Investigation Into The Fatigue Damage Process Of Rubberized Concrete And Plain Concrete By Ae Analysis

Incorporation of rubber particles in Portland cement concrete is an effective way of consuming waste rubber. This paper presents results of a study on the fatigue property of plain concrete, rubberized concrete and polypropylene fiber (PPF) reinforced rubberized concrete. Fatigue test demonstrates that the inclusion of 60 kg rubber particles in 1 m(3) concrete can greatly increase the fatigue life of concrete, and the addition of PPF in rubberized concrete can further enhance the fatigue life. The S-N equations for the three types of concrete are obtained by linear regression. By analyzing the AE signals recorded during the fatigue test, it is revealed that both the activity and intensity of acoustic emission (AE) signals detected in rubberized concrete are much lower than in plain concrete. Good linear correlation between the hit and the minimum strain is observed for both concretes. By analyzing the distribution of energy during the cyclic loading, it is found that the fatigue process of concretes can be separated into 3 stages, which correspond to the initiation, the steady propagation and the coalescence of micro cracks to macro cracks, respectively. By analyzing the Fecility effect, the difference of the damage process between rubberized concrete and plain concrete is further analyzed. This investigation demonstrates the health condition of a concrete under repeated loading can be assessed by real time monitoring of AE activity and energy with the help of AE technique.