1 - Specifications.pdf

SPECIFICATIONS

COAL CREEK WAREYARD ASPHALT 2021

DENSE-GRADED ASPHALT AND RECLAIMED ASPHALT PAVEMENT (RAP). This work shall consist of mixing, laying and compacting an asphalt course of one or more layers composed of aggregate, asphalt cement, applicable additives and lime, as required. All materials shall be mixed at a central mixing plant (plant-mix). When a ¾” mix design is used for a surface course, a fogseal shall be applied. The proportion of reclaimed asphalt pavement (RAP) used in the mix shall not exceed fifteen (15) percent.

4.5.10.2 ASPHALT DESIGN. Prior to delivering any plant-mix asphalt to any site, the supplier shall submit, in writing, a job-mix formula to the COR for approval. The job-mix formula shall be determined by a testing laboratory under the direction and control of a Registered Professional Engineer, based on tests performed in accordance with the “Marshall Method of Mix Design” as described in the Asphalt Institute Manual No. 2 latest edition. The job-mix formula asphalt shall satisfy all design criteria as shown in Traffic Category 1 of Table 4.11 (next page).

Job-mix formulas, together with test reports, shall be submitted in writing to the COR for approval prior to or upon selection of new job-mix formulas or when there is a change in the source of materials or a change in the percentage of RAP used in the mix. The test report shall give the recommended asphalt content and the values for unit weight, stability, flow, air voids, voids filled with aggregate, voids in mineral aggregate, and indirect tensile strength.

Any revisions to the approved formula shall fall within the requirements listed above. All material must come from same source and be same job mix formula. Design requirements must comply with Traffic Category I in Table 4.11 (next page).

TABLE 4.11

MARSHALL DESIGN REQUIREMENTS

TRAFFIC CATEGORYⴕ I II

ASTM D-1559 (number of blows) 75 50

TEST PROPERTY MIN MAX MIN MAX

MARSHALL STABILITY, LB.

FLOW, 0.01 IN

AIR VOIDS: PERCENT

- - 18

VOIDS IN MINERAL AGGREGATE (VMA)

FRACTURED FACES RETAINED ON THE NO.

4 (4.75 mm) SIEVE PER FLH DESIGNATION:

T-506-94 2.1

75%

SAND EQUIVALENT PER AASHTO T-

176-86 (1993) 4.3.2, 4.3.3

WEAR TEST AASHTO T-96 - - - 30% - - - 30%

DRY-RODDED UNIT WEIGHT

AASHTO T-19

AM. STD.

75 pounds per cubic foot minimum

STRIPPING TESTS:

AASHTO T-283

ASTM D-4687 including Note 5

Shall be used to determine the required amount of hydrated lime or anti-stripping agent in the asphalt. The mix design shall have a tensile strength minimum of 70 percent.

ⴕ Traffic Category I applies to arterial streets or truck routes with a Traffic Index of seven (7) or more.

ⴕ Traffic Category II applies to streets with a Traffic Index of less than seven (7).

4.5.10.3 ASPHALT CEMENT. Viscosity graded asphalt cement shall meet AASHTO designation M-226. Viscosity is to be measured at 140°F when used in pavement construction. The asphalt cement shall be homogeneous, free from water, and shall not foam when heated to 350° F. Sampling and testing of asphalt cements shall be in accordance with the following AASHTO Standard Methods:

• Sampling T40

• Viscosity at 140°F T202

• Viscosity at 275°F T201

• Penetration T49

• Flash point (COC) T48

• Solubility in bituminous materials T44

• Thin-film oven test T179

• Ductility T51

• Spot test T102

• Rolling thin film oven test T240

• Water T55

The asphalt cements shall conform to the requirements given in AC-10 of Table 4.12

TABLE 4.12

Paving Grade Liquid Asphalt Requirements

AC-10 AC-20

Viscosity: 140°F poises 1,000 + 200 2,000 + 400

Viscosity: 275°F, Cs-minimum 250 300

Penetration: 77°F, 100g, 5 sec-min. 80 60

Flash Point: COC, (°F) -minimum 425° 450°

Solubility in trichloroethylene:

percent-minimum

99.0 99.0

Tests on residue from thin-film oven test:

Loss on heating: percent - maximum (1) 0.5 0.5

Viscosity: 140°F, poises-maximum 4,000 8,000

Ductility: (77°F, 5 cm per minute), cm-minimum

75 50

Spot test (when and as specified) (2) with:

