Comparison of Drying Shrinkage Models of IOT Concrete

Abstract

Problems associated with drying shrinkage of concrete is still a major source of concern in the construction industry. Due to the hygral nature of concrete, particularly the instability of the volume as a result of drying shrinkage, concrete will crack at any stage during its service life. The depletion of the environment due to huge consumption of sand for construction is another major problem. Iron ore tailings (IOT), an industrial waste, generated during the production of iron ore is utilized in concrete to lessen the environmental problems. Their on ore tailings was sourced from a local iron ore producing mine and the material was used as partial replacement for sand to produce normal weight concrete. The drying shrinkage of this concrete was compared with that of the control normal weight concrete. The ultimate drying shrinkage of the concrete samples were further studied, using three prediction models. The inclusion of iron ore tailings as fine aggregate in concrete contributed to reduction of the drying shrinkage recorded at 28, 56 and 90 days as well as the ultimate drying shrinkage. The drying shrinkage of concrete and the predicted ultimate drying shrinkage recorded by the B3 and GL2000 models agreed more closely, as compared with the recorded values obtained using ACI209R model.