403MICRO-SURFACING SEAL COAT

194

designed and operated so that a uniform consistency is achieved to produce a free flow of material to the rear strike-off without causing skips, lumps, or tears in the finished surface.

Microsurfacing materials may be used to fill ruts, utility cuts, depressions in the existing surface, and minor surface blemishes. Ruts less than 0.5 inches in depth shall be filled with a leveling course pulled full width with the spreader box. Ruts equal to or greater than 0.5 inches in depth shall be filled independently with a rut-filling box. Ruts greater than 1.5 inches in depth may require multiple applications with the rut-filling box to restore the cross-section. The rut-filling box shall be either 5 foot or 6 foot in width. All rut-filling material shall be allowed to cure under traffic for at least 24 hours before any additional material is placed.

Suitable crack and surface cleaning equipment, barricading equipment, hand tools and other support equipment shall be provided by the Contractor as necessary to perform the work.

Each mixing unit shall be calibrated in the presence of the engineer prior to the start of the project. Any component replacement affecting material proportioning requires that the machine be recalibrated. No machine will be allowed to work on the project until the calibration has been completed and/or accepted. Additional calibrations may be required during production as directed by the Engineer. Calibrations shall be performed in accordance with ALDOT procedure 454, “Calibration of Microsurfacing Equipment”. The Contractor shall provide a copy of the of the calibration worksheets to the Engineer.

403.05Construction

The Micro-Surfacing mixture shall be spread only when the ambient temperature for the 48 hours prior to placement is at least 50 F. The current pavement surface and ambient temperature is at least 50 F and rising. The weather is not foggy or rainy and there is no forecast of temperatures below 32  F within 48 hours from the time of placement. The Micro-Surfacing mixture shall be spread at the discretion of the Engineer if the relative humidity exceeds 80 percent or the weather is overcast.

The area to be surfaced shall be thoroughly cleaned of vegetation, loose aggregate, and soil. All cracks shall be cleaned to the satisfaction of the Engineer prior to overlay. Traffic markings and stripe shall be removed flush with the pavement surface. Whenever conditions are such as to require pre- wetting the surface, the water shall be sprayed ahead of and outside of the spreader box at a rate sufficient to dampen the surface without any free flowing water ahead of the spreader box.

The paving mixture shall be spread on the prepared surface in such a way as to leave a uniform finished surface. Care shall be taken when filling ruts to restore the designed profile of the pavement cross section. Excess crowning or overfilling of the rut area will not be permitted. The Contractor shall use squeegees and lutes to spread the mixture in areas inaccessible to the spreader box and areas requiring hand spreading. A sufficient amount of material shall be carried at all times in all parts of the spreader box to ensure complete coverage. No lumping, balling or unmixed aggregate shall be permitted. No segregation of the emulsion and aggregate fines from the coarse aggregate will be permitted. If the coarse aggregate settles to the bottom of the mix, the mix will be removed from the pavement. The paving mixture shall have proper consistency so that excessive splattering and excessive free water is avoided. The paving mixture shall be applied based on dry aggregate weight as specified on the plans. Adjustments to the additive will be permitted if necessary to provide a slower setting time when hand spreading is needed. If hand spreading is necessary, the mixture shall be poured in a small windrow along one edge of the surface to be covered and then spread uniformly by a hand squeegee or lute. A smooth, neat seam shall be provided where two passes meet. Excess material shall immediately be removed from ends of each run. MICRO-SURFACING SEAL COAT 195

Longitudinal joints and transverse joints shall have no more than ¼ inch vertical space over the joint when measured with a 10 ft. straightedge placed perpendicular to the joint. A maximum of 3 inches shall be allowed for overlap of the longitudinal lane line joints. The edge lines shall be repaired if the edges vary more than 3 inches from a 100 foot straight line or from a 100 foot arc on a curved section.

Traffic shall not be allowed on the Micro-Surfacing mixture until it has cured sufficiently to prevent pick up and/or marring of the surface. Curing of the Micro-Surfacing with the ability to carry rolling traffic shall be within 60 minutes of placement. The Contractor shall maintain traffic control as necessary to prevent damage to the mixture. Any such damage done by traffic to the mixture shall be repaired by the Contractor at no additional cost to the Department. Application of the surfacing mixture shall be suspended early enough each day to permit traffic to safety travel over the completed work before sunset. Work required or materials used in controlling of traffic will not be paid for directly but shall be considered subsidiary obligations of the item of Micro- Surfacing seal coat.

The Contractor shall produce a mixture in compliance with the mix design, mixture control tolerances and spread rate placement tolerances. The Contractor shall maintain all quality control documentation. Quality control documentation shall be made available to the Engineer upon request or at the completion of work.

