Behaviour of self-compacting concrete with cement replacement materials

Abstract

Self-compacting concrete is a type of special concrete which do not require vibration for compaction. The self-compacting concrete has a major disadvantage of its cost due to additional usage of chemical admixtures and Portland Cement. The cost of self-compacting concrete can be reduced by replacement of cement by cement replacement materials.In this paper fly ash, wood ash and their combinations are used as cement replacement materials. Fly ash is an mineral admixture that can be used in concrete. The Wood ash containing less Calcium oxide and significant quantity of Silicon dioxide may be used for replacement of cement. The incorporation of these replacement materials reduces the need for viscosity modifying agents. Higher durability and greater mechanical integrity can be achieved by lowering the water content in the concrete. Experimental investigations such as split tensile strength, compressive strength, flexural strength of self-compacting concrete containing cement replacement materials are conducted to determine their Mechanical properties. Workability tests (slump, L-box, V-funnel) on the corresponding mix are also used to study the characteristics. The methodology adopted here is the cement replacement materials are replaced 10% and 20% by weight of ordinary Portland cement and the performance is measured. To improve the workability of the concrete 1.5% of super plasticizer (glenium B233) by weight of the cement is used as chemical admixture. Guidelines given by EFNARC are followed to design the mix. From this investigation it is observed that the optimum replacement of 10% of wood ash and fly ash in self- compacting concrete increases the compressive strength of the of the concrete mixture.