Behaviour of high grade concrete with recycled refractory brick aggregates and alccofine: an experimental and machine leaning based evaluation

Abstract

The extensive use of natural resources in construction and development projects across the globe poses serious environmental challenges and ecological imbalance and has led to the search for alternative construction materials. In view of this, the present study investigates performance of novel M40 grade concrete blend containing Portland Slag Cement, Alccofine as constant partial replacement (15%) for cement, and Recycled Refractory Brick (RRB) as a partial substitution for natural fine aggregate (10, 20, 30, 40, and 50%), with and without Polypropylene Fibre (PPF) (1% of binder content). The behaviour of the proposed concrete blend has been evaluated through destructive and non-destructive tests, including compressive strength, ultrasonic pulse velocity, rebound hammer, after 7 days and 28 days of normal water curing. To assess the microstructural integrity and the development of hydration products in the concrete matrix, scanning electron microscopy analysis has also been conducted. Experimental outcomes and microstructural evidence indicate that 40% RRB with 15% Alccofine as a binder replacement yielded optimal performance, followed by 30% RRB. The high pozzolanic activity of Alccofine and its fineness contribute to strength enhancement, while PPF Failure pattern observations and SEM analysis suggest improved crack-control capability and fiber-matrix interaction. The experimental compressive strength performance has also been validated using machine learning approaches. Among the proposed models, the random forest performed best. In the author's opinion, the proposed novel blend with moderate RRB and Alccofine produces eco-friendly M40-grade concrete while protecting natural resources and effectively utilizing waste.