Article 1 — Description
Construct a surface treatment consisting of one or more applications of a single layer of asphalt material covered with a single layer of aggregate.
Article 2 — Materials
Furnish materials of the type and grade shown on the plans in conformance with the following .
2.1 Asphalt . Furnish asphalt materials meeting the requirements of Item 300, “Asphalts, Oils, and Emulsions.”
Furnish Type II or Type III asphalt -rubber ( A-R) binder in accordance with Section 300.2.10., “Asphalt - Rubber Binders,” as shown on the plans. Furnish a blend design for approval. Include in the design, at a minimum, the following: manufacturer and grade of asphalt cement; manufacturer and grade of crumb rubber; manufacturer, type, and percentage of extender oil, if used; test report pertinent to crumb rubber gradation in accordance with Tex-200-F , Part I; design percentage of crumb rubber versus asphalt content; blending temperature; and test results pertinent to the properties at reaction times of 60, 90, 240, 360, and 1,440 min. in accordance with Section 300.2. 10., “Asphalt -Rubber Binders.” Furnish a new A-R blend design if the grade or source for any of the components changes. If a tack coat is specified when using A-R , unless otherwise shown on the plans or approved, furnish CSS- 1H, SS -1H, or a performance- grade (PG) binder with a minimum high- temperature grade of PG 58 for tack coat binder. Do not dilute emulsified asphalts at the terminal, in the field, or at any other location before use. If required, verify that emulsified asphalt proposed for use meets the minimum residual asphalt percentage specified in Item 300.
2.2 Aggregate . Furnish aggregate meeting Item 302, “Aggregates for Surface Treatments,” of the type and
grade shown on the plans. Unless otherwise shown on the plans, furnish aggregate with a minimum Surface Aggregate Classification B.
2.3 Materials Selections. Furnish asphalt and aggregate as shown on the plans.
Article 3 — Equipment
3.1 Distributor . Furnish a distributor that will apply the asphalt material uniformly at the specified rate or as
directed.
3.1.1 Transverse Variable Rate. When a transverse variable rate is shown on the plans, ensure that the nozzles
outside the wheel paths will output a predetermined percentage more asphalt material by volume than the nozzles over the wheel paths. Use a dual spray bar distributor as desired to provide for a transverse variable rate. 254 3.1.2. Agitation for Asphalt- Rubber . If using A-R , furnish a distributor capable of keeping the rubber in uniform suspension and adequately mixing the asphalt, rubber, and any additional additives.
3.1.3 Calibration .
3.1.3.1. Transverse D istribution. Furnish a distributor test report , less than 1 yr. old , when tested in accordance with Tex-922-K , Part III. The Dep artment reserves the right to witness the calibration testing. Notify the Engineer 3 days before calibration testing. Include the following documentation i n the test report: the serial number of the distributor, a method that identifies the actual nozzle set used in the test, and the fan width of the nozzle set at a 12- in. bar height. When a transverse variable rate is required, and a single spray bar is to be used, perform the test using the type and grade of asphalt material to be used on the project. The Engineer may verify the transverse rate and distribution at any time. If verification does not meet the requirements, correct deficiencies and furnish a new test report. 3.1.3.2. Tank Volume . Furnish a volumetric calibration and strap stick for the distributor tank in accordance with Tex-922-K , Part I. Provide documentation of distributor calibration performed no more than 5 yr. before the date first used on the project. The Engineer may verify calibration accuracy in accordance with Tex -922-K , Part II.
3.1.4 Computerized Distributor . When paying for asphalt material by weight, the Engineer may allow use of the
computerized distributor display to verify application rates. Verify application rate accuracy at a frequency acceptable to the Engineer.
3.2 Aggregate Spreader . Use a continuous -feed, self -propelled spreader to apply aggregate uniformly at the
specified rate or as directed. If racked- in aggregate is shown on the plans, furnish a second aggregate spreader for the racked- in aggregate to apply aggregate uniformly at the specified rate.
3.3 Rollers. Unless otherwise shown on the plans, furnish light pneumatic -tire rollers in accordance with
Item 210, “Rolling.”
3.4 Broom . Furnish rotary, self -propelled brooms.
3.5 Asphalt Storage and Handling Equipment . When the plan or the Engineer allows storage tanks, furnish a
thermometer in each tank to indicate the asphalt temperature continuously. Keep equipment clean and free of leaks. Keep asphalt material free of contamination.
3.6 Aggregate Haul Trucks. Unless otherwise approved, use trucks of uniform capacity to deliver the
aggregate. Provide documentation showing measurements and calculation in cubic yards. Clearly mark the calibrated level. Truck size may be limited when shown on the plans.
3.7 Digital Distance -Measuring Instrument . Furnish a vehicle with a calibrated digital distance-measuring
instrument accurate to ±6 ft. per mile.
