Strength parameters of compressed stabilized earth blocks using furnace bottom ash as a cement replacement

Abstract

Furnace Bottom Ash (FBA) is the waste by product that falls to the bottom of the pulverized coal furnaces when the ash particles become too large to be carried in the flue gases. Physical appearance of FBA is porous in nature, grey in colour and fine sand to coarse gravel range of particle size. FBA has similar chemical properties to Pulverized Fuel Ash (PFA) with the three predominant elements being silica, aluminum and iron, the oxides including considerable pozzolanic properties. Current applications of this by product include aggregate in lightweight concrete products, filler material for structural applications and embankments, Aggregate in road bases, sub-bases, and pavement and feed stock in the production of cement. In this research, FBA obtained from Norochchole power plant in Sri Lanka is used as a cement replacement in investigating dry and wet compressive strengths of Compressed Stabilized Earth Blocks with 30% and 50% replacement of cement. The CSE blocks used in the experimental programme were manufactured using a mix of laterite soil and cement (6% of cement). A Comparison and a relationship of unit strength Vs wall panel strength is obtained in order to recommend practical applications of the final product.