Chiang Mai Journal of Science

There are various kinds of agricultural waste ashes throughout the industrial processes in Thailand such as sugar cane bagasse ash (SCBA), rice husk ash, oil palm ash etc. They are currently exploited as pozzolanic materials and supplements to improve the compressive strength in terms of microstructures of cement by partly replacement of cement with them.  One of their advantages is to decrease CO₂ gas emission from decreasing consumption of cement in either mortar or concrete production.  Appropriate ratio of replacing clinker by fine (<45 micron) SCBA and w/c ratio as well as effects of SCBA on properties of cement are being studied in this research.  Initially, clinker and SCBA proportion were designed by replacing clinker with the amount of SCBA at 0, 20 and 40%, respectively, whereas gypsum was constant added.  Specimens were casted as cement mortars and pastes and, finally, analyzed for compressive strength, flow ability, chemical composition and microstructure according to curing ages of 3, 7 and 28 days. Their properties were carried out and compared with the results of commercial type I Portland cement. These test results indicated that replacing clinker with 20% SCBA was appropriate for production in laboratory scale and w/c ratio of 0.735 is suitable on workability of the resultant cement.