Thin Steel Rings as a Feasible Alternative to Connect Bamboo Culms
J.J. García, C. Benítez, L. Villegas, R. Morán
Abstract. Bamboo is highlighted by its high axial strength, lightness, tubular shape and high sustainability. Bamboo connections cannot be easily built due to the hollow cylindrical shape and the high dimensional variation and transverse weakness of the culms, which tend to fail by longitudinal splitting. Joints recommended by the Colombian construction code use bolts, curved cuts and mortar injection to increase the transverse strength. These joints require high labor intervention and cannot be used in massive projects using prefabricated processes. We explore the use of thin steel semi-rings to connect bamboo culms. As the rings (formed with two semi-rings) are thin enough they can conform to the irregularities of the culm after being tighten. Thus, the ring applies an external pressure to the culm and creates a compressive circumferential stress distribution, which counteracts the creation of longitudinal splits. Moreover, even after initial fissures the ring avoids the separation of the parts, which generates ductile modes of failure. We performed experiments of Guadua angustifolia culms wrapped with steel rings under axial and transverse loading. Axial experiments showed maximum loads in the range 7500-18000 N with signs of high plastic deformations that usually begin at around 5000 N. Experiments under transverse loading showed maximum loads in the range 12000-20000 N with ductile types of failure.
Keywords
Guadua Angustifolia, Bamboo Joints, Steel Rings
Published online , 10 pages
Copyright © 2018 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: J.J. García, C. Benítez, L. Villegas, R. Morán, ‘Thin Steel Rings as a Feasible Alternative to Connect Bamboo Culms’, Materials Research Proceedings, Vol. 7, pp 661-670, 2018
DOI: https://dx.doi.org/10.21741/9781945291838-63
The article was published as article 63 of the book Non-Conventional Materials and Technologies
References
[1] M. Vahanvati, «The Challenge of connecting bamboo,» de 10th World Bamboo Congress, Damyang, 2015.
[2] O. Arce-Villalobos, Fundamentals of the design of bamboo structures. Doctoral dissertation, Eindhoven: Eindhoven University of Technology, 1993.
[3] B. Sharma, Seismic Performance of Bamboo Structures. Doctoral dissertation, Pittsburgh, USA: University of Pittsburgh, 2010.
[4] L. Villegas, R. Moran y J. García, «A new joint to assemble light structures of bamboo slats,» Construction and Building Materials, pp. 61-68, 2015. https://doi.org/10.1016/j.conbuildmat.2015.08.113
[5] R. Moran, C. Benitez, H. Silva y J. García, «Desing of steel connector for structural bamboo members,» de AMDM 2016 Terce Congreso Internacional Sobre Tecnologías Avanzadas de Mecatrónica, Diseño y Manufactura, Cali, 2016.
[6] B. Sharma, K. Harries y K. Ghavami, «Methods of determining transverse mechanical properties of full-culm bamboo,» Construction and Building Materials, pp. 627-637, 2013. https://doi.org/10.1016/j.conbuildmat.2012.07.116
[7] R. Moran, K. Weeb, K. Harries y J. García, «Edge bearing tests to assess the influence of radial gradation on the transverse behavior of bamboo,» Construction and Building Materials, pp. 574-584, 2017. https://doi.org/10.1016/j.conbuildmat.2016.11.106
[8] J. García, C. Rangel y K. Ghavami, «Experiments with rings to determine the anisotropoc elastic constants of bamboo,» Construction and building of materials, pp. 52-57, 2012. https://doi.org/10.1016/j.conbuildmat.2011.12.089
[9] Instituto Colombiano de Normas Técnicas y Certificación , NTC 5525 – Métodos de ensayo para determinar las propiedades físicas y mecánicas de la Guadua angustifolia Kunth, Bogotá: ICONTEC, 2007.
[10] F. Bruhl y U. Kuhlmann, «CONNECTION DUCTILITY IN TIMBER STRUCTURES,» de World Conference on Timber Engineering, Auckland, 2012.
[11] AIS, Reglamento colombiano de Construcción Sismo Resistente NSR-10, Bogotá: AIS, 2010.
[12] A. Widyowijatnoko, R. Fitranto y R. Intan, «Proposing Joints for Bamboo Tensegrity,» de 10th Wolrd Bamboo Congress, Damyang, 2015.
[13] J. Janssen, «Designing and building with bamboo. Inbar, Technical report No. 20,» INBAR, Eindhoven, 2000.
[14] D. Jayanetti y P. Follet, «Bamboo in construction: an introduction. Technical report INBAR,» Inbar, Beiging, 1998.
[15] G. Minke, Building with bamboo, Birkhauser Verlag AG, 2012.
[16] O. Hidalgo, Manual de construcción con bambú, Bogotá: Estudios técnicos colombianos – Construcción rural, 1981.
[17] P. Laroque, Design of a low cost bamboo footbridge. Master Thesis, Massachusets: Massachusets Institute of Technology, 2007.
[18] K. Ghavami y L. Moreira, «Development of a new joint for bamboo space structures,» Transactions on the Built Environment, pp. 3-12, 1996.
[19] L. Moreira y K. Ghavami, «Limits states analysis for bamboo pin connections,» Key Engineering Materials, pp. 3-12, 2012. https://doi.org/10.4028/www.scientific.net/KEM.517.3
