细度
粉煤灰
材料科学
硅酸盐水泥
微观结构
抗压强度
复合材料
水泥
多孔性
火山灰
火山灰反应
膨胀的
烧结
作者
Yuxuan Li,Wenwen Ding,Cui‐Hua Zhao,Laibao Liu,Tan Ke-feng,Yongjia He
标识
DOI:10.1080/21650373.2024.2302844
摘要
To promote the safe use of MgO expansive agent (MEA) in mass concrete, the influence of fineness and sintering temperature of MEA on the expansion, mechanical properties, and microstructure of fly ash-Portland cement pastes was studied. The results indicate that the agent prepared at 950 °C does not adversely affect the compressive strength of the pastes. Whereas the agent prepared at 1150 °C (MII) has a marked negative impact on the volume stability and strength of the pastes. Furthermore, incorporating MII with coarser particle size results in a larger expansion, greater strength loss, and coarser pore structure. The presence of fly ash delays the hydration of MgO, making more MgO available for the formation of Mg(OH)2 at the late age. Meanwhile, the pozzolanic reaction leads to decreased total porosity, leaving less space available for the accommodation of Mg(OH)2. Consequently, fly ash cement pastes suffer greater strength loss than plain cement pastes when the destructive expansion occurs due to the delayed hydration of MgO.
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