FINAL SURFACE TESTING ‑ ASPHALT PAVEMENTS: 6‑16‑98

Acceptance testing of the longitudinal profile of the finished pavement surface shall be performed in accordance with these provisions using a North Carolina Hearne Straightedge (Model No. 1). The straightedge shall be furnished and operated by the Contractor to determine and record the longitudinal profile of the pavement on a continuous graph. Final surface testing is considered to be an integral part of the paving operation and is subject to observation and inspection by the Engineer as deemed necessary.

The straightedge shall be pushed manually over the pavement at a speed not exceeding 2 miles per hour (3 kilometers per hour). Profiles shall be taken in the outside wheel path (approx. 3 ft (1 m) inside the outer edge of a 12 ft (3.6 m) Lane) of all lanes except the inside lane where the profile shall be taken in the inside wheel path. One pass of the straightedge shall be made in each full width travel lane, with the recording wheel located in the appropriate wheel path for each profile. Profiles shall be taken as soon as practical after the pavement has been rolled and compacted but in no event later than 24 hours following placement of the pavement unless otherwise authorized by the Engineer. Profiles shall be taken over the entire length of final surface travel lane pavement exclusive of structures, approach slabs, paved shoulders, loops, ramps that are 1500 ft (500 m) or less in length, and tapers or other irregular shaped areas of pavement. Full width acceleration or deceleration lanes, ramps that are over 1500 ft (500 m) in length, turn lanes, and collector lanes, are considered as part of the pavement to be tested in accordance with this provision.

At the beginning and end of each day's testing operations, and at such other times as determined necessary by the Engineer, the straightedge shall be operated over a calibration strip so that correct operation of the straightedge can be verified by the Engineer. The calibration strip shall be a 100 ft (30 m) section of pavement that is reasonably level and smooth. Each day’s calibration graphs shall be submitted with that day’s test section graphs to the Engineer. The calibration of the straightedge shall be in accordance with the current NCDOT procedure titled "North Carolina Hearne Straightedge ‑ Calibration and Determination of Cumulative Straightedge Index". Copies of this procedure may be obtained from the Department’s Pavement Construction Section.

The straightedge graph shall be plotted at a horizontal scale of approximately 25 ft per inch (3 m per cm) with the vertical scale plotted at a true scale. Station numbers and references (bridges, approach slabs, culverts, etc.) shall be recorded on the graphs, and distances between references/stations shall not exceed 500 ft (150 m). The Date, Project No., Lane Location, Wheel Path Location, Type Mix, and Operator’s Name shall also be recorded on the graph by the operator.

Upon completion of each day's testing, the Contractor shall evaluate the graph and then submit to the Engineer within 24 hours after profiles are completed. The Engineer will furnish results of the acceptance evaluation to the Contractor within 48 hours after receipt. All graphs shall be retained by the Engineer.

Blanking bands of 0.2 inches, 0.3 inches, and 0.4 inches (5 mm, 7.5 mm, and 10 mm) shall be used to evaluate the graph for acceptance. The 0.2 inch and 0.3 inch (5 mm and 7.5 mm) blanking bands are used to determine the Straightedge Index (SEI), which is a number that indicates the deviations that exceed each of the 0.2 inch and 0.3 inch (5 mm and 7.5 mm) bands within a 100 ft (30 m) test section. The Cumulative Straightedge Index (CSI) is a number representing the total of the SEIs for one lot, which consist of 25 consecutive 100 ft (30 m) test sections. In addition, the 0.4 inch (10 mm) blanking band is used to further evaluate deviations on an individual basis. The Cumulative Straightedge Index (CSI) will be determined by the Engineer in accordance with the current procedure titled "North Carolina Hearne Straightedge ‑ Calibration and Determination of Cumulative Straightedge Index".

