4−21prices for HMA pavements as listed in the Proposal.
401.04 Method of Measurement.
401.04.1 Measurement of HMA Pavement. HMA Pavements will be measured by the number of
tons actually placed in accordance with the Plans and/or as directed by the Engineer.
a.Determination of Thickness. The design thickness of each course as well as of the total HMA pavement structure shall be that indicated on the Plans, or as ordered by the Engineer. Prior to the determination of placed thickness, the roadway shall exhibit acceptable workmanship and all defects shall have been corrected. The placed thickness of HMA pavement will be determined by cutting or coring holes to full depth. For courses with In-Place Density Cores specified, the average thickness of the Density Cores will be used to determine placed thickness. For courses where In-Place Density Cores are not specified the following requirements apply: For projects with less than 1 paved lane mile, two cores will be taken. For projects with 1 to 2 paved lane miles, four cores will be taken. For pr ojects with greater than 2 paved lane miles, two cores will be taken from each lane mile, except that there will be a minimum of ten cores for the project, all at the discretion of the Engineer. Cores will be measured in accordance with ASTM D3549; Standard Test Method for Thickness or Height of Compacted HMA Paving Mixture Specimens. The depth measurement will be considered as applying for the full width of the lane. Measurements will be made at random locations determined by the Engineer and all information relative thereto will be recorded in the project records. For the determination of thickness, a shoulder width of eight feet or greater will be considered to be a separate lane of the roadway. A shoulder width of less than eight feet will be considered part of the adjacent lane. The Contractor shall fill all holes cut or cored in the pavement with a compacted, dense HMA which is acceptable to the Engineer. If required by the Engineer, the Contractor shall maintain and control traffic wh ile the pavement samples are being taken and while the holes are being filled and compacted. Payment will be made for the applicable traffic control item(s).
b.Adjustment of Tonnage Quantity. The pavement thickness will be considered accept able if both of the following requirements are met:
1.The total HMA tonnage delivered and placed does not exceed the tonnage calculated from the approved area measured from the final surf ace course width by the project length and the pavement thickness specified in the Contract Documents by more than 5 percent. and,
2.When Specification Conformity Analysis (Federal Highway Administration Technical Advisory T5080.12; dated June 23, 1989) is applied to the entire roadway or sections thereof as determined by the Engineer, at least 80 percent of the total HMA pavement will have a thickness 4−22 that meets the minimum pavement thickness. The minimum pavement thickness is that contained in the contract documents minus ½-inch, (e.g., a total pavement thickness of 7 inches will have a minimum pavement thickness requirement of 6.5 inches). If the first requirement is not met, no pay ment will be made for all tonnage exceeding 5 percent, unless unusual field conditions are present and documented (e.g., pavement rutting). If the second requirement indicates that the pav ement thickness is deficient, the Contractor with permission of the Engineer shall place a corre ction course not less than one inch in depth after compaction, provided an acceptable grade and cross section can be achieved. Where an acceptable grade and cross section cannot be achieved through the above means, the Contractor shall reconstruct by cutting back and into the pavement a sufficient distance to permit the placement of an acceptable depth and place new material to achieve the proper depth, cross section and profile. These areas where a corrective course is placed or reconstruction of the pavement is performed, will be measured again as though originally constructed; no compensation will be made to the Contractor for the material removed or removal of materials and disposal thereof or for restoration of affected supporting base or adjacent construction, or for traffic control, adjusting all utility appurtenances in the roadway or for co rrecting pavement striping. Compensation will be made for the additional pavement correction course accepted in place. Determination of the quantity to be used for adjus ted payment or exclus ion for payment will be based on tons per square yard per inch thickness as determined using in-place density cores or 96% of the plant core (AASHTO T245) densities if in-place densities are not available. Sweeping and cleaning, as included in the items covered by this section, refers to the normal removal of dust, debris, etc. only. Any sweeping and cleaning necessary due to construction being held over for the winter season, in accordance with the approved construction schedule, will be paid for separately. Work described in Subsection 401.03.4; Conditioning of Existing Surface , will be paid for at the contract unit prices for the material used. Tolerance Limitation. Pavement will be considered acceptable when meeting the specifications. Pavement that is not accepted will be excluded from the tolerance allowance. When delivery tickets are directly collected by the Engi neer from each truck prior to placing in the hopper, the delivery tickets may be used in the determination of total tonnage delivered and placed. Delivery tickets not collected