BITUMINOUS TREATMENTS, SURFACE COURSES , AND CONCRETE PAVEMENT
300-1 Description.
Apply bituminous prime coats on previously prepared bases and apply bituminous tack coats on previously prepared bases and on existing pavement surfaces.
300-2 Materials.
300-2.1 Prime Coat: For prime coat, use a product listed on the Department’s Approved
Product List (APL), meeting the requirements of 916 -3, or other types and grades of bituminous material if specified in the Contract Documents. A copy of the Bill of Lading representing the material in the distributor tank must be in the truck and be always available. Where prime coats are to be diluted, certify the dilution was done in accordance with the specific dilution r equirements for each product and for each load of material used. The Contractor may select any approved prime coat unless the Contract Documents indicate the use of a specific material. The Engineer may allow types and grades of bituminous material other than those specified above if the Contractor can show the alternate material will properly perform the function of prime coat material.
300-2.2 Cover Material for Prime Coat: Uniformly cover the primed base by a light
application of cover material. The C ontractor may use either sand or screenings for the cover material. For the sand, meet the requirements as specified in 902 -2 or 902-6, and for the screenings, meet the requirements as specified in 902 -5. If the primed base course will be exposed to genera l traffic, apply a cover material coated with 2 to 4% asphalt cement. Apply the asphalt coated material at approximately 10 pounds per square yard. Roll the entire surface of asphalt coated prime material with a traffic roller as required to produce a reas onably dense mat.
300-2.3 Tack Coat: Unless the Contract Documents call for a specific type or grade of
tack coat, use PG 52 -28 meeting the requirements of 916 -2, heated to a temperature from 250 to 300ºF or use an undiluted emulsion listed on the APL, me eting the requirements of 916 -3. Heat the emulsion to the temperature recommended by the tack coat manufacturer. A copy of the Bill of Lading representing the material in the distributor tank must be in the truck and be always available. For night paving , use PG 52-28 tack coat. The Engineer may approve an emulsified tack coat for night paving if the Contractor demonstrates, at the time of use, the emulsion will break and not affect the progress of the paving operation.
300-3 Equipment.
300-3.1 Pressure Distributor: Provide a pressure distributor equipped with pneumatic
tires having a sufficient width of rubber in contact with the road surface to avoid breaking the bond or forming a rut in the surface. Ensure the distance between the centers of openings o f the outside nozzles of the spray bar is equal to the width of the application required, plus or minus two inches. Ensure the outside nozzle at each end of the spray bar has an area of opening greater than the opening of an interior nozzle by 25% to 75%. Ensure all other nozzles have uniform openings. When the application covers less than the full width, the Contractor may allow the FY 2023-24 Return to Table of Contents normal opening of the end nozzle at the junction line to remain the same as the interior nozzles. A trailer-mounted pressure distributor can be used for non -mainline applications, if approved by the Engineer. It shall have a self -contained heat system, clean out system, calibration chart, manhole, and shall meet the requirements herein. Clean the distributor tank at a minimum of every twelve months and whenever the product type in the tank is changed. Remove all emulsion and asphalt material during cleaning. Additionally, clean the distributor tank if the quality of the tack or prime shot diminishes or buildup causes the calibr ation of the tank to be affected.
300-3.2 Sampling Device: Equip all pressure distributors and transport tanks with an
approved spigot -type sampling device.
300-3.3 Temperature Sensing Device: Equip all pressure distributors and transport
tanks with an approved dial type thermometer. Use a thermometer with a temperature range from 50 to 500ºF, no greater than 25ºF increments, and a minimum dial diameter of two inches. Locate the thermometer near the midpoint of the tank’s length and within the middle third of the tank’s height, or as specified by the manufacturer (if in a safe and easily accessible location). Enclose the thermometer in a well with a protective window or by other means as necessary to keep the instrument clean and in the proper working condition.
300-4 Contractor’s Quality Control.
Provide the necessary quality control of the prime and tack coats and application in accordance with the Contract requirements. If the application rate varies by more than 0.01 gallon per square yard from the rate set by the Engineer or varies beyond the range established in 300 -7 or 300-8, immediately make all corrections necessary to bring the application rate into the acceptable range. The Engineer may take additional measurements at any time. The Engineer will randomly check the Contractor’s measurement to verify the application rate.
300-5 Cleaning Base and Protection of Adjacent Work.
