Optimizing natural fiber reinforced polymer strengthening of RC beams

The performance of natural fiber reinforced polymer (NFRP) in the flexural strengthening of reinforced concrete (RC) beams is evaluated and optimized in this paper. The optimization comprehensively considers the structural performance, cost efficiency and environmental impacts. Main design parameters – such as the fabrication, the bond condition and the section shape of NFRP laminates – are investigated. The test results revealed that the partial bonded NFRP laminates tended to increase the flexural stiffness within the elastic range. Given the same reinforcement ratio, narrow and thick NFRP yielded the best structural performance. The prefabrication of NFRP laminates using vacuum infusion method greatly decreased the volume fraction of epoxy resin and the related environmental impacts without changing structural performance. The assessment of material cost and environmental impacts indicated that the prefabrication NFRP laminates had obvious advantages over the carbon FRP laminates.