383The Engineer will determine these locations by using a stratified random selection process. The Department will test cores in the Department’ s laboratory in accordance with VTM-128. For the surface to be acceptable, the average results for shear strength specified herein shall be met.
1.Milled surfaces: The average shear strength shall meet or exceed 100 psi with no single core having a shear strength less than 50 psi.
2.Un-milled surfaces: The average shear strength shall meet or exceed 50 psi with no single core having a shear strength less than 30 psi. The Contractor shall remove and replace the area if the minimum shear strength requirements in that area are not met at no cost to the Department.
310.04 Measurement and Payment
Tack coat , whether standard Tack Coat or Non-Tracking Tack Coat, when a pay item, will be measured in gallons and paid for at the Contract gallon price. The volume will be based on daily volume with temperature corrections in accordance with Section 109. When not a pay item, the Contractor shall include the cost in the contract unit price for other appropriate items. Payment will be made under: ——————————————————— Pay Item Pay Unit——————————————————— Tack coat Gallon Nontracking tack coat Gallon——————————————————— SECTION 311—PRIME COAT
311.01 Description
This work shall consist of preparing and treating an existing surface with asphalt, and cover material if required, in accordance with these Specifications and in conformity with the lines shown on the plans or as established by the Engineer.
311.02 Materials
a.Asphalt may be changed one viscosity grade by the Engineer during construction at no change in the contract unit price. Asphalt shall conform to Section 210 as applicable.
b.Cover material shall conform to Section 202 or Section 203 as applicable. Lightweight aggregate shall conform to Section 206. The Engineer will not permit cover material to be hauled directly from a washing plant for immediate use in the work.311.02 384311.03—Procedures The rates of application of materials shall be determined in accordance with the method described in Edu - cation Series No. 12 of the Asphalt Institute entitled Asphalt Surface Treatments Construction Techniques. The weather limitations of Section 314.03 shall apply to asphalt prime coat work. When asphalt is to be used as a cover for cement stabilization or as a primer for asphalt concrete, the weather limitations speci - fied for these particular operations shall apply. Equipment for heating and applying asphalt and cover material shall conform to Section 314.04. The maximum application temperature of the liquid asphalt shall conform to Table III-1 in Section 310.03. The Contractor shall shape the surface to be primed to the required grade and section; render it free from ruts, corrugations, segregated material, or other irregularities; and uniformly compact it prior to the ap - plication of prime. Delays in priming may necessitate reprocessing or reshaping to provide a smooth, compacted surface. The Contractor shall apply asphalt by means of a pressure distributor in a uniform continuous spread. When traffic is being maintained, not more than 1/2 the width of the section shall be treated in one appli - cation. The Contractor shall exercise care so that the application of asphalt at junctions of spreads is not in excess of the specified amount. The Contractor shall remove excess asphalt from the surface by means of a squeegee. Skipped areas or deficiencies shall be corrected. The Contractor shall exercise care during the application of asphalt to prevent spattering adjacent items. The distributor shall not be cleaned or discharged into ditches or borrow pits, onto shoulders, or along the right of way. When not in use, the Contractor shall ensure equipment is parked so that the spray bar or mechanism will not drip asphalt on the surface of the traveled way. When the Contractor must maintain traffic through the area of application, the Engineer will permit one- way traffic on the untreated portion of the roadbed. When the asphalt has been absorbed by the treated surface and will not pick up, traffic shall be transferred to the treated portion and the remaining width of the section primed. The Engineer must approve the quantity, rate of application, temperature, and areas to be treated before application of the prime coat. The Contractor shall spread cover material at no additional cost to the Department in an amount that will prevent pick up of the asphalt if after application of the prime coat the asphalt fails to penetrate within the time specified and the roadway must be used by traffic.
311.04 Measurement and Payment
Prime coat will be measured in gallons for asphalt and in tons for cover material and will be paid for at the contract unit price per gallon for asphalt and per ton for cover material. Payment will be made under: ———————————————————— Pay Item Pay Unit———————————————————— Prime coat Gallon Cover material (Type) Ton————————————————————311.03 385SECTION 312—SEAL COAT
312.01 Description
This work shall consist of applying asphalt followed by applying cover material in accordance with these Specifications and in conformity with the lines shown on the plans or as established by the Engineer.
312.02 Materials
a.Asphalt may be changed one viscosity grade by the Engineer during construction at no change in the contract unit price. Asphalt shall conform to Section 210 as applicable.
b.Cover material shall conform to Section 203 as applicable. Lightweight aggregate shall conform to Section 206. The Engineer will not permit the Contractor to haul cover material directly from a washing plant for immediate use in the work.
312.03 Equipment
The Engineer will require the Contractor to use the following equipment or its equivalent:
a.equipment for heating and applying asphalt conforming to Section 314.04(b)
b.a rotary power broom
c.at least one pneumatic tire roller. The Engineer may also require additional rollers that are tandem steel wheel or three-wheel rollers weighing at least 8 tons. The pneumatic tire roller shall be self-propelled, and the gross load adjustable to apply 200 to 350 pounds per inch of rolling width as directed. Tires shall be designed for a tire pressure of at least 90 pounds per square inch. Steel wheel rollers shall be operated at a maximum speed of 3 miles per hour, and pneumatic tire rollers at a maximum speed of 5 miles per hour.
d.a mechanical roller-type hopper or a self-propelled aggregate spreader of an approved design.
312.04 Procedures
The rates of application of materials shall be determined in accordance with the method described in Education Series No. 12 of the Asphalt Institute entitled Asphalt Surface Treatments Construction Techniques. The weather limitations specified in Section 314.03 shall apply to seal coat work. The Contractor shall not begin seal coating operations until the surface is thoroughly compacted and cleaned of dust, mud, and foreign matter and the Engineer has approved the section to be sealed. The Contractor shall apply asphalt by means of a pressure distributor in a uniform continuous spread over the section to be treated and within the temperature range given in Table III-1. A strip of building 312.04
Source: Virginia Road and Bridge Specifications, 2020 Edition. Pages 411–412 of 1,065.