Article 1 — Description
Perform full -depth reclamation (FDR) using an in- place mixing process to obtain a homogenous mixture of the existing surface and the underlying base material (with or without new material and additive added) using a foamed asphalt.
Article 2 — Materials
Furnish uncontaminated materials of uniform quality that meet the requirements of the plans and specifications. Notify the Engineer of the proposed material sources and, when necessary, changes to material sources. The Engineer will verify the specification requirements are met before approving the sources for use. The Engineer may sample and test project materials at any time during the project to verify specification compliance in accordance with Item 6, “Control of Materials.”
2.1 Asphalt . Furnish PG 64- 22 that meets the requirements of Item 300, “Asphalts, Oils, and Emulsions,” unless
otherwise shown on the plans.
2.2 Additional Material. When shown on the plans, required by the mixture design, or directed, furnish base or
reclaimed asphalt pavement material that meets the requirements of Item 247, “Flexible Base,” for the type and grade required. Unless otherwise shown on the plans, the compressive strength of the flexible base is waived .
2.3 Additive . When shown on the plans, required by the mixture design, or directed, use the type and amount of
additive required. Do not exceed 1. 0% by weight of material, unless otherwise shown on the plans.
2.3.1 Lime . When shown on the plans, required by the mixture design, or directed, furnish lime in accordance with
DMS -6350 , “Lime and Lime Slurry.” When dry lime is required, provide dry quicklime. When lime slurry is required, provide commercial lime slurry or quicklime slurry .
2.3.2 Cement . When shown on the plans, required by the mixture design, or directed, furnish hydraulic cement in
accordance with DMS -4600 , “Hydraulic Cement,” and the Department’s Hydraulic Cement Quality Monitoring Program (HCQMP). Sources not in the HCQMP will require testing and approval before use.
2.4 Mixture Design . The Engineer will provide a mixture design in accordance with Tex -134-E , unless otherwise
directed, before the start of any work pertinent to this Item. The Contractor may propose a mixture design developed in accordance with Tex-134-E . When the Contractor elects to propose a mixture design, t he Engineer will determine the location or locations to sample and witness the sampling to obtain materials. Provide asphalt and design the mixture from each sampling location selected by the Engineer meet the requirements shown in Table 1. Report the mixture design using the test template in accordance with Section 290.6.1., “Reporting and Responsibilities.” Table 1 Mixture Design Properties Mixture Property Min Requirement Foamed Asphalt Asphalt binder half-life 6.0 sec. Asphalt binder expansion ratio 8 times Laboratory Mixture Properties Indirect tensile strength (IDT) , psi 50 Moisture -conditioned IDT, psi 30 203 2.5. Mixture Design Verification . Provide the Engineer with representative samples of all materials that will be included in the treatment process at least 4 weeks before the start of production, unless otherwise directed. The Engineer will verify the foamed asphalt properties and the target foamed asphalt content that produces a mixture to meet the requirements shown in Table 1. When the foamed asphalt properties fail to meet the requirements shown in Table 1, provide the Engineer with asphalt from a different source and a new representat ive sample from the roadway to be reclaimed. When the mixture fails to meet the requirements shown in Table 1, the Engineer will provide a new mixture design.
2.6 Water . Furnish water free of industrial waste and other objectionable material that is compatible for foaming
the asphalt .
Article 3 — Equipment
Provide machinery, tools, and equipment necessary for proper execution of the work.
3.1 Storage Facility. Store cement, quicklime, and dry hydrated lime in closed, weatherproof containers.
3.2 Slurry Equipment. Use slurry tanks equipped with agitation devices to slurry cement, hydrated lime, or
quicklime at the project or another approved location. The Engineer may approve other slurry methods. Provide a pump for agitating the slurry when the distributor truck is not equipped with an agitator. Equip the distributor truck with a sampling device in accordance with Tex -600-J , Part I.
3.3 Dry Distribution Equipment . Provide equipment to spread the cement or lime evenly across the area to be
treated. Provide equipment with a rotary vane feeder to spread the cement or lime, when shown on the plans.
