32_11_20.pdf

Green Brook, Segment C-1

AMENDMENT # 1

SECTION 32 11 20

DENSE GRADED AGGREGATE (DGA)

PART 1 GENERAL

1.1 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 180 (2015) 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 C88 (2013) Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate

ASTM C117 (2017) Standard Test Method for Materials Finer than 75-um (No. 200) Sieve in Mineral Aggregates by Washing

ASTM C131/C131M (2014) Standard Test Method for Resistance to Degradation of Small-Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine

ASTM C136/C136M (2014) Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates

ASTM D75/D75M (2014) Standard Practice for Sampling Aggregates

ASTM D422 (1963; R 2007; E 2014; E 2014)

Particle-Size Analysis of Soils

ASTM D1556 (2007) Density and Unit Weight of Soil in Place by the 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 D4318 (2017) Liquid Limit, Plastic Limit, and

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Plasticity Index of Soils

ASTM D6938 (2017) Standard Test Method for In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth)

ASTM D75/D75M (2014) Standard Practice for Sampling Aggregates

ASTM E11 (2013) Wire Cloth and Sieves for Testing Purposes

NEW JERSEY DEPARTMENT OF TRANSPORTATION (NJDOT)

NJDOT Standard Specifications (2007) Standard Specifications for Road and Bridge Construction

1.2 DEFINITIONS

For the purposes of this specification, the following definitions apply.

1.2.1 Dense Graded Aggregate Subbase

Dense Graded Aggregate (DGA) subbase is well graded, crushed, durable aggregate uniformly moistened and mechanically stabilized by compaction.

1.2.2 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 are expressed as a percentage of the laboratory maximum dry density in accordance with AASHTO T 180 Method D and corrected with AASHTO T 224.

1.3 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 office that will review the submittal for the Government. Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-03 Product Data

Plant, Equipment, and Tools; G, DO

SD-04 Samples

DGA Subbase; G,DO

Submit a quantity of DGA approximately equal to a five-gallon bucket at least one week prior to initial placement of DGA material.

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SD-07 Certificates

Workplan; G,DO

Submit a workplan describing the personnel, equipment, and methods to be used in the placement and compaction of the DGA.

DGA; G,DO

Submit no less than 7 days in advance of delivery of material to the work site, in duplicate, an affidavit signed by a legally authorized official from the source of the DGA. The affidavit shall attest that the DGA meets the specific requirements stated in these specifications.

Waybills and Delivery Tickets

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

SD-06 Test Reports

Sampling and Testing; G, DO,DO Field Density Tests; G, DO,DO

1.4 WEATHER LIMITATIONS

Construction shall be done when the atmospheric temperature is above 35 degrees F. When the temperature falls below 35 degrees F, the Contractor shall protect all completed areas by approved methods against detrimental effects of freezing. Completed areas damaged by freezing, rainfall, or other weather conditions shall be corrected to meet specified requirements.

1.5 PLANT, EQUIPMENT, AND TOOLS

All plant, equipment, and tools used in the performance of the work will be subject to approval before the work is started and shall be maintained in satisfactory working condition at all times. The equipment shall be adequate and shall have the capability of producing the required compaction, meeting grade controls, thickness control, and smoothness requirements as set forth herein.

PART 2 PRODUCTS

2.1 DENSE GRADED AGGREGATE (DGA)

The DGA shall consist of clean, sound, durable particles of crushed stone, angular sand, or other approved material. The DGA shall be free of lumps of clay, organic matter, and other objectionable materials or coatings.

The portion retained on the No. 4 sieve shall be known as coarse aggregate;

that portion passing the No. 4 sieve shall be known as binder material.

2.1.1 Dense Graded Aggregate Subbase

DGA coarse aggregate shall not show more than 40 percent loss when subjected to the Los Angeles abrasion test in accordance with ASTM C131/C131M. DGA coarse aggregate shall not exhibit a loss greater

SECTION 32 11 20 Page 3 than 40 percent weighted average, at five cycles, when tested for soundness in magnesium sulfate in accordance with ASTM C88. The amount of flat and elongated particles shall not exceed 20 percent for the fraction retained on the 1/2 inch sieve nor 20 percent for the fraction passing the 1/2 inch sieve. A flat particle is one having a ratio of width to thickness greater than 3; an elongated particle is one having a ratio of length to width greater than 3. In the portion retained on each sieve specified, the crushed aggregate shall contain at least 90 percent by weight of crushed pieces having two or more freshly fractured faces with the area of each face being at least equal to 75 percent of the smallest midsectional area of the piece. When two fractures are contiguous, the angle between planes of the fractures must be at least 30 degrees in order to count as two fractured faces. Crushed gravel shall be manufactured from gravel particles 90 percent of which by weight are retained on the maximum size sieve listed in TABLE 1.