directly by the Engineer prior to placing in the hopper will not be used to determine tonnage. When delivery tickets are not used to determine tonnage, the accepted total tonnage delivered and placed will be calculated according to the following formula: [final surface course width] x [project length] x [specified pavement thickness] x [the average unit weight of all acceptance density cores] = contract tonnage. If density cores are not required then 96% of the average unit weight of the plant produced acceptance gyratory cores shall be used. Payment will be made at full contract unit bid prices with pay adjustments for all accepted HMA up to 105% of the contract quantity tonnage. Accepted HMA quantities above 105% and up to 110% of the contract quantity tonnage will be paid at 50% of the contract unit bid price with the resultant adjusted price further modified by additional pay adjustments as applicable according to the following formula: Pay adjustments will apply to 50% of the contract unit bid price for quantities above 105% and up to 110%. 4−23401.05 BASIS OF PAYMENT. The accepted quantity of the HMA will be paid for at its respective contract unit price per ton as listed in the Proposal. The price so-stated constitutes full and complete compensation for all labor, materials and equipment, and for all incidentals required to finish the work, complete and accepted by the Engineer. Pay adjustments for binder content, air voids and in-place density will be added together to determine a final pay adjustment for both the mat and the joint. If more than one pay adjustment is negative then only the most negative adjustment will be added to the remaining non-negative adjustments to determine the final pay adjustment. Pay adjustments will be applied to the unit bid price for the applicable item code. SECTION 402 FRICTION COURSES
402.01 DESCRIPTION. This work consists of placing a friction course on prepared, sound, dense
surfaces of bituminous concrete at the locations and to the thickness indicated on the Plans or as directed by the Engineer, all in accordance with these Specifications. 402.01.1 Specific Pavements. The specific pavements and mixes are designated by the column headings of the table that constitutes Subsection M.03.01 of these Specifications. They are:
a.Dense Friction Course b. Ramp Friction Course
402.02 Materials.
402.02.1 Composition. The friction course shall consist of aggregate mixed with asphaltic cement
in a bituminous hot mix plant. 402.02.2 Mixture.
a.Approval. Each year dense friction course is to be produced at the hot mix plant, either a new mix design shall be submitted or, at the discretion of the Engineer, the current mix design shall be verified.
b.Mix Design. The Contractor shall submit a mix design for the specific pavements. The design, with the allowable tolerances, shall be within the master range indicated for gradation; percent asphalt; Marshall Stability; percent voids; and flow, all as set forth in the Table that constitutes Subsection M.03.01 of these Specifications for each particular friction course.
1.Mix Tolerances Passing 3/8"and larger sieves: ± 7 percent Passing No. 4 to No. 50 sieves: ± 4 percent Passing No. 200 sieve: ± 2.0 percent 4−24 Asphalt content: + 0.2 percent to -0.3 percent The mix design shall be submitted at least six weeks prior to production.
c.Verification of Mix Design. Sufficient amounts of aggregate and asphalt cement (with additives) shall be submitted to the Engineer at least one month prior to production for the purposes of mix design verification. The materials used in the mix design will be those approved for the plant at which the friction course is to be produced.
d.Plant Trial Batches. Plant trial batches will be required at the design asphalt content.
402.02.3 Aggregate. Aggregate must be sound, durable and of high quality which includes being
resistant to polishing, degradation, and stripping or loss of strength when incorporated in the mix and exposed to water. The aggregate must be from an approved source meeting the criteria stated herein:
a.Coarse Aggregate shall be either crushed ledge stone, crushed granite, or crushed gravel but no combination, blend, or mixture of these will be permitted. It shall have at least 95 percent by weight crushed particles with one or more fractured faces, and 90 percent by weight crushed particles having at least two fractured fa ces. Coarse aggregate shall also have a loss on abrasion of no more than 40 percent as tested in accordance with AASHTO T96.
1.Crushed gravel is defined as the product of crushing material that is retained on the ¾- inch sieve.
2.The retained coating of coarse aggregate shall be at least 95 percent when tested in accordance with AASHTO T182.
b.Fine Aggregate shall be crushed stone screenings, natural sand, or a blend thereof. No more than 20 percent of the fine aggregate may be natural sand.
c.Aggregate Stockpiles from approved sources shall be available at the plant site no later than two days prior to production for verification testing by the Engineer. 402.02.4 Asphalt Cement. The asphalt cement shall be PG 64-28. It shall contain an approved silicone additive in quantities of 1 ounce per 5,000 gallons of asphalt cement. To provide adequate stripping resistance, the asphalt cement shall be blended with an approved anti-stripping compound (100 percent active). The dosage level shall be as recommended by the manufacturer. The anti- stripping compound shall be heat stable and capable of remaining in storage indefinitely. 402.03 CONSTRUCTION METHODS.
