Frequency Effect on the Compressive Fatigue Behavior of Ultrahigh Toughness Cementitious Composites: Experimental Study and Probabilistic Analysis

Ultrahigh toughness cementitious composite is a cementitious material that exhibits the characteristic of pseudo strain hardening under uniaxial tension, and has potential use in structures that experience repeated or fatigue loads. A series of quasi-static, dynamic, and fatigue tests were performed to evaluate the frequency effect on the compressive fatigue behavior of this material; in this paper the results are reported. It is found that the fatigue life and deformation pattern are influenced by loading frequency. The relationship between the secondary strain rate, the secondary strain rate per cycle, and the fatigue life is illustrated and equations applied to predict the fatigue life of specimen are developed. The failure strain of each loading frequency is found to follow the Weibull distribution. Based on the distribution of the static failure strain at the same stress level, a probabilistic model of the fatigue failure strain is proposed to describe the frequency effect, which gets a considerable agreement with the experimental results. (C) 2017 American Society of Civil Engineers.