- 366 - SECTION 515 -- ARMOR COAT OR CHIP SEAL
515.01 Description
1.Armor Coat and Chip Seal is the sprayed application of emulsified asphaltic material with a covering of aggregate at the locations shown in the contract or as directed by the Engineer.
515.02 Material Requirements
1.Armor Coat and Chip Seal emulsified asphaltic material shall be the type and grade shown in the contract and shall conform to the requirements of Sections 1031 or 1032.
2.Aggregate for Armor Coat and Chip Seal shall conform to the requirements of Subsection 1033.02 , Paragraphs 1. and 2. The aggregates shall have a Los Angeles Abrasion loss percentage of not more than 40.
3.Aggregate for Armor Coat sha ll have a soundness loss of not more than 5% by mass at the end of 5 cycles using sodium sulfate solution. The aggregate shall also conform to the grad ation requirements of Table 515.01. Table 515.01 Armor Coat Aggregate Gradation Limits Sieve Size Percent Passing 3/8 inch (9.5 mm) 99 to 100 No. 4 (4.75 mm) 60 to 85 No. 10 (2.0 mm) 0 to 15 No. 50 (300 m) 0 to 10 No. 200 (75 m) 0 to 3
4.Aggregate for Chip Seal s hall be limestone, expanded shale, granite, or quartzite. The aggregate shall have a soundness loss of not more than 7% by mass at the end of 5 cycles using sodium sulfate solution.
a.The limestone, granite, and quartzite chip seal aggregates shall conform to the gradation requirements of Table 515.02. Table 515.02 Limestone, Granite, and Qua rtzite Chip Seal Aggregate Gradation Limits Sieve Size Percent Passing 3/8 inch (9.5 mm) 99 to 100 No. 4 (4.75 mm) 0 to 70 No. 10 (2.0 mm) 0 to 10 No. 50 (300 m) 0 to 5 No. 200 (75 m) 0 to 3
b.The expanded shale chip seal aggregate shall conform to the gradation requirements of Table 515.03. Armor Coat or Chip Seal 515.03 - 367 - Table 515.03 Expanded Shale Chip Seal Ag gregate Gradation Limits Sieve Size 1/2 inch (12.5 mm) Percent Passing 95 to 100 3/8 inch (9.5 mm) 85 to 100 No. 4 (4.75 mm) 0 to 30 No. 10 (2.0 mm) 0 to 10 No. 200 (75 m) 0 to 3
5.Aggregates shall be sample d and tested as per the Department’s Materials Sampling Guide.
515.03 Construction Methods
1.The Contractor shall furnish and place the Armor Coat or Chip Seal as indicated in the contract.
2.The application equipment and surface preparation shall be in accordance with Section 501.
3.Armor Coat or Chip Seal Application: a. The application of asphaltic materials shall be allowed only when:
1.The ambient air temperature is above 60°F (16 C).
2.The surface is dry. The Engineer may allow the application of emulsified asphalt to a damp surface if all standing water has been removed from the surface and no fu rther precipitation is expected.
b.The Contractor shall demons trate the ability to distribute a uniform coat of emulsified asphalt and aggregate before beginning work. A coat of the specified emulsified asphalt shall be applied to a test strip of tar paper or other suitable material. The st rip shall be 10 feet (3 m) long and as wide as the spray bar. A coat of the specified aggregate shall follow. If the Engineer determines the a pplication to be unsatisfac tory, the Contractor will be required to adjust the equipment and repeat the test procedure until satisfactory results are obtained. The Contractor shall properly dispose of the test strip after use.
c.Emulsified asphaltic material shall be applied at a minimum temperature of 160 oF (71oC). The distributor shall be shut off before the tank is entirely empty. The application rates shall be as follows:
1.Armor Coat: 0.27 to 0.30 Gal/SY (1.22 to 1.36 L/m2).
2.Limestone, Granite or Quartzite Chip Seal: 0.29 to 0.33 Gal/SY (1.31 to 1.49 L/m2).
3.Expanded Shale Chip Seal: 0.30 to 0.36 Gal/SY (1.36 to 1.63 L/m2).
4.The Engineer may adjust these rates as a result of the test strip or field results.
d.Hand sprayers shall be used in applying asphaltic materials to small or irregular sections.
e.Special care shall be taken to secure an overlap of adjoining longitudinal applications.
