| According to the request of environment characteristic and durability design of concrete engineering about sixteen segments of qingzang railroad, the author assurance the durability design sign of concrete engineering including freeze resistance, chlorine ion soak resistance, sulfate attack resistance and shrinkage crack resistance and the main results are as follows:Firstly, the research of appropriative admixture for high performance concrete on freeze soil area showed that freeze-resisting admixture has disadvantageous effect on the freeze resistance, chlorine ion soak resistance, sulfate attack resistance and shrinkage crack resistance of concrete, but concrete can attain preferable durability by the use of many mixtures about air entraining, water-reducing and active mineral additive. At the same time concrete also can attain salient early freeze resistance through reduce water-gel ratio, and concrete strength of minus temperature curing 28days all is over 60% concrete strength of standard curing and reach the request of the development of concrete strength.Secondly, the research of prepare with the construction of minus temperature early strength high performance concrete showed that based on the use of multi-function multiple admixtures including air entraining, water-reducing, freeze-resisting admixture and active mineral additive active and the appropriate mix proportions of concrete, we can prepare the minus temperature early strength high performance concrete of C20, C25, C30 and C40 different strength grades. The performance of concrete satisfies the request of durability design of concrete engineering about sixteen segments of qingzang railroad by the right construction technique.Thirdly, the research of hydration of concrete effect on the hot disturbed freeze soil layer showed that the heat of hydration of concrete almost has no effect on the hot disturbed freeze soil layer and the heat of hydration of concrete does not influence on the concrete engineering about sixteen segments of qingzang railroad. |
