Attachment N - UFGS 32 11 20 Base Course.pdf

SECTION 32 11 20 Page 1

SECTION TABLE OF CONTENTS DIVISION 32 - EXTERIOR IMPROVEMENTS

SECTION 32 11 20

BASE COURSE FOR RIGID AND SUBBASES FOR FLEXIBLE PAVING

08/17

Table of Contents

PART 1 GENERAL

1.2 REFERENCES

1.3 DEGREE OF COMPACTION

1.4 SUBMITTALS

1.5 EQUIPMENT, TOOLS, AND MACHINES

1.6 QUALITY ASSURANCE

1.7 ENVIRONMENTAL REQUIREMENTS

PART 2 PRODUCTS

2.1 MATERIALS

2.2 TESTS, INSPECTIONS, AND VERIFICATIONS

PART 3 EXECUTION

3.1 GENERAL REQUIREMENTS

3.2 STOCKPILING MATERIAL

3.3 PREPARATION OF UNDERLYING COURSE OR SUBGRADE

3.4 GRADE CONTROL

3.5 MIXING AND PLACING MATERIALS

3.6 LAYER THICKNESS

3.7 COMPACTION

3.8 EDGES OF SELECT MATERIAL

3.9 FINISHING

3.10 SMOOTHNESS TEST

3.11 FIELD QUALITY CONTROL

3.12 TRAFFIC

3.13 MAINTENANCE

3.14 DISPOSAL OF UNSATISFACTORY MATERIALS

SECTION 32 11 20 Page 2

SECTION 32 11 20

BASE COURSE FOR RIGID AND SUBBASES FOR FLEXIBLE PAVING

08/17

PART 1 GENERAL.

1.1 Waybills and Delivery Tickets

Submit copies of waybills and delivery tickets during progress of the work. Before the final payment is allowed, file certified waybills and certified delivery tickets for all aggregates actually used.

1.2 REFERENCES.

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS

(AASHTO)

AASHTO T 88 (2013) Standard Method of Test for

Particle Size Analysis of Soils

AASHTO T 180 (2017) Standard Method of Test for

Moisture-Density Relations of Soils Using a 4.54-kg (10-lb) Rammer and a 457-mm

(18-in.) Drop

AASHTO T 224 (2010) Standard Method of Test for

Correction for Coarse Particles in the

Soil Compaction Test

ASTM INTERNATIONAL (ASTM)

ASTM C29/C29M (2017a) Standard Test Method for Bulk

Density ("Unit Weight") and Voids in

Aggregate

ASTM C117 (2017) Standard Test Method for Materials

Finer than 75-um (No. 200) Sieve in

Mineral Aggregates by Washing

ASTM C131/C131M (2020) Standard Test Method for Resistance to Degradation of Small-Size Coarse

Aggregate by Abrasion and Impact in the

Los Angeles Machine

ASTM C136/C136M (2019) Standard Test Method for Sieve

Analysis of Fine and Coarse Aggregates

ASTM D75/D75M (2019) Standard Practice for Sampling

Aggregates

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ASTM D1556/D1556M (2015; E 2016) Standard Test Method for

Density and Unit Weight of Soil in Place by Sand-Cone Method

ASTM D1557 (2012; E 2015) Standard Test Methods for

Laboratory Compaction Characteristics of

Soil Using Modified Effort (56,000 ft-lbf/ft3) (2700 kN-m/m3)

ASTM D2167 (2015) Density and Unit Weight of Soil in

Place by the Rubber Balloon Method

ASTM D2487 (2017; E 2020) Standard Practice for

Classification of Soils for Engineering

Purposes (Unified Soil Classification

System)

ASTM D4318 (2017; E 2018) Standard Test Methods for

Liquid Limit, Plastic Limit, and

Plasticity Index of Soils

ASTM D6938 (2017a) Standard Test Method for In-Place

Density and Water Content of Soil and

Soil-Aggregate by Nuclear Methods (Shallow

Depth)

ASTM E11 (2020) Standard Specification for Woven

Wire Test Sieve Cloth and Test Sieves

1.3 DEGREE OF COMPACTION.

Degree of compaction required, except as noted in the second sentence, is expressed as a percentage of the maximum laboratory dry density obtained by the test procedure presented in ASTM D1557 abbreviated as a percent of laboratory maximum dry density. Since ASTM D1557 applies only to soils that have 30 percent or less by weight of their particles retained on the

3/4 inch sieve, the degree of compaction for material having more than 30 percent by weight of their particles retained on the 3/4 inch sieve will be expressed as a percentage of the laboratory maximum dry density in accordance with AASHTO T 180 Method D and corrected with

AASHTO T 224.

