402.1 Description. This work shall consist of placing, spreading and compacting a bituminous mixture as shown on the plans or as directed by the engineer. Spot wedging will not be required. 402.2 Material. All material shall be in accordance with Division 1000, Material Details, and specifically as follows: Item Section Coarse Aggregate 1004.2 Fine Aggregate 1002.3 Mineral Filler 1002.4 Asphalt Binder, Performance Graded (PG) 1015.3 402.2.1 Asphalt Binder. The grade of asphalt binder will be specified in the contract. 402.2.2 Wet Bottom Boiler Slag. The contractor may furnish wet bottom boiler slag of approved quality in lieu of coarse aggregate specified in Sec 402.2. If wet bottom boiler slag is used, the slag shall meet the requirements for coarse aggregate, except that the percentage of wear specified in Sec 1004.2.1 will not apply. 402.2.3 Reclaimed Asphalt. Recycled asphalt materials may be used and shall be in accordance with Sec 401.2.2. 402.3 Composition of Mixture. Aggregate sources shall be from the specific ledge combination of ledges within a quarry, or processed aggregate from a particular product, as submitted in the mix design. The total aggregate prior to mixing with asphalt binder shall be in accordance with the following gradation requirements: Sieve Size Percent Passing by Weight 3/4 inch 100 1/2 inch 99-100 3/8 inch 90-100 No. 4 60-90 No. 8 40-70 No. 30 15-35 No. 200 5-12 BP-3 in accordance with Sec 401.3 is an allowable substitution. 402.3.1 Mixture Characteristics. Bituminous surface leveling mixture shall have the following properties, when tested in accordance with AASHTO T 245 or AASHTO T 312. The number of blows with the compaction hammer shall be 35 or the number of gyrations shall be 35 with the gyratory compactor. The mixture shall have a minimum voids filled with asphalt (VFA) of 75 percent. The dust to effective binder ratio shall be 0.8 to 1.6. Percent Air Voids AASHTO T 245 Stability lb Voids in Mineral Aggregate (VMA) 3.5 750 14.5 402.4 J ob Mix Formula. The mixture shall be in accordance with Sec 401.4. 402.5 Gradation and Deleterious Content Control. In producing mixture for the project, the plant shall be operated such that no deviations from the job mix formula are made. The contractor shall determine on a daily basis, at a minimum, the combined gradation and binder content if production exceeds 100 tons per day. Gradation and asphalt content of RAP shall be determined once every 10,000 tons of production. Mixture as produced will be subject to the following tolerances and control:
a.The total aggregate gradations shall be within the master range specified in Sec 402.3.
b.Material passing the No. 200 sieve shall not vary from the job mix formula by more than ± 2.0 percentage points.
c.The deleterious content of the material retained on the No. 4 sieve shall not exceed the limits specified in Sec 1004.2.
d.If the plasticity index of any fraction exceeds that of the material approved for the mix design, additional testing may be required.
e.The quantity of asphalt binder introduced into the mixer shall be that quantity specified in the job mix formula. No changes may be made to the quantity of asphalt binder specified in the job mix formula without written approval from the engineer. The quantity of asphalt binder determined by calculation or tests on the final mixture shall not vary more than - 0.3 to +0.5 percent from the job-mix formula. 402.6 Sample Location. The gradations of the total aggregate will be determined from samples taken from the hot bins on the batch-type plants, from the combined cold feed on dryer-drum plants or from aggregate residue from the ignition oven during production. The deleterious content of the total aggregate will be determined from the samples taken from the combined cold feed belt. Samples for plasticity index will be taken from the stockpile. Aggregate samples shall be taken in accordance with AASHTO R 90. The RAP shall be sampled from the RAP feeding system on the asphalt plant. 402.7 Moisture Content. The bituminous mixture, when sampled and tested in accordance with AASHTO T 329, shall contain no more than 0.5 percent moisture by weight of the mixture. 402.8 Contamination. The bituminous mixture shall not be contaminated with deleterious agents such as unburned fuel, objectionable fuel residue or any other material not inherent in the job mix formula. 402.9 Field Laboratory. The contractor shall provide a Type 3 field laboratory in accordance with Sec 601.
402.10 Construction Requirements.
402.10.1 Weather Limitations. No mixture shall be placed on any wet surface or frozen pavement. No mixture
shall be placed when either the air temperature or the temperature of the surface on which the mixture is to be placed is below 50 F, except as otherwise allowed in Sec 402.10.1.1. Temperatures shall be obtained in accordance with MoDOT Test Method TM 20.
