Section 306 — Full Depth Reclamation with Asphalt
Description
306.01This work consists of pulverizing an existing pavement and base in- place, adding crushed aggregate if required, mixing this material with emulsified asphalt or foamed asphalt, and shaping and compacting the mix to produce a stabilized base.
Material
306.02Conform to the following Subsections: Asphalt binder 702.01 Crushed aggregate 703.06 Emulsified asphalt 702.02 Fly ash 701.03( a) Portland cement 701.01(a) Water for construction 725.01(c)
Construction Requirements
306.03Proportioning. Collect representative samples of the pavement and aggregate base from the project. Replace removed pavement with asphalt concrete conforming to Section 403, Type II or approved cold patch material. Design a mix according to FLH T 522. Conform to the requirements shown in Table 306-1. If using foamed asphalt, provide a binder conforming to the requirements shown in Table 306-2. Submit the mix design and the following for approval 30 days before production:
(a)Optimum emulsified or foamed asphalt binder content based on total mass of mixture;
(b)Source and grade of emulsified or foamed asphalt binder;
(c)Optimum moisture content for compa ction based on total mass of mixture;
(d)Recommended cement or fly ash content;
(e)Maximum wet and dry density for the mixture at the recommended proportions of binder, water, and cement or fly ash according to AASHTO T 180, Method D;
(f)Gradation and proportion of imported crushed aggregate;
(g)Results of tests and applicable graphs;
(h)A representative 350- pound sample of pavement, base, and imported crushed aggregate, if requested;
(i)Three 1 -gallon samples of emulsified or asphalt binder, if requested;
(j)15-pound sample of portland cement or fly ash, if requested; and
(k)Optimum percent of injection water for foaming based on total mass of asphalt binder (if using foamed asphalt for the binder). Start production only after the mix design is approved. Submit a new mix design if there is a change in a material source. Table 306-1 Asphalt Stabilized Base Course Mix Design Requirements Binder type Material or Property Requirement
Emulsified asphalt and foamed
asphalt Indirect tensile strength, AASHTO T 283(1) Tensile strength wet 25 psi minimum Tensile strength ratio 60% minimum
(1)Follow the modified AASHTO T 283 procedures as indicated in FLH T 522. Table 306-2 Foamed Asphalt Binder Property Requirements
Property Requirement
Foamed asphalt expansion characteristics at 320, 338, & 356 °F(1) Asphalt expansion ratio 10 minimum Half-life of foamed expansion 6 seconds minimum
(1)See FLH T 522 for test procedures.
306.04General. Establish existing pavement cross- section according to Subsection 152.05. Maintain the established cross-section or construct to proposed cross-section. Protect manholes, valve covers, and other buried facilities from damag e.
306.05Production Start -Up Procedures. If an asphalt overlay is required, do not start FDR production until the asphalt overlay mix design has been approved.
(a)Preparatory phase meeting. Conduct a pre -stabilization preparatory phase meeting according to Subsection 153.06(a) at least 7 days before the start of stabilizing operations .
(b)Control strip. Provide 7 days’ notice before starting production. On the first day of production, stabilize a 1000-foot- long control strip, one -lane wide, and at the designated lift thickness. Construct the control strip on the project at an approved location. Construct the control strip using the construction procedures intended for the entire project. Cease production after construction of the cont rol strip until the stabilized base and the control strip are evaluated and verified for acceptance. After the reclaimer has pulverized and mixed one reclaimer width for 100 feet of the control strip and before compaction, dig a test pit to evaluate the mi xing and distribution of the asphalt. If homogeneous mixing is not occurring, modify the process and pulverize, mix, and verify another 100 feet. Continue until acceptable mixing and distribution of asphalt is obtained. Take three random loose mix samples within the control strip and verify that 100 percent passes the 2-inch sieve. Take nuclear gauge density readings behind each roller pass according to AASHTO T 310 to determine the roller pattern necessary to achieve at least 97 percent of the maximum wet density. Determine the maximum wet density by sampling processed material from behind the reclaimer (before compaction) and testing the material according to AASHTO T 180, Method D. Repeat the control strip process until an acceptable control strip is produced. See Subsection 106.01 for the disposition of material in rejected control strips. Accepted control strips may remain in place and will be accepted and measured as a part of the completed base.
(c)Control strip verification. The control strip is verified when the specified density, gradation, and moisture content are obtained. Full production may start once the control strip is verified. Provide the CO with the reclaimer speed, emulsified or foamed asphalt application temperature, and asphalt and water line pressures used on the verified control strip. Use these start -up procedures when changing construction procedures, when resuming production after a termination of production due to unsatisfactory quality according to Subsection 106.04, or the starting of a new construction season.
306.06Adding Crushed Aggregate. Conform to Subsectio n 304.04.
306.07Pulverizing and Mixing.
