00711.10 719 Section 00711 - Pre-Coated Aggregate Asphalt Chip Seal
Description
00711.00Scope - This Work consists of applying a chip seal using a modified hot asphalt binder and
precoated graded Aggregate as shown.
Materials
00711.10Aggregates - Furnish Aggregate meeting the following requirements:
Aggregate meeting the foll owing gradation:
3/8" - No. 4 Percent Passing Sieve Size (by Weight) 1/2" 100 3/8" 85 - 100 No. 4 0 - 15 No. 8 0 - 5 No. 200 Wet 0 - 1.5
combination of both. Crush Aggregate such that at least 90 percent by weight of the total Aggregate retained on the No. 8 and larger sieves is fractured on two faces, as determined according to AASHTO T 335.
cubic foot according to AASHTO T 19.
subjected to five cycles of the soundness test using sodium sulfate according to AASHTO T 104.
Test Method Maximum Test ODOT AASHTO Values Abrasion T 96 30.0% Degrade (Plus No. 4) Passing No. 20 Siev e TM 208 30.0% Sediment Height TM 208 3.0"
requirements:
Test Method Test ODOT AASHTO Limit Lightweight Pieces T 113 1.0% maximum Wood Particles TM 225 0.1% maximum Elongated Pieces (5:1 ratio) TM 229 10.0% maximum Cleanness Value TM 227 75 minimum
00711.11 720 00711.11 Asphalt Binder - Furnish AC15-5TR or AC -15P asphalt conforming to the requirements of ODOT's publication Standard Specifications for Asphalt Materials . Copies of the publication are available from the ODOT Pavement Services Engineer . The applicable Specifications are those contained in the current publication on the date the Project is advertised.
00711.12Asphalt and Additives for Pre -Coated Aggregate - Furnish PG64-22 grade asphalt to
pre coat the Aggregate meeting the requirement of ODOT's publication, Standard Specific ations for Asphalt Materials . Copies of the publication are available from the ODOT Pavement Services Engineer. The applicable Specifications are those contained in the current publication on the date the Project is advertised.
Obtain samples of asphalt according to AASHTO R 66 when requested by the Engineer. Samples may be tested at the discretion of the Engineer at the Agency's expense.
00711.15Aggregate Production Quality Control - Provide sampling, testing, and quality control
during production of Aggregates according to Section 00165. .16 Acceptance of Aggregate - The Contractor ’s quality control tests will be used for acceptance of Aggregates if verified by the Quality Assurance Program. The Agency will perform Aggregate production quality assurance according to Section 00165.
Obtai n asphalt binder samples according to AASHTO R 66 at a frequency of one sample for each 50 Tons of asphalt binder used. Samples will be tested at the ODOT Materials Laboratory, or other laboratory as designated by the Agency.
00711.17Pre -Coated Aggregate Mixture - Pre-coat, cure, store, and maintain the pre-coated
Aggregate mixture according to the following:
• Waste all bag house dust during production of the pre-coated Aggregate mixture. • Use an asphalt hot plant to coat the Aggregate with asphalt. • Achieve at least a 90 percent coating on all the material retained on the No. 4 sieve by applying between 0.7 and 1.0 percent liquid asphalt of the total weight of the material. Establish the target value and obtain the Engineer's approval before beginning the coating process. The acceptable liquid asphalt tolerance is ± 0.2 percent. Test according to ODOT TM 321 at a frequency of one test for every 500 Tons of mixture. Coated Aggregate that is not within the acceptable toleranc e will be rejected. • Maintain the plant dryer temperature between 190 °F and 230 °F. Maintain the liquid asphalt temperature at the liquid asphalt Supplier 's recommended temperature. • The maximum moisture content of the pre- coated Aggregate mixture is limited to 1.3 percent. Test according to AASHTO T 329 at a frequency of one test for every 500 Tons of mixture. • After pre -coating, stockpile, cool, and cure the Aggregate mixture for at least 7 Calendar Days before using it. • Use multiple stockpiles to store t he pre -coated Aggregate mixture. Do not place additional pre-coated Aggregate mixture into an existing stockpile until the temperature of the additional pre-coated Aggregate mixture is no more than 140 °F. • Turn the pre-coated Aggregate mixture with a loader or other means to accelerate cooling, to increase uniformity of the coating on the Aggregates, to avoid heat buildup, and to prevent burning of the asphalt coating. Excessive clumping may require re screening of the mixture before acceptance. If excessive dust is encountered when placing the pre-coated Aggregate mixture, re -screen it at the stockpile site. • Final acceptance of the pre-coated Aggregate mixture will be completed at the stockpile staging site. 00711.23 721 Equipment
00711.20Equi pment - Provide pressure distributors, hauling vehicles, chip spreader, compactors,
power brooms and other necessary Equipment to insure efficient operation and construction to meet specified results. Provide Equipment in sufficient number and capacities that will provide coordinated and uniform progress of the Work .
