301.06 162 Correct variations in excess of slope or surface tolerances by adding or re moving material in a manner satisfactory to the Engineer. The Contractor may use asphalt concrete approved by the Engineer.
301.06 Basis of Payment. The Department will pay for accepted quantities,
complete in place, at the contract price as follows: Item Unit Description 301 Cubic Yard Asphalt Concrete Base (Cubic Meter) ITEM 302 ASPHALT CON CRETE BASE
302.01 Description
302.02 Composition
302.03 Mixing
302.04 Spreading and Finishing
302.05 Spreading and Surface Tolerances
302.06 Basis of Payment
302.01 Description. This work consists of constructing a base course of
aggregate and asphalt binder, mixed in a central plant and spread and compacted on a prepared surface. The requirements of Item 401 apply, except as modified by this specification.
302.02 Composition
A.General. Furnish a mixture that conforms to the following gradation: Sieve Size Total Percent Passing 2 inch (50 mm) 100 1 1/2 inch (37.5 mm) 85 to 100 1 inch (25.0 mm) [1] 68 to 88 3/4 inch (19.0 mm) [1] 56 to 80 1/2 inch (12.5 mm) [1] 44 to 68 3/8 inch (9.5 mm) [1] 37 to 60 No. 4 (4.75 mm) 22 to 45 No. 8 (2.36 mm) 14 to 35 No. 16 (1.18 mm) 8 to 25 No. 30 (600 µm) 6 to 18 No. 50 (300 µm) 4 to 13 No. 200 (75 µm) 2 to 6 [1] Provide aggregate to retain a minimum of 7 percent of the material on each of these sieves. This requirement applies to the gradation of the JMF and the mix production according to Item 403. In the design of the asphalt concrete base, the requirements of Item 441 apply, except as follows: The Contractor may use reclaimed asphalt concrete pavement according to
401.04 Should problems with proper coating or other material issues related to the 302.02
163 use of reclaimed asphalt concrete pavement or reclaimed asphalt shingles be evident, OMM may restrict the allowable percent age of reclaimed asphalt concrete pavement to the reduced limits shown in tables 401.04 -1 and 401.04 -2 or may eliminate use of reclaimed asphalt shingles. In this case the virgin binder content will be adjusted by OMM. Add hydrated lime in the dry form at a rate of 0.75 percent by the dry weight of aggregate for asphalt concrete base, if antistrip additive is required and hydrated lime is used. Design the asphalt concrete base to yield 4.0 percent air voids and the following properties: Property Acceptable Range of Values Minimum Maximum Binder Content, % Note 1 6.0[Total] Stability, lb (N), 70 blow 3000 (13,345) -- Flow, 0.25 mm, 70 blow -- 28 Voids in Mineral Aggregate % 12.0 -- Note 1: See tables in 401.04 Use equipment that meets the requirements of a Level 3 laboratory as specified in Supplement 1041. Ensure that the following equipment is designed and manufactured according to ASTM D5581 to prepare and test a Marshall specimen with a 6.0 -inch (152.4 mm) diameter and a 3.75 ±0.05 inch (95 ±1.3 mm) height:
1.Specimen mold assembly
2.Specimen extractor
3.Compaction hammer.
4.Compaction pedestal specimen mold holder.
5.Marshall test apparatus. Produce batches of asphalt concrete base in the amount that will result in a compacted specimen 3.75 ±0.05 inch (95 ±1.3 mm) in height. This amount is about 4050 grams.
B.Compaction of Specimens. Fill the mold with asphalt concrete base by placing approximately one -half of the batch in the mold and spading it vigorously with a heated spatula or trowel 15 times around the perimeter and ten times over the interior. Place the second half of the batch in the mold and spade the mixture in the same manner. Compact the specimen on both sides with 70 blows.
C.Stability Correlation Ratios. Convert measured stability values for specimens that depart from the standard 3.75 -inch (95 mm) thickness to an equivalent 3.75 -inch (95 mm) value by multiplying the stability value by the appropriate correlation ratio as follows: 302.03 164 Approximate Thickness of Specimen, inches (mm) Correlation Ratio 3 1/2 (89) 1.12 3 9/16 (90) 1.09 3 5/8 (92) 1.06 3 11/16 (94) 1.03 3 3/4 (95) 1.00 3 13/16 (97) 0.97 3 7/8 (98) 0.95 3 15/16 (100) 0.92 4 (102) 0.90
302.03 Mixing. Conform to the requirements of 301.03.
302.04 Spreading and Finishing. Ensure that the compacted depth of any one
layer is a minimum of 4 inches (100 mm) and a maximum of 7.75 inches (190 mm). If the plan thickness is 7.0 -7.75 inches (178 mm – 190 mm) and District Testing confirms the JMF and mixture production has 95% passing the 1.50 inch (37.5 mm) sieve, the 302 may be placed in two lifts if requested by the Contractor. One lift of plan thickness will be required if top size aggregate dragging occurs. Ensure that the temperature of the mixt ure when delivered to the paver is a minimum of 250 °F (120 °C). Ensure the temperature of the mixture is sufficient for the roller coverage to be effective in compacting the mixture .
302.05 Spreading and Surface Tolerances. Conform to the requirements of
301.05.
