시멘트계 혼화재로서 POFA의 수화반응 특성에 관한 실험적 연구

Abstract

Palm Oil Fuel Ash (POFA), a pozzolanic material based on biomass, have been studied in many countries. However, researches about microstructure of POFA are insufficient. Therefore, in this study, hydration properties of POFA were assessed by using many test and Flyash was set as control group. Type 1 portland cement was replaced by POFA and Flyash at 0%, 10%, 20% by weight of binder. A water to binder ratio(W/B) of 0.5 was used for all cement mortar with POFA and Flyash according to KS L ISO 679 and Compressive Strength, Mercury Intrusion Porosimetry(MIP), TG/DTA, X-ray Diffraction(XRD) and Scanning Electron Microscope(SEM) were conducted. The results showed that mortars with POFA had bigger engineering performance than ones with Flyash and the mortar with POFA at 10% by weight of binder had the highest compressive strength due to formation of CaOH)2 and C-S-H in the early ages and dense structures. Formation of Ca(OH)2 and C-S-H was confirmed by using TG/DTA, XRD and SEM. Dense structures were confirmed by MIP. Through all the results, it was concluded that the best replacement ratio of POFA was 10% by weight of binder.