2.1.2 Binder Material

The binder material shall be angular particles of uniform density. Liquid limit and plasticity index requirements shall apply to any component that is blended to meet the required gradation and shall also apply to the completed course. The portion of any component or of the completed course passing the No. 40 sieve shall be nonplastic. Binder material shall consist of angular particles produced by crushing stone that meets the requirements for wear and soundness specified for DGA coarse aggregate.

The binder material shall be produced by crushing only particles larger than No. 4 sieve in size. The binder material shall contain at least 90 percent by weight of particles having two or more freshly fractured faces in the portion passing the No. 4 sieve and retained on the No. 10 sieve, and in the portion passing the No. 10 sieve and retained on the No. 40 sieve.

2.1.3 Gradation Requirements

DGA shall be in accordance with Section 901.10 of the NJDOT Standard Specifications.

PART 3 EXECUTION

3.1 GENERAL REQUIREMENTS

When the DGA is constructed in more than one layer, clean the previously constructed layer of loose and foreign matter by sweeping with power sweepers or power brooms, except that hand brooms may be used in areas where power cleaning is not practicable. Provide adequate drainage during the entire period of construction to prevent water from collecting or standing on the working area. Provide line and grade stakes as necessary for control. Grade stakes shall be in lines parallel to the centerline of the area under construction and suitably spaced for string lining.

3.2 PREPARATION OF SUBGRADE

Immediately prior to construction of the DGA course, the subgrade shall be prepared as specified in Section 31 00 00.

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3.3 INSTALLATION

3.3.1 Placing

The material shall be placed on the prepared subgrade or existing DGA in layers of uniform thickness with an approved spreader. No layer shall exceed 8 inches or be less than 5 inches loose thickness. The layers shall be so placed that when compacted they will be true to the grades or levels required with the least possible surface disturbance. Immediately prior to installation of a lift of DGA, the previously constructed layer shall be cleaned of loose and foreign matter by sweeping with power sweepers, power brooms, or hand brooms, as directed. Adjustments in placing procedures or equipment shall be made as may be directed to obtain true grades, to minimize segregation and degradation, to adjust the water content, and to insure an acceptable DGA.

3.3.2 Grade Control

The finished and completed DGA shall conform to the lines, grades, and cross sections shown. Underlying material(s) shall be excavated and prepared at sufficient depth for the required DGA thickness so that the finished DGA with the subsequent courses will meet the designated grades.

3.3.3 Compaction

Each layer of the DGA shall be compacted as specified with approved compaction equipment. Water content shall be maintained during the compaction procedure to within plus or minus 2 percent of the optimum water content determined from laboratory tests as specified in paragraph SAMPLING AND TESTING. Rolling shall begin 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. Alternate trips of the roller shall be slightly different lengths. Speed of the roller shall be such that displacement of the aggregate does not occur and shall in no case exceed 1.5 miles per hour. In all places not accessible to the rollers, the mixture shall be compacted with hand-operated power tampers. Compaction shall continue until each layer has a degree of compaction that is at least 98 percent of laboratory maximum density through the full depth of the layer. The Contractor shall make such adjustments in compacting or finishing procedures as may be directed to obtain true grades, to minimize segregation and degradation, to reduce or increase water content, and to ensure a satisfactory DGA. Any materials that are found to be unsatisfactory shall be removed and replaced with satisfactory material or reworked, as directed, to meet the requirements of this specification.

3.3.4 Thickness

Compacted thickness of the aggregate course shall be as indicated. The total compacted thickness of the DGA course shall be within 1/2 inch of the thickness indicated. Where the measured thickness is more than 1/2 inch deficient, such areas shall be corrected 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 shall be considered as conforming to the specified thickness requirements.

Average job thickness shall be the average of all thickness measurements taken for the job, but shall be within 1/4 inch of the thickness indicated. The total thickness of the DGA course shall be measured at intervals in such a manner as to ensure one measurement for each 500 square yards of course. Measurements shall be made in 3 inch diameter test holes

SECTION 32 11 20 Page 5 penetrating the course.

3.3.5 Finishing

The surface of the top layer of DGA shall be finished after final compaction by cutting any overbuild to grade and rolling with a steel-wheeled roller. Thin layers of material shall not be added to the top layer of course to meet grade. If the elevation of the top layer of DGA is 1/2 inch or more below grade, then the top layer should be scarified to a depth of at least 3 inches and new material shall be blended in, compacted to bring to grade. Adjustments to rolling and finishing procedures shall be made as directed to minimize segregation and degradation, obtain grades, maintain moisture content, and insure an acceptable course. Should the surface become rough, corrugated, uneven in texture, or traffic marked prior to completion, the unsatisfactory portion shall be scarified, reworked and recompacted or it shall be replaced as directed.

