长江科学院院报 ›› 2008, Vol. 25 ›› Issue (4): 77-80.

• 水工结构与材料 • 上一篇    下一篇

内含氧化镁水泥混凝土自生体积变形问题探讨

 陈文耀, 李文伟   

  • 出版日期:2008-08-01 发布日期:2012-03-05

Remark on Autogenous Volume Deformation ofMgO Content Cement Concrete

 CHEN  Wen-Yao, LI  Wen-Wei-   

  • Online:2008-08-01 Published:2012-03-05

摘要: 根据室内混凝土自生体积变形试验结果,归纳了内含氧化镁水泥混凝土自生体积变化规律。内含氧化镁水泥混凝土自生体积变形与配合比参数有关,较大水胶比有利于氧化镁的较快水化,粉煤灰对混凝土变形有抑制作用,内含氧化镁水泥适用于强度等级较低的重力坝混凝土。高强度等级混凝土可采用低氧化镁水泥外掺轻烧氧化镁来改善补偿收缩性能。当氧化镁含量在4%左右时,混凝土自生体积变形在2 a左右即趋于稳定,不会影响结构的安全性。

关键词: 三峡工程, 混凝土, 内含氧化镁水泥, 轻烧氧化镁, 自生体积变形

Abstract: On the basis of indoor experimental results, the factors affecting the autogenous volume deformation of MgO-involving (up to 4.5%) cement concrete are concluded. The results show as follows: Autogenous volume deformation of MgO concrete is closely relative to mix proportions, high water content will accelerate hydration of MgO, thus increases expansion of concrete; the addition of fly ash will suppress the expansion of concrete. Corresponding to the increase in strength, the expansion of MgO concrete decreases; adding lightly burnt MgO powder to concrete will improve the autogenous expansion of high strength concrete; when the MgO content is about 4%, the autogenous volume deformation of the concrete will be approximate to a constant at about two years and would dont affect the safety of a structure.