Long Term Pavement Performance Project Laboratory Materials Testing and Handling Guide

Chapter 3. Test Preparation

This chapter covers information regarding forms that were completed prior to testing and preparation of test samples.

3.1 Standard Forms for Laboratory Testing

This chapter contains LTPP standard forms which were used in the laboratory material handling and testing work. These forms were prepared and submitted prior to laboratory testing. Table 3.1 provides a list of these forms and their purpose.

The following entries were made on each of the standard forms in this section: Sheet, Laboratory Performing Test, Laboratory Identification Code, Region, State, Experiment Number, State Code, SHRP ID, Field Set Number, Sampled by, Date Sampled, Submitted by, Date, Checked and Approved, and Date.

SHEET: All data sheets from the laboratory material testing work on a particular project or test section were assigned sequential numbers starting from 1 for the sample receipt report (Form L01) followed by the sample inspection report (Form L02), preliminary laboratory test assignment (Form L03), laboratory test assignments (Form L04) and so on in increasing order through all of the respective L-type laboratory testing forms and continuing through the T-type laboratory testing forms.

If the information was not completely filled out on one sheet for one type of sample/test then multiple sheets were used and numbered accordingly ... 1 of 30, 2 of 30, 3 of 30 ....

LABORATORY PERFORMING TEST: The name of the laboratory where the laboratory materials test was conducted was written on this line.

LTPP LABORATORY IDENTIFICATION CODE: The laboratory identification code number assigned to the laboratory performing the test was recorded. The first two digits of the code indicated the state in which the laboratory was operating.

REGION: Identified the LTPP region in which the project or test section was located:

NA = North Atlantic Region
NC = North Central Region
S = Southern Region
W = Western Region

STATE: Two letter abbreviation (shown in Table 3.2) of the state, District of Columbia, Puerto Rico or the Canadian Province in which the project or test section was located.

EXPERIMENT NO: One of the eight GPS experiments (GPS-1, GPS-2, GPS-3, GPS-4, GPS-5, GPS-6, GPS-7, or GPS-9) or one of the seven SPS experiments (SPS-1, SPS-2, SPS-3, SPS-4, SPS-5, SPS-6, SPS-7, SPS-8, SPS-9P, or SPS-9A) as shown in Table 3.3 of this Guide.

STATE CODE: Two-digit code as shown in Table 3.2 for the state in which the project or test section was located.

SHRP ID: The four-digit code identifying the specific LTPP test section within the state.

FIELD SET NO: The field set number was a sequentially assigned number to indicate the different time periods in which material samples and field testing were conducted on the project. These time periods usually referred to different stages in the pavement life, such as prior to overlay construction, after overlay construction, end of test, etc. A field set number could apply to more than one day since sampling of SPS test sections usually required more than one day. As a general rule, the same field set number was applied to all material samples and field tests conducted in a continuous 30 day period, unless a construction event occurs between the two sampling sessions. The number 1 was used for the first time that material sampling and field testing were conducted on the project.

SAMPLED BY: Identified the Drilling and Sampling Crew who performed the field material sampling and field testing work for this particular project.

DATE (OR DATE SAMPLED): Dates were recorded as mm-dd-yyyy. This date was the date on which the field material sampling and field testing was conducted.

At the bottom of each LTPP Standard Form, the following information was entered:

SUBMITTED BY, DATE: The Laboratory Chief’s signature and date of signature was required. Underneath this signature, the corporate affiliation of the Laboratory Chief was identified.

Note: The U.S. Codes are consistent with the Federal Information Processing Standards (FIPS) and Highway Performance Monitoring System.

3.1.1 Form L01 – Sample Receipt Report

This form was used to record information regarding the samples which were received from the drilling and sampling crew by the participating laboratory. This form provided information about receipt of materials for one GPS section or one SPS project. If sampes were received for more than one GPS section or SPS project at a given time, then the samples were separated and separate Form L01s were completed for each individual GPS test section or SPS project reflected within the shipment. The following information was provided on this form:

NUMBER OF SAMPLE CONTAINERS RECEIVED: The number of cartons, boxes and other types of sample containers was provided.

