409Chip and Fog Seals

Chip and Fog Seals

409.1DESCRIPTION

1 This section describes the requirements for placing chip seal and fog seal, which the department defines as follows:

aggregate and, when specified, an emulsified asphalt overshoot.

409.2MATERIALS

1 Provide materials in accordance with the following:

Material Subsection General 803.1 Aggregate for Chip Seal 803.8 Aggregate for Blotter 803.9 Emulsified Asphalt 804.3 Performance Graded Asphalt 804

2 For fog seals and overshoots, use emulsions SS-1h or CSS-1h, SS-1 or CSS-1, or CQS -1h.

3 Ensure emulsion and aggregate are compatible for chip seals in accordance with the Materials Testing Manual , Section 850.0, Chip Seal Aggregate/Emulsion Compatibility Test. Compatibility is defined as the ability of aggregate to allow sufficient coating by emulsion residue and resist coating loss from adverse water exposure. Ensure final retained coating of at least 80 percent. If necessary, change the emulsion type or the aggregate source to ensure compatibility. If a polymer-modified emulsion is specified, do not change to a non-polymer-modified emulsion.

4 When the contract allows and the contractor elects to use a department -furnished source as a contractor-furnished source for the chip seal aggregate, meet the applicable requirements of Subsection 106.3.3, Contractor-Furnished.

409.3EQUIPMENT

409.3.1 General

1 Ensure that equipment meets the following:

Chip and Fog Seals SECTION 409

Subsection 407.3, Equipment.

409.3.2 Chip Seal

1 In addition to the equipment required above, provide the following equipment for the application of a chip seal:

Rollers in accordance with Subsection 210.3.6, Roller; ballast loaded so that tire contact pressure is 80 psi [550 kPa] minimum; uniform (equal) air pressure in all tires. For areas other than mainline operations, provide an adequate number of roller(s) to ensure sufficient time for proper embedment of aggregate into emulsion.

pneumatic tires on two axles and equipped with positive controls so that the specified quantity of material is deposited uniformly over the width of the surface. Other types of aggregate spreaders that produce equivalent results may be used.

409.3.3 Fog Seal

1 Provide mechanical spreading equipment for the blotter material . D o not distribute blotter with hand tools.

409.4CONSTRUCTION

409.4.1 Weather and Seasonal Limitations

1 Place chip and fog seals from June 1 to August 31 except as noted in the contract. Obtain approval in writing from the engineer for exceptions to these time periods such as high elevation or special events. Place seal only on a dry surface.

2 Place the applicable seal in accordance with the following criteria:

1.1Air and pavement surface temperatures at least 60 °F [15 °C] or higher;

1.2No fog;

1.3Precipitation not expected within 4 hours; and

1.4Applied seal material not at risk of freezing within 24 hours

Chip and Fog Seals SECTION 409

409.4.2 Sampling Procedures

1 Provide emulsified asphalt samples and certification documents in accordance with Subsection 407.4.2, Sampling Procedures. For liquid asphalt, provide samples and certification documents in accordance with the Materials Testing Manual, Section 840.0, Liquid Asphalt Sampling.

409.4.3 Emulsified Asphalt Application

1 Clean surface of extraneous material, including vegetation, dirt, mud, and loose materials before applying the emulsified asphalt.

2 Provide a daily log of the usage of emulsified asphalt using “Daily Emulsion Application Rate Record,” (Form E-58). Submit the form to the engineer no later than the working day following placement.

3 Apply the emulsified asphalt so that there is uniform, complete coverage at the rate established (chip seal) or specified (fog seal). Correct deficiencies and areas not covered. Apply the emulsion in accordance with Table 409.4.3- 1, Emulsion Application Temperatures for Chip and Fog Seals.

