DAMAGE AND ITS EVOLUTION FOR PARTIALLY HIGH PERCENTAGEFIBER REINFORCED CONCRETE UNDER FLEXURAL FATIGUE

Partially High Percentage Fiber Reinforced Concrete (PHPFRC) is a kind of fiber concrete in which fibers are concentrated with high density in the tension region of component under bending. PHPFRC possessesmuch higher load bearing capacity, rigidity, fatigue and fracture properties than conventional steel fiber reinforcedconcrete (SFRC), but its cost is similar to that of SFRC. In the paper, the fatigue damage evolution rule for PHPFRC is proposed to predict its fatigue life under multi-amplitude cycle load. It was observed that the fatigue damage of PHPFRC is tough damage from test results, being different from plain concrete and most SFRC. Based on the continuum damage mechanics and fatigue behavior of the specimens, damage variable D for fatigue of PHPFRC is defined, and the elementary form of damage evolution function is determined. For the specimens in which average fiber volume fraction is 1.2%, the function parameters are given according to the test results.