3.4 Rollers. Provide rollers in accordance with Item 210, “Rolling ,” and Section 291.6.6., “Compaction.”
3.5 Proof Rollers . Provide proof rollers in accordance with Item 216, “Proof Rolling,” when required.
3.6 Asphalt Transports . Provide asphalt transports with a pintle hitch on the rear bumper to allow the reclaimer
to connect and push the transport during mixing.
3.7 Reclaimer for Foamed Asphalt Treatment . Use a reclaimer with the following equipment and capabilities :
self-propelled mixer capable of fully mixing the existing road to the depth shown on the plans with foam asphalt, water, and when applicable, additives and additional material to produce a homogeneous material; minimum power capability of 600 horsepower; a pintle hitch on the rear bumper to allow the reclaimer to connect and push the transport during mixing; ability to increase the effective volume of the mixing chamber in relation to depth of cut; two microprocessor -controlled systems, complete with two independent pumping systems and spray bars, to regulate the application of foamed asphalt cement, separate from water that is used to increase the moisture content of the mixed material; • Both systems must perform in relation to the forward speed of the reclaimer and the mass of the material being processed. two spray bars, one for foamed asphalt cement and one for compaction moisture, each fitted with self-cleaning nozzles at a maximum spacing of one nozzle for each 6 in. in width of the mixing chamber; • Monitor the flow rate of each nozzle to verify that all nozzles are producing foamed asphalt at the same rate. foamed asphalt cement produced at the spray bar in individual expansion chambers into which hot asphalt cement, water, and air are injected under pressure through individual and small orifices that promote atomization; 204 • The rate of addition of water into the hot asphalt cement must be kept at a constant percentage by mass of asphalt cement by the same microprocessor. system within the operator cabin to verify the foamed asphalt is being evenly distributed across the full width of the spray bar at the rate specified, demonstrated to the Engineer to verify even spraying; electrical heating system capable of maintaining the temperature of asphalt cement flow components above 300°F; single asphalt cement feed pipe installed between the recycler and the supply tanker; and • Do not use circulating systems that incorporate a return pipe to the supply tanker. inspection or test nozzle fitted at one end of the spray bar that produces a representative sample of the foamed asphalt cement.
Article 4 — Staffing Requirements
Provide at least one staff member with at least 2 years’ experience in supervising FDR projects using foamed asphalt onsite to oversee the startup operations, unless otherwise directed. This staff member must be onsite for the first 3 days of production of the FDR process or as deemed necessary by the Engineer. Provide Soils & Base 102 (SB102) Field Specialists certified by the Department -approved soils and base certification program to conduct daily sampling and testing for the duration of the project, in accordance with this Specification. Supply the Engineer with a list of certified personnel and copies of their current certifications, either hardcopy or electronic, before beginning production and when personnel changes are made.
Article 5 — Control Section
Construct a control section at an approved location. Process material in the control section for an area within the typical section, minimum 300 ft. in length, and to the depth shown on the plans. Meet the requirements of Article 291.7., “Process Control,” with the Engineer witnessing the sampling and testing, and provide test results and any pertinent information to the Engineer upon completion of the control section. Compact the control section in accordance with Section 291.6.6., “Compaction,” and Section 291.6.6.2., “Density and Moisture Control,” unless otherwise directed. The Engineer will determine the moisture content of the reclaimed and treated material in accordance with Tex-103-E . The Engineer will use this moisture content to determine a correction factor in accordance with When directed, proof roll the control section in accordance with Item 216. Proceed to full construction when approved.
Article 6 — Construction
Construct each layer uniformly, free of loose or segregated areas, and with the materials, density, and moisture content as required by the approved mixture design. Provide a smooth surface that conforms to the typical sections, lines, and grades shown on the plans, or as directed.
6.1 Reporting and Responsibilities . Use Department -provided templates to record and calculate all test data
and pertinent information for the mixture design and process control testing. Obtain the current version of the templates from the Department’s website or from the Engineer. The Engineer and the Contractor will provide any available test results to the other party when requested. Record and electronically submit all test results and pertinent information on Department -provided templates.
6.2 Preparation of Existing Pavement for Treatment. Before treating, remove existing asphalt pavement in
accordance with Item 105, “Removing Treated and Untreated Base and Asphalt Pavement,” when shown on 205 the plans or as directed. Shape existing material in conformance with applicable bid items to conform to typical sections shown on the plans and as directed.