The Contractor shall calculate the % asphalt content of the mixture from the equipment computer display readings, a minimum of 3 times a day.

The Contractor shall calculate the yield of the course being placed from the equipment computer display readings, a minimum of 3 times a day.

The daily report shall include aggregate used in tons, asphalt emulsion used in tons, mineral filler used in tons, water used in mixture in gallons, and additive used in mixture in gallons.

Prior to production application, the Contractor shall place a 1,000 foot test section to verify the mix design and the ability to carry rolling traffic within 60 minutes. If rolling traffic cannot be carried within 60 minutes, the emulsion or mixture must be adjusted and another test strip shall be required. The test section shall be placed at the same time as the paving is to take place, night or day, and under the same ambient conditions.

The Engineer will take samples of the aggregate and liquid asphalt emulsion for every 1000 tons of aggregate used in production and as otherwise deemed appropriate. A BMT-91 is required for all aggregates shipped for use on the project. Aggregates will be sampled in accordance with AASHTO R 90. If tests on either component material or the mixture fails, the operation shall cease. It will be the responsibility of the Contractor to prove that the problems have been corrected and that a satisfactory operation can be accomplished before work can be started again. A LOT is normally defined as 10,000 square yards. For each LOT, the Contractor shall provide a lot sheet containing the following information:

residue in emulsion;

of cement;

application rate in lbs./sy.;

TACK COAT 196

403.06Method of Measurement

The quantity of Micro-Surfacing mixture, of the type specified, used and accepted will be measured in tons. A means, suitable to the Engineer, for confirmation of the weights of the materials shall be furnished by the Contractor. The weight of the dry aggregate, asphalt emulsion, and the cement used in the mixture shall be calculated and included in the total weight measured for payment. Additional materials such as mineral fillers, water, and chemical additives shall be included in the contract price for micro-surfacing seal coat and will not be measured separately for payment. Deductions in measurement will be made for all material wasted or lost or applied beyond the limits of the work.

403.07Basis of Payment

Compensation for the Micro-Surfacing material, measured as provided above, will be made on a tonnage basis and the contract unit price per ton shall be full compensation for construction of the Micro-Surfacing complete in place as shown on the plans or directed. This price shall include all materials, procurement, handling, hauling, and processing and includes all equipment, tools, labor, and incidentals required to complete the work, with the following exception: Tonnage placed in excess of the amount shown on the plans or directed in writing, plus two pounds per square yard, will be paid for at eighty percent of the contract unit price bid. No payment will be made for unacceptable material; for material furnished or used in excess of the amount indicated or directed, except as provided above; for material used in replacing defective or condemned work; for material wasted in handling, hauling, or otherwise; or for maintaining the work.

403-B Micro-Surfacing Seal Coat, Type * - per ton * Specify Type “II” or “III”. TACK COAT

405.01Description

The work under this Section shall cover the furnishing and placing of a bituminous tack coat on a surface which is to be covered by a bituminous plant mix material in accordance with these specifications and in reasonably close conformity with the lines shown on the plans or directed by the Engineer. The work shall include cleaning the surface prior to application of the tack coat. The area of treatment and the rate of application of a tack coat shall be based on the plans and specifications after evaluating the actual surface condition on which the plant mix overlay is to be placed.

405.02Materials

Bituminous material for tack coat shall be Emulsified Asphalt or one of the Performance Graded

application. The Contractor shall have the option of using the following materials for the tack coat:  PG 58-22 performance graded asphalt binder  PG 64-22 performance graded asphalt binder  PG 67-22 performance graded asphalt binder  PG 76-22 performance graded asphalt binder  CRS-1H emulsified asphalt  CRS-2 emulsified asphalt  CRS-2H emulsified asphalt  CMS-1HP emulsified asphalt  CSS-1 emulsified asphalt TACK COAT 197

