Investigating the optimal combination for gravel and granite in blended palm oil fuel ash concrete

Abstract

Global production of palm oil in 2022 was estimated at 73 million metric tonnes. The processing of palm oil generates a huge quantity of waste which is often left unprocessed leading to environmental pollution. Gravels are obtained from weathered rocks and are readily available and cheaper than granite as coarse aggregate in concrete. An innovative way of transforming waste into wealth is by incorporating these materials into concrete for construction purposes. Thus, this study was done to obtain an ideal combination of gravel and granite in palm oil fuel ash (POFA)-blended concrete. A water/cement (w/c) ratio of 0.5 in a nominal concrete mix ratio of 1:2:4 was adopted to achieve a strength of 20 N/mm 2 . The central composite method of optimization was utilized in designing the experiments. The best combination was determined to be 67% gravel, 33% granite and 32% POFA. This combination produced concrete with compressive strength of 23.80 N/mm 2 which is 19% higher than the 20 N/mm 2 target strength.

Characterization of groundnut shell ash as partial replacement of cement for cheaper construction in north-western Nigeria

“…The Slump Test of the GSA Table 3.3 shows the result of water to binder ration with percentage replacement of cement with groundnut shell ash, where it indicates that groundnut shell ash mixture content required more quantity of water than cement to attained same workability status as that of the cement. This shows the groundnut shell ash has greater adsorption ability than the cement which could be due to high carbon content as reported by Akanbi et al, ( 2022) : Odeyemi, et al, (2023).…”

“…The burnt ash was then sieved through British Standard sieve of 75 microns after grinding. The portion passing the sieve was recorded to the required degree of fineness that is 63 microns while the ash to be retained on the sieve was reground and sieve again according to the methods of Odeyemi, et al, (2023).…”

“…The analysis of the groundnut shell ash was carried out by x-ray fluorescence analysis using fused bead XRF VFD45000. Silt content and particle size distribution was carried out on the sand sample to ensure its suitability for block making in accordance to BS8110 (1985) and adopted by Odeyemi, et al, (2023). The mix ratio adopted was one part of binder to eight parts of sand (1:8) at 0%,10%,20%,30%,40%, and 50% replacement levels of cement with the groundnut shell ash.…”

“…In the third world countries, the most common and readily available material that can be used to partially replace cement without economic implications are agro based wastes, notable ones are Acha husk ash (AHA), Bambara groundnut shell ash (BGSA), Bone powder ash (BPA), Groundnut shell ash (GSA), Rice husk ash (RHA) and Wood Ash (WA). Additionally, agro waste materials include Ashes from the burning of dried banana leaves, bagasse, bamboo leaves, some timber species, sawdust and Periwinkle Shell Ash (PSA) (Odeyemi, et al 2023). Some of the advantages for using agro-waste residues in the partial replacement of cement include; low capital cost per tonne production compared to cement, promotion of waste management at little cost, reduced pollution by these waste and increased the economy base of farmers when such waste is sold, thereby encouraging more production, conservation of limestone deposits and a reduction in CO2 emission (Ogork et al, 2015).…”