材料期刊网

Based on the Wuhan Yangtse River Tunnel Project, the low-penetration fiber concrete used in the protecting layer of Wuhan Yangtse River Tunnel tube has been studied in this paper. With the effect of silica fume, slag and polypropylene fiber on the anti-penetration of tunnel concrete by means of NEL test, XRD and SEM, some conclusions has been drawn. The affection on the anti-penetration capability of the four factors is capacity of silica fume＞portion of short and long fiber＞fiber VOL Portion＞length of Fiber. Fiber capacity of 0.15% is still not good enough for the anti-penetration capability of concrete. While that of 0.5% has exceed the maximum, and the fiber tends to assemble together. Silica fume may greatly enhance the anti-penetration capability of concrete, while the relationship between them is not direct proportion. The average of chloric ion pervasion coefficient with 8% capacity of silica fume is the lowest. Slag may reacted with other component to generate lots of C-A-H. When reacted with free chloride ion, C-A-H may form friedel salt which may also enhance the Anti-penetration capability of concrete.