SAMPLES RECEIVED BY: The name(s) of the laboratory personnel who received the samples was written here along with the date the samples were received.

AUTHORIZED BY: The name of the laboratory personnel who authorized the receipt of the samples and checked the sample shipment for completeness. The date of authorization was also included.

LTPP LABORATORY MATERIAL HANDLING AND TESTING
SAMPLE RECEIPT REPORT

LAB DATA SHEET L01 - PAGE 1

LABORATORY PERFORMING TESTS:_____________________________________________________________

LABORATORY IDENTIFICATION CODE:__ __ __ __

REGION _________________ STATE ___________________ STATE CODE __ __

EXPERIMENT NO _____ SHRP ID __ __ __ __

SAMPLED BY: _______________________________________ FIELD SET NO. __

DATE SAMPLED: __ __/__ __/__ __ __ __

NUMBER OF SAMPLE CONTAINERS RECEIVED: ________CARTONS _______BOXES _______OTHER

SAMPLES RECEIVED BY:_____________________________________________ DATE:__ __/__ __/__ __ __ __

AUTHORIZED BY:____________________________________________________ DATE:__ __/__ __/__ __ __ __

WORK INITIATED BY:________________________________________________ DATE:__ __/__ __/__ __ __ __

SAMPLES CHECKED WITH THE MATERIALS SAMPLES INVENTORY RECEIVED WITH THE SHIPMENT:

__________

TOTAL NUMBER OF:

1) AC CORES: (a) 4" Diam.________(b) 6" Diam.________(c) 12" Diam.________

NUMBER OF AC CORES TO BE SAWED FROM:

(a) BOUND BASE/SUBBASE________ (b) PCC AND BOUND BASE/SUBBASE_____ (c) PCC ______

NUMBER OF PCC CORES TO BE SAWED FROM BOUND BASE OR SUBBASE: __________

2) BOUND BASE CORES (4" Diam.): ____________

3) BOUND SUBBASE (INCLUDING TREATED SUBGRADE) CORES (4" Diam.) ____________

4) UNBOUND BASE SAMPLES: (a) BAGS (BULK) ____________ (b) JARS (MOISTURE)_______________

5) UNBOUND SUBBASE SAMPLES: (a) BAGS (BULK)____________ (b) JARS (MOISTURE)_______________

6) SUBGRADE SAMPLES: (a) BAGS (BULK) ____________ (b) JARS (MOISTURE)_______________

(c) THIN-WALLED TUBES:____________ (d) SPLITSPOON SAMPLES ________JARS

7) PCC CORES: ________________ 8) PCC BEAMS: ________________

9) AC MIX BULK SAMPLES: ______________ 10) AC-TREATED BASE BULK SAMPLES: ______________

CONTINUED ON PAGE 2 OF FORM L01

_______________________________________________________________________________________________

LTPP LABORATORY MATERIAL HANDLING AND TESTING

SAMPLE RECEIPT REPORT

LAB DATA SHEET L01 - PAGE 2

11) OTHER:

(12) SAMPLES TO BE SHIPPED TO OTHER LABORATORIES:

VERBAL REPORT TO: FHWA-LTPP REGION __________ DATE__ __/__ __/__ __ __ __

REPORT DISTRIBUTION: ____ FHWA-LTPP REGION __ __/__ __/__ __ __ __

____ FHWA-LTPP LABORATORY PROJECT MANAGER __ __/__ __/__ __ __ __

____ FHWA-LTPP COTR __ __/__ __/__ __ __ __

SPECIAL INSTRUCTIONS:____________________________________________________________________

_________________________________________________________________________________

_________________________________________________________________________________

_________________________________________________________________________________

Immediately inform the FHWA-LTPP Region, if any substantial discrepancy is found in the actual samples received, as compared to the Material Samples Inventory (Field Operations Information Form 1 and Form 2) provided by the drilling and sampling crew or the state/province highway agency laboratory.

TOTAL NUMBER OF:

1) AC CORES: The number of 4-inch (102-mm), 6-inch (152-mm) and 12-inch (305-mm) AC cores, respectively, received by the LTPP participating laboratory.

