179 SECTION 408 DESCRIPTION
408.01.01 General. This work consists of an application of bituminous material and cover of screenings applied
on a previously compacted and bonded bituminous surface. This work also consists of the production and stockpiling of screenings. MATERIALS
408.02.01 Bituminous Material. The type and grade of bituminous material will be specified in the contract.
The bituminous material shall meet the applicable requirements of Section 703. Submit a 3.75 L (1 gal) sample of emulsified bituminous material for approval at least 14 days before use.
408.02.02 Field Testing for Acceptance. The Engineer reserves the right to selectively test emulsified
bituminous materials for Saybolt Furol Viscosity at the job site or at any other designated area before application. Equip delivery trucks and trailers supplying emulsified bituminous materials with a sampling valve that provides a sample from the approximate mid-point of the load . Sample valves shall conform to AASHTO T40. If a sampling valve is not provided, samples may be obtained by the dip method according to Test Method No. Nev. T723. All samples are to be provided by the driver and the sampling process is to be observed by the Engineer. Sample bottles will be provided. When tested for Saybolt Furol Viscosity, the specification limits contained in Subsection 703.03.04 will be used as the basis for using or rejecting the material and the demerit schedule for Saybolt Furol Viscosity will not apply. If the material fails to meet specification limits, a second test will be run on the same sample. If the second test also fails, the material represented by that sample will be rejected and returned to the supplier. No payment will be made for rejected material or for the shipping or handling thereof. Do not blend any rejected material. Samples representing material that is accepted for use on the project will be forwarded to the Department’s Materials Division for further testing (excluding Saybolt Furol Viscosity tests) and the regular demerit schedule will apply.
408.02.03 Screenings. Screenings shall meet the requirements of Subsection 705.03.04, for the size
specified. Submit screenings for testing a minimum of 14 days before use. CONSTRUCTION
408.03.01 Distributors. The distributor shall meet the requirements of Subsection 405.03.01. Calibrate the
distributor for transverse and longitudinal application rates according to ASTM D2995 Test Method A or B, or other calibration method as approved. Verify calibration a s directed.
408.03.02 Aggregate Spreader. The aggregate spreader shall be self-propelled and supported by at least 4
wheels equipped with pneumatic tires on 2 axles. Equip the aggregate spreader with positive control so that the required amount of material will be deposited uniformly over the full width of the bituminous material. On divided highways, operate the aggregate spreader against the flow of traffic in order to allow the hauling trucks to enter and leave with the flow of traffic. Calibrate the aggregate spreader according to ASTM D5624, or other calibration method as approved, at a rate to apply the quantity of cover aggregate as specified . Verify calibration as directed.
408.03.03 Rollers. On a new surface, operate with each aggregate spreader, two pneumatic tired rollers and
one steel wheel roller. On an old surface, operate no less than three pneumatic tired rollers and no steel wheel rollers. The pneumatic tired roller shall meet the requirements of Subsection 401.03.04 (b). The steel wheel roller shall meet the requirements of the Subsection 401.03.04 (a) or (c). Additional rollers may be required if the aggregate placement rate exceeds the capabilities of the initial rollers. 408 SURFACE TREATMENT 180 408.03.04 Weather Limitations. Do not spread bituminous material when weather conditions are unsuitable, when rain is imminent, when the pavement surface is wet, when excessive wind causes problems, or when the humidity is higher than 50%. Do not spread bituminous material when the atmospheric temperature is below 18 °C (65 °F), when the pavement temperature is below 27 °C (80 °F), or when the pavement temperature is more than 60 °C (140 °F). Do not place screenings if there is a forecast of the atmospheric temperature falling below 2 °C (35 °F) within 24 hours of placement.
408.03.05 Maintaining Traffic. When traffic is maintained, do not apply the surface treatment to more than half
the width of the traveled way at a time, and keep the remaining half width free of obstructions and open for use by public traffic a t all times. Place dust hazard and loose gravel signs with advisory speed plates alternatively spaced at 1.6 km (1 mi) intervals. Do not place traffic on the newly placed bituminous material and screenings until they have sufficiently set and bonded. When the newly completed surface treatment is open to public traffic, control traffic by use of flaggers and a pilot car for a minimum of 24 hours or for such time as deemed necessary as follows:
a.Station a flagger at the beginning of each newly complete d section, to stop oncoming traffic preparatory to piloting operations. Keep the flaggers on duty during the entire control period.
b.Do not operate the pilot car at speeds greater than 40 k m/hr (25 mph) on newly constructed surface treatments.
c.Move traffic control as described above, ahead progressively as the newly completed surface is open to traffic.