515.03 Armor Coat or Chip Seal
- 368 - f. Seamless transverse joints shall be obtained by placing 15 pound tar paper at the joint at the beginning and end of each shot. This should ensure that the correct rate of application is achieved for the full length of the shot and avoid double application of emulsified asphalt. The emulsified asphalt application shall commence with a running start on a strip of tar paper. The spray bar needs to be stopped on the tar paper at the end of each shot to ensure a straight tr ansverse construction joint. Transverse joints shall have no more than 0.25 inch (6.5 mm) difference in elevation across the joint as measured with a 6 foot (2m) straightedge. The Armor Coat or Chip Seal edge shall be neat and uniform along the roadway lane, shoulder and curb lines. The Armor Coat or Chip Seal edge shall have no more than 2 inches (50 mm) variance in any 100 fo ot (30m) section, along the roadway edge or shoulder.
g.The moisture content of mi neral aggregate for Armor Coat or Chip Seal, at the time of application, shall be satisfactory to the Engineer. Except in the case of expanded shale, if the aggregate is dry, water shall be applied to thoroughly and uniformly moisten the aggregate before application.
h.The cover aggregate shall be applied within 1 minute after the application of the emulsified asphal t. The application rates shall be as follows:
1.Armor Coat: 17 to 20 lb/SY (9.2 to 10.8 Kg/m2).
2.Limestone, Granite or Quartzite Chip Seal: 17 to 23 lb/SY (9.2 to 11.4 Kg/m2).
3.Expanded Shale Chip Seal: 9 to 12 lb/SY (4.9 to 6.5 Kg/m2).
4.The Engineer may adjust th ese rates as a result of the test strip or field results.
i.For irregular areas, the C ontractor may employ hand methods to provide uniform distribution.
j.The Contractor shall condu ct the operations to minimize construction traffic on completed portions of the Armor Coat or Chip Seal. Armor Coat or Chip Seal equipment will not be allowed to travel on uncovered asphaltic materials.
k.Application widths shall coincide with existing traffic lane lines to the maximum extent possible. The Armor Coat or Chip Seal shall be applied to the entire traffic lane at a time, confining traffic to the portion of the surface not being treated.
l.When Armor Coat or Chip Seal is required on both roadway and surfaced shoulders, Armor Coat or Chip Seal materials shall be applied to the shoulder's full width before Armor Coat or Chip Seal materials are applied on any section of the adjacent traffic lane. Application widths shall coincide with lane and shoulder widths.
m.Traffic will not be allowed on the completed Armor Coat or Chip Seal until the aggregate is well embedded in the bituminous material. Armor Coat or Chip Seal 515.05 - 369 - 4. Rolling:
a.Immediately after the Armor Coat or Chip Seal materials have been distributed, the rolling shall begin.
b.The entire area shall be rolled within 15 minutes after the cover material is applied and an additional 4 full rolling coverages shall be made within 1 hour after the cover material is applied.
c.Rolling operations shall provide uniform embedment of the aggregate and shall be arranged to ensure uniform rolling of all portions of the area to which the materials have been applied.
d.The Contractor shall perfor m all rolling with self-propelled, multiple-wheel, pneumatic-tired roller s. A minimum of three rollers will be required. The first two, drive side-by -side rolling the outer edges. The third roller then follows closely behind, rollin g the center of the lane. The roller speed shall be no more than 5 mph (8 km/hr).
e.As soon as the emulsified asphalt has set and no further aggregate can be embedded, but by the end of the day of the application of the Armor Coat or Chip Seal materials, all loose aggregate shall be swept from the roadway surface by the Contractor. Care shall be taken to avoid dislodging embedded aggregate.
f.Sweeping shall be conducted between 1/2 hour after sunrise and 1/2 hour before sunset.
515.04 Method of Measurement
1.The emulsified asphalt is measured in gallons (kiloliters). Refinery certified volume shall be used as a basis of measurement of the emulsified asphalt if the entire shipment is used.
2.a. Aggregate for Armor Coat or Chip Seal will be measured by the cubic yard (cubic meter) at the poi nt of delivery. The Contractor shall strike off the material s to uniform height for volume determination.
b.The Contractor may request early sampling and testing at the point of delivery, in which case the aggregate shall be stored in lot size stockpiles as defined in the Depar tment’s Material Sampling Guide.
515.05 Basis of Payment
1.P a y I t e m P a y U n i t Armor Coat Emulsified Gallon (Gal) [liter (L)] Asphalt _____ Armor Coat Aggregate Cubic Yard (CY) [ C u b i c M e t e r ( m3)] Chip Seal Emulsified Gallon (Gal) [Liter (L)] Asphalt _____ Chip Seal Aggregate Cubic Yard (CY) [Cubic Meter (m3)]
515.05 Armor Coat or Chip Seal
- 370 - 2. Aggregate not meeting the gr adation requirements listed in Table 515.01, 515.02, or 515.03 will not be accepted for payment.
