489ULTRA-THIN BONDED WEARING COURSE

489.1DESCRIPTION—This work is the construction of a polymer-modified emulsified asphalt membrane

(UTFCEM – Ultra-Thin Friction Course Emulsified Asphalt) immediately overlaid with an ultra- thin bonded wearing course of hot-mix asphalt concrete ( UTWC – Ultra-Thin Wearing Course) in one pass of a single paving machine.

489.2MATERIAL—

for Performance-Graded Asphalt Binder, AASHTO M 332, except as revised in Bulletin 25. Obtain material from an approved producer and source listed in Bulletin 15 for the specified grade and provide quality control testing and certification as specified in Sections 106.03(b) and 702.1(b)1.

producer and source listed in Bulletin 15 and provide quality control testing and certification as specified in Sections 106.03(b) and 702.1(b)1.

the requirements in Table A.

TABLE A FINE AGGREGATE PROPERTIES TEST TEST METHOD MINIMUM MAXIMUM Sand Equivalent AASHTO T 176 45 - Methylene Blue AASHTO T 330 - 10 Uncompacted Void Content AASHTO T 304 40 -

the requirements in Table B.

TABLE B COARSE AGGREGATE PROPERTIES TEST TEST METHOD AVERAGE DAILY TRAFFIC (ADT) < 5,000 5,000 < 20,000 > 20,000 Abrasion Max. % AASHTO T 96 35 30 30 Micro-Deval (MD)* Max. % AASHTO T 327 18 18 18 Skid Resistance Level (SRL) . Bulletin 14 G or higher H or higher E Absorption Max. % AASHTO T 85 2 2 2 Thin and Elongated Pieces Max. % ASTM D4791 10 10 10 Soundness Max. % PTM No. 510 10 10 10 Min % Crushed, 1 Face ASTM D5821 95 95 100 Min % Crushed, 2 Face ASTM D5821 85 85 85 *MD > 18, requires approval of DME/DMM.

Axle Loads (ESALs).

aggregate, coarse aggregate, filler, and asphalt binder. Size, uniformly grade, and combine aggregate fractions in such proportions that the total aggregate and the asphalt in the JMF conform to the composition specified in Table C, and meet the mixture characteristics of Table D.

TABLE D MIXTURE CHARACTERISTICS MIXTURE CHARACTERISTIC TEST METHOD MINIMUM MAXIMUM Moisture sensitivity, % TSR AASHTO T 283* 80 - Average % Draindown AASHTO T 305 - 0.1 Apparent Asphalt Film Thickness, microns Bul. 27, Sec 12.4.1 10.0 - *Prepare specimens according to Department's modified procedures for Superpave Mix Design, detailed in Bulletin 27, Chapter 2A referencing AASHTO R 35 Section 11, except:

void content of all specimens at a maximum difference of 1.0%).

to Bulletin 27.

Representative.

review at the start of the project and at least annually thereafter. Do not start work until the QC Plan has been reviewed and the JMF has been submitted. When unsatisfactory results or other conditions make it necessary, a new JMF may be required. If a change in sources of materials is made, submit a revised JMF to the DME/DMM before using any new material.

the mixture within the JMF tolerances specified in Table E.

TABLE C COMPOSITION, TOTAL PERCENT BY MASS (WEIGHT) PASSING SIEVE SIZE TYPE A TYPE B TYPE C 19.0 mm (3/4 inch) 100 100 100 12.5 mm (1/2 inch) 100 100 85 - 100 9.5 mm (3/8 inch) 100 75 - 100 65 - 85 6.3 mm (1/4 inch) 75 - 100 28 - 45 28 - 45 4.75 mm (No. 4) 40 - 60 23 - 37 23 - 37 2.36 mm (No. 8) 15 - 30 21 - 31 21 - 31 1.18 mm (No. 16) 12 - 20 15 - 23 15 - 23 600 µm (No. 30) 8 - 15 10 - 18 10 - 18 300 µm (No. 50) 6 - 12 8 - 14 8 - 14 150 µm (No. 100) 5 - 10 5 - 10 6 - 10 75 µm (No. 200) 4.0 – 6.5 4.0 – 6.5 4.0 – 6.5 Asphalt % by mass (weight) 4.5 - 5.8 4.5 - 5.7 4.5 - 5.7 Note: Material finer than the 75 µm (No. 200) sieve will be determined as per PTM No. 100.

TABLE E JMF TOLERANCE REQUIREMENTS OF COMPLETED MIX (n≥1) Percent Passing 9.5 mm (3/8 inch) and larger sieves ±5% Percent Passing 6.3 mm (1/4 inch) to 2.36 mm (No. 8) sieves ±4% Percent Passing 1.18 mm (No. 16) to 0.3 mm (No. 50) sieves ±3% Percent Passing 150 µm (No. 100) sieve ±2% Percent Passing 75µm (No. 200) sieve ±1.5% Asphalt % by mass ±0.5% TEMPERATURE OF MIXTURE (F) CLASS OF MATERIAL TYPE OF MATERIAL MINIMUM MAXIMUM PG 64S-22 Asphalt Binder 285 330 PG 64E-22 Asphalt Binder 295 340

the Inspector-In-Charge within 1 working day following any QC tests for asphalt determination and sieve analysis of the mixture. The mixture will be accepted by certification at the plant when quality control tests conform to the JMF within the tolerances specified in Table E. Acceptance by certification may be suspended if QC tests or QA samples obtained by QA Teams from the BOPD deviate from the tolerances in Table E for acceptance values. The acceptance values are:

• Asphalt Content by mass (weight),

• Percent passing the 75µm (No. 200) sieve,

• Percent passing the 2.36 mm (No. 8) sieve, and

• Percent passing the 6.3 mm (1/4 inch) sieve.

