5-31 Section 503. Paver -Placed Surface Seal
503.01. Description This work consists of the surface preparation and application of a paver -placed surface seal (PPSS). 503.02. Materials Provide materials in accordance with the following sections: Aggregate ................................................................................................ 902 Asphalt Emulsion , PPSS .......................................................................... 904 Asphalt Binder ......................................................................................... 904
A.Asphalt Binder Selection Criteria. Provide PG a sphalt binder in accordance with Table 503-1. Table 503- 1: Performance -Graded (PG) Asphalt Binder Selection Criteria Location PG Asphalt Binder North of M -72 in the Lower Peninsula and Upper P eninsula PG 64 -28P South of M -72 (including M -72) PG 70 -28P MDOT Metro Region only PG 70- 22P
B.PPSS Mixture Design . The mixture must be designed by a Department -approved laboratory. Design the mixture in accordance with Table 503-2 so the asphalt binder produces a film thickness of at least 10 microns. Calculate the film thickness in accordance with the National Center for Asphalt Technology ’s Hot Mix Asphalt Materials, Mixture Design and Construction. Submit the mix design to the Engineer at least 7 days before beginning construction. Do not use reclaimed material in the mixture.
C.Mixture Design Documentation. Provide the following documentation with the mixture design:
1.Contractor Bituminous Mix Design Communication (Form 1855) ;
2.Sample Identification, include with AWI sample (Form 1923) ;
3.Average maximum percent draindown for each test t emperature (report) ;
4.Tensile Strength Worksheet (Form 1937) ;
5.Calculation of film thickness ( report) ; MDOT Standard Specifications for Construction Section 503
5-32 6. The material sources for the mixture design; and
7.Test results verifying the mixture meets the requirements in Table 503-2 and the specified film thickness . Table 503- 2: Mixture Requirements Mix Type Aggregate % Asphalt Binder Content Draindown Test (% Max) AASHTO T305(a) Moisture Sensitivity (% Min) AASHTO T283(b) B 30SS 4.8–6.2 0.10 80 C 27SS 4.6–6.2 0.10 80
a.Conduct the draindown test at the JMF asphalt content plus 0.5%. Test the draindown at the mixing temperature plus 27°F but do not exceed 350°F.
b.Compact specimens for AASHTO T283 testing using the SGC at 100 gyrations with target dimensions of 6 inch diameter by 3¾ inch ± ⅛ inch height or 4 inch diameter by 2½ inch ± ⅛ inch height. Do not adjust the number of revolutions to target an air void range. Cure the loose bituminous surface course mixture 1 hour at the specified application temperature. The minimum time for vacuum saturation is 20 minutes. Subject specimens to freeze -thaw conditioning. If an anti -stripping agent is needed, report the amount and type with the mixture design. 503.03. Construction
A.Equipment
1.Self-Priming Machine . Provide a self -priming machine that spray s polymer modified emulsion membrane and places a PPSS over the membrane in a single pass, continuous application. The self -priming machine must not contact the polymer -modified emulsion membrane before applying the PPSS. The self -priming machine must incl ude the following:
a.A receiving hopper with at least two heated, twin screw, and mix-feed augers ;
b.An integral storage tank for the polymer -modified asphalt emulsion;
c.Twin expandable emulsion spray bars, immediately in front of the PPSS feed augers and ironi ng screed. The spray bars must be able to measure the application of polymer -modified asphalt emulsion and monitor the rate of spray across the width of the paving pass ; and
d.A variable-width vibratory heated ironing screed that is adjustable and capable of providing positive and negative crowns to the thickness and cross section shown on the plans.
2.Compacting Equipment . Use at least two 10-ton steel -wheeled rollers meeting the requirements in subsection 501.03.A.5. MDOT Standard Specifications for Construction Section 503
5-33 B. Pre-Production Meeting. Before beginning work, conduct an on-site
pre-production meeting with the Engineer to discuss the following:
1.Work schedule ;
2.Traffic control plan;
3.Equipment calibrations and adjustments ;
4.Condition of equipment ;
5.QC plan; and
6.Contractor ’s authorized representative.
