605.08 479 A. Excavation . Excavate trenches for aggregate drains to a minimum width of 12 inches (0.3 m) and to the depth shown on the plans. Slope the bottom of the trench to drain and keep it free from l oose particles of soil. Excavate the trench to furnish a clean exposure of the granular pavement courses. B Placing and Backfilling . Use granular material for the drains. Place the aggregate to a minimum depth of 8 inches (200 mm) above the bottom of the trench. The remaining depth of the trench backfill with suitable embankment material according to Item 203.
605.08 Method of Measurement . The Department will measure Unclassified
Pipe Underdrains, Shallow Pipe Underdrains, Deep Pipe Underdrains, Base Pipe Underdrains Construction Underdrains, Rock Cut Underdrains, and Prefabricated Edge Underdrains by the number of feet (meters) completed and accepted in place, measured from end to end of each run. The Department will measure Aggregate Drains by the number of feet (meters) completed and accepted in place, measured along the bottom of the trench.
605.09 Basis of Payment . The Department will pay for pipe outlets under 611.
The Department will pay for precast reinforced concrete outlets under 611 Precast Reinfo rced Concrete Outlet. The Department will pay for tied concrete block mats Type 1 grouted under 601 Tied Concrete Block Mat. Rock Cut Underdrains are placed in rock and all required trenching in the rock is included under Rock Cut Underdrain. The Departmen t will pay for accepted quantities at the contract prices as follows: Item Unit Description 605 Foot (Meter) ____ " (____ mm) Unclassified Pipe Underdrains 605 Foot (Meter) 6" (150 mm) Construction Underdrains 707.31 605 Foot (Meter) ____ " (____ mm) Shallow Pipe Underdrains 605 Foot (Meter) ____ " (____ mm) Deep Pipe Underdrains 605 Foot (Meter) ____ " (____ mm) Base Pipe Underdrains 605 Foot (Meter) Aggregate Drains 605 Foot (Meter) ____ " (____ mm) Rock Cut Underdrains 605 Foot (Meter) ____ " (_ ___ mm) Prefabricated Edge Underdrains ITEM 606 GUARDRAIL
606.01 Description
606.02 Materials
606.03 Setting Posts
606.04 Erecting Rail Elements 606.01
480 606.05 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 For guardrail, use deep beam rail Type MGS. 5, 5A, or 8 . Type MGS may be constructed using round wooden posts of 72” length until March 2019. After that date, round wooden posts shall be 69” in length. Prior to March 2019, posts may be trimmed or may extend above the blockout .
606.03 Setting Posts. Set or dr ive 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 m aterial, 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 nu ts. For double -faced guardrail, provide bolts that extend from 1/4 to 1 inch (6 to 25 mm) beyond the nuts. 606.05 481 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 spe cial 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 except the Department will not allow aerosol spray applications of paints containing zinc dust . 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 o n 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 n ew 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 inst allation 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 measu re 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.