Utilization of Steelmaking By-Products and Aluminum Sludges in Alkali-Activated Materials: A Sustainable Approach for Construction Applications

Abstract The sustainability of resources, including construction and building materials, is becoming an increasingly pressing issue due to the world’s rapidly increasing population. Research on alternatives to ordinary Portland cement (OPC) for use as concrete binder, such as alkali-activated cements (AAC) is a continuing endeavor. Due to reduced CO 2 emissions associated with their manufacture, they pose less of a threat to the environment while having mechanical properties that are on par with the OPC. Building alkali-activated materials (AAM) with acceptable qualities for building applications while minimizing CO 2 emissions and costs is the goal. These materials maximize the incorporation of recycled materials. A number of initiatives are therefore underway to develop environmentally friendly building materials from a variety of sources and raw ingredients. The by-products of the steelmaking sector have recently attracted a lot of attention, mainly because they are easily accessible. The utilization of ladle slag (LS), a waste product from the steel industry, as an essential component in AAC was the focus of this research. Aluminum surface treatment’s by-product, aluminum anodizing sludge (AS), and phosphate treatment’s byproduct, phosphating bath sludge (PS) were mixed with it at additional rates of 15 % and 25 %, respectively. A commercial solution (COM) made up of NaOH and Na 2 SiO 3 and a solution that was wasted after cleaning aluminum extrusion steel dies (CLE) were the two alkaline solutions that were used to activate the precursors. Through the use of X-ray diffraction and Fourier transform infrared, as well as the rheology, heat of hydration, compressive strength (CS), and performance of alkali-activated LS, this study investigates the effects of steelmaking by-products (PS, AS, and CLE). The findings demonstrated that the CLE did not weaken the AAM with PS or AS, but it did double the strength of the LS when used alone. Also, compared to the CLE, more fluid pastes were produced when a commercial activator (COM) was used and this was true regardless of the precursor combination.