10-90 (A) Chemical Requirements
pH between 5.0- 8.0 in accordance with TMECC 04.11- A, "Electrometric pH Determinations for Compost".
B.Physical Requirements
1.Weed free.
2.Derived from a well- decomposed source of organic matter.
3.Produced using an aerobic composting process meeting CFR 503 regulations Including time and temperature data indicating effective weed seed, pathogen and insect larvae kill.
4.Free of any refuse, contaminants or othe r materials toxic to plant growth.
5.Non-composted products will not be accepted by the Engineer .
6.For seeded Compost Blankets, seed should be incorporated at the time of application in the entire depth of the compost blanket, at rates per foot, per square ya rd, or per acre, as acceptable to the Engineer. The following particle sizes shall also be followed: 100% passing a 2 inch sieve; 99% passing a 1 inch sieve; minimum of 60% passing a 1/2 inch sieve. All other testing parameters remain the same. The seedin g rates are generally similar or slightly higher than those used when considering application of seed via hydroseeding or other seeding methods.
7.Moisture content of less than 60% in accordance with standardized test methods for moisture determination.
8.Material shall be relatively free (<1% by dry weight) of inert or foreign man- 22 made materials. 1070 -1 GENERAL All reinforcing steel and welded wire reinforcement m ust be current with the applicable AASHTO Product Evaluation & Audit Solutions workplan. Standard drawing details for reinforcement products are found in the Roadway Standard Drawings. Steel reinforcement shall be stored above the surface of the ground on platforms, skids, or other supports and shall be protected from mechanical injury and surface deterioration caused by exposure to conditions producing rust. When placed in the work, rei nforcement shall be free from dirt, loose rust or scale, mortar, paint, grease, oil, or other nonmetallic coatings which could reduce bond as determined by the Engineer. Reinforcing steel placement and fastening shall conform to the requirements of AASHTO LRFD Bridge Construction Specifications, Section 9 and these specifications of which the more stringent shall apply. When approved by the Engineer, field welding of reinforcing steel materials shall be performed in accordance with Section 1072 and at a mi nimum, comply with the current edition of AWS D1.4. 1070 -2 STEEL BAR REINFORCEMENT FOR ROADS AND STRUCTURES Use reinforcing steel provided by a NCDOT approved facility as found on the Department’s producer/supplier list . All producer/suppliers must be current with the applicable AASHTO Product Evaluation & Audit Solutions workplan to remain on the NCDOT producer/supplier list. Supply deformed steel bar reinforcement conforming to ASTM A615 for Grade 60. For uncoated deformed and/or pla in reinforcing, furnish the Engineer a Type 1 certification in accordance with Article 106 -3 and attach it to Materials and Tests Form 913 for each shipment of reinforcing material. Bend and cut d uring fabrication with tolerances in accordance with the AASHTO LRFD Bridge Construction Specifications, Section 9 . Bend the bars cold to the details shown in the plan s.
10-91 Weld steel bar reinforcement only where shown in the plans or approved by the Enginee r.
