140L5723Q0033_Amendment_0001_Chip_Seal_Specifications_0001.pdf

CHIP SEAL SPECIFICATIONS

4.6 BITUMINOUS SEAL COAT (CHIP SEAL). Bituminous surface treatments (chip seals) shall be applied to the road surface only when required, or approved by the Government's representative. The bituminous surface treatment shall consist of an application of bitumen covered with mineral aggregate and rolled to a smooth surface presenting an even texture. The materials used in the application of the bituminous surface treatment shall be bituminous mineral, and mineral aggregate, as specified below.

4.6.1 MATERIAL SPECIFICATIONS.

4.6.1.1 BITUMINOUS MATERIAL. The bituminous material shall be cationic emulsified asphalt with a natural latex rubber material (type LMCRS-2H) and shall conform to the following requirements:

TABLE 4.19 BITUMINOUS MATERIAL

TEST SPECIFICATION PARAMETERS

Viscosity @ 122 F.

Sieve Settlement, 5 days Demulsibility Storage Stability

(1 day test) Ash Content

AASHTO T-59

AASHTO T-59

AASHTO T-59

AASHTO T-59

AASHTO T-59

ASTM D3723

100-300 sec.

0.3% max.

5% max.

40% min.

1% max.

0.2% max.

Tests on Residue by Drying:

Percent Residue Penetration @ 77 F., (100 g., 5 sec.)

Ductility @ 77 F., (5 cm./min.)

Torsional Recovery

NV 756

AASHTO T-49

AASHTO T-51

NV 756

65% min.

40-150 mm.

40 cm. min.

18% min.

Particle Charge AASHTO T-59 POSITIVE

4.6.1.2 AGGREGATE (CHIPS). Mineral aggregate shall consist of crushed stone or crushed gravel, free from adherent films of clay or dust, and shall be of such nature that a thorough coating of the bituminous material used in the work will not strip off upon contact with water.

The gravel or rock shall have a percent of wear not greater than thirty (30) when tested by (AASHTO T-9 ASTM C 131). Chips shall be cubical or pyramidal in shape with at least ninety-five (95) percent fractured faces. The crushed aggregate shall have a weighted percent of loss not exceeding ten (10) percent by weight when subjected to five (5) cycles of sodium sulfate and tested in accordance with AASHTO Designation T-104.

Stripping tests of the mineral aggregate which the Contractor proposes to use shall be furnished to the Contracting Officer Representative before crushing operations begin. During aggregate crushing, additional stripping tests shall be furnished to the COR upon request. No stripping test shall show a percent stripping greater than ten (10) for LMCRS-2H asphalt. The chip shall be electrically compatible to the asphalt emulsion used.

The crushed aggregate shall conform to the gradation requirements shown in following table.

TABLE 4.20

GRADATION OF AGGREGATE FOR CHIP SEAL COATS

SIEVE SIZE PERCENT BY

WEIGHT PASSING

(Ideal)

IDEAL GRADATION

TOLERANCE

(Percent)

1/2 Inch 100 0

3/8 Inch 95 +/- 5

No. 4 10 +/- 5

No. 8 2 +/- 2

No. 200 0.5 +/- 0.5

The initial mineral aggregate used for the production of chips shall be retained on a one-inch sieve prior to being crushed to the gradation specified.

4.6.2 AGGREGATE QUALITY CONTROL. Prior to delivery to the project site the designated wear test, stripping test, sodium sulfate test, fracture face count, and gradation tests shall be performed on the crushed aggregate. Each time a source changes said tests will be repeated.

All aggregate (chips) shall be tested for compliance with the gradation and fracture face count during the production of the chips. There shall be no less than one (1) test performed for every one hundred tons of material produced or one (1) day’s production, whichever is less. One gradation test and fracture face count test shall be defined as the average results of tests taken on three (3) different samples taken at one particular time.

All material produced shall be stockpiled in designated stockpile site(s).