6.3 Application of Additive . Apply the required additive uniform ly across the roadway in advance of the mixer,
when required. Minimize dust and scattering of additives by wind. Do not apply additives when, in the opinion of the Engineer, wind conditions cause blowing additive to become dangerous to traffic or objectionable to adjacent property owners.
6.3.1 Lime . Uniformly apply lime using dry or slurry placement as shown on the plans or as directed. Add lime at
the percentage determined in the mixture design. Apply lime only to the area to be reclaimed during the same working day. 6.3.1.1. Dry Placement . When necessary, sprinkle in accordance with Item 204, “Sprinkling.” Distribute the required quantity of hydrated lime using approved equipment. Do not use a motor grader to spread hydrated lime. 6.3.1.2. Slurry Placement . Provide slurry free of objectionable materials, at or above the approved minimum dry solids content, and with a uniform consistency that will allow ease of handling and uniform application. Inject slurry directly into mixing chamber using an independent metered spray system. A lternatively, distribute slurry uniformly by making successive passes over a measured section of roadway until the specified lime content is reached. Deliver commercial lime slurry to the jobsite or prepare lime slurry at the jobsite or other approved location by using hydrated lime, as specified.
6.3.2 Cement . Uniformly apply cement as shown on the plans or as directed. Add cement at the percentage
determined in the mix ture design. Apply cement only on an area where mixing the cement and foamed asphalt , compacti ng, and finishing can be completed during the same working day. 6.3.2.1. Dry Placement . Distribute the required quantity of dry cement using approved equipment. Minimize dust and scattering of cement by wind.
6.4 Weather Restrictions. Suspend additive and foaming appli cation when:
the surface temperature is below 50°F , the weather forecast calls for freezing temperatures within 3 days after incorporation of the f oamed asphalt , or the Engineer determines the weather condition is unsuitable.
6.5 Mixing . Thoroughly mix the material using approved equipment. Mix until a homogenous mixture is obtained.
6.5.1 Moisture . Do not start mixing the material being treated if the moisture content determined in accordance
with Section 291.7.4., “Foamed Asphalt Treatment Water Content,” is greater than the optimum moisture content from the mixture design, unless otherwise directed. Sprinkle when necessary, in accordance with Item 204, or aerate the treated material to adjust the moisture content .
6.5.2 Lime . When applicable, begin mixing within 6 hr. of application of lime. Hydrated lime exposed to the open
air for 6 hr. or more between application and mixing, or that experiences excessive loss due to washing or blowing, will not be accepted for payment. Thoroughly mix the material and lime using appr oved equipment. Allow the mixture to mellow for a minimum of 24 hr., or as directed, before mixing with foamed asphalt.
6.5.3 Foamed Asphalt . Supply transports of asphalt to the project site at a minimum of 320°F and meeting the
requirements shown in Table 1, unless otherwise approved. Collect haul tickets from each load of mixture delivered to the project and provide the Department’s copy to the Engineer after each day of treatment, or as directed. Record the temperature determined from the temperature gauge on the transport and record on each ticket, or as directed. 206 Apply the foamed asphalt to obtain the optimum foamed asphalt content determined in accordance with Section 291.2.4. , “Mixture Design.” Apply foamed asphalt only to areas where mixing and compaction can be completed during the same working day. Monitor the required depth of mixing and meet the gradation requirements shown in Table 2. Complete the entire operation of mixing the existing road and incorporating additional flexible base and cement when applicable, water, and foamed a sphalt in one pass . Overlap each adjacent pass of the mixer with the previous pass by a minimum of 6 in. and apply foamed asphalt to the overlapped material . Use multiple passes if the process control requirements specified in Article 291.7., “Process Control,” are not met. After mixing, the Engineer will sample the mixture at roadway moisture for a minimum of one per 3,000 cu. yd. or one per day at roadway moisture and test in accordance with Tex -101-E , Part III, to determine compliance with the gradation requirements shown in Table 2. When test results fail to meet the requirement shown in Table 2, modify operations until the Engineer’s test results meet the gradation requirements. Table 2 Gradation Requirements Sieve Size Min Percent Passing 1-3/4 in. 100 3/4 in. 85
6.5.4 Asphalt Binder Sampling . Obtain a 1- qt. sample of the asphalt binder witnessed by the Engineer for each
day of production. The Contractor will notify the Engineer when the sampling will occur. Sample in accordance with Tex -500-C , Part III. Label the container with the corresponding producer name, producer facility location, grade, district, date sampled, all applicable bills of lading (if available), and project information including highway and control number. The Engineer will retain these samples for 1 yr. The Engineer may also obtain independent samples. If obtaining an independent asphalt binder sample and upon request of the Contractor, the Engineer will split a sample of the asphalt binder with the Contractor. At least once per project, the Engineer will collect split samples of the binder grade and source used. The Engineer will submit one split sample to the Materials and Tests Division to verify compliance with Item 300, and will retain the other split sample for 1 yr.