When welding steel bar reinforcement use bars conforming to ASTM A706. 1070 -3 COLD DRAWN STEEL WIRE AND WIRE REINFORCEMENT Provide cold drawn steel wire for use as spirals or in fabricated form for the reinforcement of concrete meeting AASHTO M 336. When required by the plans, apply epoxy coating by a NCDOT approved facility. Use steel welded wire reinforcement, p lain or deformed , conforming to AASHTO M 336. 1070 -4 REINFORCING STEEL BAR SUPPORTS Provide all wire bar supports of smooth cold drawn industr ial quality basic wire having a minimum tensile strength of 65,000 psi. When the legs of the bar supports are in contact with the forms, ensure that the entire leg of the bar support is stainless steel wire or a minimum thickness of 1/4 inch stainless ste el at points of contact with the forms. Use stainless steel wire meeting ASTM A493 except having a minimum chromium content of 16% and a minimum tensile strength of 95,000 psi. Ensure that wire sizes, height tolerance, and leg spacing for wire bar suppor ts are in accordance with the Manual of Standard Practice published by the Concrete Reinforcing Steel Institute. As an option to the stainless steel wire for the legs of bar supports at points of contact with the forms, provide legs of cold drawn steel wir e plastic protected in accordance with the Manual of Standard Practice published by the Concrete Reinforcing Steel Institute, except provide plastic protection by dipping or by premolded plastic tips in accordance with ANSI/CRSI -RB4. Do not use plastic le gs molded to the top wire. Use plastic bar supports meeting the requirements listed in ANSI/CRSI -RB4 published by the Concrete Reinforcing Steel Institute only when approved by the Engineer. 1070 -5 PRESTRESSING STRAND Use prestressing strands for use in prestressed concrete consisting of seven wire strands, stress relieved after manufacture to remove internal stresses. Use the size and the grade of the strand as shown in the plan s. Use strands conforming to AASHTO M 203 except provide a specimen for test purposes, if required, from each reel of cable instead of each 20 ton production lot. For precast prestressed deck panels, use 3/8 inch round seven- wire stress -relieved G rades 250 or 270 prestressing strands meeting AASHTO M 203. Mark the outer layer of each reel pack of strand with a wide color band as follows: white for Grade 270 stress relieved strand, green for low relaxation strand, and a double marking of green and r ed for special low relaxation strand. In addition, attach a metal tag to each reel pack labeled in accordance with AASHTO M 203. 1070 -6 DOWELS AND TIE BARS FOR PORTLAND CEMENT CONCRETE PAVEMENT Use dowel and tie bars from the Department’s approved producer/supplier list . Use smooth plain round steel dowel bars conforming to AASHTO M 31 Grade 60 conforming to the Roadway Standard Drawings . Do not use dowel bars with burred ends. A tolerance of ± 1/4 inch is permitted from the dowel length required by the plans. A straightness tolerance of 0.075 inch from a straight line is permitted. Epoxy coat and fabricate all dowel bars /baskets by a NCDOT approved facility as found on the Department’s producer/supplier list . Use dowel assemblies for supporting dowel bars of rigid construction capable of holding the dowel bars in proper position during placing of concrete, and of such design to permit unrestricted movement of the pavement s lab. Use wire for dowel assemblies meeting AASHTO M 336. Use a dowel assembly that holds the dowels in the required position within a tolerance
10-92 of ± 1/4 inch in vertical and horizontal planes. Obtain written approval from the Engineer for
the dowel assembly before use. Coat dowel bars and the entire dowel assembly with an approved wax base coating. Apply the coating by dipping or spraying such that the wax coating on the dowel bars is of uniform thickness sufficient to allow pulling of the dowel from the concrete as provided in AASHTO T 253 Type B coated dowel . When required by the Department’s Minimum Sampling Guide, f urnish for testing one dowel basket assembly for each 200 assemblies incorporated into the project. Each Department approved producer/supplier, coater and fabricator shall provide the Department a Type 1 material certification in accordance with Article 106 -3, M&T DB-06 Dowel Basket Fabrication Report and when required by the Engineer the Materials and Tests Form 913 for al l coated dowel baskets and loose dowels with each shipment . Use deformed tie bars conforming to AASHTO M 31 for Grade 40 or Grade 60. Storage, handling and transportation of epoxy coated dowel and/or tie bars shall be in accordance with Section 1070 -7(D). 1070 -7 EPOXY COATED REINFORCING STEEL
A.General Use reinforcing steel from the Department’s approved producer/supplier list . All producer/suppliers must be current with the applicable AASHTO Product Evaluation & Audit Solutions workplan to remain on the NCDOT producer/supplier list. Facilities coating and fabricating epoxy coated reinforcing steel shall establish proof of the ir competency and responsibility in accordance with the Concrete Reinforcing Steel Institute ’s Fusion Bonded Epoxy Coating Applicator Plant Certification Program. Registration and certification of the plant or shop under the CRSI Program and submission of the valid annual certificate to the State Materials Engineer is required before beginning any coating. The same requirement applies to coaters subcontracting work from the coater directly employed by the contractor. Obtain approval of each coater and/or fabricator of epoxy coated reinforcing steel before coating or fabrication of bars. The coating applicator and/or fabricator is responsible for establishing and maintaining an effective quality control program, and employ equipment for cleaning, coating a nd/or fabricating that produces coated material conforming to the Standard Specifications. Include in requests for approval a well -defined quality control program and direct the requests to the State Materials Engineer. Before Department approval is issued, the condition of equipment for blast cleaning, coating and/or fabricating material is evaluated by the Engineer for determining the equipment capability of producing a coated product conforming to the Standard Specifications . Use Department approved ep oxy coating and fabricating companies as found on the Department’s approved producer/supplier list .
