高海拔地区水泥水化特性研究

Research on cement hydration characteristics in high altitude area

主要以水泥为研究对象,分别放入38.7、47、57.6、70.7、101 kPa的养护气压环境,模拟水泥浆体在高海拔地区的环境,通过观测水泥的含水率、孔隙率变化,研究水泥浆体内部孔结构发展,最后通过净浆抗压强度试验加以验证。结果表明:低压会阻碍水泥浆体内部凝胶孔的发展,低气压较常压,水泥的含水率、孔隙率变化缓慢;14 d之后,水泥的强度增长、孔径发展速度变缓;低压使净浆内部自由水减少,内部孔径发展不充分,导致低压净浆的强度增长比常压环境下的净浆缓慢,28 d时很少能达到设计强度。

The cement is mainly taken as the research object,and the curing pressure environment of 38.7,47,57.6,70.7,101 kPa is respectively added to simulate the environment of cement slurry in high altitude area.By observing the change of water content and porosity of cement,the development of internal pore structure of cement slurry is studied.Finally,it is verified by the compressive strength test of pure slurry.The results show that low pressure can hinder the development of gel pores in cement slurry,and the change of water content and porosity of cement at low pressure is slower than that at normal pressure.After 14 days,the strength of cement increases and the development rate of pore diameter slows down.Under low pressure,the free water inside the net slurry decreases,and the internal pore size is not fully developed.As a result,the strength of the net slurry under low pressure increases slowly compared with that under atmospheric pressure,and it rarely reaches the design strength at 28 d.