(a)If using emulsified or foamed asphalt, provide a road reclaimer that is:
(1)Self-propelled;
(2)Specifically manufactured for in -place reclamation;
(3)Capable of reducing the existing material to the required size;
(4)Equipped with at least an 8-foot cutting width;
(5)Equipped with standard automatic depth controls adjustable in increments of ½ inch;
(6)Equipped with independent asphalt application nozzles that can be turned off individually and verified open and working from within the operator cabin; and
(7)Equipped with an asphalt and water application control system including full width spray bars and positive displacement pumps automatically interlocked to the machine speed.
(b)In addition to the above, if using foamed asphalt, provide a road reclaimer that is:
(1)Equipped with an exterior test nozzle to verify proper foaming action;
(2)Equipped with individual expansion chambers for each nozzle where asphalt binder and water are injected under pressure through individual orifices for atomization and foam expansion; (3) Equipped with an internal electric heat cleaning system to self- clean foaming nozzles;
(4)Equipped with maximum nozzle spacing of 6 inches; and
(5)Equipped with a compressor that can provide at least 45 pounds per square inch of pressure. Use the reclaimer to pulverize the existing roadway material in -place until 100 percent passes the 1½ -inch sieve. Reprocess or remove larger particles and dispose of them according to Subsection 203.07.
306.08App lying Cement or Fly Ash. Do not apply cement or fly ash when conditions allow for excessive loss to blowing. Use a metered mechanical spreader to uniformly apply cement or fly ash on the roadway surface. Use skirts around the spreader box to minimize dust.
306.09Applying Asphalt.
(a)Requirements for emulsified and foamed asphalt. Apply emulsified or foamed asphalt when the surface and air temperatures in the shade are at least 50 ºF. Do not start applying emulsified asphalt when fog, precipitation, or temperatures below 35 ºF are anticipated within 48 hours. Automatically adjust the asphalt and water flow based on the reclaimer speed and recycled material mass for the approved mix design. Maintain the asphalt temperature within the range recommended by the supplier. If the lane width exceeds the width of the reclaimer, complete pulverizing and mixing operations in continuous one lane -width segments up to ½ mile in length. Mix the pulverized roadway material with emulsified asphalt binder, other additives, and the necessary mixing water for optimum dispersion. If two passes are used, shape and compact the reclaimed material with a steel drum roller after the first pass to provide depth control for the second pass of the reclaimer. Add the required quantity of emulsified or foamed asphalt during the final pass of the reclaimer. Verify that the emulsified or foamed asphalt is evenly dispersed and coating the pulverized material. Dig test pits within the mix at least every ¼ mile and observe the distribution of the emulsified or foamed asphalt in each pit.
(b)Additional requirements for foamed asphalt. Do not use foamed asphalt with an application temperature below 320 °F. Do not apply foamed asphalt on previously treated foamed asphalt areas.
306.10Compacting and Finishing. Compact and finish each segment before starting mixing operations on the next segment. Maintain the moisture content of the mixture within 2 percent of optimum. Compact the processed material uniformly to at least 97 percent of the maximum wet density as determined from the control strip. If the material changes, reestablish the maximum wet density according to Subsection 306.05(b) . Det ermine the in -place density according to AASHTO T 310. Use at least three rollers: primary, secondary, and finish rollers sized and configured to achieve the required compaction and finish. Operate rollers according to the manufacturer’s recommendations. Compact the processed material full width by rolling the material between the reclaimer wheel paths first then from the sides to the center, parallel to the centerline of the road. Along curbs, headers, walls, and places not accessible to the roller, compact the material with approved tampers or compactors. Shape and grade the mixture to the correct lines, grades, and cross -section. Finish the compacted surface according to Subsection 301.06 to produce a surface that is smooth, dense, and free of compaction planes, ridges, or loose material. Clean the compacted surface of loose material, dirt, and other deleterious material by approved methods. Do not leave uncompleted segments at the end of the workday.
306.11Construction Joints.
(a)Longitudinal joints. Make longitudinal joints coincide with each change in cross slope , regardless of the overlap width. Provide a minimum longitudinal overlap of 6 inches.
(b)Transverse joints. After full depth reclamation operations stop, ensure conti nuity across transverse joints by cutting back into the completed work for a distance recommended by the manufacturer of the reclaimer.
306.12Curing and Maintenance.
(a)Emulsified asphalt. Keep traffic and equipment off the stabilized base for at least 1 hou r after completing compaction. Do not allow traffic and construction equipment on the stabilized base until it is sufficiently stable to withstand marring and permanent deformation.
(b)Foamed asphalt. After completing compaction, moisten the surface and roll with a pneumatic - tire roller to create a tight and closed surface. Do not allow traffic and construction equipment on the stabilized base until compaction and surface moistening is complete. Continue to keep the surface moist until placement of the next course or final surface. If shown i n the plans , place a fog seal on the surface of the stabilized base after final compaction according to Section 406. Route hauling and other construction equipment uniformly over the full width of the recycled surface to minimize non -uniform compaction. Maintain the stabilized base to the correct line, grade, and cross- section until placement of the next course or final riding surface. If the stabilized base loses stability, density, o r finish before placement of the next course, reprocess and recompact as necessary to restore the strength of the damaged material. Overlay the stabilized base material within 14 days after completing finishing operations according to Subsection 306.10.
