Combined Effect of Ternary Blended Cementitious Materials in Self-compacting Concrete

Abstract

Self Compacting Concrete (SCC) is a type of special concrete which possess self packing and flowability to fill the formwork space completely by its own weight without any external vibration or compaction. Research studies on finding efficient, economical and eco-friendly materials to replace the conventional concrete materials are increasing day-by-day. An important constituent material of concrete is cement which contributes to the environmental hazardous problem of CO2 emission. In this view, the present study investigated the fresh and hardened properties of SCC in which cement is partially replaced by multi-cementitious materials namely fly ash, alccofine and Recycled Concrete Powder (RCP). Fly ash and alccofine are evident materials to replace cement in concrete. In addition to the substitution of cement by 20% replacement by fly ash and 10% replacement by alccofine, recycled concrete powder collected from construction wastes are also incorporated (5%, 10%, 15%, 20%) and investigated. Water/binder ratio is kept constant as 0.45. Polycarboxylate based super plasticizer (Conplast SP430) was used. The experimental program comprises testing the fresh stability by determination of flowability, passing ability and viscosity, mechanical strength testing including compressive strength, split-tensile strength and flexural strength and durability properties such as water absorption, sorptivity and acid-attack of SCC specimens. The test results showed that 10% recycled concrete powder exhibited better performance in fresh stability and satisfied performance mechanical strength. Increase in RCP content beyond a limited proportion possesses detrimental effects on the durability characteristics.