In-Depth Review 2022 Section 302 186 SECTION 302
302.01 Description
This work consists of furnishing and placing aggregate or salvaged material on a prepared foundation.
302.02 Equipment
Equipment Section Pneumatic -Tired Rollers 151.01 Vibratory Sheeps Foot/Pad Foot/Extended Pad Foot Rollers 151.02 Water Trucks 152.01 B Aggregate Trucks 152.01 C Roadbed Planers 153.02
302.03 Materials
Material Section Aggregates 816 Salvaged Base Course 817 Traffic Service Aggregate 816 Class 5 ; or 817 When the plans specify a class of aggregate for the base, the Contractor may substitute Salvaged Base Course that meets Section 817, “Salvaged Base Course.”
302.04 Construction Requirements
A.Acceptance of Aggregate.
1.General. The requirements of Section 302.04 A.3, “Miscellaneous Properties”, will not apply to salvaged base course.
2.Gradation. The Engineer will collect three samples for each 1,000 tons of material placed with a maximum of three samples collected in one day . The three samples constitute one lot of material. If the aggregate fails to meet the specified gradation, the Engineer will apply a price reduction as specified in Section 302.06 B, “Contract Price Adjustments” . Halt aggregate placement operations if two consecutive lots deviate from the specified gradation. Restart placement operations after taking corrective actions and passing a gradation test. In-Depth Review 2022 Section 302 187 3. Miscellaneous Properties. The Engineer will collect three samples for each 10,000 tons lot of material produced to determine shale content, plasticity index, and the number of fractured faces . The Engineer will include fraction lots of less than 2,500 tons in the previous lot. If the material fails to meet the requirement for plasticity index or fractured faces, make corrections to the stockpile before incorporating additional material into the work. If the material exceeds the maximum shale content by less than 3 percentage points, the Engineer will apply a price reduc tion as specified in Adjustments” . The Engineer will reject the material if the maximum shale content is exceeded by 3 or more percentage points.
B.Placement and Compaction. Place aggregate on a damp surface in lifts not exceeding 6 inches of compacted material. Uniformly mix aggregate placed in windrows before spreading. Compact aggregate, utilizing pneumatic -tired rollers, until the surface is tightly bound, shows no rutting, and no displacement occurs under the roller operation. The Engineer may allow other compaction methods when placing aggregate under sidewalks, driveways, or medians. Compact material over geosynthetic geogrid as specified in Section 709.04 C, “Geosynthetic Geogrid (Type G)”. Compact material over geotextile reinforcement fabric as specified in Section 709.04 D, “Geosynthetic Reinforcement (Type R)”.
C.Surface Tolerance.
1.General. Unless one of the following surface tolerances is specified, construct the surface to within 0.08 feet of the proposed elevation.
2.Surface Tolerance Type B. Use trimming equipment, including motor graders, equipped with automatic grade control to adjust for the cross slope and longitudinal profile. Construct the finished surface to within 0.04 feet of the proposed elevation. Reincorporate material removed from high points during trimming into other portions of the base.
3.Surface Tolerance Type C. Use roadbed planers to construct the finished surface. The Engineer will allow the base or surface course to be used as the grade reference when trimming shoulders. Construct the finished surface to within 0.04 feet of the proposed elevation. Reincorporate material removed from high points during trimming into other portions of the base. In-Depth Review 2022 Section 302 188 D. Limitations. Do not place material on frozen subgrade. When the roadway is open to traffic, the following limitations apply: - The maximum windrow length is three miles; and - Spread material within 48 hours of placing the material in a windrow.
E.Maintenance of Completed Courses. Maintain a smooth and compacted surface on completed courses.
F.Traffic Service Aggregate. Before removing pavement, place a stockpile of traffic service aggregate within the project limits. Place a quantity of material in the stockpile equal to 10 percent of the amount shown in the plans and maintain that quantity in the stockpile until the Engineer deems the stockpile is no longer necessary, or until base operations are complete. Place a 4 in ch thick mat of traffic service aggregate in locations directed by the Engineer. Salvage and reuse placed traffic service aggregate to the extent feasible. Incorporate material that cannot be picked up into the subgrade. If material remains in the stock pile at the time of release, incorporate it into other aggregates of the same class to be used on the project. If no aggregates of the same class are part of the project, incorporate the remaining stockpile into the subgrade in areas determined by the Engineer. applies to traffic service aggregate when it is incorporated into other aggregates of the same class that require acceptance testing.
302.05 Method of Measurement
The Engineer will measure, completed and in place, as specified in Section 109.01, “Measurement of Quantities” and the following: The Engineer will measure traffic service aggregate when it is placed in the stockpile. No measurement will be made for traffic service aggregate that is picked -up and reused on the roadway.
302.06 Basis of Payment
A.General. Pay Item Pay Unit Salvaged Base Course Ton or Cubic Yard Traffic Service Aggregate Ton Aggregate Base Course Cl__ Ton or Cubic Yard Aggregate Surface Course Cl__ Ton or Cubic Yard Include all costs for time, material, and labor required to supply traffic service aggregate and to place, maintain, salvage, and reuse the material in the contract price for “Traffic Service Aggregate”. In-Depth Review 2022 Section 302 189 Such payment is full compensation for furnishing all materials, equipment, labor, and incidentals to complete the work as specified.
B.Contract Price Adjustments.
1.General. The Engineer will determine contract price adjustments by multipl ying the applicable adjustment factor by the contract unit price for the aggregate and the amount of material in the lot represented by the test. If contract price adjustments are warranted in more than one category, a contract price reduction will be applied for each area of deficiency.
2.Aggregate Gradation Adjustment Factor. The Engineer will determine the aggregate gradation adjustment factor if aggregate base does not meet the specified gradations for all required samples, as calculated: Aggregate Gradation Adjustment Factor = 5 × Sum of deviations from range limits on all sieves
3.Shale Content Adjustment Factor. The Engineer will determine the shale content adjustment factor if the limits for shale are exceeded, as calculated: Shale Content Adjustment Factor = 5 × (Average of 3 Samples – Allowable Percentage) Section 401 190 SECTION 401 PRIME, TACK, OR FOG COAT
401.01 Description
This work consists of preparing and treating a surface with bitumen.
401.02 Equipment
Equipment Section Bituminous Tank Trucks 152.01 E Storage and Heating Equipment 154.01 B Liquid Bitumen Distributors 154.02 B Aggregate Spreader 154.02 C
401.03 Materials
A.General. Material Section Water 812 Blotter Sand, Class 44 816 Emulsified asphalt may be diluted with water. When diluting emulsified asphalt, the amount of water added to the dilution shall not exceed the amount of emulsified asphalt. Obtain samples of the bitumen under the observation of the Engineer. The Engineer will take immediate possession of the samples .
B.Prime Coat. Use MC 70 or MC 250 that meets the requirements of Section 818.02 C, “Medium -Curing Cutback Asphalt” .
C.Tack Coat. Use a material from Table 401-01. Table 401 -01 Material Section SS-1h 818.02 F MS-1 818.02 F CSS-1h 818.02 E.1 When MS -1 is used it may be diluted by the supplier or the Contractor.
D.Fog Seal. Use a material from Table 401-02. Table 401 -02 Material Section SS-1h 818.02 F CSS-1h 818.02 E.1
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 221–224 of 550.