Article 1 — Description
Construct a base course, a surface course, a level -up course, or any combination of these courses of the types and grades shown on the plans using a cold- mixed material consisting of native limestone rock asphalt (LRA) aggregate, fluxing material, water, and when specified, additives and virgin aggregates.
Article 2 — Materials
2.1 Lime Rock Asphalt ( LRA) Mixture . Furnish LRA in accordance with DMS -9210 , “Limestone Rock Asphalt,”
of the type, grade, and surface aggregate classification (SAC) shown on the plans.
2.2 Tack Coat . Furnish CSS -1H, SS- 1H, or a performance- graded (PG) binder with a minimum
high- temperature grade of PG 58 for tack coat binder in accordance with Item 300, “Asphalts, Oils, and Emulsions,” unless otherwise shown on the plans or approved. Do not dilute emulsified asphalts at the terminal, in the field, or at any other location before use. Verify that emulsified asphalt proposed for use meets the minimum residual asphalt percentage in accordance with Item 300, if required. The Engineer will obtain at least one sample of the tack coat per project and test the sample for specification compliance. The Engineer will obtain the sample from the asphalt distributor immediately before use.
Article 3 — Equipment
Provide required or necessary equipment in accordance with Item 320, “Equipment for Asphalt Concrete Pavement.”
Article 4 — Construction
Provide quality control (QC) testing as needed to meet the requirements of this Item. The Department will perform quality assurance (QA) testing.
4.1 Quality Control Plan (QCP) . Develop a written QCP and submit for approval before beginning production.
Follow QCP in detail. Obtain approval for changes to the QCP made during the project. The Engineer may suspend operations if the Contractor fails to comply with the QCP. Include the following items in the QCP .
4.1.1 Project Personnel . For project personnel, include:
a list of individuals responsible for QC with authority to take corrective action, and current contact information for each individual listed.
4.1.2 Loading and Transporting. For loading and transporting, include:
type and application method for release agents , and truck and rail car loading procedures to avoid segregation.
4.1.3 Placement and Compaction . For placement and compaction, i nclude:
proposed arrangements for any required pre-paving meetings, including dates and locations; 264 type and application method for release agents in the paver and on rollers, shovels, lutes, and other utensils; procedures for the transfer of mixture into the paver while avoiding segregation and preventing material spillage; process to balance production, delivery, paving, and compaction to achieve continuous placement operations; paver operations (e.g., operation of wings and height of mixture in auger chamber) to avoid physical and thermal segregation and other surface irregularities; and procedures to construct quality longitudinal and transverse joints.
4.2 Stockpiling of LRA . Provide a smooth and well -drained area, cleared of trash, weeds, and grass if stori ng
LRA at the project site. Stockpile, handle, and load LRA in a manner that will minimize aggregate degradation and segregation. Avoid contamination and mixing of stockpiles. The Engineer may reject stockpiled materials that contact the earth or other objectionable material.
4.3 Hauling Operations . Transport the LRA mixture to the project or delivery point in trucks or rail cars as
needed. Clean all truck beds or rail cars before use to ensure mixture is not contaminated. Use a release agent on the Department’s MPL to coat truck beds and inside rail cars when necessary. Waterproof tarpaulins are not required to cover loads.
4.4 Placement Operations. Prepare the surface by removing raised pavement markers and objectionable
material such as moisture, dirt, sand, leaves, and other loose impediments from the surface before placing mixture. Remove vegetation from pavement edges. Place the mixture in conformance with the typical section requirements and produce a smooth, finished surface with a uniform appearance and texture. Offset longitudinal joints of successive courses of mixture by at least 6 in. Place mixture so longitudinal joints on the surface course coincide with lane lines, or as directed. Ensure that all finished surfaces will drain properly. When desired, dump the asphalt mixture in a windrow and then place it in the finishing machine with windrow pickup equipment unless otherwise shown on the plans. Prevent the windrow pickup equipment from contaminating the mixture. Defer compaction after placing the paving mixture as directed to allow for volatilization. Allow the previous pavement course to dry and cure before placing the next course when placing more than one course. The course will be considered cured if the hydrocarbon volatile content of the mixture is 0.4% or less by weight of the mixture when tested in accord ance with Tex -213-F , unless otherwise directed. Use a motor grader to spread the mixture when shown on the plans or as approved. Thoroughly aerate the mixture and spread into place with a power motor grader in a uniform layer. Placement in narrow strips or small irregular areas may require hand spreading.
