341COLD RECYCLED ASPHALT BASE COURSE, COLD-IN-PLACE

341.1DESCRIPTION—This work is the on-grade construction and material processing of a cold recycled

asphalt base course (CRABC) that uses emulsified asphalt, or foamed asphalt stabilizing agents, combined with RAP, RAM, cement, or virgin aggregates. Construction typically includes milling to an indicated depth, adding and mixing emulsified asphalt or foamed asphalt, placing, compacting, and testing.

341.2MATERIAL—

Incorporate all reclaimed material into the CRABC.

the project or from stockpiles off the project.

conforming to AASHTO M 332, for Performance-Graded Asphalt Binder using Multiple Stress Creep Recovery

specified grade. Provide QC testing and certification as specified in Sections 106.03(b) and 702.1(b)1. Provide the Representative a copy of a signed Bill of Lading for asphalt binder on the first day of paving and when the batch number changes.

the approved mix design. Use one of the following emulsified asphalt materials, conforming to the applicable requirements of Bulletin 25:

• Emulsified Asphalt—MS-2, CMS -2, SS -1, CSS -1, SS -1h, CSS -1h, HFMS -2h, HFMS -2, HFMS -2s, HFMS-2P, SS-1hP, CSS-1hP.

testing to establish the mix design. If RAM is included in the depth indicated for removal, take separate samples of RAP and RAM. Establish the mix design according to Bulletin 27 and submit the mix design as specified in Section 108.03(b)3.

testing to establish the mix design according to AASHTO MP 38 and submit the mix design as specified in Section 108.03(b)3. Perform the mix design using the asphalt material performance grade and supplier that will be used during the project. If there is a change in source or grade of the asphalt material, a new mix design is required.

material according to the mix design and at the mix design recommended optimum moisture and emulsion or foamed asphalt content. If RAP gradations and composition vary sufficiently, make field adjustments as detailed in the QC plan to obtain satisfactory coating and the specified compaction.

start of the project. Do not start actual work until the QC Plan has been reviewed.

341.3CONSTRUCTION—

• Use equipment capable of automatically metering liquids with a variation of not more than ± 2.0% by weight of liquids.

• Place CRABC mixtures using an asphalt paver as specified in Section 413,3(e)1.

• Maintain all equipment as specified in Section 108.05(c).

cutting drum, screening/crushing plant, and pugmill mixer. Use single -unit or multiple -unit machine with plant and/or mixer as trailer(s). Use a pugmill mixer with liquid additive system and spray bar capable of volumetrically controlling liquid additive based on milling depth, milling width, and machine speed.

cutting drum with the following minimum capabilities:

• Mill the existing pavement to the indicated depth in one pass and produce RAP meeting the 1 1/4 inch maximum requirement according to AASHTO MP 38.

• Maintain a constant cutting depth and width, cross slope, and uniform grade.

• Accurate and uniform injection of water into hot asphalt binder , and uniform mixing of foamed asphalt, RAP material, and water, to meet mix design requirements.

• Provide separate computerized controls and injection bars for injection of foamed asphalt and water in the mixing chamber.

• Equip the foamed asphalt system with a test nozzle to allow field samples of foamed asphalt.

• Equip hot asphalt supply tankers with gauges that continuously display the temperature of the asphalt.

10-0; and from October 1 to April 30 in all other Districts. With written approval of the Representative, the Contractor may place CRABC when no freezing temperatures occur for 24 hours before paving and when the project ambient air temperature is 45F and rising. Maintain adequate total liquids in the mixture to ensure thorough mixing of the reclaimed material and aggregate with the emulsified asphalt material. If necessary, add water at the mill head using a calibrated meter.

the lines, grades, and depth indicated. Before compaction, cure the base course as necessary. Provide compacted layers between 2 inches to 5 inches in depth. Use rollers as specified in Section

108.05(c)

Begin rolling at the low side of each layer; except, initially leave 3 inches to 6 inches from unsupported edges unrolled to prevent distortion. Determine the target density according to PTM No. 402. Compact the base course to a minimum density of 96% of the PTM 402 target density. Determine the in-place density of each 3,000-square yard area according to AASHTO T 310. If the density of an area is less than the minimum density and if additional compaction does not achieve the minimum density, scarify, adjust the moisture content, and recompact. If the density is still below the minimum, and the base course is uniform in texture, and

stable, determine a new target density according to PTM No. 402 and then compact to minimum of 96%of the new target density. If the Representative determines that the Contractor achieved the minimum density with minimal compaction, the Representative may require the Contractor to determine a new target density according to PTM No. 402. If the completed base course is unacceptable, stop base course construction. Resume construction only after correcting the cause of unacceptable construction.

from marring, distortion, and other damage. Immediately correct damage to the base course caused by construction equipment to the Representative’s satisfaction.

both transversely and longitudinally, using a 12-foot straight edge or template. Test a 3,000-square yard area at three locations. At each location determine the maximum space under the straight edge or template. Correct each 3,000 square yard area where the average of the maximum space at the three locations exceeds 1/2 inch. To control dust or raveling, apply a fog seal as specified in Section 472.3(c) using CSS-1h or SS-1h diluted as specified in Section 472.2, Table A or other approved emulsified asphalt material at no additional cost to the Department.

Section 413.3(n). Use a pilot car for speed control if damage, such as raveling, is likely to occur.

at least 2 weeks before placing the wearing course or binder course or until the average moisture content is less than 2%. In addition, before placing a wearing or binder course, dry cut or dry extract a minimum of three samples selected at random according to PTM No. 1 from throughout the entire cold -recycled base course project. Ensure each sample size is a minimum of 1,200 grams. Determine the moisture content of each sample according to PTM No. 749. Back fill and compact core holes with CRABC material or approved alternate material.

average moisture content is less than 2%. In addition, before placing a wearing or binder course, dry cut or dry extract a minimum of three samples selected at random according to PTM No. 1 from throughout the entire cold-recycled base course project. Ensure each sample size is a minimum of 1,200 grams. Determine the moisture content of each sample according to PTM No. 749. Back fill and compact core holes with CRABC material or approved alternate material.

each 3,000 square yards or less of work done and record measurements to ensure that specified milling depth is met. Correct or replace any section deficient by 1/2 -inch or mo re from specified depth at no additional cost to the Department.

341.4MEASUREMENT AND PAYMENT—