408.03.06 Preparation of Surface . See Section 202 for removal of pavement markings. Remove such
markings as provided for in Section 202 before applying bituminous material. Remove and dispose of all vegetation that will interfere with the uniform application of bituminous material and screenings onto the existing pavement surface. Identify and protect drain s, manhole s, inlet s, monument s, and utility covers by applying a sheet of plastic, cut to fit, or use another method as approved or directed prior to surface treatment application. Identify and protect railroad tracks, bridge expansion joints, curbs, gutters, and other facilities from the applications of bituminous material and aggregates. Remove a ll traces of plastic, residual emulsion, and aggregates from the protected facilities the same working day as the surface treatment application has passed the protected locations. Place tempo rary lane line markers according to Section 633 at least 24 hours before applying the screenings. Immediately before applying the bituminous material, thoroughly clean the surface to be treated of all dirt and loose material by sweeping with power brooms supplemented by hand brooms if necessary. Continue the cleaning process until the surfacing is exposed and all dirt and loose material is removed from the entire width of surfacing.
408.03.07 Application of Bituminous Material. Uniformly apply bituminous material by means of a pressure
distributor in a continuous spread. The temperature of the bituminous material shall conform to Subsection
406.03.04 Use the quantity of bituminous material per square meter (square yard) as directed. If bituminous
material penetrates the surface too rapidly, a preliminary application of 0.45 L/m2 (0.1 gal/yd2) may be required. Use a strip of building paper at least 0.9 m (3 ft) in width and with a length equal to that of the spray bar of the distributor plus 0.3 m (1 ft), a t the beginning of each spread. Remove and dispose of the paper in a satisfactory manner. Move the distributor forward at proper application speed at the time the spray bar is opened. Adjust the distributor speed to coordinate with the chip spreader speed and rolling operations speed to prevent stop -start operations and ensure synchronized forward movement. Do not operate the distributor at speeds greater than 8 km/hr (5 mph ) when applying bituminous material . Limit distributor speed so that the distributo r pump does not operate at more than 90% of its total capacity. Correct any skipped areas or deficiencies. Carefully make junctions of spreads to assure a smooth riding surface. SURFACE TREATMENT 408 181 Do not apply bituminous material more than 50 m (150 ft) in front of the spreader. Cover immediately with screenings. Do not spread bituminous material wider than the width covered by the screenings from the spreading device. Do not allow bituminous material to chill, set up, dry, or otherwise impair retention of the screening s. Park the distributor, when not spreading, s o that bituminous materials will not drip on the surface of the traveled way. The application rate of bituminous material to be applied to the existing pavement surface may vary within the project limits due to differing surface conditions, to obtain the required embedment depth of 50% to 70%, or to achieve acceptable surface treatment application. Make adjustments to the bituminous material application rate as directed.
408.03.08 Application of Screenings. Immediately following the application of the bituminous material,
spread screenings within 10% of the required rate per square meter (square yard). Avoid building raised longitudinal joints. Construct the longitudinal joints by applying the screenings the same width as the bituminous material. Prior to the second pass of the distributor, use a power broom to broom back 100 to 150 mm (4 to 6 in.) of the first pass of the surface treatment to remove any chips that failed to get adequate embedment. Maintain a straight and uniform alignment . Offset longitudinal joints of successive courses of surface treatment 150 mm (6 in.). Place surface treatment so that final longitudinal joints are constructed at an offset of 150 mm (6 in.) from the final traffic lane line s. Do not spread bituminous material and screenings over a greater distance than can be rolled and finished within one day’s operation. Provide surface damp screenings at the time of application. Excess water on the aggregate surface will not be permitte d. Do not operate the spreader at speeds which cause the screenings to roll over after striking the bituminous covered surface. On two lane travel ways, apply bituminous material and screenings to half of a given roadway at a time and in such a manner th at every other days operation brings the limits of the surface treatment to a near common point. Cover the emulsified asphalt applied to the road surface with screenings before setting or breaking occurs. In order to eliminate hauling over the new surfac e treatment, begin screening operations at a point furthest from the material source and work toward the material source. Stagger aggregate delivery truck wheel paths across the travel lane behind the spreader to aide rolling operations. Aggregate delivery trucks shall travel at speeds less than 40 km/hr (25 mph) on the newly constructed surface treatment. Aggregate delivery truck operators shall make gradual stops, starts, and turns. After the screenings have been spread, carefully remove any piles, ridges, or uneven distribution with flat bottom shovels, or other approved methods to insure against permanent ridges or bumps in the completed surface. Spread additional screenings by hand in whatever quantities required to prevent picking up by the rolle rs or traffic.
