BASE COURSES
200-1 Description.
Construct a base composed of base rock. Do not use recycled concrete aggregate (RCA) base on interstate roadways .
200-2 Materials.
200-2.1 General: Meet the requirements of Section 911for the particular type of base to
be constructed. The Contractor may use more than one source of base rock on a single Contract provided that a single source is used throughout the entire width and depth of a section of base. Obtain approval from the Engineer before placing material from more than one source. Place material to ensure total thickness single source integrity at any station location of the base. Intermittent placement or “blending” of sources is not permitt ed. Base rock may be referred to hereinafter as “rock”. The reuse of existing base may be considered provided it meets the requirements of this Section. Submit as a Cost Savings Initiative Proposal in accordance with Section 4.
200-2.2 Existing Rock: Meet the following requirements for use of existing rock on the
same project:
1.Notify the Engineer in writing prior to excavating existing rock. Do not mill any existing rock from the roadway.
2.Submit a process control plan, herein referred to as “Pl an” consisting of the following:
a.Locations where existing rock will be removed from the roadway.
b.Locations where existing rock will be used for new construction.
c.Method of excavation, transport , and placement to ensure excavated rock will be kept separate from other approved stockpiles. Excavation methods that may result in damage to the rock rendering it unfit to be used as base will not be approved.
d.Proposed measures to prevent contamination and segregation.
e.Proposed locations and methods for constructing stockpiles for sampling and testing.
f.Method for sampling and reporting test results.
3.The Engineer will coordinate the review of the “Plan” with the District Materials Office.
4.Upon the Engineer’s review of the “Plan”, build a preliminary stockpile, not to exceed 1,000 cubic yards.
5.Collect and test a minimum of three samples from the preliminary stockpile. Once the stockpile has been sampled, do not add any additional material to the stockpile. Determine compliance with 200 -2.1, with the exception of carbonate contents. Reject any stockpile if the Limerock Bearing Ratio (LBR) is less than 100. Engineer will sample and test the preliminary stockpile to verify compliance with this Section.
6.If all test results meet the requirements of this Section, the Engineer will notify the Contractor in writing of the approved status of the preliminary stockpile based on the analysis of test data performed by the District Materials Office. FY 2023-24 Return to Table of Contents
7.If the use of exis ting rock is approved, continue to produce additional stockpiles not exceeding 1,000 cubic yards. Ensure the rock meets the requirements of this Section by sampling and testing each new stockpile at a minimum frequency of one sample per 400 cubic yards. On ce a stockpile has been sampled, do not add additional material to that stockpile. The District Materials Office may also perform sampling and testing. Materials will be accepted if test results meet the requirements of this Section.
8.After 10 consecutive quality control (QC) LBR test results meet the requirements of the Section and no individual LBR test is less than 120, the sampling and testing frequency may be reduced to a minimum frequency of one sample per 800 cubic yards for each stockpile. Notif y the Engineer in writing prior to reducing testing frequency. If any QC LBR test result falls below 120 or a stockpile is rejected, revert to original sampling frequency of one sample per 400 cubic yards.
9.Construct a new preliminary stockpile if ther e is a change in material, conditions not addressed in the “Plan” are encountered, or if production varies from the approved “Plan”.
200-3 Equipment.
Use mechanical rock spreaders, equipped with a device that strikes off the rock uniformly to laying thick ness, capable of producing even distribution. For crossovers, intersections and ramp areas; roadway widths of 20 feet or less; the main roadway area when forms are used and any other areas where the use of a mechanical spreader is not practicable; the Cont ractor may spread the rock using bulldozers or blade graders.
200-4 Transporting Rock.
Transport the rock to its point of use, over rock previously placed, if practicable, and dump it on the end of the preceding spread. Hauling and dumping on the subgrade will be permitted only when, in the Engineer’s opinion, these operations will not be detrimental to the subgrade.
200-5 Spreading Rock.
200-5.1 Method of Spreading: Spread the rock uniformly. Remove all segregated areas
of fine or coarse rock and replace them with properly graded rock.