When chips are delivered to the project stockpile site. There shall be test requirements met. the COR may require that the failed material be removed from the stockpile. Chips shall be considered to be out of specification if one test (as defined herein above) fails.

The COR may not accept any chips which do not meet all the designated specifications.

In addition to the random acceptance samples taken at the stockpile, the Government’s Representative may sample the aggregate from any portion of stockpile which exhibits a non-uniform appearance.

The Contractor shall take immediate steps to bring the aggregate into specifications when test results show any deviation from the established maximum or minimum values for any sieve as shown in Table 4.20 of these specifications.

At designated stockpile site(s), the Contractor may be required to ”push up“ the unloaded aggregate into piles suitable for loading into the delivery dump trucks.

Extreme care shall be taken so as not to mix any of the crushed aggregate with the underlying material at the stockpile or the crushing site. In the event that there is contamination of the chip seal aggregate with foreign material, as determined by the COR, or by tests conducted, the contaminated section of material shall be immediately removed from the stockpile or crushing area and properly disposed

of. All contaminated material removed from the stockpile, or crushing area, shall be replaced with aggregate which meets the requirements of these specifications.

All testing required by the COR, or by the plans and specifications, shall be performed by an independent testing laboratory. The Contractor shall do everything in his power to ensure that the Government's Representative has full access to the testing procedure and shall deliver to the Government's Representative any and all results of tests run. The Contractor shall not proceed with subsequent construction until certified copies of appropriate tests are delivered to the COR. any materials not properly tested shall be subject to rejection and removal.

4.6.3 EQUIPMENT. All tools, equipment and machines used in the performance of the work shall be subject to the approval of the COR, and shall be maintained in satisfactory working conditions at all times.

4.6.3.1 ASPHALT DISTRIBUTOR. The asphalt distributor shall be equipped with a calibrated dipstick marked in gallons per inch of length, and an accurate thermometer and speedometer. The distributor shall also be capable of maintaining proper pump pressure to ensure a uniform distribution of liquid asphalt emulsion at all times. The pump shall be able to maintain the correct pump speed, or pressure, without either atomizing the asphalt or distorting the spray fan. However, the pump shall be able to maintain a pressure which shall be sufficient to prevent streaking from a non-uniform discharge of material from the individual nozzles.

The distributor shall be equipped with a rear-mounted spray bar capable of covering widths of six to fifteen (6-15) feet in a single pass. The distributor tank shall be well insulated and be equipped with one or more heaters capable of bringing the asphalt emulsion to spray application temperature. The tank shall have a full circulating system which shall include the spray bar unit. The truck shall also be equipped with a hand-spray for applying the asphalt emulsion to areas that cannot be reached with the spray bar.

The distributor shall be equipped with a computer which will automatically determine the discharge based on the nozzle size, the truck speeds for various application rates, and the corrections for temperature-viscosity variations.

4.6.3.2 AGGREGATE SPREADER. The spreader shall be a self- propelled Flarity chip spreader, or equal, capable of uniformly spreading aggregate at varying application rates as required. The spreader shall be equipped with a tachometer and/or a speedometer to ensure the maintenance of a uniform spreader speed. The aggregate spreader shall also be equipped with a device and so operated that the coarse particles of the screening shall be deposited on the bituminous binder before the finer particles.

4.6.3.3 ROLLERS. The Contractor shall provide at least two (2) self propelled, smooth-tread, pneumatic tired rollers on the job during the chipping operations. Each roller shall weigh at least ten (10) tons and have staggered (offset) front and rear tires to obtain a uniformly rolled pass. Tire pressure in all tires shall be uniform and inflated to eighty (80) psi. No steel wheel rollers shall be used to roll the chip seal surface treatments. Rolling speed shall not exceed ten (10) miles per hour.

4.6.3.4 DUMP TRUCKS. The Contractor shall provide sufficient ten-wheel dump trucks during the chip sealing operations to ensure that the project can proceed without interruption. Frequent stops and starts during the chip seal operation will not be permitted.