Table 409.4.3-1 Emulsion Application Temperatures for Chip and Fog Seals Emulsions Spray Application Temperature Range °F [°C] Set Grade Unmodified Polymer Modified Rapid, Quick RS-1; CQS-1h 70 to 140 [20 to 60] 80 to 140 [25 to 60] RS-2, HFRS-2; CRS-1, -2 150 to 185 [60 to 85] 160 to 185 [70 to 85] Medium, Slow MS-1, HFMS-1; SS-1, -1h; CSS-1, -1h 70 to 160 [20 to 70] 80 to 160 [25 to 70] MS-2m, -2h; HFMS-2, -2h, -2s, -2ss, -1000; CMS-2, -2h 90 to 185 [30 to 85] 100 to 185 [35 to 85]

Subsection 409.4.4 Chip Seal

Subsection 409.4.4.1 General

1 Provide compatibility test results performed for the aggregate and emulsified asphalt to the engineer three working days prior to sealing operations.

Chip and Fog Seals SECTION 409

2 Operate tanker sampling valve as directed by the engineer and dispose of material after screen test in complete. The engineer will perform the field screen test in accordance with the Materials Testing Manual , Sections 844.0, Field Screen Test Pr ocedure for Emulsified Asphalt.

3 Ensure that longitudinal joints coincide with the specified locations of lane lines, edge lines, or the center of traveled ways.

4 Pre-wet the aggregate daily, at a minimum during sealing operations, to eliminate or reduce dust coating and improve adhesion.

5 Ensure an aggregate embedment depth of 65 to 75 percent by measuring pavement macrotexture depth in accordance with the Materials Testing Manual , Section 230.0, Determination of Macrotexture of Pavement Surface. Do not use stiff wire brush; use hand whisk or corn broom to avoid dislodging chip seal aggregate. The aggregate embedment depth corresponds to the average diameter of circular patch as noted in Table 409.4.4-1, Macrotexture.

Table 409.4.4-1 Macrotexture Aggregate Embedment Depth, % ⅜ in ½ in Average Diameter, Circular Patch (inch)(1) 65 10.9 9.4 75 12.9 11.1 Average Diameter, Circular Patch (inch)(2) 65 7.7 6.7 75 9.1 7.9

6 Evaluate embedment depth when constructing test section(s) and changing application rates for emulsion or aggregate during sealing operations.

409.4.4.2 Quality Requirements

1 Construct the chip seal using quality assurance procedures and perform quality control of the aggregate during production and placement. Do not continue producing material that is out of specification. Provide the following:

Ensure their accessibility to the engineer.

Chip and Fog Seals SECTION 409

accordance with the Materials Testing Manual . Before placement, test a split aggregate sample in accordance with Subsection 114.3.3.2, Aggregate Gradation.

Test for quality control and quality acceptance as required in Table 409.4.4-2, Chip Seal Test Requirements.

Table 409.4.4-2 Chip Seal Test Requirements Test Procedure Test Frequency Compatibility Tests 1/each different aggregate and emulsion combination Quality Control – Chip Seal Aggregate Production Gradation 1/90,000 yd2 [75 000 m2], 3 minimum LA Abrasion 1/90,000 yd2 [75 000 m2] Flat and Elongated Fractured Faces Plasticity Index Polish Resistance (when specified) Quality Acceptance Aggregate Gradation 1 lot/450,000 yd2 [375 000 m2] Aggregate Embedment 2 per Day Field Screen 1/each load of emulsified asphalt

laboratory and personnel in accordance with Subsection 114.3, Field Testing Laboratory and Personnel Requirements.

procedural bias in test results, correlate aggregate tests in accordance with Subsection 114.3.3, Correlation. The procedure will be repeated if the possibility of bias arises during production or if new equipment or personnel are int roduced during testing.

The department does not require recorrelation before placement if correlation testing for aggregate tests has already been performed with placement of plant mix pavement and the contractor’s and department’s personnel and equipment have remained unchanged.

Subsection 114.3.4, Resolving Field Testing Discrepancies.

results are outside the specifications, make appropriate adjustments, retest material, and make additional adjustments if necessary.

