LAUSR

Abstract The mining industry produces large amounts of waste during the iron ore processing. This material is usually discarded into tailing dams, posing high maintenance and monitoring costs as well as causing serious environmental disruptions, such as air contamination and leaching of substances. The reuse of such waste as alternative materials in the construction industry is an alternative to its disposal. Therefore, this study aimed at evaluating the effect of using iron ore tailing (IOT) on the physical, mechanical, thermal and durability properties of concrete roof tiles obtained by the extrusion process. The base trace in mass consisted of 1 : 3 : 0.56 (cement : medium grade natural sand : limestone powder). The treatments were based on 25, 50, 75, and 100% mass replacement of limestone powder by iron ore tailing. After shaping, the concrete roof tiles were taken to a saturated humidity chamber at room temperature for 28 days. Concrete roof tiles were evaluated for water absorption, dry weight, transverse breaking strength, bulk density, apparent porosity properties and microstructure at 28 curing days and after accelerated aging. Thermal conductivity, wettability, XRD, permeability and impact resistance analyses of roof tiles were also performed. There were significant transverse breaking strength and porosity values improvements as a result of using greater amount of IOT compared to traditional concrete roof tiles. The technological properties were improved by increasing the amount of waste, meeting international marketing standards. The use of iron ore tailing as total LP replacement showed great potential for use as raw material for concrete roof tiles production, allowing the correct disposal and development of new, more sustainable products, as well as the improvement of roof tiles physical and mechanical properties.