AUTHOR=Zhu Chenhui , Lou Yilong , Shen Xuemei , Xu Hesi , Yang Jie 

TITLE=Influence of CaO Content on the Fly Ash–Lime System Hydrothermal Synthesis Reaction Under Autoclave Curing

JOURNAL=Frontiers in Physics

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2021.782309

DOI=10.3389/fphy.2021.782309

ISSN=2296-424X

ABSTRACT=<p>As a substitute for traditional Portland cement, the development and research of “low-temperature-synthesized fly ash cement” has been receiving extensive attention. This study explores the effects of calcium oxide content on the fly ash–lime system hydrothermal synthesis reaction under autoclave curing, focusing on the effects of CaO content on the strength of the cement paste. The changes in phase composition, microstructure, and morphology were characterized using X-ray diffraction and scanning electron microscopy (SEM) analysis. The results show that with an increase in the CaO content, the amounts of β-C<sub>2</sub>S and C<sub>12</sub>A<sub>7</sub> in the gelling material also increase. However, when the CaO content is very high, the amounts of β-C<sub>2</sub>S and C<sub>12</sub>A<sub>7</sub> in the gelling material no longer increase, and the strength is lost.</p>