402.03.1 General Requirements. The mixing, placing and finishing of bituminous friction course
shall conform to the applicable requirements of Subsection 401.03 of these Specifications, 4−25together with the following exceptions and additional conditions:
a.Both the mixing temperature and the temperature of the friction courses at the time of placement shall be within the range of 240OF to 280OF.
b.The plant shall operate solely for the production of this mixture and exclusively for the State of Rhode Island. The unloading of silos must commence within one hour from the time loading begins, and silos must be completely emptied within one hour from the time they are filled. The use of silos for storage will not be permitted.
c.The mixture shall be compacted to the required density with adequately ballasted static steel wheel rollers. Adequately ba llasted vibratory rollers may be allowed provided they are used in the static mode.
d.The mixture shall be placed as soon as possible after completion of mixing at the plant. It shall be placed within 90 minutes from the time it is loaded in the truck, subject to the specified placement temperature range. 402.03.2 Production and Placement . When placed on a newly reconstructed surface, the thickness shall be as shown on the Plans with a tolerance of ±¼ inch. When used to overlay an existing roadway, the thickness shall be minimum of 1 inch and a maximum of 1¾ inches to accommodate for rut depths of up to ¾ inch on the existing pavement. The surface on which the friction course is to be placed shall be treated with a tack coat. Tack coat must be applied uniformly over the surface of the underlying pavement. The surface shall be broom cleaned before the application of tack coat. Spreading of the mixture shall be performed carefully and the operation shall be as continuous as possible. Particular attention shall be given to the joints and any irregularities shall be removed before compacting. After placement, the mixture shall be thoroughly and uniformly compacted with power rollers as directed by the Engineer. Sufficient rollers shall be furnished to handle the output of the plant. Rolling shall continue until all roller marks are eliminated, the surface is of uniform texture and true to grade and cross section. The first pass with the specified roller shall be completed when the temperature of the layer is 240 OF ±20OF. At least three passes must be made at all locations on the mat. Each roller shall exert a minimum average force of 150 pounds per inch along the width of each drum. At least two of the rollers must have a minimum dry weight of eight tons each. Excess concentrations of asphalt can be easily detected during paving operations. All "fat" areas shall be removed immediately. The wasted quantity, as determined by the Engineer, will be subtracted from the quantity shipped that day. 402.03.3 Weather Limitations. Friction course shall not be placed on a wet or damp surface or when the temperature of the surface course, in the shade, is less than 40 OF, measured prior to placement. It shall only be placed when the air temperature, in the shade, is at least 40OF and rising. 4−26 402.03.4 Time Limitation. Friction course shall only be placed between the period of June 1st to August 31st. 402.04 METHOD OF MEASUREMENT.
402.04.1 Dense Friction Course. "Dense Friction Course" will be measured by the number of
tons actually placed in accordance with the Plans and/or as directed by the Engineer. 402.04.2 Ramp Friction Course. "Ramp Friction Course" will be measured by the number of tons actually placed in accordance with the Plans and/or as directed by the Engineer. 402.04.3 Ten Percent Limitation. Pavement thickness will be considered acceptable when placed within the tolerances specified. The total tonnage delivered and placed shall not exceed the tonnage calculated from the approved areas measured fr om the final surface course width, by the project length, and the pavement thickness in the Contract, by more than 10 percent. A thicker pavement may be acceptable; how ever, no payment shall be made for any quantity of asphalt concrete delivered which exceeds 110 percent of the final measured length, times measured width, times specified thickness, times unit weight. 402.05 BASIS OF PAYMENT. The accepted quantities of "Dense Friction Course" and "Ramp Friction Course" will be paid for at their respective contract unit prices per ton as listed in the Proposal. The prices so-stated constitute full and complete compensation for all labor, materials and equipment and all incidentals required to finish the work, complete and accepted by the Engineer. SECTION 403 ASPHALT EMULSION TACK COAT
403.01 DESCRIPTION . This work consists of furnishing, delivering, and placing a liquid asphalt
tack coat on bituminous concrete or Portland cement concrete, prior to the placement of a bituminous concrete overlay, all in accordance with these Specifications.
403.02 MATERIALS. The asphalt emulsion shall be RS-1.
403.03 Construction Methods.
403.03.1 Equipment. Application of the asphalt emulsion tack coat shall be by means of a pressure
distributor capable of producing a uniform continuous fine spray, through multiple nozzles, resulting in a uniform continuous coat of asphalt emulsion over the entire section to be treated. Any puddles of tack coat shall be squeegeed or broomed out or corrected by whatever means chosen by the Contractor which will achieve the required surface treatment. Any areas not receiving the specified coverage of tack coat shall be corrected and brought into compliance.
Source: Rhode Island Standard Specifications (Bluebook), 2024 Edition. Pages 199–204 of 826.