特高拱坝专用低热硅酸盐水泥研究与应用

发布时间：2018-08-24 08:46

【摘要】：特高拱坝应力水平较高,对坝体混凝土整体性、安全性和耐久性要求更高,要求大坝混凝土具有较高的强度等级、抗渗等级和抗冻等级,以及较高的综合抗裂能力,为此研究了一种专门用于特高拱坝的低热硅酸盐水泥(简称"低热水泥")。根据低热水泥矿物组成与强度、水化热的影响规律,确定了专用低热水泥四种主要矿物的适宜含量;控制MgO含量在4%~5%之间以补偿混凝土温降收缩;控制比表面积不大于340 m~2/kg以减缓水泥早期水化速度。提出专用低热水泥技术要求并制定了相应的标准,采用符合该标准的专用低热水泥配制的大坝混凝土单位用水量较低、后期强度较高、绝热温升较低、综合抗裂性能较强。建立了专用低热水泥生产工艺全过程质量控制精细化管理与监造体系,实现了专用低热水泥的规模化稳定生产,为300 m级特高拱坝以及其他水电工程应用低热水泥奠定了良好的基础。
[Abstract]:The stress level of super high arch dam is higher, the integrity, safety and durability of dam body concrete are higher, and the dam concrete has higher strength grade, impermeability grade and frost resistance grade, as well as higher comprehensive crack resistance ability. In this paper, a kind of low-heat Portland cement (referred to as low-heat cement) specially used in super-high arch dam is studied. According to the mineral composition and strength of low-heat cement and the effect of hydration heat, the suitable contents of four main minerals for special low-heat cement are determined, and the MgO content is controlled at 4wt% to compensate the shrinkage of concrete at temperature. Control specific surface area not more than 340 m~2/kg to slow down the early hydration rate of cement. The technical requirements of special low heat cement are put forward and the corresponding standards are formulated. The dam concrete prepared with the special low heat cement has lower water consumption, higher later strength, lower adiabatic temperature rise and stronger comprehensive crack resistance. The system of quality control, fine management and supervision in the whole process of producing special low heat cement has been established, and the scale and stability of production of special low heat cement has been realized. It lays a good foundation for the application of low heat cement to 300m super high arch dams and other hydropower projects.
【作者单位】：中国长江三峡集团公司;中国电建集团华东勘测设计研究院有限公司;中国建筑材料科学研究总院;
【基金】：国家重点研发计划项目(2016YFB0303600) 国家自然科学基金(51209219)
【分类号】：TV421

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