2353Ultrathin Bonded Wearing Course

2353.1DESCRIPTION

This Work is the construction of an ultrathin bonded wearing course (UTBWC) on a prepared pavement. An ultrathin bonded wearing course is the application of a polymer modified emulsion membrane followed immediately with an ultrathin wearing course mixture.

2353.2MATERIALS

A Bituminous Materials A.1 Polymer Modified Emulsion Membrane ............................................................ 3151.2G Use a performance graded binder, PG 58V-34 B Aggregate ........................................................................................................................ 3139.2C B.1 Mineral Filler ............................................................................................ AASHTO M 17 C Mix Design Contractor shall design the UTBWC mixture to meet the requirements of this section. For optimum binder content the mixture shall meet the requirements in Table 2353.2-1. Each design shall include the additional design trial points that bracket the optimum AC content and with at least one point at 0.4 above and below the optimum AC content. Draindown testing and adjusted asphalt film thickness (Adj. AFT) determinations are required on these trial points. D Mix Design Submittal Submit a proposed job mix formula (JMF) in writing to the Department Bituminous Engineer for review as specified meeting the requirements in Table 3139.2-9 and Table 2353.2-1 and include the following:

Aggregate) of both coarse and fine Aggregate, for each product used in the mixture (including RAP/RAS). Use Laboratory Manual Method 1204 and 1205. The tolerance allowed between the Contractor's and the Department's specific gravities are Gsb

3139.2-7 to Table 3139.2-9

optimum AC point Table 2353.2-1 UTBWC Mixture Requirements Test Criteria Test Reference Asphalt Content 4.8-6.0 Laboratory Manual Methods 1853 or 1852 Adj. AFT (Calculated) 10.5 micrometer minimum Laboratory Manual Method 1854 Draindown Test 0.10 percent maximum AASHTO T 305 Lottman (TSR) 80 percent minimum, 7-8 percent voids Laboratory Manual Method 1813 D.1 Job Mix Formula Properties Base gradation, asphalt binder content, and adjusted AFT on the current Department reviewed mixture design report. The JMF limits are the target plus or minus the limits in accordance with Table 2353.2-2. Use JMF limits as the criteria for acceptance of Materials based on individual sample testing. Stop production if the test results vary from the JMF by more than the limits in Table 2353.2-2. Identify the cause and document in detail the corrective action. The JMF may only be adjusted if the revised JMF meets the mixture requirements in Table 2353.2-1 and Table 3139.2-9. Do not resume paving until brought back into Specification limits. Table 2353.2-2 UTBWC JMF Limits Gradation Broad Band Limits Asphalt Content ±0.4* Adj. AFT -0.5* *Note: The above limits shall not exceed the UTBWC mixture requirements in Table 2353.2-1 D.2 JMF Adjustments The Contractor may make a request to the Bituminous or District Materials Engineer for a JMF adjustment if the QC test results indicate a necessary change to the design . A Certified Level II Bituminous QM Mix Designer will review the requested change for the Department . If the request meets the requirements in Table 3139.2-9 and Table 2353.2-1 a revised Mixture Design Report will be issued.

