ITEM 606 GUARDRAIL
606.01
Description
606.02
Materials
606.03 Setting
Posts
606.04 Erecting
Rail Elements
606.05
Guardrail Rebuilt
606.06 Impact
Attenuators
606.07 Method
of Measurement
606.08 Basis of
Payment
606.01 Description. 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 MGS, 5, 5A, or 8. 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.
606.02 Materials. Furnish materials conforming to:
Concrete, Class QC Misc, QC 1, QC 2.......... 499
and 511
Reinforcing
steel...................................................... 509.02
Deep beam rail and hardware...................................
710.06
Pressure treated guardrail
posts
.... and
blockouts......................................................
710.14
Steel guardrail
posts................................................. 710.15
Guardrail posts........................................................
710.16
Galvanizing..............................................................
711.02
Use
galvanized steel posts, rails, bolts, fittings, and other accessories.
For
guardrail, use deep beam rail Type MGS. 5, 5A, or 8.
606.03 Setting Posts. Set or drive posts plumb
in a manner that prevents battering or distorting of posts. Trim posts
that are set or driven more than 1-inch (25 mm) above grade. Treat
trimmed posts with a preservative material specified in 712.06. Backfill post holes with
acceptable material, placed in layers, and thoroughly compacted.
606.04 Erecting Rail Elements. Erect
standard design (single-faced) guardrail of the type shown on the plans.
Erect barrier design (double-faced) guardrail as shown on the plans.
Erect rail
elements in a manner resulting in a smooth, continuous installation. Use
shop-curved rail on curves with radii from 5 to 70 feet (1.5 to 22.4 m).
Except where
otherwise required, such as expansion joint bolts, draw bolts tight. Tighten
bolts through expansion joints as tight as possible without preventing the rail
elements from sliding past one another longitudinally. Provide bolts long
enough to extend at least 1/4 inch (6 mm) beyond the nuts.
Do not use splice
bolts that extend more than 1/2 inch (13 mm) beyond the nuts. For
double-faced guardrail, provide bolts that extend from 1/4 to 1 inch (6 to 25
mm) beyond the nuts.
Fabricate all
metal in the shop. Do not perform 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.
Repair
galvanized surfaces 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.
Erect
guardrail so that the bolts at expansion joints are located at the centers of
the slotted holes. Splice the rail elements by lapping in the direction
of traffic. Ensure that the plates at each splice make contact throughout
the area of the splice.
606.05 Guardrail Rebuilt. As shown
on the plans, rebuild existing guardrails. Unless otherwise shown on the
plans, rebuild units of the same type and spacing of members as the existing
guardrail.
For
re-erecting, obtain the rail element from specified salvage sources.
Furnish the following new materials: 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)
reuse guardrail splice bolts that are undamaged and were not removed during
salvage may be reused.
606.06
Impact Attenuators. Before installing the attenuator, make all corresponding
shop drawings from the manufacturer available for the Engineer’s
inspection. Include installation drawings and instructions with the shop
drawings that completely describe the attenuator system.
Grade
the top of each foundation at the same elevation as the adjacent travel lane
and/or paved shoulder.
Adjust
the location of the anchors to avoid pavement joints.
The
Contractor shall use approved proprietary impact attenuator products as
required which can be found on the Office
of Roadway Engineering’s website.
606.07 Method of Measurement. The
Department will measure Guardrail, new or rebuilt, of the type specified by the
number of feet (meters) 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
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 furnished and erected complete.
The
Department will measure Guardrail Post of the kind specified by the number of
each furnished and erected.
606.08 Basis of Payment. 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.
The
Department will pay for accepted quantities at the contract prices as follows:
Item
Unit
Description
606
Foot
(Meter)
Guardrail, Type ___
606
Foot
(Meter)
Guardrail, Barrier Design, Type ___
606
Foot
(Meter)
Guardrail, Rebuilt, Type ___
606
Each
Anchor Assembly, Type ___
606
Each
Anchor Assembly, Type ___, Barrier Design
606
Each
Bridge Terminal Assembly, Type ___
606
Each
Impact Attenuator, Type ___
606
Each
Guardrail Post
606
Each
Guardrail Post, 8-foot (2.44 m)
606
Each
Guardrail Post, 9-foot (2.75 m)