Variation of Tensile Strength Parallel to the Fiber of Bamboo Guadua Angustifolia Kunth in Function of Moisture Content

Abstract:

As other natural materials used in construction, Bamboo Guadua is affected by different factors that can modify its strength. One factor is the equilibrium moisture content, which is a physical property related to temperature and relative humidity of the area where the material is used. Several studies have shown that the material strength to different load requirements decreases as moisture content increases. Samples from three different regions of the Republic of Colombia (Coffee region, Valle del Cauca and Cundinamarca) were taken to study the variation of the tensile strength parallel to the fiber of bamboo Guadua Angustifolia Kunth in function of the moisture content. Ten culms were taken from each region and three sections from different parts of each culm (bottom, middle and top) were selected. At least seven samples of each section were extracted and tested (so the samples taken from the same piece of bamboo have similar characteristics). The natural moisture content of each sample was modified to determine the strength with different moisture content. The method to vary the moisture content used in the research guaranteed that each group of samples, with similar characteristics, had a moisture-controlled variation. Colombian Technical Standard NTC 5525 "Methods for testing the physical and mechanical properties of Guadua Angustifolia Kunth were followed to determine the tensile strength parallel to the fiber, as well as to determine the material moisture content. Tensile tests were performed after immersing the specimens in water for about 72 hours, when the material showed a pronounced variation in moisture content. Finding that tensile strength did not show an obvious decrease, the range of moisture content was reduced to less than 35%. In order to have all the information with samples with moisture content below of that percentage, the tests were carried out during a 3-hour range of time. Results showed that tensile strength of parallel fiber does not decrease as the moisture content of the material was increased in the moisture content range where the material is used as a structural element.

• Periodical: Key Engineering Materials (Volume 517)
• Pages: 71-75
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.517.71
• Online since: June 2012
• Authors: Mateo Gutierrez Gonzalez, Caori Patricia Takeuchi, Michel Córdoba Perozo
• Keywords: Bamboo Guadua Angustifolia Kunth, Moisture Content, Tensile Strength

References

[1] ANTONIUS JANSSEN, Julius J. Bamboo in building structures. Netherlands. (1981).

[2] ASOCIACIÓN COLOMBIANA DE INGENIERÍA SÍSMICA. Seismic resistant building colombian code. Bogotá, 2010 (NSR-10).

[3] WOOD FEATURES AND PROPIERTIES. Junta del Acuerdo de Cartagena. COLOMBIA. (1987).

[4] GHAVAMI, Khosrow. Propriedades físicas e mecânicas do colmo inteiro do bambu da espécie Guadua angustifolia. PUC-Rio. BRASIL. (2002).

DOI: 10.1590/s1415-43662005000100016

[5] HIDALGO O. Bamboo the gift of the gods. 1 ed. Colombia: Editorial D'VINNI Ltda.; (2003).

[6] HONGYAN CHEN , MENGHE MIAO, XIN DING. Influence of moisture absorption on the interfacial strength of bamboo/vinyl ester composites. Composites: Part A. (2009).

DOI: 10.1016/j.compositesa.2009.09.003

[7] INSTITUTO COLOMBIANO DE NORMAS TÉCNICAS. Methods for testing the physical and mechanical properties of Guadua Angustifolia Kunth. Bogotá: ICONTEC, 2007 (NTC5525).

[8] INTERNATIONAL ORGANIZATION FOR STANDARIZATION. Bamboo structural design. ISO, 2001 (ISO 22156).

[9] ORDOÑEZ CANDELARIA, Rubén y DAVALOS SOTELO, Raimundo. Adjustment of the mechanical properties for timber by moisture content changes. Department of forest products and forest conservation. Ecology Institute, Mexico. MEXICO. (1995).