• Appendices

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    When pipes or box culverts are founded on compressible material, camber should be placed in the grade to compensate for the settlement. The amount of camber to be used depends on the load imposed on the foundation material and the compressibility of the material. Since these factors vary, judgement is required in selecting the amount of camber to be used. Unless provided in the plans, the camber is determined as follows for pipe culverts.

    The table below includes camber factors based on the load imposed (fill height) and the compressibility (soil type) of the material. Using the fill height and soil type, a corresponding factor is selected from the table. For continuous culverts beneath the entire width of the embankment, multiply the selected factor by the length of the culvert (L) to determine the midpoint camber.

    appendix_d_page_A26a.gif The mid point camber for pipe culverts shall be limited to one-half of the available fall in the pipe culvert or, (L/2) x (% grade), where L is the length of the culvert in feet (meters) and shall be limited to 2 ft (0.6 m). The proposed grade for the culvert at the midpoint (L/2 from the end of the culvert) should be adjusted upward by Cm where Cm is the smaller of the calculated camber and the limits stated above. The amount of camber Cx at any distance x along the length of the culvert that can be determined by:

    appendix_d_page_A26c.gif appendix_d_page_A27_1.gif appendix_d_page_A27_2.gif appendix_d_page_A27_3.gif


    North Carolina Department of Transportation Multi-Branch Evaluation Committee Policy for New Products and Technology        


    In the past, sales representatives often visited various sections of the Department of Transportation in an effort to sell their product(s). If a Branch or Unit felt the product had merit, that section may have elected to evaluate the product(s). The results of those evaluations were normally used within that section and were not distributed to other Units. At times, this has resulted in the same item or method being evaluated by more than one Unit. To provide a more thorough and orderly evaluation of products and methods, a Multi-Disciplinary Committee was formed and operates through the cooperative efforts of the Design, Construction, Maintenance, Traffic Engineering, and Planning and Research Branches. The Federal Highway Administration (FHWA) also has representation on this committee.


    The Multi-Disciplinary Committee provides a comprehensive evaluation of new products and methods. The Committee may approve or disapprove the use of these products or methods in the design, construction, and maintenance of our highways. Sales representatives submit their information to one central committee rather than visiting the many different units. The Committee also monitors installations and provides long-term documentation on the durability and performance of new products and methods.


    The Chairman of the Committee or his designated Coordinator is responsible for arranging meetings, receiving information from the various sales representatives, and disseminating it to the other Committee members conducting or coordinating product studies when needed and other miscellaneous duties as required.


    1. Sales representatives seeking approval of new products are instructed to submit their information to the Coordinator for distribution to the appropriate Committee members. The Committee members will examine product information and history of use, if applicable, relevant to their field of operations. Testing of material properties may be requested at this time. After reviewing this information, the Committee member will provide a recommendation concerning approval or rejection of the product to the Committee for a ruling.

    2. When additional information is desired by the Committee, it may request:

    (a) additional information from the sales representative,

    (b) that sales representatives work with various members of the Committee to develop an in-depth study or additional test data, or

    (c) various members perform a more in-depth study and make a recommendation to the full Committee.  The Chairman or his designate will serve as study coordinator in the development of these reports to the Committee.

    3. The Evaluation Committee will meet bimonthly to assure timely consideration of submitted products for evaluation.

    4. The Committee may approve, disapprove, recommend trial use, or recommend limited use, of new products in construction and maintenance of North Carolina highways.

    5. The Committee will coordinate the monitoring of trial installations and ensure that long term documentation on the durability and performance of the products and methods is obtained.

    6. The Committee will not normally consider new equipment products such as those handled by the Equipment Unit.

    7. Vendors failing to satisfactorily respond to inquiries or correspondence or maintain contact with the Chairman or his Coordinator for a period of one year will be subject to having their product dropped from the Evaluation Program.

    8. The Chairman has the authority to drop from the Evaluation Program products with no apparent or significant application for usage in the Highway Program or products which are deemed not to be far enough along in the development process to evaluate.

    9. This program is intended for the evaluation of new and/or proprietary products for highway use. Products meeting the "NCDOT Standard Specification for Roads and Structures" are not usually evaluated.

