Experimental Study On Fresh Concrete Using Metakaolin And Fly Ash As Partial Replacement Of Cement

Research Article
Premchand K, Sreenivasa Reddy K and Nithin Kumar A
Metakaolin, Fly Ash

Concrete is most widely used construction material because of ease of construction and its properties like compressive strength and durability. It is difficult to point out another material of construction which is versatile as concrete. It is well known that plain concrete is very good in resisting compressive strength but possesses low specific modulus, limited ductility and little resistance to cracking. Internal micro cracks inherently present in the concrete and its poor tensile strength is due to propagation of such micro cracks eventually leading to brittle failure of concrete. To ensure its high filling ability, flow without blockage and to maintain homogeneity, SCC requires a reduction in coarse aggregate content and hence a high cement content which can increase cost and also cause temperature rise during hydration as well as possibly affect other properties such as creep and shrinkage. Therefore significant quantities of additions are often incorporated to replace some of the cement, to enhance the fresh properties and reduce heat generation. Several admixtures have been developed to improve the strength and workability properties of concrete. Of all admixtures used in concrete, Metakaolin occupies a special position for quite a few reasons. The improvement of durability, resistance to chloride, sulphate, freezing and thawing, alkali silica reaction, frost attack, increase in compressive strength, reduces the permeability and bleeding. Metakaolin effectively improve the structure of interface eliminates the weakness of the interfacial zone. The present experiment is carried out to investigate the fresh and hardened properties concrete with 10% of Metakaolin and 30% of fly ash by weight of cement as partial replacement of cement.Compressive strength of Fresh concrete is measured by testing standard cubes (150mmx150mmx150mm) at the age of 7 and 28 days