4.6.3.5 LOADERS. The Contractor shall have on hand at least one loader to load the aggregate into the dump trucks from the aggregate stockpile(s).

4.6.3.6 POWER BROOMS. The Contractor shall provide at least one self- propelled rotary power broom or sweeper at the job site, and shall use said sweeper (supplemented with hand brooms as necessary) as required, to sweep the excess aggregate on the edge of each pass which will be in contact with the next pass so that there will be no build up of aggregate at the seams or joints between passes. The broomed aggregate shall be swept onto the freshly laid course.

4.6.4 BITUMINOUS CHIP SEAL CONSTRUCTION METHODS. The methods employed in installing bituminous chip seal(s) shall include, but are not limited to, the following:

4.6.4.1 SURFACE PREPARATION. All dust, dirt, tracked on clay and foreign material shall be removed from the surfaces to be sealed by sweeping the surface with power brooms, hand brooms, power blowers, or by flushing it with water or a combination of the above. All patching, crack filling and drainage improvements required by the COR, shall be completed prior to the commencement of the surface treatment application. After the cleaning operation has been completed, and prior to the application of the surface treatment, the area to be treated will be inspected by the COR, to determine its fitness for receiving the surface treatment.

All sewer manhole lids, water valve covers and survey monument covers shall be protected from the application of the seal coat by placing building paper over the lids (cut to the exact dimensions of the lids) prior to the application of the seal coat. At the completion of the sealing operations, all protective coverings shall be removed from said survey monument covers, manhole lids and valve covers.

At the edges of all passes which will form longitudinal joints in the surface treatment (chip seal) the edge of the pass shall be swept clean of all chips for a distance of from four to six (4-6) inches back from the edge prior to the application of the adjacent pass to allow for overlap without chip buildup (humps) in the previous pass. Building paper shall be laid on all cross gutters (concrete waterways) to prevent the chip seal from being applied to said gutters. The Contractor shall place building paper at the beginning of all chip passes.

Immediately after the chip application, the building paper shall be removed and properly disposed of.

4.6.4.2 ASPHALT APPLICATION. Application of the bituminous material shall not be permitted until the loaded aggregate trucks, rollers, and chip- spreader are in place and ready to apply, and roll, the cover aggregate. No surface will be chip sealed until authorization to do so has been obtained from the COR. the asphalt material shall be applied at 0.32 to

0.40 gallons per square yard or as determined by the Governments Representative and at a temperature between 125 degrees and 185 degrees Fahrenheit. The exact temperature used to apply the bituminous material shall be determined according to the supplier’s recommendations.

The bituminous material shall be applied by an asphalt distributor, as described above, so that uniform distribution in the quantities specified is obtained over all points of the surface to be treated. All lightly-coated areas and spots missed by the distributor shall be properly treated with bituminous material applied by hand. No more asphalt shall be applied than can be covered with aggregate in sixty (60) seconds or less. Distances between the distributer and chip-spreader shall be as close as possible, but in no case shall the chip-spreader be greater than fifty (50) feet behind the distributer during the chipping operations.

4.6.4.3 AGGREGATE SPREADING. Immediately following the application of the bituminous material, the aggregate shall be evenly spread over the surface at a uniform quantity of twenty-five to thirty (25-30) pounds per square yard of surface area. Upon commencement of the work, and during its progress, the individual quantities of bitumen and aggregate may be varied to meet specific field conditions. An adequate supply of aggregate shall be available on the job site to permit continual spreading operations. Aggregate shall be damp (not wet) prior to being spread on the surface. The aggregate shall be spread by using a self-propelled spreader machine (Flarity or equal). The aggregate shall be spread evenly by hand on all areas missed by the aggregate spreader. Back-spotting or sprinkling of additional aggregate over the areas having insufficient cover shall be done by hand and shall be continued during the operations whenever necessary.

