Study on the feasibility of partial replacement of cement with IOT in extruded concrete roof tiles production

Abstract

The use of mining waste (IOT) as supplementary materials for cement has the potential to significantly reduce carbon emissions, helping to mitigate the demand for natural resources and the impacts associated with their production.Concrete tiles have been gaining prominence in recent years due to practicality, aesthetics, weather resistance, attractive price, ease of fitting and useful life, however, there is no information in the literature about the effect of IOT as a pozzolanic material for partial replacement of Portland cement in these composites. Therefore, this study aims to expose the use of iron ore tailing (IOT) as a partial replacement for Portland cement in extruded concrete tiles in different proportions, qualifying and classifying them according to the marketing standards. The performance of concrete roof tiles using IOT was analyzed for bulk density, dry weight, apparent porosity, water absorption, wettability, breaking load, impact strength, coefficient of restitution, and thermal conductivity. In addition, microscopy and X-ray diffraction examined interactions between IOT particles and cementitious matrix at 28 days and after accelerated aging. Economic analyses regarding the effect of using IOT on the final cost of concrete roof tiles were also performed. The results showed that the concrete roof tiles produced with IOT presented suitable physical, mechanical, and thermal properties, highlighting the samples with 10% IOT as a replacement for cement, which proved superior to conventional tiles for the breaking load at 28 days, also presenting an average value reduction of 6.61% for porosity and 33.33% for wettability. All formulations were approved for breaking load according to the international marketing standard and may cut costs for companies producing cement roof tiles by up to 40%. In addition to reducing the potentially harmful waste in containment dams, IOT may lessen the demand for Portland cement and, consequently, CO2 emissions, producing more sustainable composites with significantly reduced manufacturing costs.