Analysis of chloride diffusivity in red mud-ordinary portland cement concrete

Resumo

Red mud is a solid waste produced in the alumina production process and, due to its high pH, is classified as hazardous. Its incorporation in concrete mixtures, acting as filler due to the particles fineness, might be an interesting reuse alternative. The focus of the actual paper is studying the chloride diffusivity of red-mud containing mixtures. The concentration of chlorides was monitored by measuring the conductivity of the anolyte, which initially is distilled water. Additionally, the estimation of the chloride ions diffusion coefficients in steady and non-steady conditions, Ds and Dns, was obtained from the ‘‘time-lag’’ and ‘‘equivalent time’’ between diffusion and migration experiments. Due to superfine particle-size distribution and the “filler” effect, the red mud addition seems to assure lower chloride diffusivity.