3.a. Any amount of Armor Coat or Chip Seal emulsified asphalt which is outside the specified property ranges of Table 515.04 shall be paid for at the contract unit price multiplied by the pay factor determined in Table
515.04 If the resultant Pay Factor for the material indicates rejection as an
option, the Engineer will determine if the non-compliant material will be removed. Table 515.04 Tolerances and Pay Factors Specified Property Tolerance Pay Facto r AASHTO T 59, Residue after Distillation ≥ 64.0% 1.00 63.0%-63.9% 0.75 < 63.0% 0.40 or Reject AASHTO T 301, Elastic Recovery, 77°F, CRS-2P ≥ 49.5% 1.00 44.0% - 49.4% 0.75 < 44.0% 0.40 or Reject Pay Factors for AASHTO Tests for ALL other Properties Specified* 1.00 for a deviation of ± less than or equal to 10% 0.75 for a deviation of ± greater than 10% to less than or equal to 25% 0.40 or Reject for deviation of ± greater than 25% * When the specification requiremen t is stated as a percentage, the test result deviation from the s pecification will be divided by the specification value. The resulting deviation percentage is then applied to the listed criteria. Note: When more than one specified property exceeds specification tolerances, the largest pay Factor Reduction will be applied.
4.When disputes arise in test resu lts, the Department will select an independent laboratory for referee test ing on the remainder of the sample. The identity of the independent labo ratory will not be revealed until the selected laboratory has completed the referee testing.
a.Only the Contractor can init iate dispute resolution, and request referee testing. Should the Contractor request referee testing, it shall be submitted in writing to t he Department within 4 days of receiving the written notification of deficienc y. This written request is also affirmation and agreement that the testing may occur beyond the 14 day testing timeframe imposed by asphaltic emulsion specifications. b. If the independent lab’s tests indicate failing results and pay deductions equal to or greater than the Department’s, the Contractor will reimburse the Department for the cost of testing. If the independent lab’s tests indicate that the material meets specifications or is at a pay deduction less than the Department’s, the Department will assume the cost of testing. Armor Coat or Chip Seal 515.05 - 371 - When the independent lab’s tests indica te a pay deduction, the lesser of the Department’s and the independent la b’s deductions will be applied.
5.Emulsified asphalt materials used in the test strip are subject to the payment adjustments in Table 515.04.
6.All test strips are subsidiary to the armor coat and chip seal pay items. 7. Payment is full compensation for a ll work described in this Section. - 372 - SECTION 516 -- BITUMINO US PAVEMENT PATCHING
516.01 Description
1.Bituminous pavement patching shall consist of the removal and disposal of unstable or disintegrated bi tuminous or concrete surfacing and/or base course and the placing and compacting of "Asphaltic Concrete, Type ___", at locations specified by the Engineer. Patching shall include the correction of faulty subgrade conditions.
516.02 Material Requirements
1.All materials shall conform to the requirements in Table 516.01. Table 516.01 Material Requirements Applicable Materials Section Asphaltic Concrete .......................... 1028 Performance Graded Binder ........... 1029 Emulsified Asphal t .......................... 1031, 1032 Aggregate ....................................... 1033
516.03 Equipment
1.All equipment used in pavement patching shall conform to the requirements in Sections 501 and 503.
516.04 Construction Methods
1.The Contractor shall patch bi tuminous and concrete pavement in accordance with the requirements in Section 503.
2.Each pavement patch shall be completed in the same work day.
3.The removal and disposal shall be performed in accordance with the requirements in Section 203.
4.The removed bituminous or concrete surfacing layers shall be replaced with asphaltic concrete.
5.Subgrade Repair: a. The underlying material shall be uniformly compacted to the Engineer's satisfaction.
b.After compaction of the underlying material, a tack coat shall be applied on the vertical faces and bottom surface as described in Section 504. The rate of application shall be as directed by the Engineer.
c.If the underlying material includes an unstable base course, it shall be removed and wasted. The base course shall be replaced with asphaltic concrete.
d.If the underlying material includes unstable subgrade materials, they shall be removed and wasted or salvaged for reused back in the repair if the moisture content of these materials is adequate or can be made adequate for proper compaction, Subgrade shall be replaced as follows:
1.Subgrade from within a repair that extend to a depth of 16 inches or less shall be replaced with asphaltic concrete.
2.Wasted subgrade from within a repair that extends to a depth greater than 16 inches shall be replaced with material as required by
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 400–405 of 1,048.