Before applying any bituminous material, remove all loose material, dust, sand, dirt, caked clay, and other foreign mate rial which might prevent proper bond with the existing surface for the full width of the application. Take particular care in cleaning the outer edges of the strip to be treated, to ensure the prime or tack coat will adhere. When applying prime or tack co at adjacent to curb and gutter, valley gutter, or any other concrete surfaces, cover such concrete surfaces, except where they are to be covered with a bituminous wearing course, with heavy paper or otherwise protect them as approved by the Engineer, while applying prime or tack coat. Remove any bituminous material deposited on such concrete surfaces.
300-6 Weather Limitations .
Do not apply prime and tack coats when the air temperature in the shade and away from artificial heat is less than 40ºF at the loc ation where the application is to be made or when weather conditions or the surface conditions are otherwise unfavorable.
300-7 Application of Prime Coat.
300-7.1 General: Clean the surface to be primed and ensure the moisture content of the
base does not exceed the optimum moisture. Heat the prime coat material to the temperature FY 2023-24 Return to Table of Contents recommended by the prime coat manufacturer. Apply the material with a pressure distributor. Determine the application amount based on the character of the surface. Use an amount sufficient to coat the surface thoroughly and uniformly with no excess.
300-7.2 Application Rate: Use an application rate as defined in Table 300-1. Control the
application rate within the minimum and plus 0.01 gallon per square yard of the minimum application rate. The minimum application rate may be adjusted by the Engineer to meet specific field conditions. Determine and record the application rate a minimum of twice per day, once at the beginning of each day’s production and, as needed, to control the operation. Table 300-1 Prime Coat - Minimum Application Rates Base Type Minimum Application Rate (gal/yd2) Limerock, Limerock Stabilized, Shell-Rock, Recycled Concrete Aggregate and Local Rock Bases 0.10 Sand-Clay, Cemented Coquina, Shell, and Shell Stabilized Bases 0.15
300-7.3 Sprinkling: If required by the Engineer, lightly sprinkle the base with water and
roll it with a traffic roller in advance of the prime coat application.
300-7.4 Partial Width of Application: If traffic conditions warrant, the Engineer may
require the application be made on only one -half the width of the base at one time, in which case, use positive means to secure the correct amount of bituminous material at the joint.
300-8 Application of Tack Coat.
300-8.1 General: Where the Engineer requires a tack coat prior to laying a bituminous
surface, apply the tack coat as specified herein below. Coat the surface completely and uniformly with tack.
300-8.2 Where Required: Place a tack coat on all asphalt layers prior to constructing the
next course. In general, the Engine er will not require a tack coat on primed bases except in areas that have become excessively dirty and cannot be cleaned, or in areas where the prime has cured to the extent all bonding effect has been lost .
300-8.3 Method of Application: Apply the tack c oat with a pressure distributor except
on small jobs, if approved by the Engineer, apply it by other mechanical devices or by hand methods. Heat the bituminous material to a suitable temperature as designated by the supplier.
300-8.4 Application Rate: Use an application rate defined in Table 300-2. Control the
application rate within plus or minus 0.01 gallon per square yard of the target application rate. The target application rate may be adjusted by the Engineer to meet specific field conditions. Determine and record the application rate a minimum of twice per day, once at the beginning of each day’s production and again , as needed, to control the operation. When using PG 52-28, multiply the target application rate by 0.6. FY 2023-24 Return to Table of Contents Table 300-2 Tack Coat Application Rates Asphalt Mixture Type Underlying Pavement Surface Target Tack Rate (gal/yd2)1 Base Course, Structural Course, Dense-Graded Friction Course, Open-Graded Friction Course Newly Constructed Asphalt Layers 0.06 Milled Asphalt Pavement Surface, Oxidized and Cracked Asphalt Pavement, Concrete Pavement 0.09 Note 1: Target tack application rates greater than those specified may be used upon approval of the Engineer. When using a meter to control the tack or prime application rate, manually measure the volume in the tank at the beginning and end of the application area for a specific target application rate. Perform this operation at a minimum frequency of once per pro duction shift. Resolve any differences between the manually measured method and the meter to ensure the target application rate is met in accordance with this Section. Adjust the application rate if the manually measured application rate is greater than plus 0.02 or minus 0.01 gallons per square yard when compared to the target application rate.