Additionally, the form provided the number of AC cores out of the total number of AC cores to be sawed each of the following base/subbase materials:

a) Bound base/subbase

b) PCC and bound base/subbase (see LTPP Protocol P31 in Chapter 4 for the definition of bound base and subbase)

c) PCC

The total number of PCC cores to be sawed from bound base or subbase material was recorded.

2) BOUND BASE CORES: The total number of 4-inch (102-mm) bound base cores received.

3) BOUND SUBBASE (INCLUDING TREATED SUBGRADE) CORES: The total number of 4-inch (102-mm) bound subbase cores received.

4) UNBOUND BASE SAMPLES: The total number of unbound base samples received.

a) BAGS (BULK)

b) JARS (MOISTURE)

5) UNBOUND SUBBASE SAMPLES: The total number of unbound subbase samples received.

a) BAGS (BULK)

b) JARS (MOISTURE)

6) SUBGRADE SAMPLES: The total number of granular subgrade samples received.

a) BAGS (BULK)

b) JARS (MOISTURE)

c) THIN-WALLED TUBES

d) SPLITSPOON SAMPLES

7) PCC CORES: The number of PCC core samples received from the drilling and sampling crew.

8) PCC BEAMS: The number of formed PCC beams received.

9) AC MIX BULK SAMPLES: The number of AC hot mix bulk samples received.

10) AC-TREATED BASE BULK SAMPLES: The number of AC-treated base bulk samples.

11) OTHER: The material type, type of sample and number of samples received for any other types of samples received.

12) SAMPLES TO BE SHIPPED TO OTHER LABORATORIES: This section was used to record the type of material, number of samples and the laboratory where the individual samples were shipped.

VERBAL REPORT TO: A "yes" was indicated here after a verbal report to the Region had been completed concerning the sample shipment. The date of this verbal report was also entered.

REPORT DISTRIBUTION: This was "checked off" whenever the Sample Receipt Report was sent to the LTPP Region or the respective laboratory supervisor.

SPECIAL INSTRUCTIONS: Any special instructions for laboratory handling and laboratory material testing were provided here.

Form L01 was not entered into the PPDB.

3.1.2 Form L02 – Sample Inspection Report

This form was Attachment "A" to the Sample Receipt Report (Form L01) and was submitted for approval to the Region with Form L01 and Form L03 after the samples were received and checked and prior to the commencement of the laboratory material testing.

This form (Form L02) was used to record the condition of material samples that were received by the laboratory. The following information was entered on this form:

SAMPLE LOCATION NUMBER: A three-digit location number obtained from field markings and from Field Operations Information Form 1. This number designated the field location of the sample.

LTPP SAMPLE NUMBER: A four-digit alphanumeric LTPP sample number obtained from field markings and Field Operations Form 1.

SAMPLE SIZE: The size of the material sample. For example, the following terms may have been used for these particular samples:

Core - 4 inch (102 mm) diameter

Moisture - jar

Bulk - bag

Block - 12 inch × 12 inch (305 mm × 305 mm)

LTPP LABORATORY MATERIAL HANDLING AND TESTING
ATTACHMENT "A" TO SAMPLE RECEIPT REPORT
(SAMPLE INSPECTION REPORT)

LAB DATA SHEET L02

LABORATORY PERFORMING TESTS:_____________________________________________________________

LABORATORY IDENTIFICATION CODE:__ __ __ __

REGION _________________ STATE ___________________ STATE CODE __ __

EXPERIMENT NO _____ SHRP ID __ __

SAMPLED BY: ______________________________________________

DATE SAMPLED: __ __/__ __/__ __ __ __ FIELD SET NO __

* Sample condition as observed during inspection.

** Remarks should include: (a) any discrepancy found after comparing with the sample data submitted by the Drilling and Sampling Crew on Field Operations Information Form 1; (b) any cores of two materials required to be sawed; (c) approximate weight of bulk samples, and (d) insufficient quantity.

SAMPLE TYPE: Type of sample. For example; core, block, piece, chunk, bulk, moisture, split spoon, etc.

SAMPLE MATERIAL: Type of material in the sample. For example: AC, PCC, base, subbase, subgrade, etc.

