- 354 - SECTION 513 -- FOG SEAL
513.01 Description
1.The fog seal shall be a light applic ation to an existing surface of an emulsified asphalt diluted with water. The emulsified asphalt shall be similar to a tack coat, and applied at the required application rate. The application locations will be as shown in the contract.
513.02 Material Requirements
1.The fog seal shall be of the ty pe and grade shown in the contract, and the emulsified asphalt shall confo rm to the requirements of Sections 1031 or 1032. Fast-Set type emulsified asphalt shall meet the requirements of Section 504, Table 504.01.
2.The Contractor shall dilute the emulsified asphalt at a rate of maximum one part water to one part emulsified asphalt. The percent residue by distillation of the diluted emulsifi ed asphalt shall be no less than 28.5%.
a.If the dilution is performed in the field, and the rate can be verified, a sample for verification of proper dilution is not required. A sample of the undiluted material may be requested by the Department.
b.If the dilution is performed in the field, and the rate cannot be verified, a sample for verification of proper dilution of each truckload is required.
c.If the emulsified asphalt was diluted at the supplier terminal, the Department Laboratory may request a sample for proper dilution verification. The bill of lading or deliver y ticket shall state the dilution rate.
513.03 Construction Methods
1.Before the application of the f og seal, the Contractor shall clean the surfaces as described in Section 501.
2.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 asphaltic material bef ore beginning work. A coat of the specified emulsified asphalt shall be ap plied to a test strip of tar paper or other suitable material. The strip sha ll be 10 feet (3 m) long and as wide as the spray bar. If the Engineer determines the application to be unsatisfactory, the Contract or shall 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.The emulsified asphalt shall be diluted in the distributor or transport with potable water as shown in the contract. The rate of application shall be 0.12 Gal/SY. The di stributor shall be shut off before the tank is entirely empty.
d.Hand sprayers shall be used in applying asphaltic materials to small or irregular sections. Fog Seal 513.05 - 355 - e. The Contractor shall condu ct the operations to minimize construction traffic on completed portions of the Fog Seal.
f.Application widths shall coincide with existing traffic lane lines to the maximum extent possible. The Fog Seal shall be applied to the entire traffic lane at a time, confining traffic to the portion of the surface not being treated.
3.a. When an excessive fog seal quantity is applied, the Contractor shall furnish and distribute clean, fine sand uniformly on the surface to blot the excess asphalt.
b.The required rate of applicat ion shall be from 3.7 to 12.9 lb/SY (2 to 7 Kg/m2); but never shall the quantity be less than that required to completely blot the surface and to prevent asphaltic material from being picked up by traffic.
c.Excess accumulations of fog seal materials within isolated low spots or pockets shall be thinned out or sand blotted.
4.Traffic shall not be placed on the Fog Seal until the emulsion has broken and all free moisture has evap orated or drained off the surface.
513.04 Method of Measurement
1.Fog seal will be measured in gallons (kiloliter) of diluted solution applied to the surface.
2.Clean fine sand will not be measured.
513.05 Basis of Payment
1.P a y I t e m P a y U n i t Fog Seal Gallon (Gal) [Kiloliter (kL)] 2. Any amount of fog seal emulsified asphalt which is outside the specified property ranges of Table 513. 01, shall be paid for at the contract unit price multiplied by the pay factor determined in Table 513.01. 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.
513.05 Fog Seal
- 356 - Table 513.01 Tolerances and Pay Factors Specified Property Tolerance Pay Factor AASHTO T 59, Pre-Dilution, Residue ≥ 56.0% 1.00 54.0% - 55.9% 0.85 52.0% - 53.9% 0.70 < 52.0% 0.40 or Reject AASHTO T 59, Post- Dilution**, Residue ≥ 28.0% 1.00 27.0% - 27.9% 0.85 26.0% - 26.9% 0.70 < 26.0% 0.40 or Reject Pay Factors for Tests for ALL other Properties Specified* 1.00 for 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 requirement is stated as a percentage, the test result deviation from the specification will be divided by the specification value. The resulting deviation perc entage is then applied to the listed criteria. ** Test requirements of Saybolt Fu rol Viscosity, Storage stability, and Cement mixing, of post-dilut ed material are not applicable. Note: When more than one specified property exceeds specification tolerances, the single largest Pay Factor Reduction will be the one applied.
3.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 of the 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 s pecifications or is at a pay deduction less than the Department’s, the Department will assume the cost of testing. 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.
4.Clean fine sand will be subsidiary to fog seal. 5. Water used to dilute emulsified asphalt is subsidiary to fog seal. 6. Payment is full compensation for all work described in this Section. - 357 - SECTION 514 -- MICROSURFACING
514.01 Description
1.This work shall consist of an app lication of microsurfacing material to an existing surface. The microsurfacing material shall be a mixture of polymer-modified emulsified asphalt, aggregate, mineral filler, water, and other additives properly proportioned, mixed, and spread.
514.02 Material Requirements
1.The asphalt emulsion for use in this work shall be CQS-1H polymer modified material and shall conform to the requirements of Section 1032.
2.a. Crushed mineral aggregate fo r use in this work shall be gravel conforming to the gradation requirements in Table 514.01.
b.Chat aggregate shall conf orm to the gradation requirements shown in Table 514.01.
c.Quartzite or granite sha ll conform to either gradation. Table 514.01 Microsurfacing Gradations Chat Gradation Sieve Size Percent Passing 3/8 inch (9.50 mm) 99 - 100 No. 4 (4.75 mm) 86 - 94 No. 10 (2.00 mm) 40 - 60 No. 50 (300 mm) 10 - 25 No. 200 (75 m) 5 - 15 Crushed Mineral Aggregate Gradation * Sieve Size Percent Passing 3/8 inch (9.50 mm) 100 No. 4 (4.75 mm) 84 - 100 No. 10 (2.00 mm) 50 - 64 No. 50 (300 m) 13 - 29 No. 200 (75 m) 5 - 15
3.Aggregate shall have a minimum fine aggregate angularity of 45% in accordance with AASHTO T 304 Method A.
4.Los Angeles Abrasion loss percentage shall not exceed 40. 5. Aggregates shall have a soundness loss of not more than 12% by weight at the end of 5 cycles using sodium sulfate solution.
6.A sand equivalent value of 60 or higher shall be required for any of the aggregates specified. The sand equivalent shall be tested according to AASHTO T 176.
7.The Contractor must pass t he aggregate over a 1/2 inch (13 mm) screen to remove any oversize material before the aggregate enters the mixing unit.
8.Mineral filler for use in this work shall be Portland cement, Type I or Type IP, that is free from lumps. Acceptance will be based on visual inspection. The amount of mineral filler needed shall be determined by the laboratory mix design and will be considered as part of the material
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 388–390 of 1,048.