Provide two -way radio communication between the asphalt distributor and chip spreader.
00711.21Asphalt Distributors - Provide asphalt distributors that are:
• Designed, equipped, maintained, and operated so the asphalt M aterial may be applied uniformly at even heat, and in a continuous operation. • Capable of applying the asphalt on variable surface widths up to 16 feet, at readily determined and controlled rates from 0.05 - 2.0 gallons per square yard, and with uniform pressure. The variation allowed from any specified rate shall not exceed 0.02 gallons per square yard. • Equipped with a tachometer, pressure ga uges, accurate volume measuring devices, and a thermometer for meas uring temperature of tank contents. • Equipped with a Computer Rate Control device. • Equipped with a positive power unit for the asphalt pump, and full circulation spray bars adjustable both laterally and vertically.
Set the bar height for triple lap coverag e.
Demonstrate to the Engineer that the asphalt distributors are properly calibrated before beginning Work .
00711.22Chip Spreaders - Provide chip spreaders that are:
• Self-propelled, computerized chip spreaders, and with a screenings hopper in the rear and a belt conveyor to carry the screenings to the front of the spreader hopper. Rear screens may be removed at the direction of the Engineer if excess build -up occurs. • Capable of providing a uniform spread rate over the entire width of the Traffic Lane in one application. • Equipped with an Aggregate segregator assembly unless otherwise allowed by the Engineer. • Of adequate width to provide full C overage of the specified Panel without placing joints in the travel lanes. • Equipped with a surface temperature thermometer which reads the surface temperature in advance of Rock placement, and be visible to the chip spreader operator.
Provide verification to the Engineer that the chip spreaders are properly calibrated before beginning Work .
00711.23Compactors - Provide at least three rollers for multiple P ass operations and at least five
rollers for continuous operations meeting the following requirements:
• Be self -propelled pne umatic -tired in good condition and capable of operating at speeds compatible with the chip seal operation. • Be tandem or multiple axle, multiple wheel type pneumatic -tired rollers with smooth-tread pneumatic tires of equal size. 00711.24 722 • Have staggered tires on the axles at spacing and overlaps that will provide uniform compaction pressure for the full compacting width of the roller. • Have minimum load per tire of 2,800 pounds, with tire inflation pressures of 45 to 100 psi. • Maintained air pressure to not vary more than ± 5 psi in each tire per machine.
00711.24Power Brooms - Provide at least four pickup or non-pickup type power brooms equipped
with a positive means to control vertical pressure.
00711.25Asphalt Storage Tank - Provide a heated asphalt sto rage tank in close proximity to the
Project.
Labor
00711.30Quality Control Personnel - Provide a technician having a CAgT technical certification
00711.31Technical Representative - Provide a qualified technical representative from the asphalt
binder Supplier , on site, during all chip seal operations. The technical representative duties are to assist the Engineer in establishing the asphalt binder and pre-coated Aggregate mixture application rates and to provide input on the temperatures for the application of the asphalt binder coat.
Construction
00711.40Season, Weather and Temperature Limitations - Construct the chip seal in warm dry
weather. Apply the hot asphalt binder only when the ambient temperature is 70 °F or higher and the Pavement surface temperature, in the sun and shade is 75 °F or higher. Do not apply if the road surface is wet or if rain is predicted. If unexpected rain does occur during application, shut off the asphalt distributor but continue with pre-coated Aggregate mixture placement until all newly sprayed asphalt binder has been covered. Do not resume the chip seal operation for at least 2 Days and when allowed by the Engineer.
00711.41Rate of Progress and Scheduling - Do not apply more chip seal in any one Day than can
be broomed the same Day .
00711.42Preparation of Underlying Surfaces - At the beginning of the shift, clean the surface to
be treated of all loose material by brooming.
00711.43Sequence of Operations - Construct the chip seal as follows:
• Apply the binder. • Distribute the pre-coated Aggregate mixture. • Compact it with pneumatic tired rollers.
When applying the asphalt binder at intersections, turn pockets, gore points, and other irregular areas do not apply the asphalt binder in excess of what can be covered with the pre-coated Aggregate mixture within the appropriate temperature range of the asphalt binder.
