Section 406 — Fog Seal

Description

406.01This work consists of applying an emulsified asphalt fog seal.

Material

406.02Conform to the following Subsections: Blotter 703.12 Emulsified asphalt 702.02 Water for construction 725.01(c)

Construction Requirements

406.03Equipment. Provide an asphalt distributor with the following:

(a)Heater for uniformly heating the asphalt;

(b)Full circulation spray bar adjustable to 15- foot width;

(c)Positive controls including tachometer, pressure gauge, volume measuring device, or calibrated tank to uniformly deposit asphalt over the full width within 0.02 gallons per square yard of the required rate; and

(d)Thermometer for measuring asphalt temperature in the tank.

406.04Surface Preparation.

(a)Clean the existing surface of loose material, dirt, and other deleterious material before placing the fog seal. Remove or protect raised pavement markers, pavement markings, reflectorized tape, and other material that interferes with the work. Protect service entrances (such as manholes, valve boxes, and drop inlets). Protect concrete work, rock walls, and other objects adjacent to the work.

(b)Dry the surface before placing the fog seal.

406.05Weather Limitations. Apply fog seals only when the following apply:

(a)Ambient air temperature is above 50 °F;

(b)Surface temperature is above 50 °F;

(c)Weather is not foggy;

(d)Precipitation or temperatures below 40 °F are not anticipated for at least 24 hours after application; and (e) Sustained winds are less than or equal to 10 miles per hour.

406.06Asphalt Application. Dilute the emulsion one part water to one part emulsified asphalt. Apply the emulsion uniformly according to Subsection 407.09. Submit a proposed application rate for approval. Refer to AASHTO R 105 for guidance. At locations where the fog seal cannot be applied with an asphalt distributor spray bar, apply the fog seal uniformly using a hand spray attachment or by another approved method. Do not allow traffic on the fog seal until it is completely cured or substantially tack free. Cover unabsorbed asphalt with blotter to protect traffic or minimize precipitation damage. Remove excess blotter after the asphalt is absorbed. Dispose of material according to Subsection 203.07.

406.07Acceptance. See Table 406-1 for sampling, testing, and acceptance requirements. Blotter will be evaluated under Subsection 106.03. Emulsified asphalt will be evaluated under Subsections 106.02 and 106.03. Provide a production certification with each load of emulsified asphalt. Construction of fog seals will be evaluated under Subsections 106.02 and 106.04.

Measurement

406.08Measure the Section 406 pay items listed in the bid schedule according to Subsection 109.02 and the following as applicable: Measure fog seal including water added for dilution. Show a breakdown of total emulsion and water added on the load invoi ces provided to the CO. Do not measure fog seal placed on newly patched areas during chip seal work.

Payment

406.09The accepted quantities will be paid at the contract price per unit of measurement for the Section 406 pay items listed in the bid schedule. Payment will be full compensation for the work prescribed in this Section. See Subsection 109.05 . Table 406-1 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

Production

Emulsified

asphalt (702.02 ) Process control (153.03 ) Placement temperature − − 1 per distributor truck minimum Distributor truck No Before incorporating into work −