Rock Wool Waste as Supplementary Cementitious Material for Portland Cement-Based Composites

Rock wool is an insulating material applied worldwide, but it gradually loses its properties and is then deposited in landfills, creating an environmental issue. Therefore, this work evaluates the use of rock wool waste (RWW) as a supplementary cementing material (SCM). Initially, RWW was physically, chemically, and mineralogically characterized. Then, the cementitious capacity of RWW was investigated in portland-cement mortars using direct methods such as quantitative X-ray diffraction based on Rietveld's Method and simultaneous thermal analysis (TG/DSC), and indirect methods such as compressive strength index with portland cement and compressive strength index with lime. Furthermore, a morphological analysis by scanning electronic microscope (SEM) was applied in a cement mortar with RWW to evaluate the mechanical role of the particles. The results indicate that RWW promotes pozzolanic reaction and at same time works as crack arrester, encouraging its application as both a versatile and sustainable supplementary cementitious material.