6.5.5 Irregularities. Avoid spilling water or asphalt onto the surface of the existing or reclaimed surface when
connecting or disconnecting transports from the reclaimer or when filling water trucks. When excess water is spilled onto the exiting or reclaimed surface, identify the location and rework material that fails to meet or loses the required density , stability, or finish within 24 hr. of completion of compaction. Reworking includes loosening, adding material , or removing unacceptable material if necessary; mixing; compacting; and finishing as directed. Continue work until specification requirements are met. Perform the work at no additional expense to the Department .
6.6 Compaction. Compact the foamed asphalt base mixture in one lift using density control, unless otherwise
shown on the plans. Use a minimum 18-ton vibratory, heavy tamping roller, and a medium pneumatic tire roller to meet density, unless otherwise directed. Begin rolling and perform initial compaction using a vibratory, heavy tamping roller applying high amplitude and low frequency. Begin rolling longitudinally at the sides and proceed toward the center, overlapping on successive trips by at least half the w idth of the roller unit. Begin rolling at the low side and progress toward the high side on superelevated curves. Offset alternat ing trips of the roller. Continue rolling until the heavy tamping roller “walks out” of the material. Walking out for the heavy tamping roller is defined as light being evident between all the pads at the material -heavy tamping roller drum interface. After the completion of tamping rolling, remove remaining tamping marks. Cut slightly below the depth of the tamping marks and ensure material being cut is kept moist at all times. Achieve the desired slope and shape 207 to the lines and grades as shown on the plans. Perform final surface shaping on the same day the foamed asphalt is incorporated. Clip, skin, or tight -blade the surface to remove and waste accumulated fines. Do not use fines to fill surface irregularities. Use a vibratory roller and pneumatic roller to compact the bladed material. Do not finish- roll in vibratory mode. If necessary, use a light spray of water to aid in final compaction density and appearance. Rework material that fails to meet or loses the required density, stability, or finish after completion of compaction. Add additional foamed asphalt and additives at the percentages determined in accordance with Section 291.2.4., “Mixture Design,” unless otherwise directed. Reworking includes loosening, adding material, or removing unacceptable material if necessary; mixing; compacting; and finishing as directed. Continue work until specification requirements are met. Perform the work at no additional expense to the Department. Suspend field operations when significant changes of materials being treated occur. Provide the Engineer with recommendations to modify operations based on the changes of materials. This may include changes in additives or percentages of foamed asphalt or verification of the maximum dry density and optimum moisture content. Provide the Engineer with a foamed asphalt treatment proposal for all areas requiring full -depth repair. Notify the Engineer when significant changes of materials being treated occur. The Engineer may suspend field operations and investigate the areas of concern. Before final acceptance, the Engineer will select the locations of tests and measure the depth of the foamed asphalt treatment in accordance with Tex -140-E at a minimum of 1 per 3,000 cu. yd. or one per day. Correct areas deficient by more than 1/2 in. in thickness by reshaping, recompacting, and refinishing at the Contractor’s expense, unless otherwise directed.
6.6.1 Ordinary Compaction. Roll using approved compaction equipment, as directed. Correct irregularities,
depressions, and weak spots immediately by scarifying the areas affected, adding or removing treated material as required, reshaping, and recompacting.
