz.wasniewski@p.lodz.pl
Department of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Lodz University of Technology; 6 Politechniki Avenue, 90-924 Łódź, Poland Poland
https://orcid.org/0000-0001-7303-4920
Authors
Ewelina KołodziejczykDepartment of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Lodz University of Technology; 6 Politechniki Avenue, 90-924 Lodz; Poland
https://orcid.org/0000-0002-3533-4145
Statistics
Abstract views: 400PDF downloads: 157 PDF downloads: 47 PDF downloads: 49
License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Budownictwo i Architektura supports the open science program. The journal enables Open Access to their publications. Everyone can view, download and forward articles, provided that the terms of the license are respected.
Publishing of articles is possible after submitting a signed statement on the transfer of a license to the Journal.
