Effect of Particle Size of Mae Moh Fly Ash on Strength Activity Index of Mortar

Abstract

The objective of this research is to study the effect of particle size of fly ashes from Mae Moh powerplant on increasing strength activity index of mortar due to packing effect and pozzolanic reaction. Both effectscan be determined by using insoluble material and fly ash which have almost the same particle size to replacePortland cement type I. From the results, it showed that strength activity index of mortar between 3 to 28 daysdue to the packing effect is higher than that of the pozzolanic reaction and the different of strength activity indexdue to packing effect is 22%. The different of strength activity indices due to the pozzolanic reaction of fly asheswith particle size of 2.7 and 160 microns are 3 and 20% at the ages of 3 and 28 days, respectively. At the age of90 days, the strength activity index of mortar due to pozzolanic reaction increases to be 29% when fly ash withparticle size of 2.7 microns is used.

Keywords : Strength Activity Index / Packing Effect / Pozzolanic Reaction / Fly Ash