Statistical modeling of rubberized concrete beams confined by FRP using RSM technique

Abstract

The use of rubber in concrete has been practiced in the engineering community for several years. However, the poor mechanical properties of rubberized concrete are a serious hurdle. This innovative research provides a closer look at improving the flexural strength of rubberized concrete beams with high rubber content using confinement technique. FRP jackets with different confinement thickness were used to recover the strength loss of rubberized concrete beams. In this paper, 66 rubberized concrete (RuC) beams having 0–50% rubber content were tested under four-point loading. RuC beams suffered up to 167% reduction in flexural strength. However, the FRP jackets were highly effective to improve the flexural strength of RuC beams. The statistical models were developed to predict the flexural strength of FRP confined rubberized concrete beams using response surface methodology (RSM). In this regard, the effect of two principle variables; unconfined strength and number of FRP layers on the flexural strength of FRP confined rubberized concrete beams was investigated. The models were found significant because the predicted and adjusted R2 was less than 0.2 (a limit proposed by Design Expert software). The predicted and experimental results for FRP confined rubberized concrete beams were found in good agreement. The developed statistical models provide insights into the sensitivity of parameters affecting the flexural strength. The proposed models can improve the reliability of the experiments and reduces the design and analysis time.