302.06 Basis of Payment. The Department will pay for accepted quantities,
complete in place, at the contract price as follows: Item Unit Description 302 Cubic Yard Asphalt Concrete Base (Cubic Meter) ITEM 304 AGGREGATE BASE
304.01 Description
304.02 Materials
304.03 Before Spreading
304.04 Spreading
304.05 Compaction
304.06 Finished Surface
304.07 Method of Measurement
304.08 Basis of Payment
304.01 Description. This work consists of furnishing, placing, and compacting
one or more courses of a ggregate on a prepared surface, including furnishing and incorporating all water required for compaction.
304.02 Materials. Furnish materials conforming to 703.17. 304.03
165 304.03 Before Spreading. Sample the material stockpile , accord ing to ASTM D75, to determine the initial moisture content to be used for compaction. Create the moisture -density curve according to AASHTO T 99, Method C, to determine the optimum moisture content .. For projects when the total volume of material is less than 1000 cubic yards (765 m3), the optimum moisture content may be obtained from a moisture -density curve that was performed on the material within 1 year prior to the date of placement. Submit moisture -density test results to the Engineer . Use material that has reasonably uniform moisture content. Ensure the moisture content is not less than 2 percent below the optimum moisture content before spreading. Add water to the stockpile if necessary to meet this moisture requirement. Handle the material in a manner to minimize segregation. If segregation occurs, thoroughly mix or regrade the stockpile.
304.04 Spreading. Spread the material on the prepared surface. Do not use
frozen material and do not spread on frozen surfaces. Do not exceed a compacted lift thickness of 8 inches (200 mm) when using vibratory rollers with effective weights greater than 12 tons (11 metric tons). Do not exceed a compacted lift thickness of 6 inches (150 mm) when using vibratory rollers with effective wei ghts from 10 to 12 tons (9 to 11 metric tons). Do not exceed a maximum compacted lift thickness of 4 inches (100 mm) when these vibratory rollers are not used. The effective weight of a vibratory roller is the weight plus the centrifugal force from vibrati on. Submit documentation from the manufacturer that shows the vibratory roller meets the minimum effective weight requirements. Place the material in two or more approximately equal lifts when the specified compacted thickness exceeds the maximum allowed. Place the material with self -propelled spreading machines capable of placing the material true to line and grade. Spreading machines such as spreader boxes or pavers are allowed. Do not use graders or dozers without spreader boxes to spread the material ex cept for areas described in the next paragraph. Spread the material such that it minimizes segregation and requires minimal blading or manipulation. The Department may perform in -place gradation testing in areas that are visually segregated according to Su pplement 1090. The Contractor may use hand -placing methods, dozers or graders when the total area of the material is 2000 square yards (1700 m²) or less or in small areas where self-propelled spreading machines are impractical. Small areas include lane wid ths less than 12 feet (3.7 m) or lengths less than 1000 feet (305 m). The Department will not take in -place gradation tests in these small areas. The Department may test for in -place gradation after spreading but before compaction testing according to Supplement 1090.
304.05 Compaction. Add water or dry the material to bring it to within 2 percent
of the optimum moisture content before compacting. Maintain the moisture content within this range during all compaction operations. The Engineer will determi ne the percentage of moisture to apply or to be dried from the material. Uniformly apply the water or dry the material throughout the lift and in a manner that does not soften 304.06 166 or disturb the lower courses. Reduce the moisture content if the material become s unstable during the compaction operation. Compact each lift of material immediately after spreading. Use rollers that correspond with the lift thickness as described in 304.04. The Contractor may use lighter rollers or vibratory equipment in small areas as specified in 304.04 or when heavier rollers are not practical. Approved compaction equipment may consist of vibratory rollers, static rollers, or vibratory equipment. At the beginning of the compaction operation, construct a test section according to Su pplement 1015. Use a minimum compactive effort of eight passes to construct the test section. Use and adjust the vibration on the vibratory rollers to maximize the density and stability. Construct a new test section when the material changes or when the su pporting materials change appreciably. Unless otherwise specified in the Contract Documents, the Engineer will perform all compaction tests according to Supplement 1015. The Engineer will use 98 percent of the test section maximum dry density for acceptanc e of the production material. Use at least the same number of passes and compactive effort used to obtain the test section maximum dry density for the production material. At a minimum, use eight passes in the production area. The Engineer may reduce the m inimum passes if the passes are detrimental to compaction. The Engineer may check the production material density before or after the finishing operations. Maintain the surface of each lift during the compaction operations in such a manner that the surface texture is reasonably uniform and the material is firmly keyed. Cover the aggregate base with the next layer of pavement before the end of the construction season. If the aggregate base is not covered up, then assume all liability for contamination of, da mage to and instability of the base, subgrade and underdrains. Provide drainage and maintain the material according to 203.04.A.
304.06 Finished Surface. Ensure that the finished surface does not vary more
than 3/8 inch (10 mm) from a 10 -foot (3 m) straigh tedge parallel to the centerline or more than 1/2 inch (13 mm) from a template conforming to the required cross - section. Furnish straightedges, templates, or other devices satisfactory to the Engineer, and check the surface for conformance with these requi rements. Do not construct the aggregate base at a consistent depth below the required minimum compacted depth thickness. When the depth is found to be less than the required depth, provide the Engineer with a written corrective action plan for approval.
304.07 Method of Measurement. The Department will measure Aggregate
Base by the number of cubic yards (cubic meters) computed from the profile grade and typical sections, compacted in place.
Source: Ohio Construction and Material Specifications, 2019 Edition. Pages 0–0 of 928.