Assessing the Strength of Lightweight Concrete using Oil Palm Shells (OPS) as Coarse Aggregates

Abstract

The usage of concrete spans the length of civilization and in modern day construction environment, concrete remains one of its major materials. As a result of high cost of construction and construction materials especially in Ghana and other developing countries in West Africa, different efforts have been made to find alternative local building materials to substitute wholly or partly some of the constituents of concrete. This paper looks at the potential of oil palm shells (OPS) as coarse aggregate in lightweight concrete by mainly assessing the compressive strength of OPS concrete and also establish the best mix ratio for OPS concrete. The coarse aggregate of the mix ratios 1:2:4 and 1:3:6 were replaced with OPS and their densities and compressive strengths determined on the 7th, 21st and 28th days of the concrete maturity. It was found that OPS can be used to replace coarse aggregate up to 75% in 1:2:4 mix ratio and up to 50% in 1:3:6 mix ratio. It is therefore recommended that the best mix ratios are 1:2:2:2 and 1:3:3:3. Single storey residential buildings, offices and footbridges are some of the recommended structures that OPS concrete could be suitable for. Keywords: Lightweight concrete; oil palm shell aggregates; density; concrete cubes; concrete maturity