MASH TL-4 Design and Evaluation of A Restorable Energy-Absorbing Concrete Barrier

A new, high-containment longitudinal barrier was designed to reduce the accelerations imparted to passenger vehicles during impacts and to be restorable and reusable. Elastomer support posts were designed to translate laterally and absorb energy when impacted and restore to their initial position after impact events. A hybrid concrete beam and steel tube combination rail was optimized to minimize weight, provide sufficient structural capacity, maintain a height to contain and redirect single-unit trucks, and to prevent passenger vehicles from snagging on the posts. Three full-scale vehicle crash tests were conducted according to Manual for Assessing Safety Hardware (MASH) Test Level (TL-4) safety performance requirements on a 240-ft long barrier with nominal height of 38⅝ in. In test SFH-1, a 5,021-lb pickup truck was redirected with minimal damage to the barrier. The peak lateral acceleration was reduced 47 percent as compared to similar impacts on rigid barriers. In test SFH-2, a 2,406-lb small car was redirected by the barrier, and the peak lateral acceleration was reduced 21 percent as compared to similar impacts on rigid barriers. In test SFH-3, a 21,746-lb single-unit truck was successfully contained and redirected, resulting in only minor damage to the concrete rail. Therefore, the barrier met all MASH TL-4 safety performance criteria. Recommendations about the performance, future design refinements, and installation requirements of the barrier were provided