Applicability of the response surface method in the optimization of compressive strengths of banana-fiber-reinforced concrete using waste glass as partial cement replacement

Natural fibers and pozzolan have gained prominence in the development of concrete; however, there are few studies that have considered the combination of banana fiber and waste glass powder. In this work, 0.5%, 1.0%, and 1.5% banana fiber (BF) was employed as fiber reinforcement, while glass powder (GP) was used as pozzolan, partially replacing cement at 10%, 20%, and 30%. Using the response surface method (RSM), the experimental data on the 7-, 28-, and 56-day concrete compressive strengths were analysed, modeled and optimized via the response surface approach. The result revealed that the variables played an important role on the trend of the 7-, 28-, and 56-day compressive strengths. The optimal combination of 1.0%, 1.1%, and 1.0% banana fiber at 17.4%, 20.8%, and 21.0% GP cement replacement yielded improvements of 11.0, 22.1, and 27.0% over the reference concrete at 7, 28, and 56 days, respectively. The developed predictive models for compressive strength were affirmed to be statistically fit for future prediction.