PERFORMANCE OF OLIVE SEED ASH AS PARTIAL REPLACEMENT OF CEMENT IN CONCRETE

Abstract

The need for partial replacement of cement in concrete production has become inevitable because of adverse environmental impact of cement production, increasing cost of cement and financial benefits of utilization of waste products. This paper presents laboratory investigation of the properties of Olive Seed Ash (OSA) as partial replacement of cement in concrete.Concrete mix of 1:2:4 (Binder: Fine aggregate: Coarse Aggregate) and water-cement ratio of 0.44 were adopted in this study. Olive seed ash was used to replace cement at various levels of 0%, 5%, 10% and 15% by mass. Partial replacement of cement with OSA resulted in decrease in initial and final setting times of concrete but the values are still within acceptable limits. The results show that compressive strength, flexural strength and split tensile strength of the concrete decreased as the percentage of OSA increases. However, at 10% replacement level, the 28 days compressive strength  achieved was 28N/mm² and this value surpasses the minimum compressive strength of 25N/mm² recognized by BS EN 1992-1-1 (2004) for reinforced concrete design. The results also showed that the water absorption decreased with increase in percentage replacement of cement with OSA portraying that replacement with olive seed ash has higher durability potentials. It is recommended that cement can be replaced with at least 10% OSA in concrete. This will reduce the cost of construction in addition to environmental advantage.