200-5.2 Number of Courses: When the specified compacted thickness of the base is
greater than 6 inches, construct the base in multiple courses of equal thickness. Individual courses shall not be less than 3 inches. The thi ckness of the first course may be increased to bear the weight of the construction equipment without disturbing the subgrade. If, through field tests, the Contractor can demonstrate that the compaction equipment can achieve density for the full depth of a thicker lift, and if approved by the Engineer, the base may be constructed in successive courses of not more than 8 inches compacted thickness. The Engineer will base approval on results of a test section constructed using the Contractor’s specified compaction effort. Notify the Engineer prior to beginning construction of a test section. Construct a test section of the length of one LOT. Perform f ive QC density tests at random locations within the test section. At each test site, test the bottom 6 inches in addition to the entire course thickness. All QC tests and a Department Verification test must meet the density required by 200 -7.2.1. Identify the test section with the compaction effort and thickness in the Earthwork Records System (ERS) portion of the Department’s database. Remove the FY 2023-24 Return to Table of Contents materials above the bottom 6 inches, at no expense to the Department. The minimum density required on the thick er lift will be the average of the five results obtained on the thick lift in the passing test section. Maintain the exposed surface as close to “undisturbed” as possible; no further compaction will be permitted during the test preparation. If unable to ac hieve the required density, remove and replace or repair the test section to comply with the specifications at no additional expense to the Department. The Contractor may elect to place material in 6 inches compacted thickness at any time. Once approved, a change in the source of base material will require the construction of a new test section. Do not change the compaction effort once the test section is approved. The Engineer will periodically verify the density of the bottom 6 inches during thick lift operations. The Engineer may terminate the use of thick lift construction and instruct the Contractor to revert to the 6 inches maximum lift thickness if the Contractor fails to achieve satisfactory results or meet applicable specifications.
200-5.3 Rock Base for Shoulder Pavement: Unless otherwise permitted, complete all
rock base shoulder construction at any particular location before placing the final course of pavement on the traveled roadway. When dumping material for the construction of a rock base on the shoulders, do not allow material capable of scarring or contaminating the pavement surface on the adjacent pavement. Immediately sweep off any rock material that is deposited on the surface course.
200-6 Compacting and Finishing Base.
200-6.1 General: Construct mainline pavement lanes, turn lanes, ramps, parking lots,
concrete box culverts and retaining wall systems meeting the requirements of 120 -8.1, except replace “embankment” with “ base”. Construct shoulder -only areas, shared use paths, and s idewalks. Meet the requirements of 120 -8.1 except replace “ embankment” with “ base” meeting the acceptance criteria of 200 -7.2. Shoulders compacted separately shall be considered separate LOTs.
200-6.1 1 Single Course Base: After spreading, scarify the en tire surface, then
shape the base to produce the required grade and cross slope, free of scabs and laminations, after compaction.
200-6.1 2 Multiple Course Base: Clean the first course of foreign material, then
blade and bring it to a surface cross slope approximately parallel to the finished base. Before spreading any material for the upper courses, allow the Engineer to make density tests for the lower courses t o determine that the required compaction has been obtained. After spreading the material for the top course, scarify finish and shape its surface to produce the required grade and cross slope, free of scabs and laminations, after compaction.
200-6.2 Moisture Content: When the material does not have the proper moisture content
to ensure the required density, wet or dry it as required. When adding water, uniformly mix it in to the full depth of the course that is being compacted. During wetting or drying operations, manipulate, as a unit, the entire width and depth of the course that is being compacted.
200-6.3 Thickness Requirements: Within the entire limits of the length and width of the
finished base, meet the specified plan thickness in acco rdance with the requirements of 200 - 7.3.1.2.
200-6.4 Correction of Defects :
200-6.4 1 Contamination of Base Material: If, at any time, the subgrade
material becomes mixed with the base course material, dig out and remove the mixture, and FY 2023-24 Return to Table of Contents reshape and com pact the subgrade. Then replace the materials removed with clean base material, and shape and compact as specified above. Perform this work at no expense to the Department.
200-6.4 2 Cracks and Checks: If cracks or checks appear in the base, either
before or after priming, which, in the opinion of the Engineer, would impair the structural efficiency of the base, remove the cracks or checks by rescarifying, reshaping, adding base material where necessary, and recompacting.
200-6.5 Compaction of Widening S trips: Where base construction consists of widening
strips and the trench width is not sufficient to permit use of standard base compaction equipment, compact the base using vibratory compactors, trench rollers or other special equipment which will achieve the density requirements specified herein. When multiple course base construction is required, compact each course prior to spreading material for the overlaying course.
200-7 Acceptance Program.
200-7.1 General Requirements: Meet the requirements of 1 20-10, except exclude the
requirements of 120 -10.1.4.3, 120-10.3.1, 120-10.4.3, and 120 -10.4.4. Use 200-7.3.1.1 instead of
120-10.1 4.1, 200 -7.2 instead of 120 -10.2, and 200-7.4.1 instead of 120 -10.4.1.
