Optimization of concrete produced from industrial waste and fibre using regresion model

Abstract

This research examined the potential for reusing glass fiber, fly-ash, and quarry dust, in concrete production through partial substitution of traditional cement and sand. The study employed an experimental mix design to ascertain the compressive strength of concrete when these waste materials are incorporated. Various tests, including compressive strength, slump, and air void tests, were conducted on concrete cube samples with varying percentages of waste material substitutions. The cube samples were designed with specific proportions: fly-ash replaced cement at increments of 10%, 20%, and 30%, while glass fibers were added as an admixture at 1%, 2%, and 3%. Similarly, quarry dust replaced sand at 10%, 20%, and 30%, with glass fibers added at the same percentages. Additional cube samples were prepared with quarry dust and fly ash partially replacing sand and cement at 5%, 10%, and 15%, with glass fibers added at 1%, 2%, and 3%. These samples were subjected to a curing process in water for durations of 7, 14, 21, and 28 days. A linear regression model was developed based on forty compressive strength test results, positioning compressive strength as the dependent variable and the volume of glass fibers, quarry dust and fly ash as independent variables. A model of the form: CS = 0.216Vgf + 0.068Vqd + 0.979Vfa + 26.078 was developed where CS is the compressive strength, while Vgf, Vqd and Vfa represent volume of glass fibers, quarry dust and fly ash with their coefficients respectively. The model's findings indicate that the industrial waste that significantly enhances the compressive strength of the concrete is fly ash, followed by glass fibers, while quarry dust has minimal influence. The optimal strength achieved was 24.89 N/mm2 at 28 days when fly-ash, quarry dust, and glass fibers were combined.