Vehicular Crash Test of a Continuous Concrete Median Barrier Without a Footing.

摘要

A vehicular impact test, 4700lb (2130kg) vehicle/61mph (27 m/s)/26degrees (0.46rad),was conducted on a continuous New Jersey concrete median barrier (CMB) without a footing cast on an asphalt concrete surface. The test barrier contained two continuous longitudinal No. 4 (12.7mm) steel reinforcing bars one at 6inches (152mm) and the other at 12inches (305mm) down from the top of the barrier. There were no contraction or construction joints in the barrier. The barrier was allowed to crack randomly. The barrier suffered no structural damage and did not move laterally or rotate about its longitudinal axis during the impact. After being redirected by the barrier,the vehicle rolled over. Based on this test,the CMB designs used in California have been changed. The 10inch (254mm) deep concrete footing has been eliminated from both the Type 50standard 32inch (813mm) high New Jersey barrier design and the Type 50C New Jersey CMB design. The Type 50C design is used for superelevated transitions and at other locations where the offset in elevation between opposing roadways varies up to 3feet (914mm). Three longitudinal No. 4 (12.7mm) steel reinforcing bars have been added to the Type 50and 50C CMB designs.