PRECAST CONCRETE MEDIAN BARRIER
Keystone Concrete Pipe Company of Greensburg, Pennsylvania, has developed a precast concrete median barrier that is simple to install and more economical than conventional methods (20% - 23% savings per linear foot). The barrier, which has dimensions similar to the "New Jersey" type barrier, is constructed of two precast outer shells. These shells can be set in place in the median area over existing steel barrier posts, or in the case of new construction, steel dowels can be inserted for the purpose of anchorage. The precast shells are then tied together with four bolts and spacers and a 1/2 inch expansion joint is placed between successive sections. Next, concrete is placed between the shells, filling the core to the top. This top surface is the only area that requires finishings and spray curing. On April 24, 1973, a demonstration was held at the plant site to demonstrate that the barrier could withstand a simulated impact of an automobile at 60 mph. In order to simulate the impact, a 2,000 lb. steel "headache" ball was pendulum-swung from a height of 10 ft. and 12 ft. - 7 in. into the face of the barrier. The ball was allowed to swing into the barrier at angles of 90 and 25 degrees. Four, full-scale test sections of the precast barrier were constructed on a full-scale mock-up of a two lane highway. Three different mix designs were used for the test sections. It was concluded that the precast concrete median barrier withstood the impacts very well. Remembering that an automobile will distribute the impact load and absorb most of the shock, the barrier should perform adequately under field conditions. With the addition of steel fibers to the concrete in the shell, the possibility of projected pieces of concrete is eliminated. The durability of the precast concrete median barrier coupled with the expected economical savings over cast-in- place barriers should make the precast barrier very competitive with other forms of rigid concrete median barriers. /HRIS/
- Appeared in "Special Reports on: Use of Equipment and Methods of Maintenance".
Washington, DC United States 20590
- Kilareski, W
- Publication Date: 1975-7
- Features: Figures; Tables;
- Pagination: 8 p.
- TRT Terms: Building; Costs; Facilities; Impact tests; Installation; Median barriers; Precast concrete; Test procedures
- Subject Areas: Construction; Design; Finance; Highways; Maintenance and Preservation; Research;
- Accession Number: 00126301
- Record Type: Publication
- Report/Paper Numbers: 73-4 Res. Proj.
- Files: TRIS, USDOT
- Created Date: Oct 18 1975 12:00AM