408.03.09 Rolling. Begin rolling immediately behind the screening application to properly embed the
screenings in the soft bituminous material. Commence rolling at the outer edge and proceed toward the inner edge on each spread. Continue ro lling until the screenings are thoroughly set. Roller speed shall not exceed 8.0 k m/hr (5 mph). Roller stops, starts, and turns shall be made gradually. Use an approved sequence of rollers and roller patterns.
408.03.1 0 Removal of Loose Screenings and Surface Maintenance. Lightly broom the surface to remove all
loose chips approximately 3 hours after the start of the screening application. Do not apply heavy pressure to the broom core which will cause dislod ging of chips from the surface. Do not allow traffic on screenings until after the light brooming operations are completed. 408 SURFACE TREATMENT 182 Use a minimum of 3 self -propelled power brooms equipped with pressure type distributor spray systems that will ensure uniform application of wa ter for dust control. The brooms shall be capable of removing loose screenings adjacent to barriers (including curbs, gutters, and railings) that prevent screenings from being swept off the pavement. Provide brooms capable of downward pressure adjust ment . Do not use gutter or steel -tined brooms. If operated at night, equip broom s with tail, stop, and directional lights , and an amber strobe light. Operate brooms at 6 to 9 km/hr (4 to 6 mph). Apply adequate water during all brooming to control dust . Rem ove and dispose of excess screenings which will interfere with drainage. Complete surface to a uniform appearance and free from ruts, humps, depressions or irregularities due to an uneven distribution of bituminous material or screenings. Repair unaccepta ble areas. Provide repair crew personnel specifically designated and dedicated to performing the necessary repairs . After the application of screenings, lightly broom and maintain the surface for a period of 4 days. Perform the light brooming to remove l oose screenings prior to the end of each day’s work or as the first order of work on the morning following application of screenings. Perform the initial brooming between sunrise and 10:00 a.m. Broom the entire surface that has had screenings applied to it on the previous day. Completely remove all loose screenings from the paved roadway surface. Perform a second brooming within 48 hours after the initial brooming. Additional brooming shall be required as often as necessary between the first and fourth day after applying screenings to maintain the surface free of loose screenings. At the end of 4 days after applying screenings, remove any excess screenings from all paved areas. Perform sweeping or brooming of the surface treatment in such a manner that the s creenings set in the bituminous material will not be displaced. Do not excessively broom the surface. Maintain the surface for the 4 day period by spreading additional screenings to absorb any free bituminous material, to cover any areas deficient in scre enings, and to eliminate surface irregularities. If approved, clean sand may be used in lieu of screenings to cover any excess bituminous material which comes to the surface. Do not use roadside material for this purpose.
408.03.1 1 Screenings (In Stockpile). Clear the stockpile area of all brush, rubbish , and deleterious material.
Give notification once the stockpile area has been cleared and not less than 72 hours prior to commencing crushing and screening operations in order that cross sections of the area may be obtained prior to stockpiling operations. Place the screenings in uniformly shaped stockpiles as directed. Keep stockpiles of different materials separated to prevent intermixing. The exact location of stockpiles will be determined. METHOD OF MEASUREMENT
