This work consists of constructing or reconstructing guardrail, guardrail posts, bridge terminal assemblies, end terminals, and impact attenuators, including the furnishing, assembling, and erecting of all component parts and materials.
Guardrail shall be deep beam rail Type 5, 5A, 8 or MGS. Appurtenances shall include bridge terminal assemblies, end terminals, and impact attenuators. Construction of the various types of guardrail include the furnishing, assembling, and erecting of all component parts and materials, complete in place at the location shown on the plans, or as directed, and according to the manufacturer’s recommendations where applicable.
The posts shall be set or driven plumb in a manner that prevents battering or distorting of the posts. The posts that are set or driven more than 1inch above grade shall be trimmed. The trimmed posts shall be treated with a preservative material specified in 712.06.
The plans shall show how to erect either a standard design (single-faced) guardrail or a barrier design (double-faced) guardrail.
Erect rail elements in a manner resulting in a smooth, continuous installation. Shop-curved rail shall be used on curves with radii from 5 to 70 feet (1.5 to 22.4 m). Do not allow straight elements to be bent or curved to fit a radius.
The bolts shall be tightened through expansion joints, as tight as possible, to prevent the rail elements from sliding past one another longitudinally. Ensure that the bolts are long enough to extend at least 1/4 inch (6 mm) beyond the nuts.
Splice bolts that extend more than 1/2 inch (13 mm) beyond the nuts shall not be used. For double-faced guardrail, the bolts shall extend from 1/4 inch to 1 inch (6 to 25 mm) beyond the nuts.
Do not allow burning or welding in the field. The Engineer may approve making holes in the field, but only for special details in exceptional cases. The Engineer may approve field punching, cutting, and drilling if the Contractor demonstrates that its methods do not damage the surrounding metal.
The galvanized surfaces shall be repaired that have been abraded such that the base metal is exposed, including threaded portions of all fittings and fasteners and cut ends of bolts as specified by ASTM A 780.
The guardrail shall be erected so that the bolts at expansion joints are located at the centers of the slotted holes. The rail elements shall be lapped in the direction of traffic. The plates at each splice shall make contact throughout the area of the splice.
Unless otherwise shown on the plans, the rebuilt guardrail shall be of the same type and spacing of members as the existing guardrail.
The following materials shall be new: posts, blockouts, bolts, washers, and incidental hardware, as necessary, to complete the guardrail, except: (1) existing steel posts and blockouts that are not damaged and have a good galvanized coating may be reused, and (2) guardrail splice bolts that are undamaged and were not removed during salvage may be reused.
Before installation of the attenuator, all corresponding shop drawings, installation drawings, and instructions from the manufacturer shall be made available for the Engineer’s inspection. Ensure the attenuator is installed as per manufacturer’s shop drawings.
The top of each foundation shall be graded at the same elevation as the adjacent travel lane and/or paved shoulder. The anchors for the attenuator shall be adjusted to avoid pavement joints.
The Department will measure Guardrail, new or rebuilt, of the type specified, by the number of feet from center-to-center of end posts, excluding anchor assemblies. If, however, end connections are made to masonry or steel structures, the Department will measure to the center of the normal post bolt slot. If rail element is used across a bridge, the Department will measure to the first post off the bridge.
The Department will measure Anchor Assembly, of the type specified, by the number of each assembly furnished and erected complete.
The Department will measure Bridge Terminal Assembly, of the type specified, by the number of each assembly furnished and erected complete.
The Department will measure Impact Attenuator, of the type specified, by the number of each attenuator furnished and erected complete.
The Department will measure Guardrail Post, of the kind specified, by the number of each post furnished and erected complete.
The additional costs associated with furnishing and installing extra-length posts instead of standard-length guardrail posts are incidental to Guardrail Post, 8 foot (2.44 m) or Guardrail Post, 9 foot (2.75 m).
For the extra costs associated with furnishing and installing extra-length posts in lieu of standard-length guardrail posts, payment for 9 foot (2.75 m) guardrail posts is considered full compensation.
Use Form CA-D-3A to document the following items:
1. Depth post driven, post spacing.
2. All cuts and abrasions on wood post treated with application of approved preservative.
3. Rail erected accurately to line and grade, all hardware drawn tight.
4. Anchor assemblies and bridge terminal assemblies.
a. Number, diameter, and depth of holes drilled.
b. Top 4 inches (10 cm) of concrete anchor formed.
c. Diameter, length, and number of anchor bolts placed.
d. Number, spacing, size, and clearance maintained on reinforcing steel.
e. Top cured.
f. Measure and pay as per 606.07.