Strengthening of RC beams using bamboo fiber composite plates in bending / Paw Keh Kui

Faculty of Civil Engineering and Earth Resources

Project Paper (Bachelors of Civil Engineering) -- Universiti Malaysia Pahang – 2019

Includes bibliographical references

Synthetic fiber composite plates have been widely used as strengthening material for existing structures due to its high water resistant, resistant to corrosion and thermal stability. However, the major limitations of the synthetic fiber composite plate are high production cost and non-biodegradable, which would lead to environment pollutions due to the production of carbon dioxide gas during the fabrication process. Therefore, a study had been conducted to examine the potential of bamboo fiber composite plate (BFCP) in replacing the synthetic fiber composite as an external strengthening material on RC beams. In this present research, bamboo species with scientific name of Gigantochloa Scortechinii Gamble (Semantan species) had been treated and used to fabricate the BFCP in various fiber volume ratios of 0, 0.30, 0.35, 0.40, 0.45 and 0.50. The BFCPs with respect to fiber volume ratios were tested for flexural (ASTM D790-03) and tensile tests (ASTM D3039) in order to determine the optimum mechanical properties of BFCP for the use of external strengthening material on RC beams. In this study, the strengthening configurations were categorized into three series, which include series ST1, ST2 and ST3. For series ST1, BFCP with a dimension of 25 x 250 and a thickness of 4 mm was strengthened in staggered at the bottom soffit of RC beams while BFCP (4 x 120 x 350 mm) was bonded at the bottom soffit of RC beams in series ST2. Other than that, RC beams in series ST3 were strengthened with BFCP with a dimension of 120 x 350 and a thickness of 4 mm at the bottom soffit and additional BFCP (4 x 25 x 250 mm) at the side of RC beams. Four-point bending test was carried out to determine the structural behaviour of RC beams strengthened with BFCP at the tension zone. In terms of mechanical properties of BFCP, both flexural and tensile strengths of the composite increases as the fiber volume ratio increases from 0.30 to 0.45. However, the flexural and tensile strength of the composite start to decrease at 0.50 fiber volume ratio. Hence, BFCP with 0.45 fiber volume ratio contributed the highest mechanical properties which increased about 154% and 369% higher than the neat epoxy specimen in flexural and tensile strength, respectively. In terms of load-deflection behaviour of RC beams, strengthened beams in series ST2 and ST3 contributed a load carrying capacities about 15.7% and 15.5%, respectively higher than the control beams and reduced its deflection. Meanwhile, the strengthened beams in series ST1 failed to improve the load carrying capacity compared to the control beams. Thus, BFCP strengthened beams in series ST2 was the most effective strengthening configuration in improving the strength of RC beams. Other than that, BFCP has reduced and diverted the cracks at the tension zone along the RC beams away from the strengthened region. The failure mode of the BFCP in strengthening RC beams were in flexural. This obtained findings proved that the BFCP has the potential in replacing the synthetic fiber composite plate as external strengthening material on RC beams.