B.Coating Materials Obtain approval for the epoxy resin powder before use. A list of prequalified powder sources is available from the State Materials Engineer.
C.Coated Reinforcing Steel Use coated steel reinforcing bars meeting AASHTO M 31, Grade 60 and free of contaminants such as oil, grease and paint. Use bars free of surface irregularities as defined in ASTM A775 and/or that produce holidays in the coating.
D.Handling, Storage and Transportation When handling, storing and transporting coated steel reinforcing bars, all contact areas shall be padded.
10-93 All bundling bands shall be padded or suitable banding shall be used to prevent damage to
the coating. All bundles of coated steel reinforcing bars shall be lifted with a strong back, spreader bar, multiple supports, or a platform bridge to prevent bar -to-bar abrasion from sags in the bundles of coated steel reinforcing bars. Packaging of uncoated and coated bars is strictly prohibited. When loading/unloading coated bars; pallets, ba gs or bundles shall not be dropped or dragged. During storage, protect steel r einforcement at all times from damage and make sure it is free from dirt, dust, loose mill scale, loose rust, paint, oil or other foreign materials until the time of placement. For s torage outside at the fabrication shop and project site , store epoxy coat ed reinforcing steel bars at least 1 foot above the ground on wooden or padded supports placed 10 f eet apart, and completely cover with an opaque cloth, canvas or woven fiber reinforced polyethylene white tarp. Storage of uncoated and coated material shall not be mixed or in direct contact. Do not use solid plastic sheeting. Cover the bars such that adequate ventilation is provided to prevent condensation from forming on the material during storage, and completely protect the bars from direct sunlight. D o not allow water to pond under the epoxy coated reinforcing steel. Do not expose epoxy coated reinforcing steel to outdoor weather for more than 30 days. If the coated steel reinforcing bars are stored outdoors without cover, the date on which the coate d bars are placed outdoors shall be recorded on the identification tag for the bundled steel. Transport the bundled bars from the producer/supplier to the project site with padding, such as carpet padding, placed over each bundle of steel upon which anot her bundle of steel is placed unless wooden spacers are placed between each bundle to prevent contact. Load all bundles of bars horizontally for transporting. Transport the bars on a flatbed trailer. Do not allow the length of bars to exceed 8 f eet beyo nd the trailer bed. Repair coating damage associated with handling and transporting or other causes in accordance to Subarticle 1070- 7(E). Coated steel reinforcing bars should be off -loaded as close as possible to their points of placement or under the crane so that the bars can be hoisted to the area of placement to minimize re -handling. If the material is being transported in adverse weather conditions the producer/supplier, coater, fabricator and/or Contractor shall co- coordinate a material protec tion plan, test for the presence of chlorides, and, if necessary, clean the material as directed by the Engineer.
