疲劳载荷作用下超高程泵送钢纤维混凝土的耐久性

研究了疲劳载荷作用下的超高泵送钢纤维混凝土(SFRC)的氯离子扩散规律,对相应临界疲劳循环次数作用的SFRC试件的碳化性能进行了分析.通过对疲劳试件的不同深度自由氯离子浓度和表面氯离子扩散系数的研究表明:只要疲劳次数超过某一临界值时,SFRC试件内部的氯离子含量和表面扩散系数就会随着疲劳次数的增加而增大;在相应临界疲劳循环次数作用下,SFRC试件具有较强的抗碳化能力;该SFRC具有优异的抗氯离子扩散性能和抗碳化能力.这不仅拓展了SFRC的应用领域,也为动荷载作用下的混凝土耐久性研究提供了很好的参考和依据.

Fatigue durability of steel fiber reinforced concrete with super-high vertical pumping distance

The diffusion of chloride ion in steel fiber reinforced concrete (SFRC) with super-high vertical pumping distance under fatigue load was studied. The carbonation resistance of SFRC specimens under corresponding critical number of fatigue cycles was also analyzed. The experimental results of the chloride ion concentration at different depths and the surface chloride diffusion coefficients of the fatigue specimens show that, so long as the number of fatigue cycles exceeds a critical value, the interior chlorine ion's concentration and the surface diffusion coefficients of the SFRC specimens would increase with the number of fatigue cycles. The experimental results also indicate the good carbonation resistance of the SFRC specimens under corresponding critical number of fatigue cycles. The research results manifest excellent resistance of the SFRC to chloride ion diffusion and carbonation, which not only benefit to the further application of the SFRC but also provide a good reference and basis for the research of concrete durability under dynamic load.