629 Page 420629 CABLE GUARDRAIL
629.1DESCRIPTION
This work consists of constructing 3 cable guardrail.
629.2MATERIALS
A.Cable: Cable will be 3/4 inch Type I, Class A coating, conforming to AASHTO M 30. B.Cable Splices, Ends, Fittings, and Anchor Assembly: When galvanizing is specified, these materials will be galvanized after fabrication to meet the requirements of ASTM A123. The top 6 inches of the anchor bolts and the nuts and washers will be galvanized in accordance with ASTM F2329. C.Compensating Device: Design for alternate combination, or single unit compensating device and turnbuckle assembly, may be submitted for approval. D.Hook Bolts: Hook bolts will develop an ultimate pull open strength, applied in a direction normal to the longitudinal axis of the post, from 500 to 1000 pounds. The bolts will be galvanized in accordance with ASTM F2329. E.Steel Posts:
1.Structural Steel Posts: Structural steel posts and anchor plates will conform to the requirements of ASTM A709 Grade 50. The posts will be galvanized after fabrication in accordance with ASTM A123. 2.Flanged Channel Posts: Flanged channel posts will be fabricated from rerolled rail steel bars conforming to ASTM A499, Grade 60. The post will meet the chemical properties of ASTM A1 for rails 30 pounds per foot and heavier. Post lengths will be as specified plus or minus 1 inch and will weigh a minimum of 4.0 pounds per foot plus or minus 3.5%. Posts will be painted with a baked on high quality dark green enamel. All punching, boring, cutting, shearing, and welding will be done prior to painting. Holes 3/8 inch in diameter will be punched or bored on 1 inch centers beginning at the top of the post and extending to the bottom. F.Concrete: Concrete will be Class M6, as specified in Section 462.
629.3CONSTRUCTION REQUIREMENTS
A.Guardrail Alignment: Posts and rail will be set to the plans shown alignment using a string line or other approved methods. B.Posts: Posts will be set plumb. Regardless of the method of setting posts, the posts will be firm, and at the locations, spacing, and height shown on the plans. When guardrail posts are installed through asphalt concrete shoulders, the Contractor will take care to minimize damage to the asphalt concrete. If during post installation the asphalt 629 Page 421concrete shoulder is raised more than 2 inches, lowered more than 1 inch, or otherwise damaged, the Contractor will repair the damaged shoulders. The method of repair may require patching, recompacting, or removal and replacement of the affected asphalt concrete. The method of repair is subject to the approval of the Engineer, depending on the type and extent of the shoulder damage. All repair costs will be at the Contractor’s expense. Drilling postholes in pavement will be done without damage to the surrounding pavement. The Engineer must approve the proposed drilling method and equipment before the work begins. Upon completion of the installation of the guardrail posts, the Contractor will place and compact asphalt concrete or asphalt concrete cold mix material around the posts to fill and level any voids created by the driving of the posts through the asphalt concrete. The material will be placed 1/2 inch to 1 inch high around the posts to force water to flow away from the post-hole. Cost for this work will be incidental to the contract unit prices for the various guardrail items. C.Pretension of Three Cable Guardrail : The Contractor will pretension the three cable guardrail in accordance with the following: 1.Properly seat the spring in the compensator device and permanently mark the unloaded spring position on the compensator rod. 2.Install spring end assemblies at one end of the barrier and secure to the anchor. 3.With cable strung through the hook bolts, introduce tension in the cable at the opposite end of the barrier to compress the installed springs approximately 3½ inches. 4.Clamp this tension in the cable while the end assemblies are installed at the second anchor. 5.Remove the slack between the clamp point and the second anchor by taking up the turnbuckle. If springs are also used at this end, compress them approximately 3½ inches. 6.After two weeks at this setting, reset the spring compression as indicated in the standard sheet table on the plans. Ample turnbuckle take up must be left at both ends to permit future adjustments. D.Remove Cable Guardrail: Cable guardrail removed, including cable, posts, and hardware will become the property of the Contractor unless otherwise noted on the plans. Any holes left after removal of the cable guardrail will be backfilled with material furnished by the Contractor. Wherever posts were set through asphalt, the top 3 inches of the hole will be backfilled with bituminous mix. 629 Page 422E.Completion Requirements: On projects where existing cable or steel beam guardrail is to be removed and replaced or reinstalled and the roadway will be open to traffic during construction, the guardrail installation will be completed within 14 calendar days from the day the controlling item of work is sufficiently complete to allow guardrail installation. A guardrail installation is defined as each individual run of guardrail (i.e., a typical bridge would have 4 guardrail installations). Controlling items for guardrail include, but are not limited to structure, structure end block, and surfacing work. Typically, there will be a sequence of controlling items for guardrail. Prior to any guardrail removal, the Contractor will submit, and the Engineer must approve a written construction schedule for work in the guardrail area. In no case will work cease between controlling items of work for more than 4 working days. Once the existing guardrail is removed from a bridge end, box culvert, bridge column, etc., the Contractor will place drums or Type II barricades at 25 foot intervals at each location where existing guardrail is removed. These devices will extend 175 feet beyond the item of concern for each direction of traffic. Drums and barricades will remain in place until new guardrail has been installed. Cost for furnishing, installing, and maintaining drums and barricades will be incidental to the contract lump sum price for traffic control miscellaneous. Post end, beam, and end terminal sections will be installed in a continuous operation within each individual run of guardrail. Incomplete guardrail installations will be marked by delineation as noted in the previous paragraph. If the Contractor does not complete the required work within the time allowed, the Contractor will install an approved safety treatment that complies with crashworthy requirements for test level 3 of National Cooperative Highway Research Program (NCHRP) Report 350 or the AASHTO Manual for Assessing Safety Hardware (MASH) to protect the site at no additional cost to the Department.