E.Field Coating Repair The maximum amount of repaired damaged coating shall not exceed 1% of the total surface area in each 0.3 m [1 foot] of th e bar. This limit on repaired damaged coating shall not include sheared or cut ends that are coated with patching material. When degraded coating is observed additional inspection or non- destructive testing may be required by the Engineer at no additiona l cost to the Department. Ensure th e Contractor uses a Department approved patching or repair material that is compatible with the coating and inert in concrete. When repair is required, clean the areas in accordance to SSPC -SP 1 prior to performing addit ional surface preparation. Surface preparation shall be in accordance with SSPC -SP 11 (Power Tool Cleaning to Bare Metal) and/or in accordance with the manufacturers recommendations. The more stringent of the two shall apply. Ensure that the material is suitable for making repairs with a minimum dr y film thickness of 7 mils. Ensure that the C ontractor has a copy of the manufacturer’s written instructions for application of the patching material and the instructions are closely followed during any coating damage repair. Do not apply any patch material when the surface temperature of the steel or the air temperature is below 40°F. Do not ship or place steel until the patch material is dry to the touch. 1070 -8 SPIRAL COLUMN REINFORCING STEEL Furnish spiral column reinforcing steel with the following areas and weights as required in Table 1070- 1 and in the plans .
10-94 Table 1070 -1
SPIRAL COLUMN REINFORCEMENT STEEL PROPERTIES Material Size Area, sq.in. Weight, lb/ft Plain Cold Drawn Wire W 20 0.20 0.668 W 31 0.31 1.043 Deformed Cold Drawn Wire D-20 0.20 0.680 D-31 0.31 1.054 Plain or Deformed Bar #4 0.20 0.668 #5 0.31 1.043 Use cold drawn wire conforming to AASHTO M 336 . Use plain or deformed bars conforming to AASHTO M 31 for Grade 60. Use deformed cold drawn wire conforming to AASHTO M 225. The diameter of the spiral reinforcing steel is the outside to outside measurement of the bars or wire, with an allowance of 1/2 inch more or 1/2 inch less than the specified diameter as shown in the plan s. Furnish spirals with 1.5 extra turns at top and at bottom of the completed spiral cage. Where splicing of the s pirals is necessary other than those shown in the plan s, provide a minimum lap splice of 3 f eet. Do not weld on the spiral reinforcing steel. When required by the plans, use epoxy coated spiral column reinforcing steel and spacers provided by a NCDOT appro ved supplier available on the Department’s approved producer/supplier list . Use the minimum number of spiral spacers as shown in the plan s. Ensure a minimum section 14 modulus per spiral spacer of 0.030 cu . in. 1070 -9 MECHANICAL BUTT SPLICES When called for by the contract or when approved by the Engineer, use a m echanical butt reinforcing steel splice from an approved source that is found on the Department ’s producer/supplier list . Use a standard metal filled sleeve, cement mortar filled sleeve, threaded steel couplings, forged steel sleeve or cold- forged sleeve. An exothermic process whereby molten filler metal, contained by a high strength steel sleeve of larger inside diameter than the bars, is introduced into the annular space between the bars and the sleeve and between the ends of the bars may be used. Provide a splice that is capable of transferring at least 125% of the yield strength of the bars from one bar to the other by the mechanical strength of the splice components. For splices not on the approved list, before use and as a condition of approval, ass emble three test splices in the presence of the Engineer for each size of bar which is proposed for use on the project. Forward the test splices to the Materials and Tests Unit in Raleigh, NC for testing and approval. 1070 -10 REJECTION Reinforcing material that does not meet the Standard Specifications is rejected by the Engineer . When required by the Engineer, replace reinforcing material that is bent, deformed, exhibits cracked material or welds, contaminated and when the maximum amount of coating damage exceeds the limits herein or degraded coating is observed and as determined by the Engineer.
Source: North Carolina Standard Specifications for Roads and Structures, 2024 Edition. Pages 506–510 of 857.