2353.3CONSTRUCTION REQUIREMENTS

A Weather Restrictions The pavement surface temperature and ambient air temperature shall be at least 50 °F. A damp pavement surface is acceptable, if it is free of standing water and favorable weather conditions are expected. B Surface Preparation Complete the following Incidental Work before the paving operations. Remove thermoplastic and tape traffic markings greater than 0.2 inches thick. Protect with plastic or building felt manhole covers, drains, grates, catch basins, and other utility Structures. Clean the pavement surface. C Equipment Use a paver designed and built for the purpose of applying the ultrathin bonded wearing course. The paving machine shall incorporate a receiving hopper, feed conveyor, a storage tank for polymer modified emulsion membrane, polymer modified emulsion membrane spray bar and a variable width, and heated vibratory or tamper bar screed. The screed shall have the ability to crown the pavement at the center both positively and negatively and have vertically adjustable extensions to accommodate the desired pavement profile. D Paving Mixture must be produced by a certified plant. Apply the polymer modified emulsion membrane and the ultrathin bonded wearing course in one pass. Spray the polymer modified emulsion membrane so it is not driven on immediately before the application of the UTBWC. Use a metered mechanical pressure spray bar at a temperature of 120 – 180°F. Accurately and continuously monitor the rate of spray and provide a uniform application across the entire pavement width. Use a spray rate in the range of 0.20 gallons per square yard ± 0.07 gallons per square yard. Make adjustments based upon the existing pavement surface conditions and recommendations of the polymer modified emulsion membrane supplier. Apply the UTBWC at a temperature of 290 -330°F as measured in front of the screed. No wheel or other part of the paving machine shall come in contact with the polymer modified emulsion membrane before the UTBWC is applied. Use a heated vibratory or tamper bar screed. Open the new pavement to traffic after the rolling operation is complete and the Material has cooled below 158°F. E Thickness The minimum finished wearing course thickness is 5/8 inch with a maximum 1/2 inch vertical edge at the adjacent Shoulder pavement edge. F Rolling Roll the wearing course a minimum of two passes, before the Material temperature has fallen below 185°F. Use steel double drum asphalt rollers with a minimum weight of 11 tons. Do not allow the roller(s) to remain stationary on the freshly placed UTBWC. Roll in static mode only immediately following the placement of the UTBWC in order to seat the mix. G Pavement Smoothness After placement, the ultrathin bonded wearing surface shall show no variation greater than 1/8 inch from the edge of a 10 foot straightedge laid parallel to or at right angles to the centerline. Evaluation of pavement surface Smoothness, per 2399, “Pavement Surface Smoothness,” is required only when UTBWC is placed over a new Lift(s) of asphalt. When 2399, “Pavement Surface Smoothness,” is required make the following modification.

Replace section 2399.3C.2, “Areas of Localized Roughness,” with the following: ALR will be evaluated only on the asphalt pavement placed prior to the placement of the UTBWC. Identify ALR using the ProVAL “Smoothness Assurance” module, calculating MRI with a continuous short interval of 25 feet, with a 250 millimeter filter applied. Smoothness will not be evaluated on the asphalt pavement under the UTBWC. H Quality Control The Contractor is responsible for Quality Control (QC) sampling and testing as per the Schedule of Materials Control. I Polymer Modified Emulsion Membrane Verify the application rate of the polymer modified emulsion membrane by dividing the volume of polymer modified emulsion membrane used by the area of paving for that day. J Quality Assurance The Engineer is responsible for Quality Assurance (QA) sampling according to Schedule of Materials Control. The QA sample is the Department’s companion sample to the Contractor’s QC sample and tested as required. J.1 Verification Sampling and Testing The Department will test at a minimum 1 verification sample per day to assure compliance of the Contractor's QC program. The Department will decide daily, which QC/QA companion samples are to be submitted and tested as the verification sample. The verification sample can be any one or all of the QC/QA split samples. In addition, the Engineer may obtain additional verification samples at any time and location during production to determine quality levels of the mixture. When additional verification samples are taken, the Department will provide the Contractor a verification companion. The Contractor is required to test and use this verification companion sample as part of the QC program. Use the verification companion sample to replace the next scheduled QC sample. Compare the verification companion sample to the verification sample for compliance with allowable tolerances in Table 2353.3-1. The Department’s verification test results will be available to the Contractor within two Working Days from the time the sample is delivered to the district laboratory. If the tolerances between the Contractor’s verification companion sample and the Department’s verification sample do not meet the requirements of Table 2353.3-1, the Department will retest the Material. If the retests fail to meet tolerances, the Department will substitute the Department's verification test results for the Contractor’s results in the QC program and use those results for acceptance. The Department will only substitute the out -of- tolerance parameters. The Department will test the previously collected QA samples until they meet the tolerances or until the Department has tested all of the remaining samples. After testing the samples, the Department will test QA samples subsequent to the verification sampl e until tolerances are met. If the adjusted AFT calculation does not meet the tolerance in Table 2353.3-1, equalize the Departments adjusted AFT result by increasing the original Department value by 0.5 microns. The increased Department adjusted AFT will be the basis for acceptance.

