CFRP reinforced glulam beam 

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... composite fiber-reinforced polymer (FRP) is used in this study. FRP consists of a polymer matrix that is reinforced with fibers. The fibers are usually fiberglass, carbon, or aramid, while the polymer is usually an epoxy, vinylester or polyester thermosetting plastic. FRPs are commonly used in the aerospace, automobile, marine, and construction industries. Fig. 1 shows the CFRP reinforcement. The reinforcement materials used in this research are SikaWrapTM HEX-230C carbon fiber fabric unidirectional woven in 230 gr/m 2 and the epoxy resin of SikadurTM HEX300. SikadurTM HEX300 is an epoxy system which has high strength, a high modulus of elasticity, and which adheres even in the presence of moisture. For this research, it is used as primer and impregnating resin, as a bonding agent between the glulam beam and the reinforcement. These reinforcements are glued laterally on the glulam beam as shown in Fig. 2. The glulam beam is reinforced in tension (bottom of the beam) and on its sides with CFRP (U-shaped half wrapping). This reinforcement contributes to improvement in the wood’s mechanical behaviour and giving the necessary strength to avoid brittle failures. In particular, the shear and tensile strength of the reinforced wood increase considerably. The elastic constants and material properties of CFRP reinforcement are summarized in Table 2. These properties are typically provided by the manufacturer of the FRP material product. Nevertheless, independent checks (via theoretical calculations) and tests have been conducted to verify the FRP material properties reported here. CFRP becomes an alternative which is particularly useful for reinforcement in existing structures. Recyclability and environmental friendliness are important ecological attributes. Natural fibers, which serve as reinforcement in composite materials, have gained a renewed interest for use as construction material. Guadua Angustifolia is the predominant Bamboo in Colombia. Bamboo is mainly used in Colombia for household objects and roof systems; it is also employed for flooring and furniture. There are other more industrial-scale uses which are being developed and investigated. The process for obtaining Bamboo in sheets and planks involves cutting stalks into thin strips, making them flat, and finally boiling and drying the strips. Thin flat strips of bamboo are used in our research as reinforcement to improve the behaviour of the glulam beam. Fig. 3 shows the reinforcement, which is constituted by the bamboo ( Guadua Angustifolia ) and the epoxy resin of Sikadur HEX300TM . The bamboo strip reinforcements are glued laterally on the glulam beam as shown in Fig. 4 and 5. Elastic constants and material properties are summarized in Tables 3 and 4. Bamboo exhibits interesting specific mechanical properties compared to CFRP, especially regarding the modulus of elasticity. In all cases, the application of reinforcement must be carried out with precautions. The bonding of fiberglass and bamboo reinforcements must be prepared very carefully: - The wood surface must be flat, clean, and not weathered to insure proper adhesion. - The wood surface must be dry when carrying out the gluing process, in order to optimize the bonding between the wood and the reinforcement (the CFRP or the bamboo). This paper presents a comparative study: 10 non-reinforced glulam beams made of Carbonero ( Licania Campestre ), 8 CFRP reinforced glulam beams and 8 bamboo reinforced glulam beams were prepared and tested under four point bending. By reinforcing the glulam beams with bamboo or CFRP, a more homogeneous mechanical behaviour is obtained, since load capacity and ultimate displacement are increased. The tensile and shear strength must be enhanced mainly by the judicious use of reinforcement. Laboratory tests on non-reinforced and reinforced glulam beams were performed. The cross section of the beams is rectangular with a width of 50 mm and a height of 150 mm. The beam is simply supported with a span of 2.40 m represented by the geometry shown in Fig. 6 and 7. The glulam beams were made of Carbonero kiln-dry lumber. Prior to gluing, the laminas were conditioned to attain 12% equilibrium moisture content. Specific gravity based on oven-dry mass and volume at 12% moisture content of the specimens varied from 0,50 to 0,60 as determined per ASTM D2395-02 [3]. For each lamina, wood elastic properties were determined non-destructively using transverse vibration (E-computer) and visual grading criteria. Material shear strength and tensile strength parallel-to-grain were determined using ASTM D143-94 [2] test methods. Tests were conducted on small, clear, straight-grained specimens at 12% moisture content. The elastic constants of Carbonero are summarized in Table ...