SAMPLE CONDITION: This entry provided the sample condition observed during inspection. Possible entries may have been good, cracked, loose, bag torn, spilled, etc.

REMARKS: The remarks included such items as discrepancies found after comparing the samples with Field Operations Information Form 1, identification of cores for which sawing was required to separate layers, approximate weight of bulk samples and a comment if there was an insufficient quantity than that required to complete the laboratory material handling and testing program.

GENERAL REMARKS: Any other pertinent comments were supplied here.

The Sample Inspection Report was made in the following sequence.

1) Samples from locations of C-type cores starting from cores of pavement surface layers.

2) Samples from A-type boreholes.

3) Samples from BA-type boreholes.

4) Samples from the test pit.

5) Any other samples.

Form L02 was not entered into the PPDB.

3.1.3 Form L03 – Preliminary Laboratory Test Assignment

This form (Form L03) was used for the preliminary assignment of laboratory tests to a particular laboratory. It was the second attachment, or Attachment "B", to the Sample Receipt Report (Form L01). Form L03 was submitted for approval to the Region along with Form L01 and Form L02 after the samples were received and checked, and prior to the commencement of the laboratory material testing.

A checkmark was placed in the blank space before the test designation if this test was to be performed in the participating laboratory in which the samples were received. A checkmark (Ö) was placed in this column beside the appropriate test if the test was being performed in a laboratory separate from the laboratory that completed the form and the laboratory that was performing the test was provided in the appropriate location on the form.

Form L03 was not entered into the PPDB.

LTPP LABORATORY MATERIAL HANDLING AND TESTING
ATTACHMENT "B" TO SAMPLE RECEIPT REPORT
PRELIMINARY LABORATORY TEST ASSIGNMENT

LAB DATA SHEET L03

LABORATORY PERFORMING TEST:______________________________________________________________

LABORATORY IDENTIFICATION CODE:__ __ __ __

REGION _________________ STATE ___________________ STATE CODE __ __

EXPERIMENT NO _____ SHRP ID __ __ __ __

SAMPLED BY: ______________________________________________

DATE SAMPLED: __ __/__ __/__ __ __ __ FIELD SET NO. __

* If the test is being performed at this laboratory, place a (Ö) in this column beside the appropriate test.

3.1.4 Form L04 – Laboratory Test Assignments

The Participating Laboratory was responsible for identifying and assigning a pavement layer number on Form L04, getting approval of the LTPP Region for the test assignments, and correcting Form L04 if required.

The following information was entered on Form L04:

LAYER NUMBER: Column 1 of Form L04 was for the designation of the layer number. The layer number was assigned beginning with layer number 1. Layer number 1 was always assigned for the subgrade and the last layer number was always the pavement surface layer. An example of layer numbers for a five-layer pavement structure was:

Subgrade ................................... 1

Subbase ..................................... 2

Base .......................................... 3

AC Binder Course ..................... 4

AC Surface Course .................... 5

An independent layer identification was completed by the Participating Laboratory and layers identified on Form L04 accordingly. Detailed instructions for layer number assignments are provided in Chapter 5 of this Guide.

LAYER DESCRIPTION: Column 2 of Form L04 was for the description of the layer. The two-digit codes presented in Table 3.4, taken from the LTPP Inventory Data Collection Guide, were to be used for layer description. (19)

LAYER TYPE: The layer type code was assigned in Column 3 using the codes presented in Table 3.5.

LTPP LABORATORY MATERIAL HANDLING AND TESTING
LABORATORY TEST ASSIGNMENTS

LAB DATA SHEET L04

LABORATORY PERFORMING TEST:________________________________________________________________________________

LABORATORY IDENTIFICATION CODE:__ __ __ __

REGION _________________ STATE ___________________ STATE CODE __ __

EXPERIMENT NO _____ SHRP ID __ __ __ __

SAMPLED BY: _____________________________________________ FIELD SET NO. __

DATE SAMPLED: __ __/__ __/__ __ __ __

NOTES: COLUMN 1. Layer number 1 is the subgrade soil, the last layer is the existing pavement surface layer.