 CSS-1H emulsified asphalt  CQS-1H emulsified asphalt  CQS-1HP emulsified asphalt  CRS-2P emulsified asphalt  CRS-2L emulsified asphalt  CBC-1HT emulsified asphalt  CNTT-1HS emulsified asphalt  BC-1HT emulsified asphalt (anionic)  NTSS-1HM emulsified asphalt (anionic)  NTQS-1HL emulsified asphalt (non-ionic)  Ultrafuse  DOT C-10  eTac HB In lieu of tack coat, materials listed in Subarticle 405.02(b) may be applied to adjacent pavement edges and joints as described in Item 2 of Subarticle 405.03(d). Unless shown otherwise on the plans, the contractor shall have the option of using any of the allowable bituminous materials, subject to other limitations of these specifications. In making the selection of materials, the Contractor shall take into consideration seasonal, weather, temperature, and other placement conditions, while keeping in mind that SS stands for slow setting, RS stands for rapid setting, and QS stands for quick setting (QS is the faster setting or breaking emulsion). Low temperatures and humid or damp conditions will retard the breaking or setting of all emulsions. The mixing of a cationic and an anionic emulsion will result in failure of emulsion materials. All materials shall meet the requirements of Section 804. CQS-1HP shall be a cationic emulsion blended with a minimum of 1.2% polymer meeting the requirements given in Article 811.03 and the requirements given in the following table: CQS-1HP MODIFIED ASPHALT EMULSION TEST OF EMULSION Parameter Test Method Value Residue % By Distillation ALDOT 415 60 % Min. - Viscosity, SF @ 77 F, sec. AASHTO T 59 20 SF Min. 100 SF Max. Sieve Test, % AASHTO T 59 - 0.1 % Max. Particle Charge AASHTO T 59 Positive TEST OF RESIDUE FROM EMULSION Parameter Test Method Value Penetration, 100 g, 5 secs. @ 77 F AASHTO T 49 60 mm Min. 130 mm Max. Ductility, cms., @ 39.2 F AASHTO T-51 40 cms Min. - Elastic Recovery @ 50 F, % AASHTO T-301 50 % Min. -

The Contractor may use the following materials in lieu of tack coat for application on adjacent pavement edges and joints.  Pavon™;  Crafco™ Pavement Joint Adhesive Part No. 34524. Pavon™ is a proprietary product that shall also meet the requirements given in the following tables.

REQUIRED PROPERTIES FROM THE TESTING OF Pavon™ Parameter Test Method Value Residue % By Distillation ALDOT 415 60 % Min. - Viscosity, SF @ 77 F, sec. AASHTO T 59 20 SF Min. 100 SF Max. Sieve Test, % AASHTO T 59 - 0.1 % Max. Particle Charge AASHTO T 59 Positive

TACK COAT 198

REQUIRED PROPERTIES FROM THE TESTING OF DISTILLATION RESIDUE FROM Pavon™ Parameter Test Method Value Penetration, 100 g, 5 secs. @ 77 F AASHTO T 49 60 mm Min. 130 mm Max. Ductility, cms., @ 39.2 F AASHTO T-51 40 cms Min. - Elastic Recovery @ 50 F, % AASHTO T-301 50 % Min. -

Crafco™ Pavement Joint Adhesive Part No. 34524 is a proprietary product that shall meet the requirements given in the following table: REQUIRED PROPERTIES FROM THE TESTING OF Crafco™ PAVEMENT JOINT ADHESIVE PART NO. 34524 Parameter Test Method Value Cone Penetration, 77 ºF ASTM D5329 60-100 Flow, 140 ºF ASTM D5329 5 mm-Maximum Resilience, 77 ºF ASTM D5329 30 %-Minimum Ductility, 77 ºF AASHTO T51 30 cm-Minimum Ductility, 39.2 ºF AASHTO T51 30 cm-Minimum Softening Point AASHTO T53 170 ºF Minimum

405.03Construction Requirements

In general, it shall be the Contractor's responsibility to select the proper size and amount of equipment to provide the desired results. Equipment furnished shall meet the requirements of Subarticle 401.03(a).

Grades CSS-1 and CSS-1h Emulsified Asphalts shall not be placed between the dates of October 1 and May 1 in North Alabama and between the dates of November 1 and April 1 in South Alabama regardless of weather conditions. For the purpose of identification, South Alabama shall be referred to for projects lying partly or wholly in the area of the State lying south of latitude 33 °N, with North Alabama encompassing the remaining portion of the State. These seasonal limitations shall not apply to the placement of other bituminous materials for tack allowed by Article 405.02.

Grade CSS-1 and CSS-1h Emulsified Asphalts shall not be used for tack during nighttime paving operations.

Tack material shall not be applied on a wet surface or when in the Engineer's opinion weather conditions are not suitable. NTSS-1HM may become slippery when wet.

When approved by the Engineer, grade CSS-1 and CSS-2 tack coats may be placed when the pavement temperature is 40°F and rising. Temperature limitations for the placement of all other tack coat materials shall be the same as specified in Subarticle 410.03(b) for the plant mix being placed. NTSS-1HM material shall not be used for cold applied asphalt pavement.

Loose material, dust, dirt, and all foreign matter shall be removed from the surface to be treated. All existing surfaces (new pavement, milled pavement, old pavement, or concrete) shall be clean and dry prior to the tack coat application. Cleaning operations can be achieved either through mechanical brooming, by flushing with water, vacuuming, blowing off debris using high-pressure air or other methods as determined by the contactor, unless otherwise shown on the plans. The existing surface shall be approved by the Engineer before application of the tack material.