The Table of Contents for this section is available.
The work covered by this section consists of the construction of an asphalt surface treatment consisting of one or more applications of liquid asphalt material and one or more applications of aggregate cover coat material on a prepared surface.
All materials shall meet the requirements of Division 10 shown below:
Asphalt for mat coat shall be one of the following grades:
Asphalt, Grade CRS-2 Article 1020-7
Asphalt, Grade RS-2 Article 1020-6
Asphalt for seal coat shall be one of the following grades:
Asphalt, Grade CRS-2 Article 1020-7
Asphalt, Grade RS-2 Article 1020-6
Asphalt, Grade CMS-2 Article 1020-7
Asphalt, Grade MS-2 Article 1020-6
Aggregate for mat and seal coat Article 1012-2
Blotting sand Article 1012-3
Before any asphalt surface treatment is placed, the Contractor shall obtain from the asphalt supplier and furnish to the Engineer a certification of compatibility of the asphalt with the aggregate proposed for use. Anionic or cationic emulsion, as indicated by the compatibility test, shall be used.
660-3 WEATHER AND SEASONAL LIMITATIONS.
No asphalt surface treatment shall be placed between October 15 and March 16, except for asphalt surface treatment which is to be overlaid with asphalt plant mix.
Asphalt material shall be applied only when the surface to be treated is dry and when the atmospheric temperature is above 60F. in the shade away from artificial heat.
When placing asphalt surface treatment which is to be subsequently overlaid with asphalt plant mix, the seasonal and temperature limitations of Article 6104 shall apply.
Asphalt material shall not be applied when the weather is foggy or rainy.
The surface to be treated shall be cleaned of all dust, dirt, clay, grass, sod, and any other deleterious matter prior to application of the asphalt surface treatment.
660-5 ACCEPTANCE OF ASPHALT MATERIALS.
The acceptance of asphalt materials shall be in accordance with the provisions of Article 10201.
Asphalt application equipment shall meet the requirements of Article 6005.
Aggregate shall be applied by the use of a self-propelled, pneumatic tired aggregate spreader capable of maintaining a specified rate with a uniform application for the width of asphalt material being covered. Tailgate spreaders will not be permitted. Areas which are inaccessible to the aggregate spreader may be covered by hand spreading or other acceptable methods.
660-7 APPLICATION OF ASPHALT MATERIALS.
The grades, rates of application, and the temperature at which the asphalt material is to be applied shall be within the limits shown in Table 6601.
The required rates of application shall be based on the volume of material at the application temperature.
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| Sand Seal |
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* Use No. 6 or No. 78M aggregate for retreatment prior to an overlay on existing pavement
Use No. 5 aggregate for initial treatment on new construction
** 8-12 lbs/sq. yd. of blotting sand shall be applied after final application of No. 78M has been completed and rolled
660-8 APPLICATION OF AGGREGATES.
The size of the aggregate shall be as shown in Table 6601 for the mat coat or the type of seal coat to be constructed.
The rate of application for mat and seal aggregates shall be within the limits shown in Table 6601.
When directed by the Engineer, the Contractor shall weigh a sufficient number of truck loads of aggregate prior to spreading to verify that the rate of application is within the required limits.
(A) Asphalt Mat Coat:
The surface on which the mat coat is to be applied shall have been approved by the Engineer before the mat coat liquid asphalt is applied.
The Contractor shall place a string line guide for application equipment unless otherwise permitted by the Engineer.
The mat coat shall be placed in full-lane widths unless otherwise permitted by the Engineer.
The application of mat liquid asphalt shall be followed immediately by the spreading of the aggregate. No more than 5 minutes shall elapse from the time the liquid asphalt is applied and the aggregate is spread.
The mat coat aggregate shall have been tested and approved and shall be drained of free moisture prior to use. The aggregate shall be spread uniformly at the required rate and all nonuniform areas shall be corrected prior to rolling.