SAMPLE LOCATION NO.: Column 4 contained the LTPP Sample Number. This was a three-digit alphanumeric code obtained from field markings and Field Operations Information Form 1. This number designated the field location of the sample.

LTPP SAMPLE NO.: Column 5 of Form L04 contained the LTPP Sample Number. This was a four-digit alphanumeric code which was obtained from field markings and Field Operations Information Form 1.

LAB TEST NO.: Column 6 contained the Laboratory Test Number which indicated the general area of the test section from which the sample was taken. The number one (1) was used for samples retrieved from locations at Stations 0-. The number two (2) was used for samples retrieved from locations at Stations 5+... The number three (3) was used for samples retrieved from locations within the test section (Stations 0+00 to 5+00). The number four (4) was for samples obtained by combining material from different areas of the test section. The number five (5) was for samples obtained by combining material from multiple test sections. This combining of samples across test sections was required on some SPS projects.

In some tables within the PPDB, laboratory test numbers higher than 5 were used. In these cases, test numbers 6 and 11 have the same meaning as test number 1. Test numbers 7 and 12 have the same meaning as test number 2. Test numbers 8 and 13 have the same meaning as 3. Test numbers 9 and 14 have the same meaning as 4. Test numbers 10 and 15 have the same meaning as 5.

LAB CONTROL NO.: This number was placed in column 7 and was the control number assigned by the Participating Laboratory in accordance with their own practice.

LTPP TEST DESIGNATION: A four-digit alphanumeric code was provided in column 8 as shown to the left of the laboratory test titles on Form L03.

LTPP PROTOCOL: A three- or four-digit code was completed in column 9 which corresponded to the appropriate LTPP Test Designation as shown to the right of the laboratory test titles on Form L03 or in Table 1.1.

TEST DATE SCHED: Column 10 of this form indicated the test date on which the test was scheduled to be performed.

The layering information on corrected and approved Form L04 was used throughout the laboratory testing. However, Form L04 was not recorded in the PPDB. After completion of all tests, Forms L05, L05A, and L05B were prepared using Form L04 and other test data forms, and recorded in the PPDB.

Proper layering identification and information was critical to the PPDB.

3.2 Sample Preparation

3.2.1 Asphalt Concrete

One element identified as vital to the LTPP program was the proper identification of individual layers within AC cores and assignment of AC laboratory tests for these various different layers within an asphalt concrete core. Great effort was expended by the laboratories to properly identify individual layers prior to commencing testing.

The LTPP protocol P01, Visual Examination and Thickness of Asphaltic Concrete cores, (included in Chapter 4 of this Guide) was written to provide detailed procedures for identification and determination of thickness of individual layers within the AC core. The test results were recorded on Form T01A (for the entire AC core) and Form T01B (for the individual layers within the AC core). Based on these test results, designated asphalt concrete laboratory tests may have been required on one or more layers within each AC core.

After completion of the AC01 tests (Visual Examination and Thickness of AC Cores, Protocol P01) on all AC cores, the test results were used by the laboratory to compare the AC01 information with the pavement layering recorded in the laboratory test assignments made on Form L04 for samples from each pavement section. Form L04 was completed by the laboratory following the procedure given in Section 3.1.4.

After obtaining approval of the testing assignments and completing the visual examination of the AC core and measuring layer thicknesses using the P01 protocol, the laboratory separated all individual layers within the AC core or block sample using the following rules.

Rule #1: If the AC core, block, or piece consisted of only one layer, the sample was not sawed. The testing was conducted on the core(s), block or piece using the instructions in the designated protocol.

Rule #2: Two or more layers within an AC sample (core, block, piece) were not combined for any specified tests.

Rule #3: Any 1.5-inch (38-mm) or thicker AC layer was separated from the AC sample by carefully sawing the sample. The AC cores were sawed so as to provide as little disturbance to the sample as possible. The sawing operation was performed on the interface of the layer to be separated so that the AC was not weakened by shock or by heating. The sawed surfaces of cores were required to be smooth, plane, parallel, and free from steps, ridges and grooves. The specimens were dried in air at an approximate room temperature (60–75°F [16–24°C]). Sample identification was assigned and traffic direction marked on the core specimen using an arrow to show the direction of travel. The laboratory was required to saw and separate the bottom layer first, followed by the next layer over the bottom layer in ascending order until reaching the top layer.

