Section 410 — Slurry Seal

Description

410.01This work consists of applying an emulsified asphalt slurry seal mix on a pavement surface.

Material

410.02Conform to the following Subsections: Emulsified asphalt 702.02 Mineral filler 725.05 Slurry seal aggregate 703.10(a) Water for construction 725.01(c)

Construction Requirements

410.03Qualifications. Submit a r ésumé for the foreperson describing experience on at least five slurry seal projects of similar complexity for approval at least 14 days before starting slurry seal work.

410.04Composition of Mix (Job -Mix Formula). Submit a written JMF for asphalt slurry seal that conforms to I SSA A105, Recommended Performance Guideline for Emulsified Asphalt Slurry Seal for approval at least 30 days before production. Include the following:

(a)Aggregate gradation values. Percent passing for each sieve size for the aggregate blend;

(b)Emulsified aspha lt content. Residual asphalt content, as a percent by mass of dry aggregate;

(c)Aggregate samples. 80-pound sample of each aggregate;

(d)Emulsified asphalt sample. 1-gallon sample with a production certification conforming to Subsecti on 106.03(b) ; and

(e)Mineral filler samples. 10-pound sample of each proposed mineral filler.

410.05Equipment.

(a)Mixing and proportioning equipment. Conform to ISSA A105.

(b)Spreading equipment. Conform to ISSA A105.

(c)Sweeper. Conform to Subsection 409.05(d) .

(d)Pneumatic -tire rollers. Conform to Subsection 409.05(e) .

(e)Auxiliary equipment. Conform to Subsection 409.05(f) . Other equipment of proven performance may be used in addition to or instead of this equipment if approved.

410.06Surface Preparation. Conform to Subsection 406.04(a) .

410.07Weather Limitations. Conform to Subsection 409.07 .

410.08Calibration. Calibrate each mixing unit according to ISSA A105. Submit calibration results before starting production.

410.09Production Start- Up Procedures. Conform to Subsection 409.09 .

410.10Application. Mix the material according to ISSA A105. Fog the surface with water in front of the spreader. Blend the additives with the aggregate. Pre -wet the aggregate in the pugmill before mixing with the emulsified asphalt. Mix the surfacing material n o more than 4 minutes. Ensure the mix is of uniform consistency as it leaves the mixer and conforms to the approved JMF. Apply surfacing material at the application rate determined from the control strip. Adjust mineral filler and emulsified asphalt conten t during construction if approved to adjust for variations in field conditions. Clean the spreader box before the start of each work shift. Carry sufficient mix in the spreader to completely cover the surface. Spread the mix with a spreader box. In areas n ot accessible to the spreader box, use hand squeegees to provide uniform coverage and match the finish of spreader. Remove streaks and transverse ripples as defined by ISSA A105 from the finished surface. Provide straight lines along curbs and shoulders and do not allow runoff on these areas. Provide straight and neat starting and ending joints by masking surfaces. Mask surfaces to provide straight and neat longitudinal or transverse joints at required locations (such as intersections and irregular shaped a reas). For transverse joints, use a butt joint. Use building paper placed over previously placed slurry seal or other suitable methods to avoid double placement of slurry seal. Remove ridges or bumps in the finished surface. For longitudinal joints, place joints on lane lines. Use half passes and odd -width passes only in turnouts and parking areas. Do not use half passes for the last pass in paved areas. Overlap longitudinal joints no more than 3 inches. Limit the elevation difference at joints to less than ¼ inch. Start rolling after the mixture has cured to the point where it will not pick up on the roller tires. Roll parking areas and turnouts with at least two full -coverage passes with the roller. Rolling the mainline roadway is not required. Allow treat ed areas to cure before opening to traffic. Cure is complete when clear water can be pressed out of the mix with a white piece of paper without discoloring the paper. Do not allow traffic in parking areas or pullouts for at least 48 hours after completing application. Remove and dispose of material spills and associated debris at the end of each shift according to Subsections 203.05 and 203.07. Two weeks to one month after completion of slurry seal application and before placing permanent pavement markings, sweep the entire treated surface. Dispose of swept material according to Subsection 203.07.

410.11Acceptance. See Table 410-1 for sampling, testing, and acceptance requirements. Emulsified asphalt will be evaluated under Subsections 106.03 and 106.04. Provide a production certification with each load of emulsified asphalt. Mineral filler will be evaluated under Subsections 106.02 and 106.03. Slurry seal aggregate will be evaluated under Subsections 106.02 and 106.04. Construction of the slurry seal will be evaluated under Subsections 106.02 and 106.04.

Measurement

410.12Measure the Section 410 pay items listed in the bid schedule according to Subsection 109.02 .

Payment

410.13The accepted quantities will be paid at the contract price per unit of measurement for the Section 410 pay items listed in the bid schedule. Payment will be full compensation for the work prescribed in this Section. See Subsection 109.05 . Table 410-1 Sampling, Testing, and Acceptance Requirements

Material or

Product

(Subsection) Type of

Acceptance

(Subsection) Characteristic Category Test Methods

Specifications Sampling

Frequency Point of

Sampling Split

Sample Reporting

Time Remarks

Source

Aggregate for

surface mixture(1) Measured & tested for conformance (106.04 & 105) Quality − Subsection

703.101 per material type Source of material Yes Before producing −

Process

control (153.03 ) Gradation − AASHTO T 27 & T 11 2 per day per stockpile Crusher belt (during production) No 24 hours Not required if using a pre - crushed commercial source

Emulsified

asphalt(2) Measured & tested for conformance (106.04 ) Quality − Subsection

702.021 per material type Emulsified asphalt supplier Yes, 2 1-quart samples Before incorporating into work − Table 410- 1 (continued) Sampling, Testing, and Acceptance Requirements

Material or

Product

(Subsection) Type of

Acceptance

(Subsection) Characteristic Category Test Methods

Specifications Sampling

Frequency Point of

Sampling Split

Sample Reporting

Time Remarks

Production

Aggregate

for surface mixture(1) Measured & tested for conformance (106.04 ) Gradation.

See

Table 703-6 for applicable sieves − AASHTO T 27 & T 11 1 per 10,000 yd2 Stockpile Yes 24 hours −

Emulsified

asphalt(2) " Quality − Subsection

702.021 per day Mixing equipment or point of delivery Yes, 2 1-quart samples − Tested by

Government

Process

control (153.03 ) Placement temperature − − Daily at start- up &

Contractor

determined thereafter Mixing equipment No Before incorporating into work −

(1)Applies to each aggregate grade provided.

(2)Applies to each asphalt material provided.