Fresh and hardened properties of self-compacting concrete produced with manufactured sand

Self-compacting concrete (SCC) is extensively applied in many construction projects due to its excellent fresh and hardened concrete properties. In recent years, manufactured sand (Msand) produced by crushing rock deposits is being identified as a suitable alternative source for river sand in concrete. The main objective of this study is to explore the possibility of using Msand in SCC. In this process, an attempt was made to understand the influence of paste volume and w/p ratio (water to powder ratio) on the properties of self-compacting concrete (SCC) using Msand. The powder and aggregate combinations were optimised by using the particle packing approach, which involves the selection of combinations having maximum packing density. The chemical admixtures (superplasticisers, viscosity modifying agent) were optimised based on simple empirical tests. Fresh concrete tests such as slump flow, T(500) and J-ring were performed on SCC: hardened concrete tests were limited to compressive strength. From the results, it was observed that relatively higher paste volume is essential to achieve the required flow for SCC using Msand, as compared to river sand. Low and medium strength (25-60 MPa) SCCs were achieved by using Msand based on the approach adopted in the study. Results showed that it is possible to successfully utilise manufactured sand in producing SCC. (C) 2010 Elsevier Ltd. All rights reserved.