300-8.5 Curing and Time of Application: When using a distributor, a pply tack coat
sufficiently in advance of placing bituminous mix to permit drying, but do not apply tack coat so far in advance that it might lose its adhesiveness as a result of being covered with dust or other foreign material. When using a spray paver, the requirements above do not apply.
300-8.6 Protection: Keep the tack coat surface free from traffic until the subsequent
layer of bituminous hot mix has been laid.
300-9 Method of Measurement.
300-9.1 General: The quantity specified will be the volume, in gallons , of bituminous
material actually appl ied and accepted. This application rate will be determined from measurements made by the Contractor and verified by the Engineer based on tank calibrations, as specified in 300 -9.2. Where it is specified prime coat material is to be diluted with water, the amount specified for the application rate will be the volume after dilution.
300-9.2 Calibration of Tanks: Ensure all distributors used for applying tack or prime
coats are calibrated prior to use by a reliable and recognized firm engaged in calibrating tanks. Submit a certification of calibration and the calibration chart to the Engineer prior to use. In lieu of a volumetrically calibrated distributor, use a distributor equipped with a calibrated meter approved by the Engineer.
300-9.3 Temperature Corre ction: Measure the volume and increase or decrease the
volume actually measured to a corrected volume at a temperature of 60ºF. Make the correction for temperature by applying the applicable conversion factor (K), as shown below. For petroleum oils hav ing a specific gravity above 0.966 at 60°F, K = 0.00035 per degree. For petroleum oils having a specific gravity of between 0.850 and 0.966 at 60°F, K = 0.00040 per degree. For emulsified asphalt, K = 0.00025 per degree. When volume -correction tables based on the above conversion factors are not available, use the following formula in computing the corrections for volumetric change: FY 2023-24 Return to Table of Contents 1 + 60) - (T KV = V1 Where: V= Volume of bituminous material at 60ºF (pay volume). V1= Volume of bituminous material as measured. K= Correction factor (Coefficient of Expansion). T= Temperature (in ºF), of bituminous material when measured.
300-10 Basis of Payment .
There is no direct payment for the work specified in this Section, it is incidental to, and is to be included in the other items of related work. FY 2023-24 Return to Table of Contents SECTION 320 HOT MIX ASPHALT - PLANT METHODS AND EQUIPMENT
320-1 General.
This Section specifies the basic equipment and operational requirements for hot mix asphalt (including warm mix asphalt) production facilities used in the construction of asphalt pavements and bases. Establish and maintain a quality control system that provides assurance that all materials and products submitted for acceptance meet Contract requirements.
320-2 Quality Control (QC) Requirements.
320-2.1 Minimum Producer QC Requirements: Perform as a minimum the following
activities:
1.Stockpiles:
a.Assure materials are placed in the correct stockpile;
b.Assure good stockpiling techniques;
c.Inspect stockpiles for separation, contamination, segregation, and other similar items ;
d.Properly identify and label each stockpile.
2.Incoming Aggregate:
a.Obtain gradations and bulk specific gravity (G sb) values from aggregate supplier for reference ;
b.Determine the gradation of all component materials and routinely compare gradations and G sb values to mix design.
3.Cold Bins:
a.Calibrate the cold gate/feeder belt for each material;
b.Determine cold gate/feeder belt settings;
c.Observe operation of cold feeder for uniformity ;
d.Verify accuracy of all settings ;
e.Verify that the correct components are being used, an d that all modifiers or additives or both are being incorporated into the mix .
4.Batch Plants :
a.Determine percent used and weight to be pulled from each bin to assure compliance with the mix design;
b.Check mixing time ;
c.Check operations o f weigh bucket and scales.
5.Drum Mixer Plants :
a.Determine aggregate moisture content ;
b.Calibrate the weigh bridge on the charging conveyor.
6.Control Charts: Maintain QC data and charts (updated daily ) for all QC Sampling and Testing and make available upon demand . Provide the following charts:
a.All components used to determine the composite pay factor (No. 8 sieve, No. 200 sieve, asphalt binder content, air voids, and density);
b.Gradation of incoming ag gregate;
c.Gradation, asphalt binder content and maximum specific gravity (G mm) of RAP; FY 2023-24 Return to Table of Contents
Source: Florida Standard Specifications for Road and Bridge Construction, 2024 Edition. Pages 266–270 of 1,299.