629.4METHOD OF MEASUREMENT
A.Cable Guardrail: Cable guardrail will be measured by the foot along the axis of the cable for the type specified. Measurement of cable guardrail will include the length of the anchorage sections. If the guardrail is anchored to a concrete bridge end anchor, measurement of cable guardrail will be up to the anchor block. B.Anchor Assembly: Anchor assembly will be measured by the each. C.Remove Cable Guardrail: Remove cable guardrail will be measured to the nearest foot along the centerline of the cable for the type specified. D.Remove Anchor Assembly: Removal of anchor assembly will be measured by the each.
629.5BASIS OF PAYMENT
A.Cable Guardrail: Cable guardrail will be paid for at the contract unit price per foot for the type specified. Payment will be full compensation for the cost of furnishing labor, materials, and equipment necessary, except anchorage units. 629 Page 423B.Anchor Assembly: Anchor assembly will be paid for at the contract unit price per each. Payment will be full compensation for end posts with base plates, anchor assemblies, turnbuckles and compensating devices, appurtenant hardware, dead man, and necessary excavation and backfill. If the cable guardrail is anchored to a concrete bridge end anchor, compensation, devices, turnbuckles, and appurtenant hardware will be incidental to the contract unit price for cable guardrail. C.Remove Cable Guardrail: Remove cable guardrail will be paid for at the contract unit price per foot for the type specified. Payment will be full compensation for the backfill of holes and the removal of the cable, posts, and hardware from the project limits. D.Remove Anchor Assembly: Remove anchor assembly will be paid for at the contract unit price per each. Payment will be full compensation for removal of end posts with base plates, anchor assemblies, turnbuckles and compensating devices, appurtenant hardware, dead man, and necessary excavation and backfill. 630 Page 424630 STEEL BEAM GUARDRAIL
630.1DESCRIPTION
This work consists of furnishing and installing steel beam guardrail.
630.2MATERIALS
A.Wood Posts and Offset Blocks: Wood posts and offset blocks will be made of a timber with a stress grade of at least 1200 psi. Stress grading will be in accordance with the rules of the West Coast Lumber Inspection Bureau, Southern Pine Inspection Bureau, or other appropriate timber association. Timber for posts will either be rough sawn or surfaced 4 sides (S4S) with nominal dimensions indicated. The size tolerance of the posts in the direction parallel to the axis of the bolt holes will not be more than ±1/4 inch. Posts and blocks with checks or cracks more than 1/4 inch wide and deeper than 3 inches will not be acceptable. Post and blocks will be treated as set forth in Section 950 after all end cuts are made and holes are drilled. B.Beam Guardrail: Beam guardrail will conform to AASHTO M 180, Type I, unless the plans specify another type. C.Bolts, Nuts and Washers: Bolts, nuts, and washers will be as specified in AASHTO M 180. D.Concrete: Concrete will conform to Class M6 as specified in Section 462.
630.3CONSTRUCTION REQUIREMENTS
A.Guardrail Alignment: Posts and rail will be set to the plans shown alignment using a string line or other approved methods. B.Posts: Posts will be set plumb. When posts are installed in augured or dug holes, the holes will be backfilled with material approved by the Engineer. The backfill will be placed and compacted in 4 inch lifts, using a mechanical tamper with an appropriate sized tamping head without displacing the post alignment. Surplus excavated material will be disposed of at locations approved by the Engineer. In lieu of the above requirements, post may be set by driving. Driving will be accomplished by mechanical means, which will give the necessary accuracy of placement without any damage. Damaged posts will be replaced at the Contractor’s expense. Regardless of the method of setting posts, the posts will be firm, and at the locations, spacing, and height shown on the plans. When guardrail posts are installed through asphalt concrete shoulders, the Contractor will take care to minimize damage to the asphalt concrete. If during post installation the asphalt concrete shoulder is raised more than 2 inches, lowered more than 1 inch, or otherwise damaged, the Contractor will repair the damaged shoulders.