Chip and Fog Seals SECTION 409

409.4.4.3 Quality Acceptance Testing

1 The department is responsible for quality acceptance testing and will test in accordance with the requirements in Table 409.4.4 -2, Chip Seal Test Requirements. Quality acceptance test results, except aggregate embedment during construction, are required prior to beginning chip sealing operations. Aggregate lots that meet or exceed a pay factor level of 0.75 are acceptable for incorporation into the project at the pay factor calculated in accordance with Subsection 409.5.2, Determination of Pay Factors.

2 Lot size is defined by the department as the number of square yards [square meters] placed, represented by five t ests as sho wn in Table 409.4.4-2 , Chip Seal Test Requirements. A sublot is the quantity represented by one test. The engineer will determine the exact lot size, which may vary due to project length, production suspension, construction schedules, material source changes, or other acceptable reasons. Except in unusual situations, the engineer will use lots consisting of five samples. When necessary due to production, project size, material source changes, or suspension, lots of from three to seven samples may be used. Partial lots with less than three samples will be included with the previous lot for analysis. Lot size will be controlled by the project size or changes in the material source and may span several days of production.

3 Obtain aggregate gradation samples in accordance with Subsection 800.2 (3), Point of Sampling, and the Materials Testing Manual at random locations determined by the engineer and in the presence of the engineer.

409.4.4.4 Test Section

1 Before full production, construct a test section 0.5 mi [0.8 km] long or less as approved by the engineer for each type of surface upon which the chip seal is to be placed to establish the following:

coverage;

requirements for opening the roadway to traffic; and

effective during test section placement for the remainder of the chip seal placement. Place another test section when changing roller pattern.

2 Do not continue chip sealing operations until the test section has been approved by the engineer.

Chip and Fog Seals SECTION 409

409.4.4.5 Application

1 Apply the emulsified asphalt and the chip seal aggregate as follows:

supplier’s recommendations and Subsection 409.4.3, Emulsified Asphalt Application.

If the texture of the surface allows the emulsified asphalt to penetrate too rapidly, spray the roadway again at a rate specified by the engineer.

Use a strip of building paper 3 ft [1 m] wide to form a uniform edge at the beginning of each spread. Make junctions of spreads to ensure a smooth riding surface. Do not spread the emulsified asphalt beyond the width of the chip seal aggregate application or allow cooling or setting before application of the aggregate. Avoid delays that could impair retention of the aggregate.

spread and seat the cover coat aggregate. Spread the material without operating the equipment’s tires on the exposed, newly applied emulsified asphalt. Immediately after spreading, cover deficient areas with additional material.

2 After the emulsion used to seal the road and bond the aggregate has cured, thoroughly broom the entire surface. Remove excess aggregate. Do not remove imbedded aggregate.

3 When specified, apply an overshoot after placing the chip seal coat. Emulsified asphalt used for overshoot may be diluted in the field at a ratio of 1 part emulsified asphalt to 1 part water (1:1). Before mixing, heat the dilution water and emulsified asphalt to a minimum temperature specified by the supplier. Dilute by introducing the water into the emulsified asphalt. When using a rapid set emulsion for the overshoot, have it diluted by the emulsified asphalt supplier at its facility. Apply at a temperature range in accordance with Table 409.4.3- 1, Emulsion Application Temperatures for Chip and Fog Seals. Overshoot the chip seal at the rate established during the test section production. Do not allow traffic on the surface until the overshoot has sufficiently cured to prevent picking up or tracking. Cover excess quantities with blotter material.

409.4.4.6 Opening to Traffic

1 Open roadways as follows:

removing excess cover coat aggregate. If placing traffic on the chip seal before the removal of excess flyrock, pilot the traffic through the work at 30 mph [50 km/h] or less. Apply blotter, as directed by the engineer, to areas where emulsion is 'bleeding through' to prevent tracking/adhering to vehicle tires. Open the roadway

Chip and Fog Seals SECTION 409

to full, unrestri cted traffic flow within 36 hours of the beginning of aggregate placement.

emulsion to fully cure and within 7 calendar days after chip placement. Do not allow traffic on the overshot surfaces until the overshoot has cured. Apply blotter, as directed by the engineer, to areas where tracking by vehicles may occur.

