Fatigue behaviour of steel fibre reinforced concrete beams

Construction materials subjected to repetitive/cyclic loading have to be qualified for their fatigue behaviour. Generally their behaviour is considered satisfactory if they withstand 2 million cycles of repetitive loading without distress or failure. This paper presents the details of experimental investigations carried out at the Structural Engineering Research Centre (Madras) to study the behaviour of reinforced concrete beams cast with steel fibres in the concrete matrix subjected to fatigue loading. Three types of steel fibres have been used in the tests with a view to formulate design guidelines for steel fibre reinforced concrete beams, with conventional reinforcements, subjected to fatigue loading. Empirical relationships to predict the deflection after being subjected to a given number of cycles, and the number of cycles to failure of the steel fibre reinforced concrete beams under fatigue loading have been developed.