1.4 SUBMITTALS.

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the government officer that will review the submittal for the Government.

SD-03 Product Data

Plant, Equipment, and Tools; G, COR

Waybills and Delivery Tickets

SD-06 Test Reports

Initial Tests; G, COR

In-Place Tests; G, COR

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1.5 EQUIPMENT, TOOLS, AND MACHINES.

All plant, equipment, and tools used in the performance of the work will be subject to approval by the Contracting Officer before the work is started. Maintain all plant, equipment, and tools in satisfactory working condition at all times. Submit a list of proposed equipment, including descriptive data. Use equipment capable of minimizing segregation, producing the required compaction, meeting grade controls, thickness control, and smoothness requirements as set forth herein.

1.6 QUALITY ASSURANCE.

Sampling and testing are the responsibility of the Contractor. Work requiring testing will not be permitted until the testing laboratory has been inspected and approved. Test the materials to establish compliance with the specified requirements and perform testing at the specified frequency.

The Contracting Officer may specify the time and location of the tests.

Furnish copies of test results to the Contracting Officer within 24 hours of completion of the tests.

1.6.1 Sampling

Take samples for laboratory testing in conformance with ASTM D75/D75M.

When deemed necessary, the sampling will be observed by the Contracting

Officer.

1.6.2 Tests

1.6.2.1 Sieve Analysis

Perform sieve analysis in conformance with ASTM C117 and ASTM C136/C136M using sieves conforming to ASTM E11.

1.6.2.2 Liquid Limit and Plasticity Index

Determine liquid limit and plasticity index in accordance with ASTM D4318.

1.6.2.3 Moisture-Density Determinations

Determine the laboratory maximum dry density and optimum moisture in accordance with paragraph DEGREE OF COMPACTION.

1.6.2.4 Field Density Tests

Measure field density in accordance with ASTM D1556/D1556M, ASTM D2167, or

ASTM D6938. For the method presented in ASTM D1556/D1556M, use the base plate, as shown in the drawing. For the method presented in ASTM D6938, check the calibration curves and adjust them, if necessary, using only the sand cone method as described in paragraph Calibration, of the ASTM publication. Tests performed in accordance with ASTM D6938 result in a wet unit weight of soil and ASTM D6938 will be used to determine the moisture content of the soil. Also check the calibration curves furnished with the moisture gauges along with density calibration checks as described in ASTM D6938. Make the calibration checks of both the density and moisture gauges using the prepared containers of material method, as described in paragraph Calibration, in ASTM D6938, on each different type of material to be tested at the beginning of a job and at intervals as directed. Submit calibration curves and related test results prior to using the device or equipment being calibrated.

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1.7 ENVIRONMENTAL REQUIREMENTS.

Perform construction when the atmospheric temperature is above 35 degrees F.

When the temperature falls below 35 degrees F, protect all completed areas by approved methods against detrimental effects of freezing. Correct completed areas damaged by freezing, rainfall, or other weather conditions to meet specified requirements.

PART 2 PRODUCTS.

2.1 MATERIALS.

2.1.1 Subbase Course

Subbase Course. Provide aggregates consisting of crushed stone or slag, gravel, shell, sand, or other sound, durable, approved materials processed and blended or naturally combined. Provide aggregates which are free from lumps and balls of clay, organic matter, objectionable coatings, and other foreign material. The percentage of loss of material retained on the No. 4 sieve must not exceed 50 percent after 500 revolutions when tested in accordance with ASTM C131/C131M. Provide aggregate that is reasonably uniform in density and quality. Provide lag that is an air-cooled, blast-furnace product having a dry weight of not less than 65 pcf. Provide aggregates with a maximum size of 1.5 inch and within the limits specified as follows:

Passing Square-Mesh Sieve

Sieve Designation No. 1 No.2 No. 3

No. 10 50 80 100

No. 200 8 8 8

Particles having diameters less than 0.02 mm must not be in excess of 3 percent by weight of the total sample tested as determined in accordance with

AASHTO T 88. The portion of any blended component and of the completed course passing the No. 40 sieve must be either nonplastic or have a liquid limit not greater than 25 and a plasticity index not greater than 5.

2.1.2 Select-Material Subbase Course

Provide materials consisting of selected soil or other materials from field excavation, stockpiles, or other sources and free from lumps and balls of clay and from organic and other objectionable matter. Provide materials with not more than 25 percent by weight passing the No. 200 sieve. The portion of material passing the No. 40 sieve must have a liquid limit less than 35 and a plasticity index less than 12. Provide materials having a maximum particle size not exceeding 3 inches. Particles having a diameter less than 0.02 mm must not be in excess of 3 percent by weight of the total sample tested as determined in accordance with AASHTO T 88.