Article 4 — Construction
4.1 General . Comply with the seal coat season as shown on the plans. Asphalt and aggregate rates shown on
the plans are for estimating purposes only. Adjust the rates for existing conditions as directed. 255 4.2. Temporary Aggregate Stockpiles . The Engineer will approve the location of temporary aggregate stockpiles on the right of way before delivery. Place stockpiles in a manner that will not: obstruct traffic or sight distance, interfere with the access from abutting property, or interfere with roadway drainage. Locate stockpiles at least 30 ft. from roadway when possible. Sign and barricade as shown on the plans.
4.3 Aggregate Furnished by the Department . When shown on the plans, the Department will furnish
aggregate to the Contractor without cost. St ockpile locations are shown on the plans.
4.4 Adverse Weather Conditions. Do not place surface treatments when, in the Engineer’s opinion, general
weather conditions are unsuitable. Meet the requirements for air and surface temperature shown below.
4.4.1 Standard Te mperature Limitations. Apply seal coat when air temperature is above 50°F and rising. Do not
apply seal coat when air temperature is 60°F and falling. In all cases, do not apply seal coat when surface temperature is below 60°F.
4.4.2 Polymer -Modified Asphalt Cement Temperature Limita tions . When using materials described in
Section 300.2.2., “Polymer -Modified Asphalt Cement,” apply seal coat when air temperature is above 70°F and rising. Do not apply seal coat when air temperature is 80°F and falling. In all cases, do not apply seal coat when surface temperature is below 70°F.
4.4.3 Asphalt -Rubber Temperature Limitations . Do not place hot A -R seal coat when, in the Engineer’s opinion,
general weather conditions are unsuitable. Apply seal coat when the air temperature is 80°F and above, or above 70°F and rising. In all cases, do not apply seal coat when surface temperature is below 70°F.
4.4.4 Cool Weather Night Air Temperature . The Engineer reserves the right to review the National Oceanic and
Atmospheric Administration (NOAA ) weather forecast and determine whether the nightly air temperature is suitable for asphalt placement to prevent aggregate loss.
4.4.5 Cold Weather Application. When asphalt application is allowed outside the above temperature restrictions,
the Engineer will approve the binder grade and the air and surface temperatures for asphalt material application. Apply seal coat at air and surface temperatures as directed.
4.5 Mixing Hot A -R Binder . If using A-R, mix in accordance with the approved blend design required in
At the end of each shift, provide the Engineer with production documentation that includes the following: amount and temperature of asphalt cement before addition of rubber, amount of rubber and any extender added, viscosity of each hot A -R batch just before roadway placement, and time of the rubber additions and viscosity tests.
4.6 Surface Preparation . Remove existing raised pavement markers. Repair any damage incurred by removal
as directed. Remove dirt, dust, or other harmful material before sealing. When shown on the plans, remove vegetation and blade pavement edges. When directed, apply a tack coat before applying the hot A -R treatment on an existing wearing surface in accordance with Section 341.4.7.2., “Tack Coat.” 256 4.7. Rock Land and Shot .
4.7.1 Definition s.
Rock Land . The area covered at the aggregate rate directed with one truckload of aggregate. Shot . The area covered by one distributor load of asphalt material.
4.7.2 Setting Lengths . Calculate the lengths of both rock land and shot. Adjust shot length to be an even multiple
of the rock land. Verify that the distributor has enough asphalt material to complete the entire shot length. Mark shot length before applying asphalt. When directed, mark length of each rock land to verify the aggregate rate.
4.8 Asphalt Placement .
4.8.1 General . The maximum shot width is the width of the current transverse distribution test required under
Section 316.3.1.3.1., “Transverse Distribution,” or the width of the aggregate spreader box, whichever is less. Adjust the shot width so operations do not encroach on traffic or interfere with the traffic control plan, as directed. Use paper or other approved material at the beginning and end of each shot to construct a str aight transverse joint and to prevent overlapping of the asphalt. Unless otherwise approved, match longitudinal joints with the lane lines. The Engineer may require a string line if necessary to keep joints straight with no overlapping. Use enough pressure to flare the nozzles fully. Select an application temperature, as approved, in accordance with Item 300. Uniformly apply the asphalt material at the rate directed, within 15°F of the approved temperature, and not above the maximum allowable temperature.
4.8.2 Limitations . Do not apply asphalt to the roadway until:
traffic control methods and devices are in place as shown on the plans or as directed, the loaded aggregate spreader is in position and ready to begin, haul trucks are loaded with enough aggregate to cover the shot area and are in place behind the spreader box, and rollers are in place behind the haul trucks.
