FLEXURAL FATIGUE PROPERTY OF PARTIALLY HIGH PERCENTAGE FIBER REINFORCED CONCRETE

摘要

Partially High Percentage Fiber Reinforced Concrete (PHPFRC) is a kind of fiber concrete with high volume fraction fibers in its tension region when the concrete is in the non-axial stress field such as in flexural situations. In this paper, the flexural fatigue strengths of PHPFRC are tested. Its fatigue performance is described and compared with that of plain concrete and SFRC. It is found that PHPFRC specimens have long post-crack fatigue life, and the fatigue cracks are very fine. Besides, it is found that, the shape of ε - n/N_F curves for PHPFRC differ for the various of stress level S as tough material does. In the statistical calculation of the fatigue data, the concept of equivalent fatigue life EN is used but the expression of EN is modified in the paper. With EN instead of fatigue life N_F, both the stress level S and stress ratio R are considered into the fatigue equation. It is testified that, under different stress levels, the distribution of e-quivalent fatigue life EN of PHPFRC agrees with two-parameter Weibull distribution.