C.Weather and Seasonal Limitations
1.Weather Limitations. Place PPSS on dry pavement. Do not place PPSS if the air temperature is below 50°F.
2.Seasonal Limitations. Place PPSS from May 1 to October 15.
D.PPSS Placement
1.Surface Preparation . Perform all surface preparation prior to applying the wearing course. Clean the existing surface of loose materials, vegetation, dirt, dust, mud, and other deleterious materials. Remove animal remains before placing the mixture. Protect drainage structures, monument boxes, water shut -offs, and other existing structures using tarpaper or other protective coverings approved by the Engineer. Remove the protective coverings before opening to traffic. Remove pavement markings.
2.Emulsion Membrane . Apply a polymer -modified asp halt emulsion membrane at a rate of 0.20 gallons per square yard. Field adjustments of the emulsion application rate for changes in existing pavement surface conditions or limitations of the HMA mix design will be allowed. Apply the polymer -modified asphal t emulsion membrane at a temperature from 140 to 175°F.
3.PPSS. Apply Type B surface course mixtures at a rate of 8 3 pounds per square yard and Type C surface course mixtures at a rate of 90 pounds per square yard. Use an application rate that provides a PPSS thickness that prevents the fracture of aggregate by the screed. Apply the PPSS mix at a temperature from 300 to 330°F and compact before the placed surface course cools to 185°F. MDOT Standard Specifications for Construction Section 503
5-34 4. Rough Joints . At no additional cost to the Department, repai r
transverse and longitudinal construction joints resulting from PPSS operations that cause bumps or poor riding joints, as determined by the Engineer. The repairs must meet the approval of the Engineer.
E.Quality Control . Prepare and implement a QC plan, in accordance with requirements of section 501, that will detail QC operations for production and construction. Submit the QC plan to the Engineer for review and approval before the pre-production meeting. Notify the Engineer immediately and stop mixture pr oduction if the QC test results exceed any tolerance shown in Table 503-3. Identify the cause of the deviation and determine the corrective action necessary to bring the mixture into compliance prior to resuming mixture placement. Perform, at a minimum, th e following QC tests .
1.PPSS Surface Course. Perform three yield checks each day to determine the application rate of the HMA surface course. The yield must be within 5 pounds per square yard of the target application rate.
2.PPSS Mixture. Take a sample of the PPSS mixture from the truck transports in accordance with ASTM D979/D979M and reduce the sample size in accordance with MTM 313. Test this sample before beginning production the following day. Test results must fall within the quality control tolerances s pecified in Table 503-3. Table 503- 3: PPSS Quality Control Tolerances Sieve Size Mix Type B Tolerance(a) Mix Type C Tolerance(a) ¾ inch — — ½ inch — ±5% ⅜ inch ±5% ±5% No. 4 ±5% ±5% No. 8 ±4% ±4% No. 200 ±1% ±1% PG asphalt binder content ±0.4% Film thickness 10 microns (min)
a.Tolerance in reference to values listed in Table 902 -7.
F.Acceptance. Review completed portions of the PPSS placement with the Engineer for compliance with the contract. If the Engineer determines the PPSS does not comply with the contract, repair defects at no additional cost to the Department. MDOT Standard Specifications for Construction Section 503
5-35 503.04. Measurement and Payment
Pay Item Pay Unit Paver -Placed Surface Seal, Type __ .................................... Square Yard The unit price for Paver -Placed Surface Seal , of the type required, includes the cost of preparing the surface, placing temporary pavement markings, and placing a membrane and paver placed surface seal course for full -width coverage, except that the Department will pay separ ately for removing pavement markings in accordance with subsection 812.04.
Source: Michigan Standard Specifications for Construction, 2020 Edition. Pages 290–294 of 1,146.