204-1 Description.
Construct a base course composed of graded aggregate.
204-2 Materials.
Use graded aggregate material, produced from Department approved sources, which yields a satisfactory mixture meeting all the requirements of these Specifications after it has been crushed and processed as a part of the mining operations. The Contractor may furnish the material in two sizes of such gradation that, when combined in a central mix plant pugmill, the resultant mixtu re meets the required specifications. Use graded aggregate base material of uniform quality throughout, substantially free from vegetable matter, shale, lumps and clay balls, and having a Limerock Bearing Ratio value of not less than 100. Use material ret ained on the No. 10 sieve composed of aggregate meeting the following requirements: Soundness Loss, Sodium, Sulfate: AASHTO T104 ...... 15% Percent Wear: AASHTO T 96 (Grading A) Group 1 Aggregates ................................ ....................... 45% Group 2 Aggregates ................................ ....................... 65% Group 1: This group of aggregates is composed of limestone, marble, or dolomite. Group 2: This group of aggregates is composed of granite, gneiss, or quartzite. Use graded aggregate base material meeting the following gradation: Table 204-1 Sieve Size Percent by Weight Passing 2 inch 100 1-1/2 inch 95 to 100 3/4 inch 65 to 90 3/8 inch 45 to 75 No. 4 35 to 60 No. 10 25 to 45 No. 50 5 to 25 No. 200 0 to 10 For Group 1 aggregates, ensure that the fraction passing the No. 40 sieve has a Plasticity Index (AASHTO T 90) of not more than 4.0 and a Liquid Limit (AASHTO T 89) of not more than 25, and contains not more than 67% of the weight passing the No. 200 sieve. For Group 2 aggregates, ensure that the material passing the No. 10 sieve has a sand equivalen t (AASHTO T 176) value of not less than 28. The Contractor may use graded aggregate of either Group 1 or Group 2, but only use one group on any Contract. (Graded aggregate may be referred to hereinafter as “aggregate”.) FY 2023-24 Return to Table of Contents
204-3 Equipment.
Provide equipment meeting the requirements of 200 -3.
204-4 Transporting Aggregate.
Transport aggregate as specified in 200 -4.
204-5 Spreading Aggregate.
Spread aggregate as specified in 200 -5.
204-6 Compacting and Finishing Base.
204-6.1 General: Meet the requirements o f 200-7.1 with density requirements of
204-6 3.
204-6.1 1 Single -Course Base: Construct as specified in 200 -6.1.1.
204-6.1 2 Multiple -Course Base: Construct as specified in 200 -6.1.2.
204-6.2 Moisture Content: Meet the requirements of 200 -6.2.
204-6.3 Density Requirements: After attaining the proper moisture conditions,
uniformly compact the material to a density of not less than 100% of the maximum density as determined by FM 1-T 180, Method D. For shoulder only areas and shared use paths, obta in a minimum density of 98% of the maximum density as determined by FM 1-T 180, Method D.
204-6.4 Density Tests: Meet the requirements of 200 -7.2.2.
204-6.5 Correction of Defects: Meet the requirements of 200 -6.4.
204-6.6 Dust Abatement: Minimize the dispersion of dust from the base material during
construction and maintenance operations by applying water or other dust control materials.
204-7 Testing Surface.
Test the surface in accordance with the requirements of 200 -7.
204-8 Priming a nd Maintaining.
Meet the requirements of 200 -8.
204-9 Thickness Requirements.
Meet the requirements of 285 -6.
204-10 Calculations for Average Thickness of Base.
Calculations for determining the average thickness of base will be made in accordance with 285-7.
204-11 Method of Measurement.
204-11.1 General: The quantity to be paid for will be the plan quantity area, in square
yards, completed and accepted.
204-11.2 Authorized Normal Thickness Base: The surface area of authorized normal
thickness base wil l be the plan quantity area, omitting any areas not allowed for payment under the provisions of 204 -9 and omitting areas which are to be included for payment under 204 -11.3. The area for payment, of authorized normal thickness base, will be the surface are a determined as provided above, adjusted by adding or deducting, as appropriate, the area of base represented by the difference between the calculated average thickness, determined as provided in 204 -10, and the specified normal thickness, converted to equ ivalent square yards of normal thickness base. FY 2023-24 Return to Table of Contents
204-11.3 Authorized Variable Thickness Base: As specified in 200 -10.3.
204-12 Basis of Payment.
Price and payment will be full compensation for all work specified in this Section, including dust abatement, c orrecting all defective surface and deficient thickness, removing cracks and checks and the additional aggregate required for such crack elimination. Payment will be made under: Item No. 285 - 7- Optional Base - per square yard. FY 2023-24 Return to Table of Contents SECTION 210 REWORKING LIMEROCK BASE
210-1 Description.
Rework (or rework and widen) the existing rock base, by adding new limerock material as required by the Plans. Construct adjacent turnouts, entirely with new limerock.
210-2 Materials.
Meet the limerock material requirements as specified in Section 911 if new limerock is needed. The Contractor may use limerock of either Miami Oolite or Ocala Formation but only use limerock of one formation on any Contract.
210-3 Equipment.
Provide equipment meeting the requirements of 200 -3.
210-4 Existing B ituminous Surfaces.
210-4.1 Asphalt Concrete: Remove asphalt concrete surfaces from the base prior to
excavating trenches or scarifying the rock. Dispose of removed materials as specified in 120 -5.
210-4.2 Bituminous Surface Treatment: Remove and dispose of existing bituminous
surface treatment only when specifically specified in the Plans. Otherwise, the Contractor may mix the existing bituminous surfacing in with the existing limerock material.
210-5 Trenches and Subgrade.
Where widening the existing b ase, excavate trenches along the edges of the existing pavement to the width and depth indicated in the Plans. Excavate the trenches before scarifying the existing base. Shape, compact, and maintain the subgrade of the trenches and turnouts as specified in 120-9, except that when stabilization of the subgrade is not included in the Plans, do not compact the trenches unless the native underlying material has been disturbed. Dispose of all excavated materials as specified in 120 -5.
210-6 Spreading, Shaping, a nd Compacting Rock.
210-6.1 General: Scarify and disk, or otherwise loosen the existing base to such extent
that no pieces larger than 3 1/2 inches in greatest dimension remain bonded together. Then, spread the material to the full width of the proposed n ew base course and to a grade and cross - section roughly parallel to the finished grade. Meet the requirements of 200 -7.1.
210-6.2 Widening Strips: Where the widening strips are not of sufficient width to permit
the use of standard compaction equipment, co mpact the rock in accordance with 200 -6.5.
210-6.3 Construction Sequence: Do not spread any material for the upper course until
the Engineer has made the density tests on the lower course and has determined that the specified compaction requirements have been met. Then, construct the second course of new limerock in accordance with the requirements of 200 -5 through 200 -7.
210-7 Priming and Maintaining.
Meet the requirements of 200 -8. FY 2023-24 Return to Table of Contents