629CONCRETE MEDIAN AND SAFETY BARRIER

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626.04Method of Measurement

Ordered and accepted concrete median strip will be measured either by linear measurement by the linear foot {meter} or volumetric measurement by the cubic yard {cubic meter} in accordance with the method of measurement designated by the pay item. Median strips on bridges will not be measured for payment, but the volume of concrete shall be included in the concrete volume for the bridge structure. Linear measurement of a median strip shall be the actual length of the median strip measured along the center line of the strip. Volumetric measurement of a median strip shall be by the cross sectional average end area method unless a more accurate method of measurement is derived.

626.05Basis of Payment

The quantity of the Concrete Median Strip, measured as provided above, will be paid for at the contract unit price per foot {meter} or per cubic yard {cubic meter} for Concrete Median Strip, which price and payment shall be full compensation for furnishing all materials, equipment, tools, labor, and incidentals necessary to complete the work.

626-A Concrete Median Strip - per linear foot {meter} 626-B Concrete Median Strip - per cubic yard {cubic meter} CONCRETE MEDIAN AND SAFETY BARRIER

629.01Description

This Section shall cover the work of constructing a concrete median or safety barrier at the location shown on the plans, proposal, or directed. Barriers shall be basically classified as to "Type" which will designate the size, shape, height, etc. all in accordance with details shown in the plans. Barriers may be cast in place, extruded by slip form equipment, or precast and installed in a permanent manner. This Section shall also cover the work of retrofitting concrete bridge rail in accordance with the requirements shown on the plans.

629.02Materials

All materials furnished for use shall conform to the appropriate requirements of Division 800, Materials, and the following:  Concrete, unless otherwise specified by plan details, shall meet the requirements of Section 501 for Class A concrete.  Steel reinforcement shall meet the requirements of Section 502.

629.03Construction Requirements

The concrete mix, construction, placing of the concrete, curing, and finishing shall be in accordance with the appropriate provisions of Section 501, unless otherwise provided in this Section or noted in the plan details.

Excavation and backfill for permanent barriers shall be in accordance with the provisions of Section 214.

Barriers constructed by the use of a slip form extrusion machine shall be well compacted, dense concrete meeting all the requirements of Section 501, except for the requirement for fixed forms. The forming portion of the extrusion machine shall be readily adjustable vertically during the forward motion of the machine so that the top of the barrier can be maintained at the predetermined grade.

The finished concrete shall be within reasonably close conformity to the lines, grades, and dimensions shown on the plans or directed; the barrier shall present a smooth uniform appearance free GUARDRAIL AND BARRIER RAIL 511

from objectional cavities or projections. A 10 foot {3 m} straightedge, laid on the top faces of the barrier, shall not vary more than 0.02 foot {6 mm} from the edge of the straightedge except at grade changes and curves and be free of humps, sags or other irregularities. Concrete surfaces shall be finished in accordance with the requirements given in Section 501 for Class 1 with exposed surfaces receiving a Class 2 coated surface finish.

Joints shall be in accordance with the provisions of Section 501, except as follows:  Surface edges on exposed vertical contraction joints shall be rounded with a 1/4 inch {6 mm} edger or sawed.  Vertical expansion joints may be open or sealed in accordance with plan requirements.

629.04Method of Measurement

Concrete barriers will be measured for payment by the appropriate method designated by the plans or proposal in accordance with the following:  Item 629-A – linear foot {meter} measured to the nearest 0.1 foot {0.1 m} along the top surface barrier.  Item 629-B – cubic yards {cubic meters} of concrete with volumetric measure computed by the average end area method except where results obtained differ from those obtained by a more accurate mathematical computation.  Item 629-C - unit measurement where each end section is in accordance with the size, shape, and length designated by the plans.  Item 629-D - per each in accordance with the details shown on the plans. One retrofit will be measured for each end of each concrete guardrail where the retrofit is constructed.  Item 629-E - per linear foot in accordance with the details shown on the plans. Excavation and backfill shall be measured in accordance with the provisions of Section 214.

629.05Basis of Payment

The various "Types" of Median or Safety Barriers End Sections, and Bridge Guardrail and Rail Retrofit, ordered and accepted, measured as noted above, shall be paid for at the appropriate unit price bid provided in the proposal. Said unit price bid shall be full compensation for the furnishing of all materials and the construction of the barrier complete in place, including all equipment, tools, labor, and incidentals necessary to complete the work.

