230-1 Description.
Construct a base course composed of roadbed soil stabilized with limerock.
230-2 Materials.
Meet the limerock material requirements as specified in Section 911.
230-3 Equipment.
230-3.1 For Mixing: For mixing in the roadway, provide a heavy -duty rotary tiller or
other equipment approved by the Engineer as equally effective for this work.
230-3.2 For Compaction: Select the equipment for compacting the stabilized material,
except that for the final finish use a steel -wheeled roller.
230-4 Preparation of Roadbed.
Complete the area to be stabilized to the lines shown in the Plans and to a grade parallel to the finished elevation of the stabilized base, before adding the stabilizing material. Ens ure that the elevation of the roadbed is such that the base will conform to the typical section upon completing the work. Dispose of any surplus excavated materials resulting from this work, as specified in 120 -5.
230-5 Incorporation of Stabilizing Materia l and Mixing -In.
230-5.1 Spreading and Mixing: Place the limerock on the areas to be stabilized, and
spread it uniformly to the loose depth shown in the Plans or ordered by the Engineer. Then, thoroughly mix the limerock with the soil. Perform mixing as s oon as practicable but not later than one week after placing the limerock on the road. Do not spread more limerock in advance of the mixing operations than can be mixed -in with the soil within one week.
230-5.2 Further Mixing Operations: Repeat the mixing operations as often as may be
necessary to distribute the limerock uniformly throughout the soil, as determined by the Engineer. Further manipulate the material to uniformly distribute the limerock throughout the width and depth of the base course.
230-5.3 Plant Mixing: The Contractor may mix the soil, limerock, and water using the
central plant -mix method in lieu of mixing in place, provided he obtains a uniform mixture with the proper amount of water.
230-5.4 Shaping Surface: After mixing, shape the su rface so it conforms to the grade
and typical section shown in the Plans after compacting.
230-5.5 Depth of Mixing Stabilizing Material: Ensure that the depth of mixing of the
stabilizing material is in accordance with Table 230-1 below: FY 2023-24 Return to Table of Contents Table 230-1 Specified Base Thickness (inches) Required Mixing Depth (inches) Minimum Maximum 6 5-1/2 7-1/2 8 7-1/4 9-3/4 10 9 12 In the event that the measured depth of mixing is less than the minimum specified above, remix the base course, as directed by the Engineer, until the stabilizing material is distributed to the required depth throughout the base course. Where the measured depth of mixing exceeds the maximum limits specified in Table 230-1 above, add 1 inch, loose measure, of stabilizing material for each 1 inch of mixing depth in excess of the allowable depth (but in no case less than 1 inch of material, for any excess depth), and mix the added material in the top 6 inches of the base as specified in 230 -5.1 and
230-5 2, at no expense to the Department. The Department will not include the volume of
stabilizing material, which is added to compensate for excess mixing depth, in the pay quant ity, and will not allow any additional compensation for the extra mixing required.
230-6 Compacting and Finishing Base.
Meet the requirements of 200 -6.
230-7 Testing Surface.
Test the surface in accordance with the requirements of 200 -7.
230-8 Priming an d Maintaining.
Meet the requirements of 200 -8.
230-9 Method of Measurement.
230-9.1 General: The quantities to be paid for will be the plan quantity, in square yards,
completed and accepted.
230-9.2 Quantity of Limerock: The quantity to be paid for will be as specified in
210-8 2.
230-10 Basis of Payment.
Prices and payments will be full compensation for all work specified in this Section, including furnishing, hauling, placing, spreading, mixing, compacting, prime coat application as specified in 300-7 and finishing all limerock stabilizing material; any necessary excavating below the finished grade of the base to provide for placing the stabilizing material; and disposing of all surplus excavation resulting from this work. Where extra limerock ma terial is placed at locations of culverts, etc., as detailed in the Plans, the volume of such material, determined as provided above, will be included in the quantity of limerock material to be paid for, but no adjustment will be made in the area of base t o be paid for. Payment will be made under: Item No. 230 - 1- Limerock Stabilized Base - per square yard. Item No. 230 - 2- Limerock Material - per cubic yard. FY 2023-24 Return to Table of Contents SECTION 234 SUPERPAVE ASPHALT BASE
234-1 Description.
Construct a Superpave asphalt concrete base course as defined in these Specifications. Base course mixes are designated as Type B-12.5. The Contractor may use a Type SP-12.5 mixture (Traffic Level B, C, or E) or a Type SP-19.0 mixture (Traffic Level B, C, or E), in lieu of a Type B-12.5 at no additional cost to the Department. Obtain Superpave asphalt base from a plant that is currently on the Department’s Production Facility Listing . Producers seeking inclusion on the list shall meet the requirements of Section 105.
234-2 Materials.
234-2.1 General: Use materials that conform to the requirements of Division III. Specific
references are as follows : Superpave PG Asphalt Binder ........................... Section 916 Coarse Aggregate, Stone, Slag or Crushed Gravel ................................ ................... Section 901 Fine Aggregate ................................ .................... Section 902
234-2.2 Reclaimed Asphalt Pavement (RAP): RAP may be used as a component
material of the asphalt mixture provided the requirements of 334 -2.3 are met.
234-3 General Composition of Mixture.
234-3.1 General: Compose the asphalt mixture using a combination of aggregate
(coarse, fine or mixtures thereof), mineral filler if required, and asphalt binder material. Size, grade and combine the aggregate fractions to meet the grading and physical properties of the mix design. Aggregates from various sources may be combined.
234-3.2 Mix Design: Unless otherwise specified, design the mix such that all
requirements for a Type SP-12.5, Traffic Level B or C mixture as specified in Section 334 are met.
234-3.2 1 Gradation Classification: Use a fine mix as defined in 334 -3.2.2.1.
234-3.2 2 Aggregate Consensus Properties: Meet the aggregate consensus
properties at design as specified in 334 -3.2.3. Meet the criteria spe cified for a depth of top of pavement layer from surface of greater than 4 inches.
234-3.2 3 Mix Design Revisions: Meet the requirements of 334 -3.3.
234-4 Contractor’s Process Control.
Meet the requirements of 320 -2, 330-2 and 334 -4.
234-5 Acceptance of the Mixture.
The mixture will be accepted in accordance with the requirements of 334 -5. Use the permissible variations from longitudinal and transverse grades as specified in 200 -7.
234-6 Plant, Methods and Equipment.
Meet requirements of Section 320, with the following modifications:
234-6.1 Paving Equipment : A motor grader may be used to spread the first course of
multiple course bases when the subgrade will not support the use of a mechanical spreader. The FY 2023-24 Return to Table of Contents