| 摘要: |
| 采用硫铝酸盐水泥-硅酸盐水泥-石膏三元复合体系制备了低收缩早强型灌浆料，探究了其微观结构形成机理.结果表明：根据最优配合比制备的灌浆料1、3 d抗压强度分别为60.1、75.5 MPa，3 d自收缩率为351.39×10-6，28 d干燥收缩率为239.75×10-6，均高于国家标准；灌浆料水化产物中的钙矾石（AFt）晶体相互交错搭接，构成了致密的网状骨架，使灌浆料具有较高的早期强度，而水化硅酸钙凝胶则促进了灌浆料后期强度的发展；AFt表现出的微膨胀作用使灌浆料的收缩变形逐渐变小，进一步保障了其早强与低收缩特性. |
| 关键词: 灌浆料 早期强度 收缩变形 配合比 微观机理 |
| DOI：10.3969/j.issn.1007-9629.2023.08.013 |
| 分类号:TU528 |
| 基金项目:国家自然科学基金资助项目（51608469） |
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| Preparation and Microscopic Mechanism of Low Shrinkage and Early Strength Grouting |
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ZHANG Yan1, GAO Qingyu1, JI Huanle2, DU Xiuhong3, PAN Huimin1
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1.Hebei Province Engineering Research Center for Harmless Synergistic Treatment and Recycling of Municipal Solid Waste， Yanshan University， Qinhuangdao 066004， China;2.School of Road and Bridge Engineering， Tianjin Transportation Technical College， Tianjin 300380， China;3.Hebei Green High-Performance Building Material Application Technology Collaborative Innovation Center， Hebei Construction Materials Vocational and Technical College， Qinhuangdao 066000， China
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| Abstract: |
| A grouting material using ternary composite system including sulphoaluminate cement， Portland cement and gypsum was prepared， which featured low shrinkage and early strength. The formation mechanism of the microstructure of the obtained grouting material was explored. The results show that the grouting material prepared according to the optimal mix proportion exhibits 1 d and 3 d compressive strengths of 60.1 MPa and 75.5 MPa， and 3 d autogenous shrinkage and 28 d drying shrinkage of 351.39×10-6 and 239.75×10-6， respectively. All of them are higher than those of national standard requirements. Ettringite（AFt） crystals in the hydration products of the grouting material overlap to form a compacted network skeleton， resulting in the high early strength of the grouting material. At the same time， calcium silicate hydrate gel in the hydration products promotes the later strength development of the grouting material. Furthermore， the micro-expansion effect of AFt gradually reduces the shrinkage deformation of the grouting material， ensuring its early strength and low shrinkage characteristics. |
| Key words: grouting material early strength shrinkage deformation mix proportion microscopic mechanism |
