OPTIMIZING COW DUNG ASH FOR USE AS A SUSTAINABLE POZZOLAN IN CEMENT

Abstract

This study was conducted to determine the optimal conditions for producing pozzolanic ashes from cow dung for use as cement substitute materials. When the cow dung is turned into ash, it develops a pozzolanic character due to the presence of silica. However, the transformation of silica from amorphous to crystalline and its associated pozzolanic reactivity depends on the calcination temperature, duration, and grinding. In this research the Cow dung were calcined at three different calcination temperatures (300^oC, 400^oC, and 800^oC) for 2-, 4-,6- and 8-hours duration. The obtained ashes were ground for 30 minutes and replaced by 20% with cement. The samples containing ashes were tested for compressive strength, X-ray diffractometry (XRD), weight loss, and strength activity index (SAI). It was observed that the CDA, the most favorable calcination condition in terms of strength development was obtained at 600^oC for 6 hours duration. The highest SAI was achieved for the mortar samples containing CDA calcinated at 600^oC for 6 hours duration (CDA600-6H). The materials ground for the higher duration is recommended for higher SAI.