Fatigue life prediction of fiber reinforced concrete under flexural load

• Published in: International journal of fatigue Vol. 21; no. 10; pp. 1033 - 1049
• Main Authors: Zhang, Jun, Stang, Henrik, Li, Victor C.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-11-1999; Elsevier Science
• Subjects: Applied sciences; Buildings. Public works; Concretes. Mortars. Grouts; Crack bridging; Exact sciences and technology; Fatigue crack growth; Fiber reinforced concrete; Flexural loading; Materials; Reinforced concrete; Strength of materials (elasticity, plasticity, buckling, etc.); Structural analysis. Stresses; Model; Crack bridging; Fatigue crack growth; Flexural loading; Fiber reinforced concrete; Fatigue life; Experimental test; Construction materials; Forecast model; Beam(mechanics); Fatigue crack; Crack opening displacement; Bend loading; Numerical analysis; Stress distribution; Fatigue strength; Behavior; Loading test(mechanics)
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/S0142-1123(99)00093-6

This paper presents a semi-analytical method to predict fatigue behavior in flexure of fiber reinforced concrete (FRC) based on the equilibrium of force in the critical cracked section. The model relies on the cyclic bridging law, the so-called stress–crack width relationship under cyclic tensile load as the fundamental constitutive relationship in tension. The numerical results in terms of fatigue crack length and crack mouth opening displacement as a function of load cycles are obtained for given maximum and minimum flexure load levels. Good correlation between experiments and the model predictions is found. Furthermore, the minimum load effect on the fatigue life of beams under bending load, which has been studied experimentally in the past, is simulated and a mechanism-based explanation is provided in theory. This basic analysis leads to the conclusion that the fatigue performance in flexure of FRC materials is strongly influenced by the cyclic stress–crack width relationship within the fracture zone. The optimum fatigue behavior of FRC structures in bending can be achieved by optimising the bond properties of aggregate–matrix and fiber–matrix interfaces.