硅酸盐通报2025，Vol.44Issue(8)：2781-2789,9.DOI:10.16552/j.cnki.issn1001-1625.2025.0068
匹配养护下氧化镁膨胀剂对砂浆性能和微观结构的影响
Effects of MgO Expansive Agents on Properties and Microstructure of Mortar under Matched Curing Condition
摘要
Abstract
To investigate the effects of MgO expansive agents(MEA)on core concrete of steel-concrete structures in closed and variable-temperature service environment,this study examined the influences of different active MEA on the macroscopic properties and microstructure of mortar under matched curing condition.The results indicate that the incorporation of MEA reduces both the slump flow and mechanical properties of mortar.In specific,high-activity MEA exhibit the greatest negative impact on the slump flow of mortar,while low-activity MEA notably affect the mechanical properties of mortar.Moreover,medium-activity MEA and high-activity MEA can generate a large quantity of Mg(OH)2 crystals during the early and middle stages of hydration.These crystals exhibit effective shrinkage compensation by growing in situ or migrating to the surface of the cement hydration products,thereby reducing the cumulative pore volume,optimizing the pore structure,and enhancing the structural compactness.In contrast,the reaction rate and degree of low-activity MEA are slower than those of high-activity MEA.As a result,fewer Mg(OH)2 crystals are generated,leading to a weaker compensation for the volume shrinkage of the mortar.关键词
氧化镁膨胀剂/扩展度/力学性能/体积稳定性/微观结构Key words
MgO expansive agent/slump flow/mechanical property/volume stability/microstructure分类
建筑与水利引用本文复制引用
白敏,龙勇,黄旺明,胡雄伟,郭蒙..匹配养护下氧化镁膨胀剂对砂浆性能和微观结构的影响[J].硅酸盐通报,2025,44(8):2781-2789,9.基金项目
中国中铁股份有限公司科技研究开发计划项目(2022-专项-02) （2022-专项-02）