200-7.2 Acceptance Criteria:
200-7.2 1 Density: Within the entire limits of the width and depth of the base,
obtain a minimum density in any LOT of 98% of modified Proctor maximum density as determined by FM 1-T180 or the Pit Proctor when using the Pit Proctor option. For shoulder only areas and shared use paths, obtain a minimum density of 95% of the modified Proctor maximum density as determined by FM 1-T180 or the Pit Proctor when using the Pit Proctor option.
200-7.2 2 Frequency: Conduct QC sampling and testing at a minimum frequency
listed in the table below. The Engineer will perform Verification sampling and tests at a minimum frequency listed in the table below. Table 200-1 Mainline Pavement Lanes, Turn Lanes, Ramps, Parking Lots, Concrete Box Culverts and Retaining Wall Systems Test Name Quality Control Verification Modified Proctor Maximum Density One per eight consecutive LOTs One per 16 consecutive LOTs Density One per LOT One per four LOTs Roadway Surface and Cross Slope One per LOT One per two LOTs Roadway Thickness Three per LOT Witness FY 2023-24 Return to Table of Contents Table 200-2 Shoulder-Only, Shared Use Path and Sidewalk Construction Test Name Quality Control Verification Modified Proctor Maximum Density One per two LOTs One per four LOTs Density One per LOT One per two LOTs Surface and Cross Slope One per LOT One per two LOTs Thickness Three per 1000 consecutive feet Witness
200-7.2 3 Pit Proctor: In lieu of Modified Proctor Maximum Density testing at
the roadway, notify the Engineer in writing that the Contractor option to use the Pit Proctor supplied by the Department will be used . The Modified Proctor maximum density frequency requirements of 200 -7.2.2 shall not apply. The Department will determine the Pit Proctor from statistical analysis of the base rock Modified Proctor maximum density at Department approved mines. For posting of Mine s and Pit Proctors for each calendar quarter refer to the Pit Proctor Quarterly report located at the following URL: https://www.fdot.gov/materials/labora tory/geotechnical/aggregates/pitproctor/index.shtm . Use the current posted Pit Proctor value in lieu of the Modified Proctor maximum density required by
200-7.2 1. Use the current posted Pit Proctor value for density acce ptance during the quarter
corresponding to the posting. Notify the Engineer in writing if returning to the provisions of 200 - 7.2 and 200 -7.2.2 but do not re -elect to use the Pit Proctor until the start of the next calendar quarter.
200-7.3 Additional Requ irements:
200-7.3 1 Quality Control Testing:
200-7.3 1.1 Modified Proctor Maximum Density Requirement: Collect
enough material to split and create three separate samples and retain two for the Engineer’s Verification and Resolution testing until the E ngineer accepts the 16 LOTs represented by the samples.
200-7.3 1.2 Depth and Surface Testing Requirements: Notify the
Engineer a minimum of 24 hours before checking base depths and surface checking. Determine test locations including Stations and Offse ts, using the Random Number generator approved by the Department. Do not perform depth and surface checks until the Engineer is present to witness. Enter test results into the Department’s database. Perform thickness check on the finished base or granular subbase component of a composite base. Provide traffic control, coring/boring equipment, and an operator for the coring/boring equipment. Traffic control is to be provided in accordance with the standard maintenance of traffic requirements of the Contract. The thickness is considered deficient, if the measured depth is over 1/2 inch less than the specified thickness. Correct all deficient areas of the completed base by scarifying and adding additional base material. As an exception, if authorized by the Department, such areas may be left in place without correction and with no payment.
200-7.3 1.3 Surface & Thickness Reduced Testing Frequency: When
no Resolution testing is required for 12 consecutive verified LOTs, or if required, the QC test data was upheld, reduce the QC surface and/or thickness checks to one half the minimum requirements as stated in 200 -7.2.2 (e.g., reduce frequency from ten per LOT to ten per two LOTs) by identifying the substantiating tests and notifying the Engineer in writing p rior to FY 2023-24 Return to Table of Contents starting reduced frequency of testing. If the Verification test fails, and QC test data is not upheld by Resolution testing the QC testing will revert to the original frequency of 200 -7.2.2. The results of the Independent Verification testing will not affect the frequency of the QC testing. Do not apply reduced testing frequency in construction of shoulder -only areas, shared use paths, and sidewalks .
200-7.3 2 Department Verification Tests:
200-7.3 2.1 Maximum Density: The Engineer will randoml y select one of
the remaining two split samples and test in accordance with FM 1-T180.
