Mechanical Behavior of White Ordinary Portland Cement Paste with Iron Oxide Powders Containing Arsenic

This paper is about the use and stabilization of iron oxide based powders with arsenic contents coming from the purification of water. Cement paste samples with 0.0, 2.5, 10 and 20wt% of waste were fabricated by mixing mechanically all components. There are two main positive impacts of using this waste, first, this waste is produced in large amounts worldwide, and therefore the stabilization has a significant impact for the environment. Second, the waste can be used as an admixture and filler for cement, and therefore reduce the amount of cement in the concrete, which has a major impact in the CO2 footprint since cement industry produces a lot of this gas. Compressive strength and density tests were tested after 28 days. Microstructure was analyzed with scanning electron microscopy and x-ray diffraction. Results show that compressive strengths greater than 20 MPa were obtained and the samples had calcite, portlandite and ettringite phases.