As the distributor moves forward to spray the asphalt, the aggregate spreader shall start right behind it, spreading the damp chips uniformly and at the specified rate. The asphalt distributor shall travel at the same rate of speed as the chip spreader and in no case shall the two machines be separated by more than fifty (50) feet during the sealing process.

Operating the chip spreader at speeds which cause the chips to roll over after striking the bituminous-covered surface will not be permitted.

Excess aggregate deposited in localized areas shall be immediately removed, and in areas where application is insufficient, additional aggregate shall be added by hand prior to the time the asphalt "breaks".

4.6.4.4 AGGREGATE COMPACTION. The treated surface shall be rolled with rubber-tired rollers immediately after the distribution of the cover aggregate, and rolling shall continue until the aggregate is properly seated in the binder. Rollers shall proceed in the longitudinal direction, working across the treated surface until the entire width and length of the treated surface has been rolled at least four (4) times. All rolling shall be completed within one (1) hour after the application of the cover aggregate. Rollers and gravel trucks shall not be operated at speeds great enough to kick up chips, and in no case shall rollers be operated above ten (10) miles per hour. In all places not accessible to the rollers, the aggregate shall be adequately compacted with pneumatic type hand tampers. Any aggregate that becomes coated, or mixed with dirt or any other foreign material shall be removed, replaced with clean aggregate over a newly-sprayed surface, and then re-rolled as directed by the COR.

Bituminous material and chips shall not be spread more than one hundred

(100) feet ahead of completion of initial rolling operations.

No aggregate will be allowed to be swept into the gutters, onto the sidewalks, or thrown onto private property. The Contractor shall be responsible for the cleanup of any and all aggregate swept into these areas.

4.6.4.5.LOOSE AGGREGATE REMOVAL. Upon completion of rolling, traffic will be allowed to use the streets at a speed not to exceed fifteen (15) miles per hour for a period of not less than twenty four (24) hours. Safety and warning signs as per MUTCD shall be provided to slow traffic and warn of loose gravel. After the chips are set in the bituminous binder, but not earlier than the following day, or as directed by the COR, loose chips on the surface of the road shall be broomed and removed in such a manner that the aggregate set in the binder will not be displaced.

Excessive brooming will not be permitted. At the end of seven (7) days, any excess chips shall be removed in such a manner that the aggregate set in the binder will not be displaced. Excessive rolling or brooming will not be permitted.

• SANDING. After the surface has been opened to traffic, any excess bituminous material that comes to the surface (bleeds) shall be im- mediately covered with clean sand. The Contractor shall be required to have sufficient clean sand (not dirt) on hand or available to immediately sand any bleeding spots when requested by the COR. Sanding shall be accomplished by evenly spreading the sand over the affected area and then hand brooming the sand to a smooth even surface with no bumps, ruts, depressions or irregularities visible.

4.6.4.6.APPEARANCE. The completed chip sealed surface shall present a uniform appearance and shall be thoroughly rolled and compacted and free from ruts, humps, depressions or irregularities due to an uneven distribution of bituminous binder or aggregate. In the event the surface presents an unacceptable appearance, as determined by the Governments Representative, the Contractor shall repair unacceptable areas in accordance with the COR's directions.

4.6.4.8 MARKINGS/PAINTING. Paint shall conform to the requirements of AASHTO M 248. The paint shall be homogeneous, easily stirred to smooth consistency, and shall show no hard settlement or other objectionable characteristics during a storage of 6 months. Pavement markings paints shall comply with applicable state and local laws enacted to ensure compliance with Federal Clean Air standards.

4.6.4.9 WEATHER LIMITATIONS. Chip seal treatments shall be placed only when the air temperature in the shade is above 75 degrees Fahrenheit. The chip seal shall not be placed when the temperature of the road surface is below 70 degrees Fahrenheit, above 120 degrees Fahrenheit, during rainy weather, when the surface is wet or during other unfavorable weather conditions as determined by the COR.