2.1.3 Rigid Pavement Base Course

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Provide aggregates consisting of crushed stone or slag, gravel, shell, sand, or other sound, durable, approved materials processed and blended or naturally combined. Provide aggregates which are durable and sound, free from lumps and balls of clay, organic matter, objectionable coatings, and other foreign material. The percentage of loss of material retained on the

No. 4 sieve must not exceed 50 percent after 500 revolutions when tested in accordance with ASTM C131/C131M. At least 50 percent by weight retained on each sieve must have one freshly fractured face with the area at least equal to 75 percent of the smallest midsectional area of the piece.

Provide aggregate that is reasonably uniform in density and quality.

Provide slag that is an air-cooled, blast-furnace product having a dry weight of not less than 65 pcf. Provide aggregates having a maximum size of 2 inches and within the limits specified as follows:

Maximum Allowable Percentage by Weight

Passing Square-Mesh Sieve

Sieve

Designation

Rigid Pavement

Base Course

No. 10 85

No. 200 15

The portion of any blended component and of the completed course passing the

No. 40 sieve must be either nonplastic or have a liquid limit not greater than 25 and a plasticity index not greater than 6. The Contractor is responsible for any additional stability required to provide a working platform for construction equipment. If the Contractor can demonstrate with a test section that a material has adequate stability to support construction equipment, the fractured face requirement can be deleted, subject to the approval of the Contracting Officer Representative.

2.2 TESTS, INSPECTIONS, AND VERIFICATIONS.

2.2.1 Initial Tests

Perform one of each of the following tests on the proposed material prior to commencing construction to demonstrate that the proposed material meets all specified requirements prior to installation. Complete this testing for each source if materials from more than one source are proposed.

a. Sieve Analysis.

b. Liquid limit and plasticity index.

c. Moisture-density relationship.

Submit certified copies of test results for approval not less than 30 days before material is required for the work.

2.2.2 Approval of Material

Tentative approval of material will be based on initial test results.

PART 3 EXECUTION.

3.1 GENERAL REQUIREMENTS.

Provide adequate drainage during the entire period of construction to prevent water from collecting or standing on the working area.

3.2 STOCKPILING MATERIAL.

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Clear and level storage sites prior to stockpiling of material. Stockpile all materials, including approved material available from excavation and grading, in the manner and at the locations designated. Stockpile aggregates on the cleared and leveled areas designated by the Contracting

Officer to prevent segregation. Stockpile materials obtained from different sources separately.

3.3 PREPARATION OF UNDERLYING COURSE OR SUBGRADE.

Clean the underlying course or subgrade of all foreign substances prior to constructing the select-material. Do not construct select-material subbase on underlying course or subgrade that is frozen. Construct the surface of the underlying course or subgrade to meet specified compaction and surface tolerances. Correct ruts or soft yielding spots in the underlying courses, areas having inadequate compaction, and deviations of the surface from the specified requirements set forth herein by loosening and removing soft or unsatisfactory material and adding approved material, reshaping to line and grade, and recompacting to specified density requirements. For cohesionless underlying courses or subgrades containing sands or gravels, as defined in

ASTM D2487, stabilize the surface prior to placement of the overlying course. Stabilize by mixing the overlying course material into the underlying course and compacting by approved methods. Consider the stabilized material as part of the underlying course and meet all requirements of the underlying course. Do not allow traffic or other operations to disturb the finished underlying course and maintain in a satisfactory condition until the overlying course is placed.

3.4 GRADE CONTROL.

Provide a finished and completed select-material subbase conforming to the lines, grades, and cross sections shown. Place line and grade stakes as necessary for control.

3.5 MIXING AND PLACING MATERIALS.

Mix and place the materials to obtain uniformity of the material at the water content specified. Make such adjustments in mixing or placing procedures or in equipment as may be directed to obtain the true grades, to minimize segregation and degradation, to reduce or accelerate loss or increase of water, and to insure a satisfactory subbase course.

3.6 LAYER THICKNESS.

Compact the completed course to the thickness indicated. No individual layer may be thicker than 6 inches nor be thinner than 3 inches in compacted thickness. Compact the course(s) to a total thickness that is within 1/2 inch of the thickness indicated. Where the measured thickness is more than

1/2 inch deficient, correct such areas by scarifying, adding new material of proper gradation, reblading, and recompacting as directed. Where the measured thickness is more than 1/2 inch thicker than indicated, the course will be considered as conforming to the specified thickness requirements.

The average job thickness will be the average of all thickness measurements taken for the job and must be within 1/4 inch of the thickness indicated.

