Normal conventional concrete has been widely used as a construction material throughout the world because of its advantages of high compressive strength, durability, mouldability, etc. The current global scenario shows increased construction of large and complex structures with heavy reinforcement and complicated shapes. Using normal concrete in such situation may often result in inadequate compaction, affecting performance and long-term durability of structures. One solution for the achievement of durable concrete structures is the use of Self-Compacting Concrete (SCC). In the present work, the behavior of fresh and hardened state properties of SCC of three different grades M₂₀, M₄₀ and M₆₀ was investigated experimentally. The results indicated encouraging strengths of SCC with Ground Granulated Blast Furnace Slag (GGBS) and Rice Husk Ash (RHA). The optimum quantities of GGBS and RHA were arrived for the three grades of SCC to achieve fresh state properties without compromising the strengths.

Nowadays, performance expectations from concrete structures are more demanding. As a result, concrete is required to have properties like high fluidity, self-compactability, high strength, high durability, better serviceability and long service life. In order to meet such requirements, Self-Compacting Concrete (SCC) was developed in 1980 in Japan (Hajime, 1997). SCC is defined as "A category of high-performance concrete that has excellent deformability in the fresh state and high resistance to segregation, and can be placed and compacted under its self-weight without applying vibration" (Ozawa, 1989).

SCC is a high-performance concrete, which distinguishes itself with self-consolidation properties and with high flowability. It offers many advantages over conventional concrete, viz., an improved quality of concrete, reduction of onsite repairs and speedy construction. An important improvement of health and safety is also achieved through elimination of handling of vibrators, which reduces environmental noise loading on and around a site. SCC can be used to achieve durable concrete by using admixtures like superplasticizer, superfine powder, and viscosity modifying agents (Peiwei et al., 2001). High flowability required by SCC allows the use of lower quantities of cement and substantial use of mineral admixtures, the disposal of which is a major problem (St. John, 1998). The usage of admixtures like Ground Granulated Blast Furnace Slag (GGBS) and Rice Husk Ash (RHA) enhanced the strength of SCC (Ferraris et al., 1999). Khayat (1999) concluded from his investigation that compressive strength and modulus of elasticity were greater for SCC samples than those obtained from the medium fluidity conventional concrete. Malathy and Govindasamy (2006) conducted experiments on SCC of grades M₂₀ to M₆₀ and developed charts for obtaining quantity of cement, fly ash and coarse aggregate required for different grades of SCC. Mohammed (2004) concluded from his investigation that the settlement of fresh SCC increases with the increase in water/powder ratio and the nature of sand also influences the maximum settlement.

Structural Engineering Journal, Mineral Admixtures, Ground Granulated Blast Furnace Slag, Rice Husk Ash, Viscosity Modifying Agent, Chemical Compositions, Conventional Workability Tests, GGBS Replacements, Construction Materials, Conventional Concrete, Superfine Powder.