摘要
Abstract
In order to improve the mechanical properties of bridge concrete in salt-frozen environment,in this paper,the changes of compres-sive strength,mass loss rate and relative dynamic elastic modulus of concrete in salt-frozen environment were studied with the content of poly-propylene fiber and freeze-thaw medium as variables,and the action mechanism of polypropylene fiber was analyzed by nuclear magnetic reso-nance test.The results show that the addition of polypropylene fiber can significantly improve the mechanical properties of concrete in salt-fro-zen environment,and the optimal content is 0.9%.Without freeze-thaw test,the compressive strength of PFC9 is 9.16%higher than that of PFC0.After 200 cycles,the compressive strength loss rates of PFC0 and PFC9 were 51.09%and 33.68%,respectively.The mass loss rate of PFC9 is 28.83%lower than that of PFC0,and the relative dynamic elastic modulus is 32.44%higher.Polypropylene fiber can effectively improve the mechanical properties of concrete in salt-frozen environment by reducing the internal porosity and pore size of concrete.关键词
盐冻耦合/桥梁混凝土/力学性能/聚丙烯纤维Key words
Salt-freeze coupling/Bridge concrete/Mechanical properties/Polypropylene fibre分类
交通工程
