VIRGINIA DEPARTMENT OF TRANSPORTATION

SPECIAL PROVISION FOR

RIDEABILITY

(Type I Projects – Plant Mix Schedule)

 June 2001

 SECTION 315 - ASPHALT CONCRETE PAVEMENT of the Specifications is amended as follows:

 Section 315.07 Pavement Tolerances is amended to include the following:

For designated pavements, the overlay ride quality acceptance will be based on the lowest average International Roughness Index (IRI) for each 0.01-mile section produced by a minimum of two test runs, using a South Dakota style road profiling device and reported for each travel lane.  The device shall measure both wheelpaths with laser height sensing instruments. The Department shall conduct the testing within 30 calendar days of completion of the final surface course over the designated section. Testing shall be conducted in accordance to VTM – 106.  The Department will conduct the testing as soon as possible after completion, providing the contractor can allow unimpeded access to the paved surface for constant highway speed test runs.

Acceptance  

An IRI number in inches per mile will be established for each 0.01-mile section for each travel lane of the overlay. The last 0.01-mile section before a bridge, the first 0.01-mile section after a bridge, and the beginning and end 0.01-mile sections of the overlay will not be subject to a pay adjustment.

Areas excluded from testing by the profiler will be tested using a 10-foot straightedge.  The variation of the surface from the testing edge of the straightedge between any two contacts with the surface shall not be more than 1/4 inch.  Humps and depressions exceeding the specified tolerance shall be subject to correction as directed by the Engineer, at no additional cost to the Department.

The following table provides the acceptance quality of pavement based on the finished rideability for interstate and primary roadways.  Pay adjustments will be applied to the theoretical tonnage of the surface mix asphalt material for the lane width and section length tested (generally 12 feet wide and 52.8 feet long) based on testing prior to any corrective action directed by the Engineer.

The method of correction shall be approved by the Engineer and correction shall be performed at the Contractor’s expense.  The Engineer may require correction of any or all adjoining traffic lanes or shoulders at the Contractor’s expense to assure uniform cross section.  Methods of correction may include, but not limited to diamond grinding, remove and replace, and AC overlay.

 Where corrections are made, the pavement will be retested to verify that corrections have produced the acceptable ride surface.  Unit price disincentives or corrections may be required based on the retested IRI measurements.  No incentives will be provided for sections on which corrective actions have been required.  The contractor will have one opportunity to perform corrective action(s).  In the event the corrective action(s) do not result in 100% payment, then the contractor will be assessed the corresponding percent payment.

 Where only one AC layer will be laid, the Department will test pavement sites subject to this special provision prior to work by the Contractor.  The Engineer will provide the IRI information to the Contractor.  If this IRI testing is conducted more than 180 calendar days prior to the schedule beginning of the work, the Engineer or Contractor may request new IRI testing if the roughness of the existing pavement is deemed to have changed.  An AC layer is defined as a material lift equal to or greater than 2.5 times the maximum nominal aggregate size for the AC mix(s) specified in the contract.  A material lift less than the specified application rate or less than 2.5 times the maximum nominal aggregate size for the AC mix(s) specified in the contract is considered a “scratch course” and not an AC layer. 

 Based on the average IRI over the length of each travel lane subject to this special provision; 

·         No incentive pay adjustment will be made if the pavement lane is rougher after completion of the work.

·         Where only one AC layer will be laid (as defined above), no disincentive will be applied nor corrective action be required if the completed surface has IRI test results which indicates a 30 percent or more improvement in the ride quality.  This percent improvement is based on the total paved section average IRI and not the individual 0.01-mile increments. 

This rideability specification does not relieve the Contractor from responsibility concerning workmanship in accordance with the requirements of the Specifications or as defined by the Engineer.