4.8.3 Nonuniform Application. Stop application if it is not uniform due to streaking, ridging, puddling, or flowing
off the roadway surface. Verify equipment condition, operating procedures, application temperature, and material properties. Determine and correct the cause of nonuniform application. If the cause is high- or low - emulsion viscosity, replace emulsion with material that corrects the problem.
4.8.4 Test Strips. The Engineer may stop asphalt application and require construction of test strips at the
Contractor’s expense if any of the following occurs: nonuniformity of application continues after corrective action; on three consecutive shots, application rate differs by more than 0.03 gal. per square yard from the rate directed; or any shot differs by more than 0.05 gal. per square yard from the rate directed. The Engineer will approve the test strip location. The Engineer may require additional test strips until surface treatment application meets specification requirements.
4.8.5 Sampling . Collect all samples in accordance with Tex -500-C
from the distributor and with witness by the Engineer. At least once per project, collect split samples of each binder grade and source used. The Engineer will submit one split sample to the Materials and Tests Division (MTD) for testing and retain the other split sample. 257 In addition, collect one sample of each binder grade and source used on the project for each production day. The Engineer will retain these samples. The Engineer will keep all retained samples for 1 yr. for hot -applied binders and cutback asphalts, or for 2 mo. for emulsified asphalts. The Engineer may submit retained samples to MTD for testing as necessary or as requested by MTD. The Department will furnish sampling containers in accordance with Tex -500-C .
4.9 Aggregate Placement . As soon as possible, apply aggregate uniformly at the rate directed without causing
the rock to roll over.
4.9.1 Nonuniform Application. Stop application if it is not uniform in the transverse direction. Verify equipment
condition, operating procedures, and transverse application rate. The transverse application rate should be within 1 lb. Determine and correct the cause of nonuniform application.
4.10 Rolling . Start rolling operation on each shot as soon as aggregate is applied. Use enough rollers to cover
the entire mat width in one pass ; i.e., one direction. Roll in a staggered pattern. Unless otherwise shown on the plans, make at least : five passes or three passes when the asphalt material is an emulsion. If rollers are unable to keep up with the spreader box, stop application until rollers have caught up, or furnish additional rollers. Keep roller tires asphalt -free.
4.11 Patching . Before rolling, repair spots where coverage is incomplete. Repair can be made by hand spotting
or other approved method. When necessary, apply additional asphalt material to embed aggregate.
4.12 Racked -In Aggregate . If specified on the plans, apply racked- in aggregate after patching, uniformly at the
rate directed. The racked- in aggregate must be applied before opening the roadway or intersection to traffic .
4.13 Brooming. After rolling, sweep as soon as aggregate has sufficiently bonded to remove excess. In areas of
racked- in aggregate, sweep as directed.
4.14 Final Acceptance. Maintain seal coat until the Engineer accepts the work. Repair any surface failures.
Before final project acceptance, remove all temporary stockpiles and restore the area to the original contour and grade.
Article 5 — Measurement
5.1 Asphalt Material . Unless otherwise shown on the plans, asphalt material will be measured by one of the
following methods .
5.1.1 Volume . Asphalt material, including all components, will be measured at the applied temperature by
strapping the tank before and after road application. The distributor calibrated strap stick will be used for measuring the asphalt level in the distributor asphalt tank. The certified tank chart will be used to determine the beginning gallons and the final gallons in the distributor tank. The quantity to be measured for payment will be the difference between the beginning gallons and the final gallons .
5.1.2 Weight . Asphalt material 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 accuracy. Upon work completion or temporary suspension, any remaining asphalt material will be weighed by a certified public weigher or measured by volume in a calibrated distributor or tank , and the quantity converted 258 to tons at the measured temperature. The quantity to be measured will be the number of tons received minus the number of tons remaining after all directed work is complete and minus the amount used for other items.
5.1.3 Quantity Adjustments . When shown on the plans, the measured quantity will be adjusted to compensate
for variation in required application or residual rates for different types of asphalt.
5.1.4 Aggregate . Unless otherwise shown on the plans, aggregate will be measured by the cubic yard in the
trucks as applied on the road. Strike off the loaded aggregate for accurate measurement when directed.
5.2 Loading, Hauling, and Distributing Aggregate . When the Department furnishes the aggregate, the
loading, hauling, and distributing will be measured by the cubic yard in the trucks as applied on the road.
Article 6 — Payment
The work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for at the unit price bid for “Asphalt” ; “Aggregate” ; and “Loading, Hauling, and Distributing Aggregate” of the types and grades shown on the plans. These prices are full compensation for surface preparation; furnishing, preparing, hauling, and placing materials; removing existing pavement markers and excess aggregate; rolling; cleaning up stockpiles; and equipment, labor, tools, and incidentals. Hauling of any aggregate to consolidate stockpiles at the end of the project when directed by the E ngineer will be paid by force account work .