Exception to Rule #3: For some 12-inch (305-mm) cores and 12-inch (305-mm) blocks, depending on their resistance to softening, that were used for extraction (LTPP Test AC04) and the subsequent extracted aggregate gradation (LTPP Test AG04), the layers, if present, may have been separated by a heating and curing technique. For the details of this technique, see the Appendix to LTPP Protocol P04, Asphalt Content of Asphalt Concrete.

Rule #4: All specified AC tests as shown on Forms L03 and L04, were performed on every 1.5 inch (38 mm) or thicker AC layer.

Rule #5: If a portion of the AC sample contained one or more layers less than 1.5 inches (38 mm) thick, then no sawing was required for those layers. No further testing of these (less than 1.5 inch [38 mm] thick) layers was required. However, all layers were appropriately marked for sample identification and appropriate layer numbers were also marked on the side of the sample for each layer.

3.2.2 Treated Base and Subbase

Cores and chunks of treated material from one layer of base or subbase were sometimes bonded with AC and/or PCC. This combination of materials was sometimes retrieved in the field and shipped to the laboratory as intact cores and chunks. The AC or PCC layer(s) were required to be removed from the treated base or subbase layers by sawing. Layer thicknesses were measured prior to sawing.

Cores and chunks of treated subgrade were sometimes bonded with other bound layers and shipped to the laboratory as intact cores and chunks. The other bound layers were required to be removed from the treated subgrade by sawing in the laboratory. Layer thicknesses were measured and recorded on Form T31 prior to sawing.

If intact cores of the treated material were available then the laboratory uses two of these cores for preliminary identification and determination of layer thickness as prescribed by Protocol P31.

If there were no intact cores, and only chunks/pieces of the treated materials were available, then the laboratory was not required to determine layer thickness and Protocol P31 was used only for identification and description.

After getting approval of the layering and testing assignment, the laboratory separated all individual treated base and subbase layers within the core, block chunk or piece sample using the following rules.

Rule #1: The laboratory was not required to saw the treated base and subbase core, block, chunk, or piece if the sample consisted of only one layer. The testing was conducted on the full thickness of the core(s), block, chunk, or piece using the instructions in the designated protocol.

Rule #2: Two or more treated layers within a sample (core, block, chunk or piece) were separated if the layers were 3 inches (76 mm) thick or more for treated materials other than asphalt treated base (OTB) materials and 1.5 inches (38 mm) or more thick for asphalt treated base (ATB) materials.

Rule #3: A treated layer of 3 inches (76 mm) or more for OTB materials or 1.5 inches (38 mm) for ATB materials were to be separated by carefully sawing the sample providing the least amount of disturbance. Tests were to be performed using Protocols P31 and P32 or P07 as appropriate. Comment code 93 was used in reporting the tests results for Protocol P31 on Form T31.

Rule #4: If the thickness of a treated layer was less than 3 inches (76 mm) for OTB materials or 1.5 inches (38 mm) for ATB materials, then the laboratory performed only Protocol P31 testing on this thin layer. An appropriate comment code 91 or 92 was used in reporting the test results for Protocol P31 on Form T31. No separation of this layer was done.

Rule #5: The treated layer was separated from the sample according to the criteria given in Rules #3 and #4. Sawing treated base and subbase cores required special care so as to provide minimum disturbance. The sawing operation was performed on the interface of the treated layer to be separated so that the material was not weakened by shock or by heating. The sawed surfaces of cores were required to be smooth, parallel, and free from steps, ridges and grooves. The specimens were dried by air at an approximate room temperature (60–75°F [16–24°C]. Sample identification for core, block, chunk, or piece samples was assigned using the procedure described in the Field Handling Guide.⁽²⁾

Some pavement sections contained very thin layers such as leveling courses or bond breaker courses placed on top of the base or subbase layers. These very thin layers were not tested and were removed prior to testing the treated base or subbase core(s). These thin layers were identified on Forms L04 and L05A.