The pavement will be accepted for surface smoothness on a lot by lot basis. A test section represents pavement one travel lane wide and 100 ft (30 m) in length. A lot will consist of 25 consecutive test sections, except that separate lots will be established for each travel lane, unless otherwise approved by the Engineer. In addition, full width acceleration or deceleration lanes, ramps that are over 1500 ft (500 m) in length, turn lanes, and collector lanes, will be evaluated as separate lots. If after the placement of an applicable pavement layer, a lot is less than 2500 feet (750 m) any relevant incentive or disincentive shall be prorated over that section.

The pay adjustment schedule for the Cumulative Straightedge Index (CSI) test results per lot is as follows:

CSI ACCEPTANCE CORRECTIVE PAY ADJUSTMENTS

Before CATEGORY ACTION

or After Before After

Corrective Corrective Corrective

Actions Action Action

00 Acceptable None $300 incentive ---- None

10, 20 Acceptable None $100 incentive ---- None

30, 40 Acceptable None No Adjustment ---- Either

Before or After Correction

11, 21, Acceptable Allowed $300 disincentive --- Either

50, 60 Before or After Correction

31, 41, Acceptable Allowed $600 disincentive --- Either

51, 61 Before or After Correction

Any other Unacceptable Required Per CSI after Correction(s) number (not to exceed 100% Pay)

Any deviation that exceeds a 0.4 inch (10 mm) blanking band shall be corrected by the Contractor such that the deviation is reduced to 0.3 inches (7.5 mm) or less.

Corrective actions shall be performed at the Contractor's expense and shall consist of cold milling, diamond grinding, overlaying, by removing and replacing, by indirect heating and rerolling, or other methods subject to approval of the Engineer. Scraping of the pavement with any blade type device will not be allowed as a corrective action. Cold milling and grinding shall be performed until the required surface tolerance and a uniform cross section are achieved. Milled areas shall be neat and of uniform surface appearance. Overlays shall be of the same type mix, full roadway width, and to a depth established by the Engineer. Tapering of the longitudinal edges of the overlay will not be allowed.

Corrective actions will not be allowed for lots having a CSI of 40 or better. If the CSI indicates “Allowed” corrective action, the Contractor may elect to take necessary measures to reduce the CSI in lieu of accepting the disincentive. Corrective action as specified above shall be taken by the Contractor if the CSI indicates “Required” corrective action.

Where corrective action is allowed or required, the entire lot will be retested, unless the Engineer allows retesting of the applicable test section(s) only. No disincentive will apply after corrective action if the CSI is 40 or better. If the retested lot after corrective action has a CSI indicating a disincentive, the appropriate disincentive shall be applied.

Incentive pay adjustments will be based only on the initially measured CSI, prior to any corrective work. Where corrective actions have been taken, payment will be based on the CSI determined after correction, not to exceed 100 percent payment.

In the event the Contractor produces a pavement surface that is unacceptable according to the requirements of this provision, the Engineer may suspend the Contractor's operations. Production shall not resume until such time as the Contractor assures the Engineer that he can produce a pavement surface that will meet these requirements. The Contractor may do this by making necessary adjustments to the equipment, methods, and/or personnel.

Areas excluded from testing by the N.C. Hearne Straightedge will be tested by using a non‑mobile 10‑foot (3 m ) straightedge. The variation of the surface from the testing edge of the straightedge between any two contact points with the surface shall not be more than 1/8 inch (3 mm). Deviations exceeding the allowable tolerance shall be corrected in accordance with the corrective actions specified above, unless other corrective measures are permitted by the Engineer.

The Contractor is required to furnish the North Carolina Hearne Straightedge(s) necessary to perform this work. The Contractor will be responsible for all costs relating to the procurement, handling, and maintenance of these devices. The Department has entered into a license agreement with a manufacturer to fabricate, sell, and distribute the N.C. Hearne Straightedge. The Department’s Pavement Construction Section may be contacted for the name of the current manufacturer and the approximate price of the straightedge.

No direct payment will be made for the work covered by this section. Payment at the contract unit prices for the various items covered by those sections of the specifications directly applicable to the work constructed will be full compensation for all work covered by this section including, but not limited to, performing testing in accordance with this specification, any corrective work required as a result of this testing and any additional traffic control as may be necessary.         

D6G02