200-7.3 2.2 Thickness and Surface Testing Requirements: The
Department will witness the base depth and surface checks to ensure compliance with 200 - 7.3.1.2. If the QC test results are not deficient as defined in 200 -7.3.1.2, the LOT or 500 -foot section will be accepted. If the QC test results are deficient, resolve deficiencies in accordance with 200-7.3.1.2. Repeat acceptance testing. Provide traffic control , coring/boring equipment, and an operator for the coring/boring equipment.
200-7.4 Verification Comparison Criteria and Resolution Procedures:
200-7.4 1 Modified Proctor Maximum Density: The Engineer will compare the
Verification test results of 200 -7.3.2.1 to the corresponding QC test results. If the test result is within 4.5 lb/ft3 of the QC test result, the LOTs will be verified. Otherwise, the Engineer will collect the Resolution split sample corresponding to the Verification sample tested. The Stat e Materials Office or an AASHTO accredited laboratory designated by the State Materials Office will perform Resolution testing. The material will be sampled and tested in accordance with FM 1-T180. The Engineer will compare the Resolution Test results wi th the QC test results. If the Resolution Test result is within 4.5 lb/ft3 of the corresponding QC test result, the Engineer will use the QC test results for material acceptance purposes for each corresponding set of LOTs. If the Resolution test result is not within 4.5 lb/ft3 of the corresponding QC test, the Engineer will collect the remaining Verification split sample for testing. Verification Test results will be used for material acceptance purposes for the LOTs in question .
200-7.4 2 Pit Proctor: When using the Pit Proctor option, the Engineer will select
a random location to sample and test at the minimum frequency in the table below, to obtain an Independent Verification (IV) maximum density as determined by FM 1-T180. The Engineer will collect enough material to split and hold a sample for Resolution testing. Table 120-3 Test Name Mainline Pavement Lanes, Turn Lanes, Ramps, Parking Lots, Concrete Box Culverts and Retaining Wall Systems Shoulder-Only, Shared Use Path and Sidewalk Construction IV Modified Proctor Maximum Density One per 16 consecutive LOTs One per 4 consecutive LOTs The Engineer will compare the IV results with the Pit Proctor. If the IV result is lower than or equal to the Pit Proctor plus 4.5 pcf, keep the option to use the Pit Proctor. If the IV result is more than 4.5 pcf higher than the Pit Proctor the Engineer will test the Resolution sample and compar e the Resolution result with the Pit Proctor. If the Resolution FY 2023-24 Return to Table of Contents result is lower than or equal to the Pit Proctor plus 4.5 pcf, keep the option to use the Pit Proctor. Otherwise return to the provisions of 200 -7.2.2, 200 -7.3.1.1, 200 -7.3.2.1, and 200 -7.4.1.
200-7.4 3 Density: When a Verification or Independent Verification density test
does not meet the requirements of 200 -7.2.1 (Acceptance Criteria), retest at a site within a 5 feet radius of the Verification test location and observe the following:
1.If the QC retest meets the Acceptance Criteria and compares favorably with the Verification or Independent Verification test, the Engineer will accept the LOTs in question.
2.If the QC retest does not meet the Acceptance Criteria and compares favorably with the Verification or Independent Verification test, rework and retest the material in that LOT. The Engineer will re -verify the LOTs in question.
3.If the QC retest and the Verification or Independent Verification test do not compare favorably, comp lete a new equipment -comparison analysis as defined in 120 -10.1.1. Once acceptable comparison is achieved, retest the LOTs. The Engineer will perform new verification testing. Acceptance testing will not begin on a new LOT until the Contractor has a gauge that meets the comparison requirements.
200-7.4 4 Surface Testing Requirements: Resolve deficiencies in accordance
with 200-7.3.1.2.
200-7.5 Cross Slope: Construct base surface with cross slopes in compliance with the
requirements of the Contract Documents. Furnish a level with a minimum length of 4 feet with a digital slope measuring device approved by the Engineer for the control of cross slope. Make thi s level or measuring device available at the jobsite at all times during base construction operations.
200-7.5 1 Quality Control Requirements: Measure the cross slope of the base
surface by placing the measuring device perpendicular to the roadway cente rline. Report the cross slope to the nearest 0.1%. Record all the measurements and submit to the Engineer for documentation. Measure the cross slope at a minimum frequency of one measurement per lot to ensure the cross slope is uniform and in compliance wi th the design cross slope. When the difference between the measured cross slope and the design cross slope exceeds ±0.2% for travel lanes (including turn lanes) or ±0.5% for shoulders, make all corrections in accordance with 200 - 7.5.3 to bring the cross sl ope into the acceptable range.
