Reliability analysis of freeze–thaw damage of fiber concrete based on Miner theory

In the cold regions of north China, due to special climatic and environmental factors, the degradation of concrete durability caused by freeze–thaw cycles has been a widespread concern among researchers. Freeze–thaw damage is considered the main form of damage that causes concrete durability to deteriorate. Aiming at investigating the influence of freeze–thaw damage on the service life of concrete structures in building structures, a freeze–thaw test was carried out in this work to study the frost resistance of the formed concrete under different fiber blending modes. The durability degradation of fiber concrete under different freeze–thaw cycles was analyzed, and the concrete microstructure was evaluated by scanning electron microscopy. This study found that the frost resistance of single-fiber concrete is not obvious, the frost resistance of integral fiber concrete is greatly improved and layered hybrid fiber concrete has excellent frost resistance performance. In addition, based on the fatigue cumulative damage Miner theory, the reliability calculation model of freeze–thaw damage is established, which can directly reflect the relationship between the reliability of the test sample and the freeze–thaw cycle. The reliability of concrete with different fiber-blending methods gradually decreases to varying degrees. This theory has good applicability in the reliability analysis of concrete freeze–thaw.