6.6.2 Density and Moisture Control . Compact to at least 97.0 % of the maximum dry density , and moisture within
2.0 percentage points below the optimum moisture content and no more than 0.5 percentage point above the optimum moisture content as determined in accordance with Tex -134-E
, unless otherwise shown on the plans. Do not achieve density by drying the material after compaction. Unless otherwise directed: perform additional compaction or rework using the reclaimer unless otherwise directed, and recompact when the material does not meet the density but meets the moisture content, aerate and recompact when the moisture content is more than 0.5% above the optimum moisture content, and rework, add moisture, and recompact when the moisture content is more than 2.0% below the optimum moisture content. Provide the Engineer with the beginning and ending station numbers of the area completed for testing. The Engineer will determine the roadway density and moisture content of completed sections in accordance with Tex-115-E , Part I using the correction factor determined in accordance with Article 291.5. , “Control Section.” The Engineer will determine random locations for testing in accordance with Tex-115-E , Part IV. The Engineer will perform testing for each day of production at a minimum of one per 3,000 cu. yd. or one per day. When the density is less than 97.0% of the maximum dry density, the Engineer may perform additional testing to determine the extent of the area to correct. The Engineer may accept the section if no more than one of the five most recent density tests is below the specified density and the failing test is no more than 3 pcf below the specified density . 208 6.6.3. Miscellaneous and Small Areas . Miscellaneous areas are those that typically involve discontinuous operations, such as temporary detours, driveways, mailbox turnouts, crossovers, gores, and other similar areas . Miscellaneous and small areas are not subject to density testing but may be tested as directed by the Engineer.
6.7 Curing. Cure the finished section for a minimum of 2 hr. , or as directed, before opening to traffic . The
Engineer may allow traffic on the finished section during curing when proof rolling indicates adequate stability. Apply fog seal daily at a rate between 0.05 and 0.10 gal. per square yard in accordance with Item 315, “Fog Seal,” when traffic is allowed on the finished section during curing, unless otherwise directed. Proof roll the roadbed in accordance with Item 216. If deformation occurs, do not allow traffic to return to the finished section until the mixed material is firm enough to accommodate traffic without deformation. Apply prime coat and seal coat or additional courses within 14 calendar days of final compaction. When no specific detour is required, provide one-way traffic control until proof rolling permits the return of normal traffic to the compacted material.
Article 7 — Process Control
Perform process control testing during the treatment process and for the completed base in accordance with Table 3 at locations independent of the Engineer’s testing locations, unless otherwise directed. Test results from process control will not be used for acceptance. The Contractor may perform additional testing as they deem necessary for process control. Report test results and all pertinent information in accordance with Section 291.6.1., “Reporting and Responsibilit ies.” When test results do not meet specification requirements, modify operations and perform the test methods shown in Table 3. Suspend operations when any of the test results performed after the modifications do not meet specification requirements. Table 3 Min Testing Frequency Description Test Method Min Frequency Depth of pulverization Tex-140-E One per 350 cu. yd. (Min one per day of production.) Gradation Tex-101-E, Part III Foamed asphalt content Meter readings or truck w eight t ickets Foamed asphalt treatment water content Meter readings Moisture content1 Tex-103-E One per 350 cu. yd. (Min two per day of production .) 1. Measure the moisture content in accordance with Tex-103-E before adding the foamed asphalt.
7.1 Depth of Pulverization . Determine the depth of pulverization in accordance with Tex -140-E .
7.2 Gradation . Sample the roadway mixture after mixing with the moisture and measure the gradation in
accordance with Tex -101-E , Part III.
7.3 Foamed Asphalt Content . Verify the percentage of asphalt added to the pulverized material using asphalt
meter readings or truck weight tickets as approved; the quantity of material treated (depth, width, and length); and estimated in- place density. Changes in asphalt content , type, or supplier must be approved before the start of production. Notify the Engineer when adjustments to the asphalt content are made during any day’s production.
7.4 Foamed Asphalt Treatment Water Content . Apply the water content determined from the mix design t o
produce the f oamed a sphalt. Measure the water content added using a water monitoring device from the 209 reclaimer. When necessary, adjust the water content and notify the Engineer within 1 hr. after material is reclaimed and treated.
7.5 Moisture Content . Measure the moisture content in accordance with Tex -103-E before adding the f oamed
asphalt. Verify the moisture content when precipitation occurs after testing and before the f oamed a sphalt is added.
