Durability Evaluation of Steel and Recycled-PET Fiber Reinforced Concrete with a Single Crack by Salt Spray Test

Abstract

Fiber reinforced concrete (FRC) is considered to offer improved resistance against crack defects and higher toughness compared to plain concrete. Although knowledge of the durability and service life of FRC is important for a wide range of applications, only limited information is currently available. In the present study, the durability of FRC containing steel or recycled-PET fibers was investigated. In the four-point bending test, specimens were pre-loaded and cracked to reduce the testing time. Specimens for short-term tests were salt sprayed for a period of one week and then placed in a dry air-conditioned room for another week. Specimens for long-term tests were subjected to 15 cycles of salt spraying and air drying. The durability of the FRC was evaluated on the basis of the peak load and toughness index obtained in the four-point bending test. The FRC containing steel fibers suffered severe deterioration in the long-term test but no significant deterioration in the short-term test. The FRC containing PET fibers, on the other hand, suffered only slight deterioration in the long-term test and no deterioration in the short-term test. A simple model was proposed to explain the observed deterioration of FRC.