306.13Acceptance. See Table 306-3 for sampling, testing, and acceptance requirements. Cement or fly ash will be evaluated under Subsections 106.02 and 106.03. Crushed aggregate will be evaluated under Subsections 106.02 and 106.03. Emulsified and foamed asphalt will be evaluated under Subsections 106.03 and 106.04. Construction of full depth reclamation with asphalt will be evaluated under Subsections 106.02 and 106.04.
Measurement
306.14Measure the Section 306 pay items listed in the bid schedule according to Subsection 109.02 .
Payment
306.15The accepted quantities will be paid at the contract price per unit of measurement for the Section 306 pay items listed in the bid schedule. Payment will be full compensation for the work prescribed in this Section. See Subsection 109.05 . Table 306-3 Sampling, Testing, and Acceptance Requirements
Material or
Product Type of
Acceptance
(Subsection) Characteristic Category Test Methods
Specifications Sampling
Frequency Point of
Sampling Split
Sample Reporting
Time Remarks
Source
Emulsified
asphalt Measured & tested for conformance (106.04) Quality − Subsection
702.021 per type & source of material Asphalt supplier Yes 30 days minimum before production −
Asphalt
binder (foamed) " " − Subsection
702.01& Table 306 -2 " " " " −
Mix Design
Full depth
reclamation (FDR) with asphalt mixture Measured & tested for conformance (106.04 ) All − Subsection
306.03& FLH T 522 1 per submitted mix design Existing roadway Yes 30 days minimum before production − Table 306- 3 (continued) Sampling, Testing, and Acceptance Requirements
Material or
Product Type of
Acceptance
(Subsection) Characteristic Category Test Methods
Specifications Sampling
Frequency Point of
Sampling Split
Sample Reporting
Time Remarks
Production Start -up (control strip)
Asphalt
binder (foamed) Measured & tested for conformance (106.04 ) Binder temperature − Subsection
306.091 minimum Temperature gauge(3) No Upon completing test −
Half-life &
expansion ratio − Table 306 -2 & FLH T 522 " Test nozzle on reclaimer " " −
FDR with
asphalt material Measured & tested for conformance (106.04 ) Gradation − AASHTO T 27 3 minimum Behind reclaimer before compaction No Upon completing test Minus 1½-in sieve requirement only
Moisture -
density (wet density)(1) − AASHTO T 180, Method D 1 minimum " " " −
Moisture
content (in-place) – AASHTO T 255 3 minimum In-place after compaction " " − Density − AASHTO T 310 " In-place after compaction " " Report wet density
Visual
inspection (106.02 ) Homogeneous mixing − Subsection 306.05(b) Subsection 306.05(b) Behind reclaimer before compaction No Upon completing test − Table 306- 3 (continued) Sampling, Testing, and Acceptance Requirements
Material
or
Product Type of
Acceptance
(Subsection) Characteristic Category Test Methods
Specifications Sampling
Frequency Point of
Sampling Split
Sample Reporting
Time Remarks
Production
FDR
asphalt material Measured & tested for conformance (106.04 ) Moisture - density (wet density)(1) − AASHTO T 180, Method D 1 per change in material Behind reclaimer before compaction No Before using in work − Density − AASHTO T 310 1 per 2000 yd2 In-place after compaction " End of shift Report wet density
Process
control (153.03 ) Gradation − AASHTO T 27 1 per 3500 yd2 minimum
Behind
reclaimer before compaction No Upon completion of test −
Moisture
content − AASHTO T 255 1 per lane mile " " " −
Homogeneous
mixing − Subsection 306.05(b) 1 per 3500 yd2 minimum " " " −
Binder
content of mix − Calculation (yield rate) 1 per tank load minimum − " " −
Indirect
tensile strength(2) − AASHTO T 283 (as modified by FLH T 522) 1 per 15,000 yd2 " " 4 days − Table 306- 3 (continued) Sampling, Testing, and Acceptance Requirements
Material
or
Product Type of
Acceptance
(Subsection) Characteristic Category Test Methods
Specifications Sampling
Frequency Point of
Sampling Split
Sample Reporting
Time Remarks
Production (continued)
Asphalt
binder (foamed) Process control (153.03 ) Binder temperature − Subsection
306.091 per tank load Temperature gauge(3) No Upon completing test −
Half-life &
expansion ratio − Table 306 -2 & FLH T 522 " Test nozzle on reclaimer " " −
Finished Product
FDR with
asphalt material Measured & tested for conformance (106.04 ) Surface tolerance & grade – Subsection
301.06As directed Completed
FDR surface No Before
placement of next layer or as requested −
(1)At least 5 points per proctor.
(2)Immediately after collecting sample, transport to a field material laboratory and compact for indirect tensile strength testi ng. Keep sample in moisture proof container.
(3)Measure asphalt binder temperature with a calibrated thermometer. Section 307. — RESERVED