Exploratory Study on Cocoa Pod Husk Ash as a Pozzolan in Mortar Application for Sustainable Construction

Purpose: This paper investigates the feasibility of using Cocoa Pod Husk Ash (CPHA) as a partial substitution for cement in mortar applications, with the specific objective of evaluating the compressive strength and pozzolanic activity of CPHA-enhanced mortars. Design/Methodology/Approach: The CPHA was obtained by burning Cocoa Pod Husk in a controlled environment. The oxide composition of the CPHA was determined by XRF, after which mortar samples were cast into 40 mm cube moulds, with six (6) samples made per curing age for each of the PC replacement levels of 0 to 25 percentage at 5% step intervals, cured by immersion in water and crushed at 7,14, 21 and 28 days. Research Limitation: The study is limited to the CPHA obtained in Nigeria and, by extension, West Africa. The study used CPHA subjected to calcination in the furnace at 600 oC for three (3) hours. Findings: Preliminary findings indicate that CPHA can improve certain mortar properties while promoting sustainable construction practices. The results of the Strength Activity Index (SAI) indicated Pozzolanic activity are 99.3% for CPHA5, 96.8% for CPHA10, 93.1% for CPHA15, 89.9% for CPHA20, and 83.3% for CPHA25. These are all above the acceptable 75% minimum specified in ASTM C618-2015. Practical Implication: The findings indicate that CPHA has good Pozzolanic activity for mortar application. Social Implication: CPHA has a functional Pozzolanic material that offers another opportunity to develop an alternative binder to cement and to further advance low-carbon construction and sustainable development. Originality/Value: This paper contributes to the development of Pozzolanic materials from agricultural waste (the CPHA) and thus advances green building research.