200-7.5 2 Verification: The Engineer will verify the Contractor’s cross slope
measurements by randomly taking one measurement every two lots. If the average cross slope of the ten random measurements varies more than the a llowable tolerance from the design cross slope (±0.2% for travel lanes (including turn lanes ) and ±0.5% for shoulders), make corrections in accordance with 200-7.5.3 to bring the cross slope into the acceptable range. A recheck of the cross slope will be m ade following any corrections or additional work performed on the base surface. This process will be repeated until the base cross slope meets the requirements of this specification. The Engineer may waive the corrections specified above (at no reductio n in payment) if:
1.the deficiencies are sufficiently separated so as not to affect the overall ride quality, traffic safety and surface drainage characteristics of the pavement and;
2.the Contractor agrees to use asphalt to fill in areas where th e earthwork is low at no additional cost to the Department greater than the 10% allowed in Sections 234, 334, 337, and 339. FY 2023-24 Return to Table of Contents For intersections, tapers, crossovers, transitions at beginning and end of project and similar areas, adjust the cross slope to ma tch the actual site conditions or as directed by the Engineer.
200-7.5 3 Cross Slope Corrections: Correct all cross slopes out of tolerance per
200-7.5 1 and 200 -7.5.2 in accordance with 200-7.3.1.2.
200-7.5 4 Elevation Data Collection: Within curb and gutter areas and in
widening areas, measure and record elevation of finished surface of base course every 500 feet by measuring elevation of base adjacent to curb and gutter, as well as at each lane edge location. Provide the elevation mea surements to the Engineer.
200-8 Priming and Maintaining.
200-8.1 Priming: Apply the prime coat only when the base meets the specified density
requirements and when the moisture content in the top half of the base does not exceed the optimum moisture of t he base material. At the time of priming, ensure that the base is firm, unyielding and in such condition that no undue distortion will occur. Ensure the prime coat adheres to the base course.
200-8.2 Maintaining: Maintain the true crown and template, with no rutting or other
distortion, while applying the surface course.
200-9 Calculations for Average Thickness of Base.
For bases that are not mixed in place, the Engineer will determine the average thickness from the measurements specified in 200 -10.1, calculated as follows:
1.When the measured thickness is more than 1/2 inch greater than the design thickness shown on the typical section in the Plans, it will be considered as the design thickness plus 1/2 inch.
2.Average thickness will be calculated p er typical section for the entire job as a unit.
3.Any areas of base left in place with no payment will not be included in the calculations.
4.Where it is not possible through borings to distinguish the base materials from the underlying materials, t he thickness of the base used in the measurement will be the design thickness.
200-10 Method of Measurement.
200-10.1 General: The quantity to be paid for will be the plan quantity, adjusted as
specified below.
200-10.2 Authorized Normal Thickness Base: The surface area of authorized normal
thickness base to be adjusted will be the plan quantity as specified above, omitting any areas not allowed for payment under the provisions of 200 -6.3 and omitting areas which are to be included for payment under 200 -10.3. The adjustment shall be made by adding or deducting, as appropriate, the area of base represented by the difference between the calculated average thickness, determined as provided in 200 -9, and the specified normal thickness, converted to equivalent square yards of normal thickness base.
200-10.3 Authorized Variable Thickness Base: Where the base is constructed to a
compacted thickness other than the normal thickness as shown on the typical section in the P lans, as specified in the Plans or ordered b y the Engineer for providing additional depths at culverts or bridges, or for providing transitions to connecting pavements, the volume of such authorized FY 2023-24 Return to Table of Contents variable thickness compacted base will be calculated from authorized lines and grades, or by other methods selected by the Engineer, converted to equivalent square yards of normal thickness base for payment.
200-11 Basis of Payment.
Price and payment will be full compensation for all the work specified in this Section, including dust abatement, correctin g all defective surface and deficient thickness, removing cracks and checks as provided in 200 -6.4.2, the prime coat application as directed in 300 -8, and the additional rock required for crack elimination. Payment shall be made under: Item No. 285 - 7- Optional Base - per square yard. FY 2023-24 Return to Table of Contents SECTION 204 GRADED AGGREGATE BASE
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
Source: Florida Standard Specifications for Road and Bridge Construction, 2024 Edition. Pages 227–235 of 1,299.