Measure the total thickness of the course(s) at intervals of one measurement for each 500 square yards of completed course. Measure total thickness using

3 inch diameter test holes penetrating the completed course.

3.7 COMPACTION.

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Compact each layer of the material, as specified, with approved compaction equipment. Maintain water content during the compaction procedure to within plus or minus 2 percent of optimum water content determined from laboratory tests as specified in this Section. Begin rolling at the outside edge of the surface and proceed to the center, overlapping on successive trips at least one-half the width of the roller. Slightly vary the length of alternate trips of the roller. Adjust speed of the roller as needed so that displacement of the aggregate does not occur. Compact mixture with hand-operated power tampers in all places not accessible to the rollers. Continue compaction of the select-material until each layer is compacted through the full depth to at least 100 percent of laboratory maximum density. Continue compaction of the rigid base course until each layer is compacted through the full depth to at least 95 percent of laboratory maximum density. Make such adjustments in compacting or finishing procedures as may be directed by the Contracting Officer Representative (COR) to obtain true grades, to minimize segregation and degradation, to reduce or increase water content, and to ensure a satisfactory select-material subbase course. Remove any materials that are found to be unsatisfactory and replace with satisfactory material or rework, as directed, to meet the requirements of this specification.

3.8 EDGES OF SELECT MATERIAL.

Place approved material along the outer edges of the select-material subbase in sufficient quantity to compact to the thickness of the course being constructed. When the course is being constructed in two or more layers, simultaneously roll and compact at least a 2 foot width of this shoulder material with the rolling and compacting of each layer of the select-material course, as directed.

3.9 FINISHING.

Finish the surface of the top layer of rigid pavement base course after final compaction by cutting any overbuild to grade and rolling with a steel-wheeled roller. Do not add thin layers of material to the top layer of rigid pavement base course to meet grade. If the elevation of the top layer of rigid pavement base course is ½ inch or more below grade, scarify the top layer to a depth of at least 75 mm 3 inches and blend new material in and compact to bring to grade. Make adjustments to rolling and finishing procedures as directed by the Contracting Officer to minimize segregation and degradation, obtain grades, maintain moisture content, and insure an acceptable rigid pavement base course. Should the surface become rough, corrugated, uneven in texture, or traffic marked prior to completion, scarify the unsatisfactory portion and rework and recompact it or replace as directed.

3.10 SMOOTHNESS TEST.

Construct the top layer so that the surface shows no deviations in excess of

3/8 inch when tested with a 12 foot straightedge. Take measurements in successive positions parallel to the centerline of the area to be paved.

Also take measurements perpendicular to the centerline at 50 foot intervals.

Correct deviations exceeding this amount by removing material and replacing with new material, or by reworking existing material and compacting it to meet these specifications.

3.11 FIELD QUALITY CONTROL.

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3.11.1 In-Place Tests

In-Place Tests. Perform one of each of the following tests on samples taken from the placed and compacted select-material course. Take samples and test at the rates indicated.

a. Perform density tests on every lift of material placed and at a frequency of one set of tests for every 500 square yards, or portion thereof, of completed area. COR must be notified 24 hrs prior to testing.

b. Perform sieve analysis including 0.02 mm size material on every lift of material placed and at a frequency of one sieve analysis for every 1,000 square yards, or portion thereof, of material placed.

c. Perform liquid limit and plasticity index tests at the same frequency as the sieve analysis.

d. Measure the thickness of each course at intervals providing at least one measurement for each 500 square yards or part thereof. Measure the thickness using test holes, at least 3 inches in diameter through the course.

3.11.2 Approval of Material

Final approval of the materials will be based on tests for gradation, liquid limit, and plasticity index performed on samples taken from the completed and fully compacted course(s).

3.12 TRAFFIC.

Completed portions of the rigid pavement base course may be opened to limited traffic, provided there is no marring or distorting of the surface by the traffic. Do not allow heavy equipment on the completed rigid pavement base course except when necessary for construction. When it is necessary for heavy equipment to travel on the completed rigid pavement base course, protect the area against marring or damage to the completed work.

3.13 MAINTENANCE.

Maintain the completed course in a satisfactory condition until the full pavement section is completed and accepted. Immediately repair any defects and repeat repairs as often as necessary to keep the area intact.

Retest any course that was not paved over prior to the onset of winter to verify that it still complies with the requirements of this specification. Rework or replace any area that is damaged as necessary to comply with this specification.

3.14 DISPOSAL OF UNSATISFACTORY MATERIALS.

Dispose of any unsuitable materials that have been removed outside the limits of Government-controlled land. No additional payments will be made for materials that have to be replaced.

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