ระยะเวลาก่อตัวของเพสต์และกำลังรับแรงอัดของมอร์ต้าร์ผสมเถ้าชานอ้อย-แกลบ-ไม้บด (Setting Time of Paste and Compressive Strength of Mortar Containing Ground Bagasse-Rice Husk-Wood Ash)

Abstract

This research was to study the effect of percentage replacement and fineness of ground bagasse-rice husk-wood ash on setting time of cement paste and compressive strength of mortar. Bagasse-rice husk-wood ash obtained from sugar mills’ biomass power plant was ground into 3 levels of fineness, namely, course, moderate, and fine with 30%, 10%, and 0% of particle size retained on sieve no.325, respectively. Portland cement was replaced with ground bagasse-rice husk-wood ash at the dosage of 0%, 20%, and 40% by weight of binder to produce mortar with similar flow of 110±5 %. The flow was maintained by varying water content and using superplasticizer. The results of tests indicated that the initial and final setting time increased with increasing level of replacement and fineness of bagasse-rice husk-wood ash. The compressive strength decreased with increasing level of replacement of bagasse-rice husk-wood ash. In both cases, mortar containing 20% fine ground bagasse-rice husk-wood ash had the highest compressive strength. At 28 and 90 days, in the case of varied water content the normalized compressive strength was 98% and 97%, respectively, and in the case of using superplasticizer the normalized compressive strength was 131% and 126%, respectively.