จีโอโพลิเมอร์เพสต์ที่ทำจากเถ้าถ่านหินและเถ้าชีวมวล ตอนที่ 2 : ความสัมพันธ์ระหว่าง อัตราการเกิดปฏิกิริยาและกำลังอัด

Abstract

This research paid attention on the reactivity rate of monomers (fly ash and rice husk bark ash, FA and RHBA, respectively) in geopolymer paste. It is called geopolymerization, sometimes. The experiment was based on the chemistry hypothesis that alkali-reacted monomer was easily dissolved in a mild acid whereas the unreacted monomer was rarely dissolved. Picric acid was employed as the media in this experiment to recognize the amount of reacted monomer which in turn, the rate of geopolymerization could be calculated.

           The results revealed that the rate of geopolymerization did not depend on water to binder ratio (w/b). Pastes with w/b of 0.28 and 0.42 showed the same rate of reactivity. However, w/b affected to microstructure and compressive strength of paste. The paste with higher w/b weakened microstructure and resulted on the lower compressive strength. Moreover, it was found that the FA particle was more reactive than that of RHBA. There was no different in compressive strength when NaOH between 14 and 18 molars were used. Finally, elevated curing temperature at 60 ^oC for 24 hours could accelerate the rate of reactivity which enhanced high compressive strength of the paste in short time.