Properties of IOTs concrete produced using fly ash cement

Abstract

Abstract. This work studied the effect of using iron ore tailings (IOTs) as partial replacement for sand, on some mechanical properties of concrete, using class F brand fly ash (FA) cement as the binder. The results obtained, were compared among the different concrete samples produced, varying the percentage of iron ore tailings content in the concrete. Basic properties of the focused material, iron ore tailings (waste material generated during the production of iron ore), were determined and compared with those of natural sand, which is conventionally used to produce normal strength concrete. Similarly, the field emission scanning electron microscopic image and the energy dispersive X-ray spectroscopy of sand and the iron ore tailings were evaluated. Five different types of concrete samples were produced. The percentage of IOTs as partial replacement for sand, used in producing the concrete samples was varied from 0% to 40% at 10% interval. Water/cement ratio of 0.54 with class F fly ash cement content of 463kg/m3, was used in preparing fresh concrete samples. The concrete samples produced, recorded lower workability with increase in content of iron ore tailings, but concomitantly there was increase in cohesiveness. There was increase in strength of hardened concrete samples with increasing content of the IOTs up to the optimum at 30%. This trend is similar for the compressive strengths, splitting tensile strengths and the flexural strengths. The outcome of this study revealed that, IOTs can be used to partially replace sand, for the production of normal strength concrete, using class F fly ash cement.