The Department will base acceptance on QC data with substitution of Department test results for those parameters that are out of tolerance. Cease mixture production and placement if reestablished test results do not meet tolerances within 48 hours. Resume production and placement only after meeting the tolerances. Table 2353.3-1 Allowable Differences between Contractor and Department Test Results Test Item Allowable Difference Asphalt Binder Chemical Extraction Incinerator Oven 0.4 0.3 Mixture maximum gravity (Gmm) Rice Test 0.019 Adjusted AFT

Gradation Percent Passing 3/8 inch 6 percent No. 4 5 percent No. 8 No. 16 No. 30 4 percent No. 50 3 percent No. 100 2 percent No. 200 1.2 percent

2353.4METHOD OF MEASUREMENT

Measure the Ultrathin Bonded Wearing Course by area of pavement surfaced.

2353.5BASIS OF PAYMENT

Payment for the accepted quantity of Ultrathin Bonded Wearing Course at the Contract U nit Price of measure will be compensation in full for all costs of furnishing and applying all Materials required in this section. The Unit Price includes all labor, Materials, and Equipment necessary to complete the Work. A Monetary Adjustments The Department must apply Incentives and Disincentives and may apply monetary deductions for Ultrathin Bonded Wearing Course. The amounts of these adjustments are deemed reasonable. Replace the first paragraph in section 2399.3D.1, “Smoothness,” with the following: Evaluate Smoothness after the UTBWC is placed using the following tables:

ALR will not be evaluated on the UTBWC. Replace the second and third paragraphs in 2399.3E, “Corrective Work,” with the following: Perform any corrective Work for ALR on the asphalt pavement placed before the UTBWC is paved. No corrective Work is allowed on the UTBWC. A.1 Pavement Smoothness Any Smoothness value on the UTBWC indicating corrective Work may be assessed a monetary deduction of $400.00 per 0.1 mile segment.

A.2 Failures The Department will base Material acceptance on individual test results and those exceeding the JMF limits as failing. The Department will apply monetary deductions for failing tests in accordance to Table 2353.5-1. The Department will calculate the quantity of unacceptable Material on the tonnage placed from the sample point of the failing test to the sample point when the testing result is back within the JMF. If the failure occurs at the first test after the start of daily production, the Department will include tonnage from the start of production that day with the tonnage subjected to reduced payment. If an individual failing test for percent asphalt binder content, adjusted AFT, or gradation exceeds the limits in Table 2353.2-1, or Table 3139.2-9 then the mix will be subject to an assessment according to Table 2353.5-1. Table 2353.5-1 UTBWC Monetary Deduction Schedule Item Percent * Asphalt Content, percent 20 Adjusted AFT ≥ 10.5 0 Adjusted AFT 10.4 to 10.0 10 Adjusted AFT 9.9 to 9.1 25 Adjusted AFT ≤ 9.0 R & R ǁ Gradation 5 * Highest monetary deduction applies when there are multiple deductions on a single test. ǁ Remove and replace at no expense to Department.

The Department will reduce payment if the mat thickness is less than 5/8 inch, or greater than 1 inch, or the pavement edge is greater than 1/2 inch. Any mixture placed outside of this requirement will be assessed a 50 percent pay reduction or removed and replaced, as determined by the Engineer, full width, by station. B Schedule The Department will pay for the Ultrathin bonded wearing course on the basis of the following schedule: Item No. Item Unit

2353.504 Ultrathin Bonded Wearing Course Square yard