Experimental Investigation of Rheological Properties of Recycled Aggregate Concrete

Abstract

Increasing construction activity has increased the demand for construction materials, and concrete is one of the most widely used construction materials. Concrete is popular for its property of mold-ability and fluidity at early stages. The fluidity of concrete can be characterized by the study of its flow behavior in fresh state. The rheological behavior of recycled aggregate concrete is affected by superplasticizer and mineral admixtures. Hence, this study is carried out with the inclusion of mineral and chemical admixtures. Plastic viscosity of concrete is predicted using models which are essential for concrete production. An attempt is done to study the compressive strength of concrete by replacing the natural coarse aggregates by recycled coarse aggregates. After understanding the compressive strength of various replacement ratios, an optimum replacement ratio is identified using Taghuchi method. Using the Taghuchi method—which is based on principles of design of experiments—the optimum replacement ratio was found to be 45% [2]. The rheological properties were studied using direct shear box test to obtain the corresponding yield stress and plastic viscosity of concrete made from natural coarse aggregates and concrete made from recycled coarse aggregates.