Investigating the Pozzolanic Potentials of Cowdung Ash in Cement Paste and Mortars

Abstract

This paper reports on the investigation into the pozzolanic potentials of cowdung ash. Cowdung was calcined at a temperature range of 400-500 14??/m:t>"> , sieved through 212µm sieve and characterized using chemical and physical methods. Cement paste and mortar were produced using CDA as cement replacement at 0, 5%, 10%, 15%, 20%, 25% and 30%. Standard consistency, soundness and setting time test were conducted on the blended cement paste, while compressive strength test was conducted on the hardened mortar samples after curing for 7, 28, 60 and 90days. The sum of SiO₂, Al₂O₃ and Fe₂O₃ in CDA exceeds the 70% minimum specified by ASTMC 618-12. The test results revealed that addition of CDA to cement paste prolonged the setting time and increased standard consistency, while the compressive strength decrease with increase in CDA and increase with curing age. One way ANOVA conducted on the strength results indicates that there was no statistically significant difference between control mortar (0% CDA) and those containing up to 15% CDA. Linear regression model developed to predict compressive strength with cowdung ash and curing age as predictors was highly significant. 

Keywords: Cement, Compressive strength, Cowdung ash, Mortar, Pozzolana, Regression model, Setting times.