408.04.01 Measurement. Bituminous material will be measured by the metric ton (ton).
Screenings will be measured by the metric ton (ton) or cubic meter (cubic yard). Screenings (In Stockpile) will be measured by the me tric ton (ton) or cubic meter (cubic yard). The mass of any water added to the screenings before weighing will be deducted from the quantity measured for payment. BASIS OF PAYMENT
408.05.01 Payment. The accepted quantities, measured as provided above, will be paid for at the contract
price per unit of measurement for the pay items listed below that are shown in the proposal. Payment will be full compensation for the work prescribed in this Section. If the results of the Cleanness Value test for screeni ngs, as required in Subsection 705.03.04, is below 81, remove the surface treatment represented by such test. No single Cleanness Value test will represent more than 1800 metric tons (2000 tons). SURFACE TREATMENT 408 183 If requested in writing and approved, surface treatments co ntaining screenings with a Cleanness Value below 81, but not less than 73, may remain in place. Pay to the Department as liquidated damages the following amount for such screenings left in place. Cleanness Value Liquidated Damages Per metric ton (ton) 79 to 77 ................................ ................................ ......... $13.20 ($12.00) 75 to 73 ................................ ................................ ......... $26.40 ($24.00) The Department will deduct these amounts from any monies due, or that may become due, under the Contract. Flagger s, pilot car , and construction signs will be paid for according to Section 624 and 625 . Payment will be made under: Pay Item Pay Unit Emulsified Asphalt (type) ................................ ................................ ................................ ................................ ................. Metric Ton (Ton) Screenings (size) ................................ ................................ ................................ .................. Metric Ton (Ton), Cubic Meter (Cubic Yard) Screenings (size) (In Stockpile) ................................ ................................ ............................. Metric Ton (Ton), Cubic Meter (Cubic Yard) 185 SECTION 409 PORTLAND CEMENT CONCRETE PAVEMENT DESCRIPTION
409.01.01 General. This work consists of constructing Portland cement concrete pavement on a prepared
surface. MATERIALS
409.02.01 General. Material shall conform to the following Sections:
Portland Cement Concrete ..................................................................................................................................................... Section 501 Reinforcing Steel .................................................................................................................................................................... Section 505 Portland Cement .................................................................................................................................................................... Section 701 Concrete Curing Materials and Admixtures ............................................................................................................................ Section 702 Aggregates for Portland Cement Products ............................................................................................................................. Section 706 Water ..................................................................................................................................................................................... Section 722 Concrete for Por tland cement concrete paving shall be Class PCCP conforming to Section 501 with the modifications and additional requirements specified herein. Use a three aggregate system consisting of a blend of two Coarse Aggregates from Subsection 706.03.01 and Fine Aggregate conforming to Subsection 706.03.03. Use American Concrete Institute, Manual of Concrete Practice, Guide 302.1R-04, Section 5.4.3 Combined Aggregate Grading to optimize the combined aggregate grading within the grading limits below. Submit the results with the mix design. For mix design approval and as a project control requirement, the proposed proportions of individual aggregates, combined mathematically, by volume or mass, shall produce a mixture within the grading limits for combined aggregates as follows: Grading Limits of Combined Aggregates Sieve Size Percent Passing by Mass 50 mm (2 in.) .............................................................................. 100 37.5 mm (1 1/2 in.) ....................................................................... 90-100 25 mm (1 in.) ............................................................................. 50-86 19 mm (3/4 in.) ........................................................................... 45-75 9.5 mm (3/8 in.) ........................................................................... 38-55 4.75 mm (No. 4) .......................................................................... 30-45 2.36 mm (No. 8) .......................................................................... 23- 38 1.18 mm (No. 16) ......................................................................... 15-33 600 μm (No. 30) ........................................................................... 8- 22 300 μm (No. 50) ........................................................................... 4- 13 150 μm (No. 100) ............................................................................ 1-5 75 μm (No. 200) ............................................................................ 0-3 The air range indicated is not required in Clark County. For mix design approval, testing shall demonstrate that a minimum flexural strength of 4.5 MPa (650 psi) will be achieved at 28 days. An average of 3 beams, when cured and tested according to Test Method No. Nev. T442, shall meet or exceed 4.5 MPa (650 psi) with no individual beam having a strength less than the specified strength. CONSTRUCTION
409.03.01 Equipment . (a) General. Equipment and tools necessary for handling materials and performing all
parts of the work must be approved as to design, capacity, and mechanical condition. Provide this equipment on the site, available for inspection, testing, and approval before paving operations are started. Maintain all equipment, tools, and machinery in a satisfactory working condition. Provide equipment of such capacity that the paver will operate continuously or at a constant rate of production. If any piece of equipment does not have sufficient capacity to keep pace with the other operations, the Engineer may limit the size of the batch or otherwise limit the rate of production to prevent poor workmanship, overloading of equipment, or frequent delays.
Source: Nevada Standard Specifications for Road and Bridge Construction, 2014 Edition. Pages 185–190 of 610.