DURABILITY OF CONCRETE CONTAINING FLY ASH (FA) IN AGGRESSIVE ENVIRONMENT

¹J.O. Afolayan and ²A. Y. Alhassan

¹Department of Civil Engineering, Federal University of Technology, Akure, Nigeria

²Department of Civil Engineering, Federal Polytechnic, Idah, Nigeria

Email: joafol@yahoo.com; alhassanay2@yahoo.com

ABSTRACT

This paper examines the strength and durability of Portland-pozzolana cement (PPC) concrete. Different composition of PPC samples were prepared, sample A comprises  Ordinary Portland Cement (OPC) and served as the control sample, samples B, C and D comprises OPC and fly ash (FA) in the ratio 90:10, 80:20, 70:30, respectively. Concrete cubes were then made using these samples, and were cured in water after which compressive strengths were tested at 7, 14, 21, and 28 days. The rest of the cubes were then immersed in solution of 2.5% CuSO₄ and solution of 2.5% NaCl for a period of 3 months, after which their strengths at 30, 60 and 90 days were tested for durability. The results of the chemical analysis on the pozzolana (fly ash) indicated that the total percentage of iron, silicon and aluminum oxides is above the minimum of 70% specified by ASTM for pozzolana [1]. Though the results of the compressive strength and durability of the concrete cubes made from PPC were not higher than that of the control, they were all higher than the minimum specified standard by BS code [2]. On the average, sample D was the best PPC used in this research.

Keywords: Portland–Pozzolana Cement, Ordinary Portland Cement, Fly Ash, Compressive

Strength, Durability.