409.4.5 Fog Seal

1 The specified application rate is for specification material before additional dilution for field application. Emulsified asphalt used for fog seal may be diluted in the field at a ratio of 1 part emulsified asphalt to 1 part water (1:1). Before mixing, heat the dilution water and emulsified asphalt to a minimum temperature specified by the supplier. Dilute by introducing the water into the emulsified asphalt. Apply at a temperature range in accordance with Table 409.4.3- 1, Emulsion Application Temperatures for Chip and Fog Seals.

2 Apply fog seal to the full top width of the plant mix pavement and its tapers plus 6 in beyond.

3 Apply fog seal to the portion of the shoulders not covered by the chip seal including the pavement taper plus 6 in beyond. Allow the shoulder fog seal to cure a minimum of 24 hours prior to placing the travel way emulsified asphalt and chip seal aggregate.

4 Cover areas where the emulsified asphalt would be picked up or damaged by traffic with a uniform, protective coat of blotter.

5 Sweep and remove loose blotter cover from the roadway surface no more than 24 hours after the emulsified asphalt has cured.

409.4.6 Acceptance

1 The engineer will accept:

Material.

Aggregate.

2 If a chip seal, with or without overshoot, experiences chip loss or bleeding within two weeks of placement, repair it at no additional cost to the department. Provide and maintain temporary traffic control required on the project to repair areas of failing seal coat at no additional cost to the department.

Chip and Fog Seals SECTION 409

409.5MEASUREMENT and PAYMENT

409.5.1 General

1 The engineer will measure:

the length placed and the lesser of the measured or specified width placed.

by the short ton [metric ton] in accordance with Subsection 109.1.3, Measurement Methods. Quantities of water to dilute the emulsified asphalt for application will not be measured and paid for as Emulsified Asphalt.

2 The department will pay as follows:

Pay Item

Pay Unit Measure to the Nearest Pay to the Nearest Chip Seal SY [m2] 0.1 ft [0.05 m] SY [m2] Chip Seal (Overshoot) SY [m2] 0.1 ft [0.05 m] SY [m2] Emulsified Asphalt TON [t] 0.01 ton [0.01 t] 0.01 TON [0.01 t] Emulsified Asphalt Modified TON [t] 0.01 ton [0.01 t] 0.01 TON [0.01 t] Emulsified Asphalt (Overshoot) TON [t] 0.01 ton [0.01 t] 0.01 TON [0.01 t] Fog Seal TON [t] 0.01 ton [0.01 t] 0.01 TON [0.01 t]

409.5.2 Determination of Pay Factors

1 The engineer will evaluate the gradation for chip seal aggregate in accordance with Subsection 113.1, Acceptance of Aggregate, and adjust payment accordingly.

409.5.3 Price Adjustment

409.5.3.1 Emulsified Asphalt

1 If sample(s) for a truckload are not received by the Materials Program with proper documentation within seven calendar days of sampling, in accordance with Subsection 407.4.2, Sampling Procedures, the engineer will reduce the payment by as much as 25 percent for that load.

2 The engineer may adjust the price for emulsified asphalt that does not meet specifications but is accepted in accordance with Subsection 113.2, Acceptance of Asphalt Materials.

Chip and Fog Seals SECTION 409

409.5.3.2 Chip Seal

1 The engineer may adjust payment as follows:

engineer will assess liquidated damages of $125 per hour for each hour or partial hour after 36 hours.

equation: PAA = (PFA - 1.00) (LSA) (CS)

Where: PA A = Pay Adjustment for Aggregate Gradation ($$) PFA = Aggregate Gradation Pay Factor for evaluated lot LSA = Lot Size for evaluated lot (SY [m2]) CS = Contract Unit Price of the Chip Seal pay item ($$/SY [$$/m2])