402.10.1 1 Cold Weather Paving. If the contractor implements all remedial actions listed herein, at no
additional cost to the Commission, bituminous mixtures may be placed when both the air temperature, and the temperature of the surface on which the mixture is to be placed, are 40 F and rising. Remedial actions required for cold weather paving:
a.Reclaimed Asphalt Pavement (RAP) content in the mix does not exceed 20% asphalt binder replacement.
b.No Reclaimed Asphalt Shingles (RAS) are added to the mix.
c.A material transfer vehicle is utilized to transfer the mix from the haul trucks to the paver.
d.Warm mix technology is to be incorporated into the mix (either by chemical additive or foaming), as approved by the engineer.
402.10.2 Bituminous Mixing Plants. Bituminous mixing plants and preparation of material and mixtures shall
be in accordance with Sec 404.
402.10.3 Application of Prime or Tack. Application of prime or tack coat shall be in accordance with Sec
402.10.4 Hauling Equipment. Trucks used for hauling bituminous mixtures shall be in accordance with Sec
404.
402.10.5 Spreading. The existing surface shall be cleaned of all dirt, packed soil or any other foreign material
prior to spreading the bituminous mixture. The mixture shall be spread in the quantity required to obtain the compacted thickness and cross section shown on the plans. The paver shall be operated at a speed that will give the best results. The rate of delivery of the mixture to the paver shall be coordinated to provide, where practical, a uniform rate of placement without intermittent operation of the paver. On small areas and on areas that are inaccessible to mechanical spreading and finishing equipment, the mixture may be spread and finished by hand methods when permitted by the engineer.
402.10.5 1 Irregularities. The mixture shall be spread without tearing the surface and struck off such that the
surface is smooth and true to cross section, free from all irregularities and of uniform density throughout. Care shall be used in handling the mixture to avoid segregation. Areas of segregated mixture shall be removed and replaced with suitable mixture. The outside edge alignment shall be uniform and any irregularities shall be corrected by adding or removing mixture before compacting.
402.10.5 2 Pavement Edge Differential. No pavement edge differential shall be left in place for more than
seven days, without written approval from the engineer.
402.10.6 J oints. Transverse joints shall be formed by cutting back on the previous run to expose the full depth
of the layer. When a transverse vertical edge is to be left and opened to traffic, a temporary depth transition shall be built as approved by the engineer. The longitudinal joint shall be at the lane lines of the traveled way except that the placement width of bituminous surface may be adjusted such that temporary raised pavement markers will not fall on a longitudinal joint. Each side of the joint shall be flush and along true lines.
402.10.7 Compaction. The mixture shall be thoroughly compacted by at least three complete coverages over
the entire area with either a pneumatic tire roller or a tandem-type steel wheel roller each weighing no less than 10 tons. All rollers used shall be in satisfactory condition, capable of reversing without backlash, and steel wheel rollers shall be equipped with scrapers. Rollers shall have a system for moistening each roll or wheel. Rolling shall begin as soon after spreading the mixture as the new surface will bear the weight of the roller without undue displacement. Final rolling shall be done by the steel wheel roller. Rolling shall be performed at proper time intervals and shall be continued until there is no visible evidence of further consolidation and until all roller marks are eliminated.
402.10.8 Surface Condition. The surface of the mixture after compaction shall be smooth and uniform. Any
mixture showing an excess of asphalt binder or that becomes loose and broken, mixed with dirt or is in any way defective shall be removed and replaced at the contractor’s expense with a satisfactory mixture, which shall be immediately compacted to conform to the surrounding area.
402.10.9 Hauling Over Completed Surface. Hauling of plant mix bituminous mixture over any completed
portion of the project will not be permitted unless allowed by special provision.
402.11 Method of Measurement. The weight of the mixture will be determined from the batch weights if a
batch-type plant is used. If other types of plants are used, the weight of the mixture will be determined by weighing each truck load on scales in accordance with Sec 310. Measurement will be made to the nearest 0.1 ton for the total tonnage of material accepted.
402.12 Basis of Payment. The accepted quantities of plant mix bituminous surface leveling will be paid for at
the contract unit price for each of the pay items included in the contract.
Referenced in this section
Get an email when 402 changes
Missouri revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.
Source: Missouri Standard Specifications for Highway Construction, 2026 (Oct) Edition. Pages 175–177 of 874. View official source ↗