Effect of early overloading of concrete on strength at later ages

Abstract An experimental investigation to study the effect of early over-loading of concrete on its strength development is reported. Concrete and mortar samples were subjected to different loading levels at ages of 8, 16, 24 and 72 hours. The samples were then retested, along with control specimens, at ages of 7, 28, and 90 days. More than 900 specimens were used in this investigation. Ultrasonic pulse velocity measurements were taken to evaluate the healing capacity of damaged specimens. The results indicate that loading concrete, beyond 8 hours after casting, up to 90% of its compressive strenght has no effect on later strength development. However, loading concrete up to failure resulted in strength loss between 10% to 50%, depending on age at time of loading, age at time of retesting and curing conditions.