Regression analysis and optimization of compressive and tensile strengths of concrete incorporated with sodium hydroxide treated rubber crumb and steel wire using statistical method and 3D graphing calculator model

In most recent times, the indiscriminate disposal of scrap tyres is highly contributing to the reduction in environmental sanitation of many global communities. One of the ways in managing this problem is via incorporating into cement composites as an ingredient. Despite the applications of rubber crumb (RC) in concrete, the combined effects of treated RC and steel wire is yet to be explored. This research works on mitigating the problem of RC-concrete’s strength reduction by jointing applications of sodium hydroxide (NaOH) treated RC and scrapped tyres steel wire (SW). The aim of the study is to produce RC-concrete with enhanced mechanical properties such as compressive and tensile strengths; model and optimize the outcomes using regression analysis (RA) and 3D graphing calculator (3DGC). In the process, the RC-SW-concretes were produced using a mix ratio of 1:2:3, 0.43 water–cement ratio. Addition of 3% SW being kept constant was jointly used with RC at varying levels of 1.5, 2.5, 3.5, and 5.0%, respectively. The RC-SW-concrete’s workability, consistency, setting times, compressive and tensile strengths were determined accordingly. The experimental results show that, RC-SW-concrete has good workability with slump values of 80–100 mm and setting times of 88–181.02 min. Also, it was observed that incorporation of RC and SW in concrete increased the concrete’s compressive strength by 1.03 and 5.86% at 1.5% of RC and a constant 3.0% of SW at 7 and 28 days; and tensile strength by 7.60, 6.11 and 3.55% at 1.5, 2.5, 3.5% of RC and a constant 3.0% of SW at 28 days of curing than that of control respectively. The RA model predicted results validate the experimental outputs with the predicted optimum compressive and tensile strength (CS and TS) values of 81.34 and 9.37 MPa at 1.5% of RC and 3.0% of SW which are closer to those of experimental values, 84.87 and 9.73 MPa respectively. Also, 3DGC model optimized the best CS and TS as 84.9 and 9.73 MPa at 5.0% of RC and a constant 3.0%SW at 28 days of curing respectively. In conclusion, 1.5–3.5% of RC and 3.0% SW have great potential benefits for the production of good strength concrete for construction practice.