4-87 (E) Repairs
Repair any damage that occurs as directed by the Engineer . Repair by patching when permitted by the Engineer . Extend the first ply of the patch at least 12 inches beyond the outermost damaged portion of the membrane and extend the second ply at least 3 inches beyond the first.
F.Backfilling Do not backfill without permission and until the final mop coat thoroughly hardens. Place backfill so the waterproofing is not damaged.
458-4 Method B Damp Proofing
A.General Method B dampproofing consists of 2 coats of tar, Grade RT 6.
B.Preparation of Surface Make sure the surfaces are dry. Immediately before applying the first dampproofing coat, thoroughly clean the surfaces of dust and loose materials. Permit the concrete to cure for at least 14 days for Class A concrete, at least 10 days for Class AA concrete or 7 days for high early strength concrete before dampproofing.
C.Application Give the concrete surfaces 2 applications of tar, Grade RT 6. Apply the tar with suitable brushes to secure uniform and thorough applications. Do not a pply the second coat of tar until the first coat thoroughly sets. Do not apply dampproofing during any time that the surface is exposed to any moisture. Make sure that the temperature of the tar is such that uniform and thorough application is obtained. Do not backfill until the second coat thoroughly sets.
458-5 Measurement and Payment
Method A Waterproofing will be measured and paid as the actual number of square yards of surface that is waterproofed. In measuring this quantity, measurement is made along the actual surface that is to be waterproofed before the waterproofing is applied. Method B Dampproofing will be measured and paid as the actual number of square yards of surface that is dampproofed. In measuring this quantity, measurement is made along the actual surface that is to be dampproofed before the dampproofing is applied. These prices and payments will be full compensation for all items required to waterproof and dampproof including, but not limited to, those items contained in Article 45 8-1. Payment will be made under: Pay Item Pay Unit Method A Waterproofing Square Yard Method B Dampproofing Square Yard CONCRETE AND METAL RAIL S
460-1 Description
Furnish and place metal, pipe or concrete barrier bridge rails, concrete curbs and concrete end posts in accordance with these specification s and as shown in the plan s. Provide concrete barrier rails with moment slabs above retaining walls in accordance with the contract and accepted submittals. Furnish posts, rail bars, pipe fittings, hardware, paint, barrier delineators, concrete, reinforcing steel, admixtures, form s, falsework and all other materials; galvanize; paint; fabricate and erect rail; and place, finish and cure concrete.
4-88 460-2 Materials
Refer to Division 10. Item Section Aluminum Rail 1074 -5 Barrier Delineators 1088 -2 Curing Material s 1026 Epoxy Coated Reinforcing Steel 1070 -7 Galvanized Steel Rail 1074 -5 Paint 1080 Pipe Rail 1074 -6 Portland Cement Concrete 1000 Reinforcing Steel 1070 Use Class AA c oncrete for concrete barrier rails , concrete curbs and end posts, and Class A concrete for moment slabs in accordance with Article 1000 -3. Use epoxy coated reinforcing steel for concrete barrier rails in accordance with Article 1070 -7.
460-3 Construction Methods
Adhere to the construction load limitations of Article 420 -20 while placing concrete for all bridge rails.
A.Metal Rail Use either aluminum or galvanized steel rail, but use the same material on all structures on the project on which metal rail is required. Use shims if necessary to obtain correct post alignment. Drive aluminum rivets cold. Thoroughly coat the base of aluminum rail post, closure plates, shims or any other aluminum surface in contact with concrete with an approved aluminum impregnated caulking compound.
B.Pipe Rail Give galvanized pipe rail one field coat of organic zinc repair paint, of minimum wet thickness of 1.5 mils, after erection in accordance with Section 442 unless otherwise required in the contract.
C.Concrete Barrier This subarticle applies to the construction of concrete barrier rail , vertical concrete barrier rail, concrete curbs, median barrier rail and concrete parapet, referred to collecti vely as concrete barrier rail. Plans for the concrete barrier rail are detailed for slip -formed CIP concrete. Unless otherwise noted, construct concrete barrier rail detailed in the plan s using conventional forms or by slip- forming using an approved self -propelle d extrusion machine. Except as noted herein, construct in accordance with Section 420. Construct joints in the barrier rails at the locations and of the type shown in the plans. Construct concrete barrier rail to the shape, line, grade and dimensions show n in the plan s except that when slip -forming rails, either radius or chamfer the corners. Check slip - formed rail concrete directly behind the extrusion machine using successive overlapping applications of the 10 foot straightedge. Correct high and low ar eas while the concrete is still workable. Limit horizontal and vertical deviation from plan line and grade to no more than 1/4 inches in 10 feet. Provide sufficient internal vibrators to consolidate the concrete along the faces of forms and adjacent to jo ints. Consolidate the concrete by internal vibration in one pass of the
4-89 extrusion machine. Produce a dense and homogeneous barrier free of voids and honeycomb
with minimum hand finishing. Coordinate concrete delivery and placement to provide uniform progress while minimizing stopping and starting of the extrusion machine. When plans require horizontal deck drains through the barrier rails, use drain couplings with slip -formed rails. Correct all exposed surfaces that are not satisfactory to the Engineer as to uniformity of color and texture or because of excessive patching as required. Give the roadway face of barrier rails constructed using conventional forms a Class 2 surface finish in accordance with Subarticle 420 -17(F). Use a broom finish on the roadway face of slip -formed barrier rails. Provide barrier rail delineators in accordance with Section 854.
D.Concrete Barrier Rail with Moment Slab Construct concrete barrier rails with moment slabs in accordance with the plans and accepted submittals . Constru ct concrete barrier in accordance with Subarticle 460 -3(C) and moment slab in accordance with Section 420. Do not remove moment slab false work until concrete achieves a minimum compressive strength of 2, 400 psi.
460-4 Measurement and Payment
____ Bar Metal Rail will be measured and paid as the actual number of linear feet of metal rail, measured along the top bar of the rail that is completed and accepted. 32" Alaska Rail and 42" Oregon Metal Rail will be measured and paid as the actual number of linear feet of bridge railing and concret e curb. Concrete end post payment shall be included in the cost to provide the concrete curb. The price and payment will be full compensation for all materials, labor, equipment, tools, and incidentals necessary to construct the bridge railing, the concr ete curb and concrete end posts. __" Galvanized Steel Pipe Rail will be measured and paid as the actual number of linear feet of pipe rail, measured along the top pipe of the installed pipe rail, that is completed and accepted. Concrete Barrier Rail will be measured and paid as the number of linear feet of concrete barrier rail shown in the plan s. Concrete Barrier Rail with Moment Slab will be measured and paid for in linear feet. Concrete barrier rails with moment slabs will be measured as the length of concrete barrier rail above retaining walls. The contract unit price for Concrete Barrier Rail with Moment Slab will be full compensation for earthwork, materials, hauling and any incidental labor for providing concrete barrier rails with moment slabs in accordance with the contract. Vertical Concrete Barrier Rail will be measured and paid as the number of linear feet of vertical concrete barrier rail shown in the plan s. Concrete Median Barrier will be measured and paid as the number of linear feet shown in the plans. ____ x ____ Concrete Parapet will be measured and paid as the number of linear feet of concrete parapet shown in the plans. There will be no direct payment for bridge rail delineators as they are incidenta l to the work being performed. These prices and payments will be full compensation for all items required to provide bridge railing including , but not limited to, those items contained in Article 460 -1.
Source: North Carolina Standard Specifications for Roads and Structures, 2024 Edition. Pages 223–225 of 857.