Rolling shall be done immediately after the aggregate has been uniformly spread. Initial rolling shall consist of one complete coverage with a 5 to 8 ton steel wheel roller after which pneumatic tired rollers shall be used. Rolling shall continue until the aggregate is thoroughly keyed into the mat liquid asphalt. The use of rollers which result in excessive crushing of the aggregate will not be permitted. The rollers shall be designed to prevent picking up material. The use of a combination steel wheel and pneumatic tired roller will not be permitted. Two individual rollers shall be used.
At the beginning of each mat liquid asphalt application, a paper shall be spread over the end of the previously completed mat coat and the asphalt application shall begin on the paper. After use, the paper shall be removed and satisfactorily disposed of by the Contractor.
Traffic may be permitted on the mat coat immediately after the rolling is complete. After the aggregate is thoroughly seated, all excess aggregate shall be broomed off of the surface of the mat coat as directed by the Engineer.
Defects or damage to the mat coat shall be corrected prior to the application of seal coat or plant mix overlay.
The seal coat may be applied the same day the mat coat is placed provided the mat coat has been satisfactorily applied and rolled.
(B) Asphalt Seal Coat:
The type of seal coat to be used shall be as required by the contract.
Seal coat aggregates shall have been tested and approved and shall be drained of free moisture prior to use.
Where it is necessary to permit traffic on sections of a completed seal coat before it has cured sufficiently to prevent picking up, the aggregate rates shall be adjusted to provide a sufficient quantity of cover material to be spread over the surface of the seal coat to prevent traffic damage.
Rolling for all seal coats shall be accomplished as described in the following paragraph, except that only the pneumatic tired roller shall be used on sand seal.
Rolling shall be done immediately after the aggregate has been uniformly spread. Initial rolling shall consist of one complete coverage with a 5 to 8 ton steel wheel roller after which pneumatic tired rollers shall be used. Rolling shall continue until the aggregate is thoroughly keyed into the
liquid asphalt. A final coverage with the steel wheel roller may be required to provide a satisfactory finished surface. The use of rollers which result in excessive crushing of the aggregate will not be permitted. The rollers shall be designed to prevent picking up the material. The use of a combination steel wheel and pneumatic tired roller will not be permitted. Two individual rollers shall be used.
The provisions of Subarticle 6609(A) shall apply to the width of seal coat construction, application of liquid asphalt and aggregate, and the construction of joints.
When directed by the Engineer, the Contractor shall apply blotting sand in accordance with the provisions of Section 818.
The construction of the various types of seal coats shall be in accordance with the following additional requirements:
1. Straight Seal:
The full required amount of asphalt material shall be placed in one application and immediately covered with seal coat aggregate. The full required amount of aggregate shall be uniformly spread in one application and all non-uniform areas shall be corrected prior to rolling.
Immediately after the aggregate has been uniformly spread, rolling shall be done as previously described.
When directed by the Engineer, excess aggregate material shall be broomed from the surface of the seal coat.
2. Drag Seal -- Type A:
Approximately 0.20 to 0.25 gallons/square yard of asphalt material shall be applied to the existing surface immediately followed by the application of approximately 18 to 22 pounds/square yard of seal coat aggregate spread uniformly over the treated surface. The remainder of the required amount of asphalt material shall then be applied and the aggregate and asphalt material thoroughly mixed by the use of approved drag brooms.
Immediately after acceptable mixing, the remainder of the required amount of seal coat aggregate shall be uniformly spread over the surface and rolled as previously described.
3. Drag Seal -- Type B:
Approximately 0.10 to 0.15 gallons/square yard of asphalt material shall be applied to the existing surface immediately followed by the application of approximately 15 to 17 pounds/square yard of seal coat aggregate. A second application of 0.15 to 0.20 gallons/square yard of asphalt material shall be applied and followed immediately by the application of the remainder of the required amount of seal coat aggregate. The remainder of the required amount of asphalt material shall then be applied and the aggregate and asphalt material thoroughly mixed by the use of approved drag brooms.
Immediately after the aggregate has been uniformly mixed, rolling shall be done as previously described.
