Effect of vehicle-bridge interaction vibration on young concrete

The purpose of this investigation was to study the effect of vehicle-bridge interaction vibration on repairing concrete. A newly developed systematic test was used to simulate the vibration and evaluate its effect. The results indicated that both external damage and internal damage were serious when the simulated vibration test was conducted during a special time period. And this special time period was defined as the concrete disturbance sensitive period when the penetration resistance ranged from 3.5 MPa to 28 MPa. Anti-cracking fiber and self-healing admixture improved the vibration resistance of young concrete. When the dosage of anticracking fiber came to 800 g/m3 by volume of concrete, the 3-day crack area on the concrete surface decreased over 50%. When 9% self-healing admixture was added to the concrete, the ultrasonic pulse velocity of concrete subjected to vibration was higher all the time than without the admixture added. And the ultrasonic pulse velocity at the age of 28 days reached 95% of the control concrete which suffered no vibration. Sand percentage and maximum aggregate size were found to significantly influence the vibration resistance of concrete.