Standard naphtha solvent

Negative for all grades

1. The use of loss on heating requirement is to be used only if required by the County representative.

2. The use of the spot test is to be used only if required by the County representative.

4.5.10.3 SHIPMENT OF ASPHALT MATERIAL. Asphalt cement shall be uniform in appearance and consistency and show no foaming when heated to the specified loading temperature. Shipments of asphalt shall not be contaminated with any other type or grade of asphalt material. A bill of lading shall accompany each shipment of material and shall include the following information:

• Type and grade of material

• Type and amount of additives used, if applicable

• Destination

• Consignee's name

• Date of shipment

• Truck identification

• Loading temperature

• Net weight or net gallons corrected to 60 degrees Fahrenheit

• Specific gravity

• Bill of lading number

• Manufacturer of asphalt material

4.5.11 HYDRATED LIME FOR ASPHALT MIXTURE.

The physical properties of hydrated lime shall conform to ASTM C-1097, subparagraph d.1; use test method ASTM C-110, paragraph 6.

The water used in saturating the aggregate to be coated shall be potable or water that is clean and free of dirt, silt, and other damaging material. The aggregate bulk specific gravity (saturated-surface-dry (SSD)) shall be not less than one and one-half (1½) percent or more than three (3) percent using AASHTO T-85 for the course aggregate retained on a No. 4 sieve and AASHTO T-84 for the fine aggregate passing the No. 4 sieve. Hydrated lime shall be applied at a rate determined during the Marshall Design requirements in Table 4.12, unless otherwise directed by the COR. Two options for coating the aggregate with lime are as follows:

A. Aggregate shall be monitored for SSD by taking a belt cut between the stockpile and the pugmill or drum. The pugmill or drum shall be equipped with metering devices that will introduce the required amount of hydrated lime and water into the mixer to produce an aggregate SSD of one and one-half (11/2) percent to three (3) percent.

B. Use of lime slurry of one (1) part lime and three (3) parts water by volume may be used, if the plant is equipped with a mixing chamber that can maintain the lime suspension in the slurry. Spraybars for introducing the required quantity of slurry into the mixer shall be equipped with a positive shutoff. If this option is used, the aggregate stockpile shall be maintained at two (2) percent SSD.

Asphalt plants shall provide a positive signal system that automatically closes down the cold feed when the appropriate amount of hydrated lime and water ceases to be introduced into the aggregate. This shall be accomplished by the use of interlocked and synchronized metering devices and feeders. The plant shall be equipped in such a way that the quantity of hydrated lime incorporated into the mix can be readily checked at any time.

4.5.12 AGGREGATE. The requirements for crushed rock, rock dust, gravel, stone, slag, and sand are included in this subsection. All aggregate shall be clean, hard, sound, durable, and uniform in quality. The quality of soft, friable, thin, elongated, laminated pieces and disintegrated materials will be determined by the supplier’s professional Geotechnical Engineer at the time the mix design is submitted, at which time the COR will have the option to approve or reject the material. Organic matter, oil, alkali, or other salts shall not exceed two (2) percent total weight. In the surface course this material may be restricted to less than one (1) percent by weight.

A. Aggregate for three-quarter (3/4) inch Category I (NR), (see Table 4.13) shall be one hundred (100) percent crushed material (all manufactured). This is considered a non-rutting (NR) mix.

B. Course aggregate for three-quarter (3/4) inch standard and one-half (½) inch

Category II (see Table 4.13) shall be retained on the No. 4 sieve and shall have no less than seven-five (75) percent fractured face material as defined in FLHT 506-94 2.1.

C. Fine aggregate for other than the three quarter (3/4) inch NR, may be a natural or manufactured product. It shall pass the No. 4 sieve. It shall be clean, hard-grained angular, non-plastic, and have no more than two percent by weight of organic matter or other detrimental substances, including gypsum.

D. Rape must be screened or crushed to (3/4) inch and must not contain tar, trash, dirt, and debris.

1. Surface courses, or asphalt wearing courses, shall be free from organic materials and contain less than one percent by weight of soluble minerals, such as gypsum, and phosphates.

TABLE 4.13

DENSE-GRADED ASPHALT AGGREGATE GRADATION

PERCENT OF TOTAL AGGREGATE PASSING (DRY

WEIGHT)

TRAFFIC CATEGORY I II

3/4 inch NR* 3/4 inch std.* 1/2 inch

SIEVE SIZE (American Standard)

1 inch --- --- ---

3/4 inch 100 100 ---

1/2 inch 74 - 99 --- 100

3/8 inch 69 - 91 75 - 91 ---

#4 49 - 65 46 - 62 60 - 80

#8 33 - 47 --- ---

#16 21 - 35 22 - 34 28 - 42

#50 6 - 18 11 - 23 11 -23

#200 2 - 6 5 - 9 5 - 9

* When a ¾” mix design is used for a surface course, a fogseal shall be applied.