629-A Concrete Median or Safety Barrier, Type ___ - per linear foot {meter} 629-B Concrete Median or Safety Barrier, Type ___ - per cubic yard {cubic meter} 629-C Concrete Median or Safety Barrier End Section - per each 629-D Bridge Guardrail Retrofit, Type ___ - per each 629-E Bridge Rail Retrofit, Type ___ - per linear foot {meter} GUARDRAIL AND BARRIER RAIL

630.01Description

This Section shall cover the work of the furnishing and installation of complete sections of steel or aluminum beam guardrail, guardrail end anchor systems, and shaped tube type barrier rail, at the locations shown on the plans or designated and in conformity with the detailed requirements of the plans and these specifications. The plans will designate the Class of guardrail to be used and, in the case of steel rail, also the Type to be used. When it is optional as to the choice of either steel or aluminum, the alternate once selected shall be used throughout the contract. Unless specified otherwise, Class A guardrail will be used for roadways and Class B guardrail will be used for bridges.

630.02Materials

Materials shall conform to the requirements set forth in Division 800, Materials. Specific reference is made to Section 864, Guardrail and Barrier Rail Materials, and detail drawings provided in the plans. Material will be accepted by Brand Registration and Guarantee, as provided by AASHTO M 180, and List GUARDRAIL AND BARRIER RAIL 512

II-17 of Materials, Sources, and Devices with Special Acceptance Requirements. Spot checks will be made for material delivered to the project. The material may be accepted or rejected based on these tests. If alternate approved end anchors are shown to be allowed on the plans the Contractor shall obtain a copy of the details from the manufacturer prior to installation. The Contractor shall also obtain a certification from the manufacturer that the end anchors meet the "crashworthy" requirements given in the National Cooperative Highway Research Program (NCHRP) Report 350 or Manual for Assessing Safety Hardware (MASH), 2016, based upon the project requirements. The Contractor shall furnish a copy of the details and certification to the Engineer upon request.

630.03Construction Requirements

The Contractor shall place stakes to mark the location where guardrail is required. The Contractor shall not begin the installation of the guardrail posts until the Engineer has approved the staked location of the guardrail.

Unless otherwise provided by the plans or proposal, the Contractor may use one of the optional type posts shown on the plans; however, once selected, the same type shall be used throughout the contract. Posts shall be erected in such a manner that they shall be vertical with their top inside edges within 1/4 inch {6mm} of their correct position for both vertical and horizontal line. The posts shall be erected to the dimensions shown on the plans and compacted by tamping, puddling, or as directed, to obtain a rigid installation. Where posts are driven, the tops shall be protected by a suitable driving cap and the adjacent area compacted, if deemed necessary by the Engineer. If raising or other movement of the post is required, the earth shall be compacted to fill any voids caused by such movement. All posts damaged in any way during erection shall be removed and replaced without additional compensation.

The Contractor shall use one of the Type End Anchors provided by the plans, or directed. The anchor assemblies shall be erected to the dimensions shown on the plans, and the area backfilled with suitable material and compacted as provided in Item 2 above. Posts that are attached to the anchor assembly shall be erected to the requirements for individual posts as provided in Item 2 above.

burning, or welding shall be done in the field. Holes for special details in exceptional cases may be made in the field when approved, after it has been demonstrated that punching will not result in damage to the surrounding metal.

to the established line and grade of the surface the rail parallels. The top of the rail shall be constructed to the height designated on the plans.

slotted holes. Bolts may be rethreaded after galvanizing if necessary. All bolts, except where otherwise required at expansion joints, shall be drawn tight; however, bolts through expansion joints shall be drawn up as tight as possible without being tight enough to prevent the rail elements from sliding past one another longitudinally. Bolts shall be sufficiently long to extend at least 1/4 of an inch {6 mm} beyond the nuts. Except where required for adjustments, bolts shall not extend more than 1/2 of an inch {13 mm} beyond the nuts. Bolts through variable thickness posts shall be cut off 1/4 of an inch {6 mm} beyond the nuts and burred.

All steel elements (posts and rail), including all accessories used in the construction of guardrail and barrier rails shall be galvanized, except when otherwise provided by the plans or proposal. Aluminum elements (posts and rail) and accessories will require no special treatment, except where otherwise noted on the plans or proposal.