After rolling the seal coat aggregate (No. 78M), the surface shall be lightly sanded using 8-12 pounds per square yard of blotting sand.
4. Split Seal:
Approximately 0.20 to 0.25 gallons/square yard of asphalt material shall be applied to the existing surface immediately followed by the application of approximately 20 to 22 pounds/square yard of seal coat aggregate spread uniformly over the treated surface.
Immediately after the first application of seal aggregate has been made uniform, the remainder of the required amount of asphalt material and seal coat aggregate shall be applied and the seal coat shall be rolled as previously described.
5. Triple Seal:
Approximately 0.20 to 0.25 gallons per square yard of the required liquid asphalt shall be applied to the existing surface immediately followed by the application of approximately 15 to 17 pounds per square yard of the required amount of seal coat aggregate spread uniformly over the treated surface. This operation shall be performed 3 times and after the final application of aggregate is applied, it shall be rolled as previously described.
6. Sand Seal:
The full required amount of asphalt material shall be placed in one application and immediately covered with the seal coat aggregate. The full required amount of aggregate shall be uniformly spread in one application and all non-uniform areas shall be corrected prior to rolling.
Immediately after the aggregate has been uniformly spread, rolling shall be done as previously described.
When directed by the Engineer, excess aggregate material shall be broomed from the surface of the seal coat.
When the sand seal is to be constructed for temporary sealing purposes only and will not be utilized by traffic, other grades of asphalt material meeting the requirements of Articles 10206 and 10207 may be utilized in lieu of the grade of asphalt required by Table 6601 when approved by the Engineer.
(C) Asphalt Mat and Seal:
The mat coat shall be constructed in accordance with Subarticle 6609(A) using the size aggregate required by the contract.
The seal coat shall be constructed in accordance with Subarticle 6609(B) using the type seal required by the project special provisions.
660-10 MAINTENANCE AND PROTECTION.
The Contractor shall maintain and protect the asphalt surface treatment until it is accepted by the Department. All necessary repairs shall be made in such a manner as to preserve the uniformity of the surface.
The quantity of asphalt surface treatment to be paid for will be the actual number of square yards of asphalt surface treatment which has been completed and accepted. In measuring this quantity, the length will be the actual length constructed, measured along the surface. The width will be the width required by the plans or directed by the Engineer measured along the surface.
The quantity of asphalt surface treatment, measured as provided in Article 66011, will be paid for at the contract unit prices per square yard for "Asphalt Surface Treatment, Mat Coat, No. ___________ Stone", "Asphalt Surface Treatment, ___________ Seal", Asphalt Surface Treatment, Drag Seal, Type _________", or "Asphalt Surface Treatment, Mat and Seal" in accordance with the type of asphalt surface treatment actually constructed. Payment at the above prices will be made for replacing any satisfactorily completed asphalt surface treatment when such replacement has been made necessary by defects in subgrade or base which has been constructed by others.
When the Engineer directs that the rate of application of asphalt material be decreased below the minimum rate shown in Table 6601, no reduction in compensation will be made.
When the Engineer directs that the rate of application of asphalt material be increased above the maximum rate shown in Table 6601, compensation to the Contractor will be made in the amount of 5 cents plus the verified cash cost to the Contractor at the point of delivery for each gallon of asphalt material, measured at application temperature, necessitated by the increase.
Blotting sand will be paid for as provided in Article 8185 for "Blotting Sand".
Furnishing and applying prime will be paid for as provided in Article 60010 for "Prime Coat".
The above prices and payments will be full compensation for all work covered by this section including but not limited to furnishing, hauling, spreading, and rolling the asphalt material and aggregate; furnishing and spreading blotting sand; and maintaining and repairing the asphalt surface treatment.
Payment will be made under:
Asphalt Surface Treatment, Mat Coat, No. ________ Stone Square Yard
Asphalt Surface Treatment, _______ Seal Square Yard
Asphalt Surface Treatment, Drag Seal, Type ________ Square Yard
Asphalt Surface Treatment, Mat and Seal Square Yard