Abstract:
This study was aimed at arriving at an optimal particle size of bagasse ash as filler material for use in SCM systems. The schematics of this research included firstly the preparation of bagasse ash. This was done by burning it at 500ºC for one hour in a semi oxidizing environment. The attained ash was then divided in four batches and put to grinding in Los Angeles abrasion machine for varying grinding times. The grinding times chosen were 5, 10, 15 and 20 min. PSDs of the ground bagasse ash batches were acquired and a comprehensive particle characterization was performed using SEM, XRD and XRF. The four bagasse ash batches prepared were then studied for their behavior in various fresh and hardened properties in SCM systems. Water demand, SP demand and flow time required for 30+1 cm flow spread were determined for the control mix as well as that for the mortar formulations containing 20 % cement replacement of bagasse ash. Setting times were also worked out for all the mortar formulations. Strength samples were casted for 3, 7 and 28 day flexural and compressional strength. 72 hour calorimeric and shrinkage studies were also performed on the fresh mortar formulations. The strength results, calorimetry and shrinkage findings were then verified using TGA and SEM along with EDS analyses. The study concluded that amongst all the bagasse ash formulations, BA28 yielded best overall response in strength attainment, volume stability and heat evolution during hydration and hence offers enhanced durability along with improved strength as compared to the control mix. So, we can say that the particle size of 28 microns is the optimal size of bagasse ash for use in SCC systems as filler material with 20% replacement level.