If at any time during the course of the work any acceptance values deviate from the tolerances in Table E in consecutive tests, immediately make necessary changes to comply with the JMF. If the material cannot be brought into compliance within 150 tons of production, suspend operations and notify the Inspector-In- Charge. Do not resume production for the project until the Representative has reviewed any corrective action. If the asphalt content or the percent passing the 75µm (No. 200) sieve deviates from the tolerances specified in Table E, the material represented will be considered defective and acceptance will be determined as specified in Section 413.3(o).

Certify each day’s shipment of material delivered to the job site.

489.3CONSTRUCTION—Section 413.3 with additions and modifications as follows:

Address in the QC plan material delivered to the paver as it relates to paver speed. Provide calculations to support material production, haul units used for delivery and paver speed to eliminate placement stoppages during laydown.

Do not place asphalt paving mixtures containing PG 64S-22 from November 1 to March 31 and asphalt paving mixtures containing PG 64E-22 from October 15 to March 31, unless allowed in writing by the District Executive. Do not place asphalt paving mixtures when the surfaces are wet or when the air or surface temperature is below 50F. If work is halted because of weather

conditions, the Representative may allow the Contractor to place limited quantities of mixture that are enroute to the project.

Use pavers that include a built -in spray bar placed in front of the variable- width heated screed unit, so that the operations of spreading UTFCEM and the UTWC are performed in succession, within a period of less than 5 seconds.

At least 24 hours before paving operations, seal longitudinal and transverse joints and cracks 1/4-inch and wider as specified in Section 469. Use rubberized sealant as specified in Section 469 and minimize the sealant over-band thickness and width. Do not exceed Section 469 over-band tolerances. Remove thermoplastic and tape traffic markings greater than 0.2 inches thick. Thoroughly clean pavements impregnated with grease, oil, or fuel. Immediately before applying the UTFCEM and the UTWC, clean the surface by sweeping or other means necessary to remove all loose particles and unsuitable material.

1.b Spreading and Finishing. Replace with the following:

Apply UTFCEM with a metered mechanical pressure sprayer, at a temperature of 120F to 180F. Continuously monitor the rate of spray, ensuring a uniform application rate over the entire width to be overlaid. Determine the spray rate given the existing pavement porosity and apply between 0.15 and 0.25 gallons per square yard. Do not allow wheels or other parts of the paving machine to come in contact with the UTFCEM before the UTWC is applied. Within 5 seconds of applying the UTFCEM, lay the UTWC within the temperature range specified in Section 489.2 Table E for the class and type of material used, and at the placement rate specified in Section

Table F.

Continuously adjust operations to obtain a quality surface free from drags marks, open areas or suspect quality. If adjustments do not obtain a quality surface free from visual surface segregation the Representative may direct work to stop. Areas identified by the Representative to have visual surface segregation are to be removed and replaced at no additional cost to the Department. Do not begin spreading and finishing until the Representative is satisfied with proposed corrective actions to provide a satisfactory surface.

TABLE F GRADATION TYPE NMAS PLACEMENT RATES FOR UTWC A 6.3 mm (1/4 inch) 45 to 65 pounds per square yard B 9.5 mm (3/8 inch) 55 to 80 pounds per square yard C 12.5 mm (1/2 inch) 60 to 85 pounds per square yard Note: Placement rates are intended as a guide and additional material may be required to obtain a quality surface. In no case should material yield be below the lower limits of the placement rate range.

Roll the UTWC immediately after placement and before the material temperature has fallen below 185F. Roll using a minimum of two passes with a steel double- drum asphalt roller having a mass of not less than 8 tons. Do not allow roller(s) to remain stationary on the fres hly placed UTWC. Maintain roller(s) in reliable operating condition and equipped with functioning water

system and scrapers to prevent adhesion of the fresh mix onto the roller drums. A release agent (added to the water system) may be required. Compact in the static mode, except joints where vibration may be necessary. A pneumatic-tire roller may be used to prevent the "bridging" effect of the steel drum roller.

joint(s) for surface courses with hot PG 64 S-22 asphalt cement at no additional cost to the Department. Heat and maintain asphalt cement sealant between 265F and 320F. Do not place sealant when the air temperature is below 40F, unless otherwise allowed by the Representative. Apply the sealant only to joints in pavement surfaces that are clean,, dry and free of any loose material and debris. Clean with a power broom as required. Utilize a pressure applicator with a wand or nozzle capable of applying hot asphalt sealant in a straight and consistent width band of 4 inches +/-1 inch and thickness of 1/16 inch +/- 1/32 inch. Center the sealant band within 1 inch of the joint. Remove and dispose of excess sealant at no additional cost to the Department. Re-seal areas of the joint that are inconsistently or not completely covered at no additional cost to the Department. Replace pavement markings that are marred by sealing operations at no additional cost to the Department.

forward paving wherever possible. Construct joints perpendicular to the direction of traffic and compact. If the QC plan proves ineffective for minimizing the number of transverse joints, stop paving and submit a plan for corrective action to the Representative. Do not begin paving until the Representative has reviewed the plan and authorizes paving to resume.

the depth of courses by the weight per square yard.

489.4MEASUREMENT AND PAYMENT—

For the type indicated.