AN EXPERIMENTAL STUDY OF CONCRETE PROPERTIES BY USING BY PRODUCT OF REPI WASTE TO ENERGY PLANT AS SUPPLEMENTARY CEMENTING MATERIAL

Abstract

Repi waste to energy plant, is power plant that consumes 80% of Addis Ababa’s city’s waste producing, 28 tones fly ash per day. However the disposal of the fly ash is becoming another challenge. To this end its use in concrete is proposed. Concrete containing this fly ash in construction is vital task due mainly to structural and economic advantages that fly ash concrete offers over conventional concrete. This thesis presents the results of an extensive experimental test which was carried out to study the influence of Repi waste to energy plants fly ash on the compressive strength, flexural strength tensile strength, shrinkage of concrete, Sulphuric acid attack and water absorption of the concrete. Parameters involved were 0%, 10%, 20% and 30% of fly ash replacement level with high strength and normal strength concretes. Test results indicate that for normal strength concrete 15% and for high strength concrete 10% cement replacement by fly ash has good compressive strength, flexural strength tensile strength. As fly ash percentage increases shrinkage of concrete decreases for both normal strength and high strength concretes. Water absorption decreases as fly ash percentage increases for normal strength and for high strength concrete water absorption decreases up to 20% fly ash. Acid resistance tested by weight loss and compressive strength, decreases as fly ash percentage increases