Article 8 — Measurement
8.1 Asphalt . Asphalt will be measured by one of the following methods.
8.1.1 Weight. Asphalt will be measured in tons using certified scales meeting the requirements of Item 520,
“Weighing and Measuring Equipment,” unless otherwise approved. The transporting truck must have a seal attached to the draining device and other openings. Random checking on public scales at the Contractor’s expense may be required to verify weight accurac y. Upon work completion or temporary suspension, any remaining asphalt material will be weighed by a certified public weigher. The quantity to be measured will be the number of tons received minus the number of tons remaining after all directed work is com plete.
8.1.2 Volume . Asphalt will be measured by the gallon.
8.2 Additive .
8.2.1 Lime . When lime is furnished in trucks, the weight of lime will be determined on certified scales, or the
Contractor must provide a set of standard platform truck scales at an approved locati on. Scales must meet the requirements of Item 520. 8.2.1.1. Commercial Lime Slurry . Lime slurry will be measured by the ton (dry weight) as calculated from the minimum percent dry solids content of the slurry, multiplied by the weight of the slurry in tons delivered. 8.2.1.2. Quicklime . 8.2.1.2.1. Dry. Lime will be measured by the ton (dry weight) of the quicklime. 8.2.1.2.2. Slurry . Lime slurry will be measured by the ton (dry weight) of the quicklime used to prepare the slurry multiplied by a conversion factor of 1.28 to give the quantity of equivalent hydrated lime, which will be the basis of payment .
8.2.2 Cement . Cement will be measured by the ton (dry weight). When cement is furnished in trucks, the weight of
cement will be determined on certified scales, or the Contractor must provide a set of standard platform truck scales at a n approved location. Scales must meet the requirements of Item 520.
8.3 Foamed Asphalt Treatment . Foamed a sphalt treatment will be measured by the square yard of surface
area. The dimensions for determining the surface area are established by the widths shown on the plans and lengths measured at placement.
Article 9 — Payment
The work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for in accordance with Section 291.8.1., “Asphalt”; Section 291.8.2.1., “Lime”; Section 291.8.2.2., “Cement”; and Section 291.8.3., “Foamed Asphalt Treatment.” Furnishing and delivering new base will be paid for in accordance with Item 247, unless otherwise shown on the plans. 210 Furnishing and delivering fog seal will be paid for in accordance with Item 315, unless otherwise shown on the plans. Removal and disposal of existing asphalt concrete pavement will be paid for in accordance with pertinent Items or Article 4.4., “Changes in the Work.” Additives and foamed asphalt used for reworking a section will not be paid for directly, but will be subsidiary to this Item. Sprinkling and rolling, including proof rolling, will not be paid for directly, but will be subsidiary to this Item unless otherwise shown on the plans. Where subgrade is constructed under this Contract, correction of soft spots in the subgrade or existing base will be at the Contractor’s expense. Where subgrade is not constructed under this Contract, correction of soft spots in the subgrade or existing base will be in accordance with pertinent Items or Article 4.4., “Changes in the Work.” When an additional additive is required by the mixture design or required by the Engineer and not shown on the plans, it will be paid for in accordance with Article 4.4., “Changes in the Work.”
9.1 Asphalt . Asphalt will be paid for at the unit price bid. This price is full compensation for mat erials, delivery,
equipment, labor, tools, and incidentals.
9.2 Lime . Lime will be paid for at the unit price bid for one of the following types: “ Hydrated (Dry), ” “Hydrated
(Slurry), ” or “Commercial Lime Slurry. ” This price is full compensation for furnishing lime.
9.3 Cement . Cement will be paid for at the unit price bid. This price is full compensation for furnishing cement.
9.4 Foamed Asphalt Treatment . Foamed asphalt treatment will be paid for at the unit price bid for the depth
specified. No payment will be made for thickness or width exceeding those shown on the plans. This price is full compensation for shaping existing material, loosening, mixing, pulverizing, spr eading, applying additives and f oamed asphalt , compacting, finishing, curing, curing materials, blading, shaping and maintaining shape, replacing mixture, disposing of loosened materials, processing, hauling, preparing secondary subgrade, water, equipment, labor, tools, and incidentals.