4.5.13 STORING, MIXING AND SHIPPING OF PLANT MIX BITUMINOUS PAVEMENTS.

Hot mix plants may be batch or drier-drum type plants (with not less than four aggregate bins). All storing, mixing, and shipping of plant mix bituminous asphalts shall conform to current UDOT and AASHTO requirements.

4.5.14 ASPHALT CONCRETE SURGE AND STORAGE SILOS.

Storage silos shall be well insulated and equipped with heated discharge cones and well-sealed discharge gates. Dense-graded asphalt may be stored up to forty-eight (48) hours in silos with heated cones, and seventy-two (72) hours with heating of the silo vertical walls and cone.

Storage silos may be used for storage or surge purposes, but under no circumstance may a surge silo be used for storage. Either silo must be equipped with high and low indicator systems.

4.5.15 SHIPPING ASPHALT MIXTURES. Asphalt used for shipping shall not adhere to the truck bed. Amounts of solution that form visible pools in the truck bed shall be removed prior to loading asphalt mix.

Asphalt mix shall be deposited in a mass into the haul truck in such a way as to prevent segregation.

4.5.16 SURFACE PREPARATION FOR ASPHALT OVERLAYS. Prior to placing asphalt overlays, all manholes, utility covers, monuments and other items affected by the paving operations shall be located, referenced and protected. The existing asphalt surface shall be thoroughly cleaned of all deleterious materials and brought to a uniform grade by spot leveling or by the application of a bituminous leveling course to the surface. A bituminous tack coat shall be applied to the existing prepared surface immediately prior to placing the finish asphalt course in accordance with Section 4.5.9 of these specifications. It may be required to remove a section of pavement at each end of the overlay to create a smooth transition onto existing asphalt. A minimum eight (8) foot wide section must be removed. Edges of the section must be saw-cut prior to removal. Feathering of the overlay onto existing asphalt will not be permitted.

4.5.17 ADJUSTMENT OF MANHOLE AND UTILITY COVERS. Prior to paving and after roadbase is placed, all manholes and utility covers shall be brought to the base grade.

Damaged valve boxes, covers, grade rings, cones, flattops, risers, or other damaged items shall be replaced. Manhole cones or flattops that are more than eighteen inches below finish grade shall be raised by using risers etc. under the cone or flattop. Existing roadbase shall not be contaminated with soil or subbase. Backfill material around adjusted manholes and utilities shall comply with roadbase standards meeting Section

4.5.7 of these specifications, and be compacted to ninety-five (95) percent as determined by ASTM D-1557 or AASHTO T-180 Method D. When paving is complete, all manhole and utility covers shall be raised to finished grade, including concrete collars, in accordance with standard requirements.

4.5.18 ASPHALT PAVING EQUIPMENT. A self-propelled paver with a screed unit that provides a smooth, steady pull on the screed arms shall be used. The screed unit shall strike off, partially compact, and iron the surface of the mat at least twelve feet wide. The screed unit shall be equipped with automatic controls and heaters and vibrators. The screed plate must be smooth and not excessively worn. All screed extensions shall be ridged, or hydraulically extendable. The screed extensions shall maintain the proper elevation and angle of attack to the main screed at all times, shall be heated, and shall provide vibration. Augers shall adequately feed all areas of the extended screed.

The automatic screed controls shall be full contact electronic or non-contact ultrasonic grade control systems. These systems shall be adaptable to a floating-beam system a minimum of thirty feet long. The floating beam shall be equipped with shoes that are allowed to rotate and can be individually displaced by isolated disruptions in the existing surface without changing the height of the whole beam. The automatic grade sensor shall be set at the midpoint of the floating beam.

Ultrasonic grade control systems may be used without the floating beam on all Traffic Category II streets unless otherwise directed. The ultrasonic grade control system must meet the following conditions in order to be used without the floating beam.

The system shall be equipped with a “self-diagnostic” function that continuously monitors all system functions and shuts the system down if an error in the system occurs.

It shall also be equipped with a “reference bail” to electronically compensate for differences in air and ground temperature with a minimum operating range not less than zero to 160 degrees F.

The system shall perform to a minimum of the following specifications:

Ultrasonic grade controller:

• On-grade tolerance +/- 0.01 foot

• Resolution 0.001 foot

• Operating range 10 in. to 42 in.

