Section 312 — Dust Palliative

Description

312.01This work consists of providing and applying one or more applications of dust palliative on a prepared surface.

Material

312.02Conform to the following Subsections: Calcium chloride, magnesium chloride, and lignosulfonate 725.02 Water for construction 725.01(c)

Construction Requirements

312.03General. Provide equipment for applying, spreading, and processing dust palliative. Make the equipment available for inspection and approval before use. Do not apply dust palliative when precipitation is anticipated within 24 hours of application, or when the ground is frozen. Apply when the ambient air te mperature is 40 °F or above. Protect structures, trees, and other objects identified by the CO from splatter or marring. Use multiple applications at a reduced rate if necessary to prevent runoff.

312.04Surface Preparation and Application.

(a)Single applica tion. Blade and shape the roadbed. Leave 1 to 2 inches of loose material on the surface. Water the loose material so it is visibly moist. Thoroughly mix the moist, loose material. Apply water, calcium chloride, magnesium chloride, or lignosulfonate liquid at an approved rate from 0.25 to 0.50 gallons per square yard. Process the dust palliative uniformly throughout the loose material. Moisten the mixture as necessary and compact by operating rollers over the full width of each layer until visual displacement ceases. Double application of calcium chloride or magnesium chloride liquid.

(1)First application. Scarify, blade, and shape the roadbed. Leave 3 inches of loose material on the surface. Water the loose material so it is visibly moist. Thoroughly mix the moist, loose material. Apply calcium chloride or magnesium chloride liquid solutions using distributor equipment at an approved rate from 0.50 to 1.0 gallons per square yard. Use a tractor rotary tiller, or other approved mixing device, immediately behind the distributor to incorporate the liquid solution into the full width of loose material. Shape the surface to the required line and grade and compact according to Subsection 204.11(a) . Allow at least one wee k of curing time between the first and second applications.

(2)Second application. Apply calcium chloride or magnesium chloride liquid to the finished surface at an approved rate no more than 0.20 gallons per square yard.

312.05Opening to Traffic. Keep traffic off the treated surface until the dust palliative has penetrated and cured to prevent excessive pickup under traffic.

312.06Acceptance. Dust palliative material (calcium chloride liquid, magnesium chloride liquid, and lignosulfonate liquid) will be e valuated under Subsection 106.03. Provide a commercial certification that includes the date, identification number (truck or trailer), net mass, and brand name with each shipment. For liquid dust palliatives provide the net volume and specific gravity at 60 °F, percent solids by mass, and pH. Construction of dust palliative treatments will be evaluated under Subsections 106.02 and 106.04.

Measurement

312.07Measure the Section 312 pay items listed in the bid schedule according to Subsection 109.02 .

Payment

312.08The accepted quantities will be paid at the contract price per unit of measurement for the Section 312 pay items listed in the bid schedule. Payment will be full compensation for the work prescribed in this Section. See Subsection 109.05 .