Finite element simulation of retrofitting of RCC beam using sisal fibre composite (natural fibre)

Abstract

Many of the existing reinforced concrete structures throughout the world are in urgent need of rehabilitation, repair or reconstruction because of deterioration due to various factors like corrosion, lack of detailing, failure of bonding between beam-column joints, increase in service loads, etc., leading to cracking, spalling, loss of strength, deflection, etc. The recent developments in the application of the advanced composites in the construction industry for concrete rehabilitation and strengthening are increasing on the basis of specific requirements, national needs and industry participation. The need for efficient rehabilitation and strengthening techniques of existing concrete structures has resulted in research and development of composite strengthening systems. Fiber Reinforced Polymer (FRP) composite has been accepted in the construction industry as a promising substitute for repairing and in incrementing the strength of RCC structures. FRP composites possess some outstanding properties such as: resistance to corrosion, good fatigue and damping resistance, high strength to weight ratio, and electromagnetic transparency. During the last decade there has been a renewed interest in the natural fibre as a substitute for conventional FRP materials such as glass fibres and carbon fibres, motivated by potential advantages of weight saving, lower raw material price, and ‘thermal recycling’ or the ecological advantages of using resources which are renewable, also natural fibres are sustainable materials. On the other hand natural fibres have their shortcomings, and these have to be solved in order to be competitive with glass and carbon. Natural fibres have lower durability and lower strength than glass fibres. However, recently developed fibre treatments have improved these properties considerably. We have enough natural resources and we must keep on researching on these natural resources. Among the various natural fibres, sisal fibre reinforced composite is of particular interest as these composites have high impact strength besides having moderate tensile and flexural properties compared to other lignocellulosic fibres. Hence encouragement should be given for the use of natural fibres, Here a nonlinear finite element analysis is carried out in order to evaluate the performance of sisal fibres in structural retrofitting by retrofitting a Plain Concrete Block by using sisal fibre reinforced polymer. It is seen that the strengthened specimens exhibit significant increase in strength, stiffness, and stability as compared to controlled specimens. It appears that the proposed simulation technique will have a significant impact in engineering practice in the near future.