Colorado Concrete Barrier
The Colorado Department of Transportation (CDOT) utilizes both guardrail Type 7 F-Shape concrete barriers, as well as precast Type 7 concrete barriers. Guardrail Type 7 F-Shape barriers may be cast-in-place or slip formed and do not typically require connecting or stabilization pins. However, for precast Type 7 concrete barriers, CDOT utilizes a design that does require barrier connecting pins and stabilization pins. Connecting pins are galvanized, high strength ASTM A449 pins with either a forged head or a welded circular washer and threads for a lifting nut. Stabilization pins are made from galvanized ASTM A36 steel with a welded washer on one end and may have an optional tapered end to facilitate driving into the asphalt or soil.
The Colorado barrier connecting pin is a galvanized, high-strength ASTM A449 rod with thread on the top and a circular washer fillet welded to the rod. Alternately, a one piece, forged head may be used in place of the welded washer design.
The purpose of the round washer/forged head is to rest on the top most connecting loop on the barrier to keep the pin in place. The purpose of the threads is to facilitate removal using a special lifting nut that is screwed onto the pin. In lieu of the threads and lifting nut, the forged head alternative may feature a horizontal hole through the head or a second lip on the head to facilitate removal.
An optional 1/2″ bevel may be added to the bottom of either style for ease of placement. Both styles can be seen on Colorado Standard Plan No. M-606-14, Sheet 2.
