Title: Strain-based fatigue failure criterion for steel-fiber reinforced concrete
Author(s): Poveda, E.; Ruiz, G.; Cifuentes, H.; Yu, R.C.; Zhang, X.X.
Publication: Symposium Paper
Appears on pages(s): 302-309
Keywords: Secondary strain rate, steel-fiber reinforced concrete, fibers, compression fatigue.
This work proposes a new strain-based failure criterion for compression fatigue in steelfiber
reinforced concrete. It is based on the Spark and Menzies’ relationship between the
logarithm of the secondary strain rate per cycle and the specimen life expressed as the
logarithm of the number of cycles until failure. This relationship permits calculating the
critical strain at the failure of the specimen as the sum of two terms. The first one is the
maximum strain in the first cycle due to the maximum compression stress. The second term is
the increase of strain due to the remaining cycles until failure. Thus, failure occurs when the
strain reaches a critical level during fatigue loading. On the contrary, the material continues
resisting while its accumulated strain is lower than the critical one. This criterion is validated
against a series of low-cycle fatigue tests in five types of concrete with different amounts of
fiber that share the same concrete matrix. Besides, the experimental results show that the
fibers delay the deformation and deterioration processes caused by fatigue. They also show
that there is an optimum fiber content that maximizes fatigue life.