Large amounts of Construction and Demolition (C&D) waste materials are generated by construction projects and there is a wide scope for reusing or recycling them. Presently, due to continuous global demand for infrastructure due to persistent increase in population growth has led to large consumption of aggregate and cement for concrete production. This would eventually lead to more extraction and depletion of natural resources and increased carbon emission. This study aims at providing an exhaustive comparison using natural aggregates and recycled aggregates to produce Self–Compacting Concrete (SCC), which is a high-performance concrete. Totally twenty one mixes were investigated. The Girish method of mix design, which is based on absolute volume concept starting with a volume of paste, was advantageously used to develop the mixes with less number of trials. The paste and the total powder content used in this study have a wide range considering the field requirements and the unfavourable aggregates used. The water to cement ratio varied widely from 0.38 to 0.67, total powder content from 455 kg/m3 to 672 kg/m3 and volume of paste from 0.37 to 0.43. Tests were carried out to assess the fresh properties as well as the compressive strength and split tensile strength of concrete. The 28 day compressive strength ranged from 22 MPa to 51 MPa. The study clearly demonstrates that an increase in paste content both for natural and recycled aggregates leads to increase of the compressive strength of SCC. However, the increase has optimality at Vp 0.43 for the materials used in this study and this can be one of the factors to be considered in the mix design. The volume of paste ranging from 0.37 to 0.43 can be successfully used for developing SCC for both natural and recycled aggregates.
