路用钢纤维砼抗折疲劳特性研究

Flexural and Fatigue Performance of Steel Fiber Reinforced Concrete for Use in Pavement

研究了路用钢纤维砼(SFRC)抗折与疲劳性能,分析了纤维体积率(V_(sf))和长径比(l_(sf)/d_(sf))对抗折和疲劳性能的影响规律,提出并讨论了可供设计应用的SFRC疲劳方程。通过结构形成与破坏过程的分析,探讨了SFRC破坏机理。用SFRC疲劳方程计算了各级路面厚度。实验研究与工程实践表明,路用SFRC的V_(sf)以1～1.2%比较经济合理,据此设计的路面厚度与普通砼相比可减小40%左右,缩缝间距有可能延长至35m以上.

The flexural and fatigue properties of steel fiber reinforced concrete (SFRC) are studied. The effect of V_(8f) and l_(8f)/d_(8f), on the flexural and fatigue properties is analysed. Through the analysis of the process of structure forming and failure, the fatigue mechanism is investigated. The fatigue equations which can be used for structure design of pavement is proposed and used to calculate the thickness of four classes of SFRC pavements. The experimental results and practical engineering show that the economical and reasonable V_(8f) of steel fiber in the reinforced concrete for pavement use is 1～1.2%. The pavement thickness of SFRC can be reduced about 40% compared with common concrete. The spacing of contration joint is increased to more than 35m.