00711.44Application Rates - Apply the asphalt binder and spread the pre-coated Aggregate
mixture within the following ranges of rates. The exact application and spread rate will be determined by the Engineer.
Asphalt binder application rate ................................. 0.35 to 0.45 gallon per square yard Pre coated Aggregate mixture spread rate ..............10 to 20 pounds per square yard
00711.60 723 00711.45 Applying Asphalt Binder Coat - Place asphalt binder to the road surface with a pressure distributor at the rates specified and according to the following:
• Apply to no more than one-half the width of the travel way at one time. • Apply so the longitudinal joint between adjacent applications of asphalt binder and pre-coated Aggregate mixture coincides with the line between designated Traffic Lanes. • Apply asphalt binder at a distance that allows the pre-coated Aggregate mixture to be applied at the binder surface temperature listed in 00711.46. Do not operate hauling and spreading Equipment on uncovered asphalt binder. • Apply at a temperature between 330 °F and 370 °F or as recommended by the asphalt binder Supplier . Do not elevate the asphalt binder above 330 °F for more than a 4 hour period or a temperature or time period recommended by the asphalt binder Supplier . • Clean all joints of excess loose material before applying the asphalt binder. • Construct joints without ridges and depressions and have uniform appearance consistent with the adjacent sealed surface. Correct all defects at no cost to the Agency. • Place buildin g paper over the treated surface at the beginning of each spread for each distributor to insure that the nozzles are operating properly before the uncoated surface is reached. Remove and dispose of building paper according to Section 00290.
00711.46Hau ling and Spreading Aggregates - Haul and spread the pre- coated Aggregate mixture
at the rates specified and the following:
• Periodically verify the gate opening to be sure a consistent spread rate is maintained. Maintain the pre -coated Aggregate mixture spread rate within ± 5% of the established rate. • Operate hauling Equipment at speeds that will not damage the new chip seal . Route hauling Equipment and pilot car traffic as uniformly as possible over the full width of the new surface. • Cover the asphalt bi nder surface with pre- coated Aggregate mixture when the asphalt binder surface temperature is between 130 °F and 180 °F. • Uniformly spread pre-coated Aggregate mixture to provide Coverage without gaps or overlapping adjacent Coverages. Do not construct longitudinal joints within the travel lanes.
Construct neat transverse cut off of pre-coated Aggregate mixture and remove all excess Aggregate from the surface before resuming operations.
00711.47Shaping and Compacting - After the pre -coated Aggregate mixture has been spread on
the asphalt binder surface, remove all piles, ridges, and uneven surfaces.
Make the initial compa ction Pass behind the spreader as soon as the pre- coated Aggregate mixture is spread. Hauling Equipment may be used to assist in compaction immediately behind the spreader. Use sufficient pneumatic rollers to cover the width of the pre- coated Aggregate mixture spread in one Pass. Roll in a staggered pattern. Operate rollers to maintain close proximity to the spreader but do not exceed 5 mph. Complete at least three roller Passes within 30 minutes of spreading pre-coated Aggregate mixture. If rollers are unable to keep up with the spreader, stop application of asphalt binder and pre- coated Aggregate mixture until to rollers catch up or furnish additional rollers. If pre-coated Aggregate mixture spreading is stopped for more than 2 minutes, m ove the spreader ahead of or off the surface so that cover M aterial may be immediately rolled.
Maintenance
00711.60Power Brooming - After rolling the pre- coated Aggregate mixture, remove loose
Aggregate by brooming the entire surface. Delay brooming if the brooms damage the surface. Broom 00711.80 724 one Pass in the opposite direction in which the pre-coated Aggregate mixture was placed. Do not allow uncontrolled traffic on the surface until all brooming of excess Aggregate is completed.
Subsequent brooming may be required for up to 2 Days after placement as directed.
Seven Calendar Days after completion of a section of chip seal , remove all loose Aggregate from the Shoulder area by brooming.
On Bridges, barrier areas, minimum width Median areas, and curbed areas, use a pick -up type power broom. On Bridges, sidewalks, and other areas off the Roadway, remove all loose Aggregates to the satisfaction of the Engineer. Dispose of loose Aggregate at least 150 feet from the nearest waterway in areas identified for this purpose.
Measurement
00711.80Measurement - The quantities of Work performed under this Section will be measured on
the weight basis.
Payment
00711.90Payment - The accepted quantities of Work performed under this Section will be paid for
at the Contract unit price, per unit of measurement, f or the following items:
Pay Item Unit of Measurement
Payment will be payment in full for furnishing and placing all Materials, and for furnishing all Equipment , labor, and Incidentals necessary to complete the Work as specified.