International Journal of Composite Materials 2012, 2(5): 97-100 DOI: 10.5923/j.cmaterials.20120205.05 Experimental Evaluation of the Employment of a Laminated Composite Material with Sisal Fibres as Reinforcement in Timber Beams Samuel Sander Carvalho, Jezrael Rossetti Dutra, André Cerávolo de Carvalho, Luciano Machado Gomes Vieira, André Luis Christoforo * Department of M echanical Engineering, Federal University of São João del-Rei, 36.307-352, Brazil Abstract Timber is the oldest construction materials in the world, have been widely used in structures in addition to having a high longevity, if treated properly (maintenance). If this does not occur, the wood deteriorates due to the action of insects, fungi and other aggressive agents. There are several materials and techniques used to reinforce the damaged parts. This paper presents an experimental study ofEucalyptus grandis and Pinus elliiottiitimber beams reinforced with sisal fibres laminated composite materials. The composite material and the wood were prepared for testing. In order to simulate the defect, some parts were cracked. The study was to determine the maximum load (rupture) applied on the timberin the conditions: without defect, with defect and without composite and with defect and with composite, aiming to verify the efficiency of the laminate as reinforcement in the wooden beams. The experimental results indicate the possible use of the laminated composite as reinforcement, presenting considerable increase in the maximum strength supported by the timber when compared to unreinforced cracked condition, being more efficient for the Pinus elliiottii species. Keywords Laminate Composite, Sisal Fibre, Timber Beams, Structural Reinforcement 1. Introduction Beams are structural elements present in most of buildings. Among the usual materials engineering highlights the wood, to be from natural and renewable source, low density and good mechanical performance. Timber structures when not treated properly can present problems due to the attack of biological degrading agents that contribute to the loss of their physical and mechanical properties, compromising the integrity of the structural components. The study of repair and reinforcement in the structure of wood has been the focus of technical and scientific papers, aimed at developing viable solutions to be used in the recovery of the same[1-7]. Of the possible materials used as reinforcement and repair wooden structures stand out from the composites, because it is a material designed, in order to obtain a resultant mechanical properties superior to those of constituent phases[8]. The use of vegetable fibres such as sisal [9-14], coir, jute, bananaand bamboo as reinforcement in laminates composite are considered as a good solution, show good tensile * Corresponding author: alchristoforo@yahoo.com.br (André Luis Christoforo) Published online at http://journal.sapub.org/cmaterials Copyright © 2012 Scientific & Academic Publishing. All Rights Reserved strength[15-18], and are materials biodegradable and of low cost when compared to synthetic fibres[19]. With the purpose of developing alternatives as reinforcement in beams, this paper aims at the development and characterization of composite laminated polymer matrix reinforced with sisal fibres to be used as reinforcement in Eucalyptus grandis and Pinus elliottii timber beams. The wooden beams with and without the use of the composite laminate is tested in bending, by making use of the static three point bending tests, and comparing the maximum strengths condition to the faultless timber, and defective unreinforced and reinforced, and faulty, making it possible to evaluate the efficiency of the manufacture composite. 2. Material and Methods The raw material used is a vegetable fiber and sisal as reinforcement and resin epoxy as matrix fase. The laminate composite was manufacture with a layer. The fiber used was obtained from the Sisal company (Brazil), with caution as the use of fibres from the same batch. The Pinus elliottii and Eucalyptus grandis timber used in the fabrication of the specimens was obtained in a local sawmill in São João del-Rei (MG-Brazil), having as a precautionary pre-screeni ng of samples free defects. Brackets have been manufactured of cast iron with 225 mm by 160 mm wide synthetic enamel coated. The sisal