• Mat thickness control 0.01 foot

Slope controller:

• Correction window - 1.0%

• On-grade tolerance - 0.1%

• Resolution - 0.01%

• Operating range 0.0% to 100%.

The systems meeting the above requirements must be properly installed on a “tight”, properly maintained self-propelled paver with a screed unit. A “tight” system shall meet the equipment manufacturer's service specification tolerances for all controlling surfaces and connecting points that affect the ability of that specific type of equipment to provide proper grade control.

The COR has the right to prohibit the use of such equipment if in his opinion the equipment has not been properly maintained or is not being properly operated.

If the automatic grade control becomes inoperative, the Contractor may finish the day's work using manual controls provided the required grade, thickness and smoothness tolerances are met. Paving shall not continue on the project, or any new project, until the automatic control system has been repaired.

4.6 ROLLERS. Rollers shall be vibratory, steel-wheeled double-drum with a static weight of not less than 10 tons for breakdown rolling. Pneumatic-tired rollers with a minimum operating weight of two thousand (2,000) pounds per tire shall be used for intermediate rolling and leveling course compaction. The roller shall be in good condition, and capable of reversing without backlash. The number of rollers shall be sufficient to compact the asphalt mixture before it cools below 175°F. Finish rolling may be performed with the breakdown roller in the static mode, or with a steel- wheeled roller of sufficient size to remove the roller marks in the finished surface. If a roller breaks down and a back-up roller is not available, paving operations shall stop until adequate rollers are available.

4.6.15 WEATHER AND DATE LIMITATIONS. Asphalt shall not be placed during the period from November 1st through April 30th unless otherwise approved by the COR.

Paving approved during this time shall conform to winter paving requirements and policies. Minor repairs and patching may be allowed during winter months.

The asphalt mixture shall not be placed upon any wet surface, or when the air and surface temperature of the underlying course is less than specified in Table 4.14. The temperature requirements may be modified, but only when so approved and directed by the COR. If a prime coat is used, then the air temperature must be 70°F and rising. Air and roadbed temperature shall be measured in the shade. Asphalt mixtures shall not be placed during adverse weather conditions such as rain, wind, hail, etc.

TABLE 4.14 CLIMATE

LIMITATIONS

Mat Thickness

Minimum Air and Surface Temperature

F

3 inches or greater 50°

Less than 3 inches 55°

Open graded asphalt mix 70°

4.6.16 SPREADING AND FINISHING. The asphalt mix shall be placed upon an approved surface, by a self-propelled paver meeting the requirements in Section

4.5.18. The travel rate of the paving machine shall be regulated to a speed dependent upon the capacity of the mixing plant and/or trucking service to supply the mixture.

The paving machine shall be operated so that material does not accumulate and cool below 250° F along the sides of the receiving hopper.

Where unavoidable obstacles make the use of mechanical spreading and finishing equipment impracticable, the mixture may be spread, raked with hand tools, and mechanically compacted. For such areas, the mixture shall conform to the required mix design, density, compacted thickness, grade and cross section.

The asphalt mix may be windrowed in front of the self-propelled paver properly equipped to transfer the asphalt mix directly into the hopper, provided that the following conditions and requirements are strictly adhered to:

The windrow is properly sized, thereby insuring the delivery of the correct amount of material to the paving machine at all times.

The asphalt mixture shall be transferred from the windrow to the paving machine in such a manner that the materials in the paver will be a uniform mixture. The base, upon which the windrow was formed, shall not be disturbed. There shall be a minimum amount of asphalt mixture remaining on the base between the pickup device and the paving machine.

The material in the hopper of the paving machine shall meet with the temperature requirements. Asphalt mixture that does not meet the minimum specified temperatures shall not be used and shall be properly disposed of.

When it is determined by the COR that the asphalt course being placed by use of a windrow is inferior to that being placed by direct transfer of the asphalt from the hauling vehicle to the spreading machine, the use of the windrow method shall be discontinued.

The asphalt mixture placed by the use of a paving machine during one day's operation shall come from a single plant manufacturer. Intermixing from more than one source shall not be allowed. Intermixing is defined as when more than one plant is used as a routine supply source to a single operation.

The asphalt mixture shall have a temperature not less than 250°F nor more than 325°F, at the time the paving machine places the asphalt mixture on grade.

Depending on environmental conditions and compaction requirements, the COR may specify more strict temperature requirements based on weather conditions.

Asphalt pavement courses of more than three and one-half 4 inches in total compacted thickness shall be placed in two or m ore courses. The first course shall be 2 inches thick and compacted before the finish 2-inch course.