    10. Acceptance of a product for evaluation by NCDOT or Committee’s approval of the product after evaluation is in no way a commitment to purchase, or specify the product investigated regardless of its performance.

    11. The following status codes have been adopted as a means of identifying the Committee’s action on products submitted for evaluation. Some codes are self-explanatory.

    appendix_e_page_A30.gif A better explanation of these codes can be found at the New Products website.

    NOTE: There may be occasions when a new product has merit potential. However, insufficient information is available concerning it’s performance to enable a Committee decision. Experimental use of these products may be coordinated through the Design, Construction or Maintenance Units interested in specifying or using the product. The information obtained through experimental usage will be used by the Committee to complete an evaluation and make a ruling.

    12. Data resulting from an evaluation of the submitted product is public information and will not be considered privileged. All information developed during this product evaluation may be released by the North Carolina Department of Transportation at its discretion.


    The Approved Products Listing is intended to tabulate information about certain proprietary products for highway use. Products covered by the Standard Specifications for Road and Structures are not usually included. Approval of a product is not to be construed as an endorsement or indication that the product(s) will be used. Project Design Engineers and Division Construction and Maintenance Engineers are made aware of approved products through a database with programs including the Approved Products Listing. However, these engineers are under no obligation to specify or use specific products once the product has been approved by this Committee. Vendors or manufacturers wanting to promote the use of their product(s) after receiving committee approval should consider the following:

    1. Vendors or manufacturers of products which meet the requirements of the "NCDOT Standard Specifications for Roads and Structures" may wish to contact contractors who have been awarded construction projects which will need the particular product. The types and quantities of materials to be used in new construction projects can be identified in the Department’s monthly publication "Invitation to Bid". Persons wishing to subscribe to this listing may contact the State Contract Office - Proposals Squad of the Design Services Unit at (919) 250-4128. The identity of contractors who have been awarded specific projects can be obtained through the Public Affairs Office @ (919) 733-2520 or the State Contract Office @ (919) 250- 4128.

    2. Committee approved products for which a Standard Specification is not applicable may be designed into a specific project by a Department Project Design Engineer. A special provision will be prepared by the design engineer and included in the contract documents to define the requirements for, and quantities of, products to be used. As stated earlier, Project Design Engineers are made aware of new products through the Approved Products Listing. However, vendors or manufacturers may wish to periodically mail product information flyers to Department Design & Maintenance Branch Units indicating that the product is available and has been approved by the New Products Evaluation Committee.

    3. In addition to constructing new projects, the NCDOT is responsible for maintaining over 78,000 miles of roadway and more than 16,500 bridges. Maintenance of these facilities is directed through both the Raleigh Central Office and Division of Highways offices located throughout the state.

    Vendors or manufacturers of roadway or bridge maintenance products approved by the Committee may wish to promote these types of products to Division Maintenance Engineers and Area Bridge Maintenance Superintendents. A list of addresses for these individuals can be provided upon a request made to the New Products Evaluation Program Coordinator at (919) 250-4128. Department Maintenance Engineers are under no obligation to use the products approved by the committee.

    4. Upon receiving product approval from the Committee vendors or manufacturers may wish to promote their products to users within the state having similar needs as the Department. Municipalities or private developers occasionally construct roadway or structures which eventually will be incorporated into the Department’s maintained system. Right-of-Way encroachment agreements are reviewed by Department engineers to ensure that, among other things, Department approved products are used by the encroaching parties.

    5. Committee approved products for which the Department’s Standard Specifications do not apply, and which have not been included as a bid alternate in a project design, may be considered in Value Engineering Proposals which can be submitted by contractors after a contract has been awarded. Product vendors or manufacturers may wish to work with contractors to develop cost saving Value Engineering Proposals which utilize their products. Contractors are awarded a 50% share of the savings obtained through approved value engineering proposals. For more information on the Value Engineering Proposal clause and procedures contact the Value Engineer’s Office at (919) 250-4128. 

    Questions regarding the New Products Evaluation Program in general or about specific products should be directed to:

    New Products Evaluation Committee Chairman
    N. C. Department of Transportation
    Design Services Unit
    P.O. Box 25201,
    Raleigh, NC 27611

    Telephone: (919) 250-4128
    Fax No.: (919) 250-4119

    Website: https://connect.ncdot.gov/resources/Products/Pages/default.aspx

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