4.4.1 Weather Conditions . Place the mixture when the roadway surface temperature is 60°F or higher unless
otherwise approved. Place the mixture only when the weather conditions and moisture conditions of the roadway surface are suitable in the Engineer’s opinion.
4.4.2 Tack Coat . Clean the surface before placing the tack coat. Apply tack coat uniformly at the approved rate,
unless otherwise directed. The Engineer will set the rate between 0.04 and 0.10 gal. of residual asphalt per square yard of surface area. Apply a thin, uniform tack coat to all contact surfaces of curbs, structures, and joints. Prevent splattering of the tack coat when placed adjacent to curb, gutter, and structures. Roll the tack coat with a pneumatic -tire roller to remove streaks and other irregular patterns when directed.
4.5 Compaction. Furnish the type, size, and number of rollers required for compaction, as approved. Furnish at
least one medium pneumatic -tire roller (minimum 12 -ton weight). Use Tex -207-F , Part IV, to establish rolling patterns that achieve maximum compaction. Follow the selected rolling pattern unless changes that affect compaction occur in the mixture or placement conditions. Establish a new rolling pattern when such changes occur. Compact the pavement to the cross -section of the finished paving mixture in conformance with the 265 plans and specifications. Operate vibratory rollers in static mode when not compacting or changing directions, or when the plan depth of the pavement mat is less than 1- 1/2 in., unless otherwise directed. Start by first rolling the joint with the adjacent pavement and then continue by rolling longitudinally at the sides when rolling using the three- wheel, tandem, or vibratory rollers. Proceed toward the center of the pavement, overlapping on successive trips by at least 1 ft., unless otherwise directed. Make alternate trips of the roller slightly different in length. Begin rolling at the low side and progress toward the high side on superelevated curves unless otherwise directed. Avoid displacement of the mixture. Correct any displacement that may occur to the Engineer’s satisfaction. Ensure pavement is fully compacted before allowing rollers to stand on the pavement. Use only water or an approved release agent on rollers, tamps, and other compaction equipment unless otherwise directed. Keep diesel, gasoline, oil, grease, and other foreign matter off the mixture. Use tamps to thoroughly compact the edges of the pavement along curbs, headers, and similar structures and in locations that will not allow thorough compaction with the rollers. The Engineer may require rolling using a trench roller on widened areas, in trenches, and in other limited areas.
4.6 Irregularities. Immediately take corrective actions if surface irregularities, including segregation, rutting,
raveling, flushing, fat spots, mat slippage, color, texture, roller marks, tears, gouges, streaks, or uncoated aggregate particles are detected. The Engineer may allow placement to continue for no more than 1 day of production while the Contractor takes appropriate action. Suspend paving if the problem still exists after that day until it is corrected to the Engineer’s satisfaction. Remove and replace any mixture that does not bond to the existing pavement or has other surface irregularities identified above at the Contractor’s expense and to the Engineer’s satisfaction.
4.7 Ride Quality. Use Surface Test Type A to evaluate ride quality in accordance with Item 585, “Ride Quality
for Pavement Surfaces,” unless otherwise shown on the plans.
Article 5 — Measurement
LRA pavement will be measured by the ton of composite LRA pavement of the type used in the completed and accepted work in conformance with the plans and specifications. Measure on scales in accordance with Item 520, “Weighing and Measuring Equipment.” Keep records on tare weight, gross weight, and net weight of the LRA paving mixture for each load of the same type of mixture. The Materials and Tests Division will measure and report the moisture content in accordance with Tex -212-F , Part II, of the LRA paving mixture used to determine payment at the plant. All water and light hydrocarbon volatiles in the mixture measured in accordance with Tex-212-F , Part II, in excess of 6.0% by weight at the time of weighing, will be deducted from the net weight to determine the quantity for payment.
Article 6 — Payment
The work performed and materials furnished in accordance with this Item and measured as provided under Article 330.5., “Measurement,” will be paid for at the unit price bid for “Limestone Rock Asphalt Pavement” of the type, grade, and SAC specified. This price is full compensation for surface preparation, materials including tack coat, placement, equipment, labor, tools, and incidentals. Payment adjustment for ride quality, when required, will be determined in accordance with Item 585.