Second course shall not be placed over another course until the compaction requirements have been met and the mat temperature has cooled to 160°F at mid-depth.

Placing of the asphalt pavement shall be as continuous as possible. Rollers should not pass over the unprotected edge of the freshly laid asphalt mixture. Transverse joints shall be formed by cutting back on the previous run to expose the full depth and proper grade of that course. A tack coat meeting Section 4.5.9 of these specifications shall be applied on the contact surface of the prepared transverse joints just before the new asphalt mixture is placed.

Longitudinal joints shall be spaced in such a manner that joints in succeeding courses will be offset at least twelve (12) inches horizontally from joints in any preceding course. Lanes will be evened up each day to minimize cold longitudinal joints and to provide proper transverse joints. Where possible, the top course longitudinal joints shall be placed a minimum of one (1) foot either side of the lane line.

Transverse joints shall be spaced in such a manner that joints in succeeding passes will be a minimum of five (5) feet horizontally from joints in any adjacent pass.

Existing roadway pavements to be widened shall be sawcut far enough into the roadway to provide the proper grade, cross-section, and thickness with a straight vertical longitudinal or transverse joint. These joints shall have a tack coat meeting Section 4.5.9 of these specifications applied on the contact surface immediately prior to paving.

Longitudinal joints on previously compacted passes should have an overlap of new asphalt mixture one (1) to one and one-half (1 ½) inches over the existing mat. Raking should be merely to “bump” the joint, pushing the asphalt mixture off the previous pass and onto the new pass directly over the joint. If the adjacent mat is overlapped too far and too much asphalt mixture is deposited on the existing mat, the excess material shall be pulled away from the new mat rather than being pushed onto the new mat. Excess mix shall never be broadcast across the newly laid asphalt. The excess mix shall be picked up and recycled.

4.6.17 ROLLING AND COMPACTING. Compaction equipment shall meet the requirements of Section 4.5.19 of these specifications, unless otherwise approved or required by the COR.

A pass shall be one movement of a roller in either direction. A coverage shall be as many passes as are necessary to cover the entire width being paved. Overlap of passes during any coverage, made to ensure compaction without displacement of material shall be in accordance with good rolling practice.

The breakdown rolling shall consist of one or more complete coverages of the asphalt mat with a vibratory steel-wheeled roller. Initial rolling shall commence at the lowest edge and shall progress toward the highest portion of the asphalt mat. Initial rolling shall not commence on the interior portion of any mat.

The breakdown rolling shall be followed immediately by additional rolling with a pneumatic-tired roller that will provide uniform density throughout the depth of the course being compacted. A minimum of two rollers, one steel-wheeled, and one pneumatic-tired, shall be used. However, the total number of rollers used beyond the minimum of two shall be sufficient to obtain the required compaction while the asphalt mixture is above 175°F.

The final rolling of the asphalt mixture shall be performed by a steel wheel roller of sufficient size to remove all roller marks caused during the compaction of the asphalt mixture. The vibratory roller used for breakdown rolling may be used as the finish roller provided it is operated with the vibratory unit turned off.

The rollers shall be kept in continuous motion while rolling so that all parts of the asphalt mixture will receive as close to equal compaction as possible. The roller speed shall be slow enough at all times to avoid displacement of the pavement. Any displacement occurring as a result of reversing the direction of the roller, or from any other cause, shall be corrected immediately by use of rakes and fresh asphalt mixture when required.

To prevent adhesion of the asphalt mixture to the rollers, the wheels/tires, bars, pads, and release agent pumps shall be kept properly maintained. The use of diesel oil on pneumatic-tired rollers shall be kept to a minimum and used only in conjunction with coca pads to prevent the asphalt mixture from adhering until the tires heat enough to prevent mix adherence.

The completed surface shall be thoroughly compacted, smooth and free from ruts, humps, depressions, or irregularities. Any ridges, indentations or other objectionable marks left in the surface of the finished pavement shall be eliminated by rolling or other means. The use of any equipment that leaves ridges, indentations, or other objectionable marks in the asphalt surface shall be discontinued, and acceptable equipment shall be furnished.

Compacting the longitudinal joint shall be performed by placing the roller on the hot uncompacted mat and overlapping the joint by a distance of approximately six (6) inches over the cold compacted mat. For proper compaction, the level of the uncompacted mix at the longitudinal joint must be above the elevation of the compacted mix by an amount equal to approximately one-quarter (1/4) inch for each one-inch compaction.