3.3.6 Smoothness

The surface of the top layer shall show no deviations in excess of 3/8 inch when tested with a 12 foot straightedge. Measurements shall be taken in successive positions parallel to the centerline of the roadway.

Measurements shall also be taken perpendicular to the centerline at 50 foot intervals. Deviations exceeding this amount shall be corrected by removing material and replacing with new material, or by reworking existing material and compacting it to meet these specifications.

3.4 SAMPLING AND TESTING

Sampling and testing shall be the responsibility of the Contractor.

Sampling and testing shall be performed by a US Army Corps of Engineers certified testing laboratory approved in accordance with Section 01 45 00 QUALITY CONTROL. Work requiring testing will not be permitted until the testing laboratory has been inspected and approved. The materials shall be tested to establish compliance with the specified requirements; testing shall be performed at the specified frequency. The Contracting Officer may specify the time and location of the tests. Copies of test results shall be furnished to the Contracting Officer within 24 hours of completion of the tests.

3.4.1 Sampling

Samples for laboratory testing shall be taken in conformance with ASTM D75/D75M. When deemed necessary, the sampling will be observed by the Contracting Officer.

3.4.2 Tests

The following tests shall be performed in conformance with the applicable standards listed.

3.4.2.1 Sieve Analysis

Sieve analysis shall be made in conformance with ASTM C117, ASTM C136/C136M and ASTM D422. Sieves shall conform to ASTM E11.

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3.4.2.2 Liquid Limit and Plasticity Index

Liquid limit and plasticity index shall be determined in accordance with

ASTM D4318.

3.4.2.3 Moisture-Density Determinations

The maximum density and optimum moisture content shall be determined in accordance with ASTM D1557.

3.4.2.4 Field Density Tests

Density shall be field measured in accordance with ASTM D6938. Determine field in-place density in accordance with ASTM D1556 or ASTM D6938. When ASTM D6938 is used, check the calibration curves and adjust using only the sand cone method as described in ASTM D1556. ASTM D6938 results in a wet unit weight of soil in determining the moisture content of the soil when using this method.

3.4.2.5 Wear Test

Wear tests shall be made on DGA course material in conformance with

ASTM C131/C131M.

3.4.2.6 Soundness

Soundness tests shall be made on DGA in accordance with ASTM C88.

3.4.3 Testing Frequency

3.4.3.1 Initial Tests

The following tests in the quantity specified shall be performed on the proposed DGA material prior to commencing construction to demonstrate that the proposed DGA material meets all specified requirements when furnished.

a. Sieve Analysis. One test shall be conducted for each material type from the source.

b. Liquid limit and plasticity index moisture-density relationship. One liquid limit and plasticity index moisture-density relationship test shall be conducted for each sieve test conducted.

c. Moisture-density relationship. One moisture-density relationship test shall be conducted for each DGA material proposed for use on the project.

d. Wear. One wear test shall be conducted for each DGA material proposed for use on the project.

e. Soundness. One soundness test shall be completed for each DGA material proposed for use on the project.

3.4.3.2 In Place Tests

The following tests shall be performed on samples taken from the placed and compacted DGA. Samples shall be taken and tested at the rates indicated.

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a. In-place density testing shall be performed on every lift of material placed and at a frequency of one set of tests for every 250 square yards, or portion thereof, of completed area.

b. Sieve Analysis including No. 635 size material shall be performed for every 500 tons, or portion thereof, of material placed.

c. Liquid limit and plasticity index tests shall be performed at the same frequency as the sieve analysis.

3.4.4 Approval of Material

The source of the material shall be selected 30 days prior to the time the material will be required in the work. Tentative approval of material will be based on initial test results. Final approval of the materials will be based on sieve analysis, liquid limit, and plasticity index tests performed on samples taken from the completed and fully compacted DGA.

3.5 MAINTENANCE

Maintain the DGA in a satisfactory condition until the placement of the overlying materials is completed and accepted. Maintenance shall include immediate repairs to any defects and shall be repeated as often as necessary to keep the area intact. Any area of DGA that is damaged shall be reworked or replaced as necessary to comply with this specification.

3.6 DISPOSAL OF UNSATISFACTORY MATERIALS

Remove any unsatisfactory materials and dispose of offsite at no additional cost to the Government. No additional payments will be made for materials that must be replaced.

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SECTION 32 11 20 Page 8

3.4.4 Approval of Material