Modelling the complementary role of inert slag aggregate and waste glass on concrete mechanical strengths using the response surface and design-of-experiment approach

Abstract

Recycling steel slag (SS) and waste glass (WG) in concrete represents a sustainability measure to promote the production of cost-effective and eco-friendly concrete. This study assessed the weight replacement effects of steel slag (SS) with coarse aggregate (up to 100 %), those of waste glass (WG) with cement (up to 30 %), and the water-to-binder ratio on the workability, density, compressive strength, and splitting strength. Multiple blends of the binary binders were examined using the design of experiments (DoE) approach to evaluate the technical feasibility of SS and WG and their synergistic effects in enhancing the properties considered. The second-order polynomial model used was sufficiently accurate to yield high correlation levels between the responses and the studied variables with high determination coefficient up to 98 %. The inclusion of WG in concrete produced with a 100 % replacement level of SS effectively addressed the site rheological pumping problems with higher strength, 58 % more in compressive and 33 % more in splitting strengths.