Low-Deflection Portable Concrete Barrier

Abstract

Temporary barriers are often required to provide positive protection for motorists and workers in a highway work zone. Most highway work zones are restricted in regard to available lateral space for accommodating traffic and the work activity. Consequently, it is desirable to minimize deflection of work zone barriers to minimize the required buffer distance between the barrier and work activity area and, thereby, maximize the space and number of lanes available for traffic. Under this study, a new connection designed to reduce dynamic deflection of portable concrete traffic barriers was developed through a program of finite element simulation and full-scale crash testing. The new cross-bolted (or X-bolt) connection uses two threaded rods in different horizontal planes across the barrier joint to form a tight, moment connection. It achieves the objective of low dynamic barrier design deflection without sacrificing constructability. In addition to being easy to install, the new barrier system is also perceived to be easy to inspect and repair. Crashworthiness and design deflection of the barrier connection were verified through full-scale crash testing using segment lengths of 10 ft and 30 ft. An F-shape barrier with X-bolt connection was demonstrated to have the lowest deflection of any approved portable concrete barrier.