The core of the treated material may have had bonded particles from an unbound layer and/or particles of an asphalt concrete layer. These bonded particles were removed by wedging, or by chisel and hammer with care to prevent damage to the cores. If the core was damaged such that it was unsuitable for thickness measurement, then the laboratory recorded this condition using the appropriate comment code identified within the protocol.

3.2.3 Unbound Granular Base and Subbase Materials

The bag(s) of the bulk sample for that layer sampled near each end of the section were weighed separately. The bulk sample may have been received from the field in one or more bags or containers. The weight of all bags was summed up to calculate the total weight of the bulk sample from that end.

The bulk samples, if contained in more than one bag or container, were then combined.

The combined bulk sample was mixed and then dried in accordance with the procedure described in Section 4.1 of American Association of State Highway and Transportation Officials (AASHTO) test method T87-86, Dry Preparation of Disturbed Soil and Soil Aggregate Samples for Test.

The average moisture content, determined in accordance with protocol P49, was used to determine the total dry weight of the sample.

Table 3.6 shows the test sample weights needed by each respective LTPP Protocol and/or pertinent AASHTO and American Society for Testing and Materials (ASTM) standards. These weights were shown for samples of 1-inch (25-mm), 2-inch (51-mm), and 3-inch (76-mm) maximum size aggregates. The required tests were listed in this table in the sequence in which the tests were performed in the laboratory. The mixed and dried bulk sample was reduced to the appropriate test sizes as shown in Table 3.6 using the procedures described in AASHTO T248-83, Reducing Field Samples of Aggregate to Testing Size. The test samples were representative of the total bulk sample.

If the total bulk sample weight, as received from the field and as determined above, was less than the total required weight shown in Table 3.6 then the test samples were obtained from the bulk sample using the following rules.

Rule #1: For 1-inch (25-mm) maximum size aggregates, separate test samples were obtained if the bulk sample from near one end of the section weighed 80 lbs (36 kg) or more. Separate test samples, in the quantities shown in Table 3.6, as appropriate, were obtained for performing the tests using Protocols P41, P43, P47, P44, and P46.

Also, a representative 30-lb (14-kg) sample was taken and stored for possible future use by LTPP. Any excess material was discarded after completing the designated tests and obtaining approval.

Rule #2: For 2-inch (51-mm) maximum size aggregates separate test samples were obtained if the bulk sample from near one end of the section weighed more than 140 lbs (64 kg). Separate test samples in the quantities shown in Table 3.6, as appropriate, were obtained for performing the tests using Protocols P41, P43, P47, P44, and P46.

A representative 30-lb (14-kg) sample was taken also if the total bulk sample was more than 140 lbs (64 kg) and stored for possible future use by LTPP. Material from P46 testing may have been reused if necessary. Any excess material was discarded after completing the designated tests and obtaining approval.

Notes:

1. Approximate weights were based on the requirements of the pertinent Protocol and/or AASHTO and ASTM standards.
2. * indicates smaller test size was permitted by the pertinent Protocol as compared to the test size requirement by the pertinent AASHTO/ASTM standards.
3. + indicates that the listed weight was a slight increase over the minimum weight required by the pertinent AASHTO/ASTM standards.

Rule #3: For 2-inch (51-mm) maximum size aggregates, separate test samples were not taken for performing the classification test (Protocol P47 for the unbound granular base or subbase), if the bulk sample weight was within a range of 80 to 140 lbs (36 to 64 kg). Approximate 40-lb (18-kg) test samples were taken for the gradation test (Protocol P41). The classification tests were performed on the test samples for gradation as described in Protocol P47. The comment code 82 was used in reporting the test results for P47 on Form T47.

Rule #4: For 2-inch (51-mm) maximum size aggregates, separate test samples were obtained for Protocols P41, P43, P44, and P46 if the bulk sample was 140 lbs (64 kg) or less but more than 95 lbs (43 kg). If the bulk sample weight was within the range of 80 to 95 lbs (36 to 43 kg) then separate test samples were taken for only Protocols P41, P43, and P44. The material from the P44 test then was reused for the P46 test. The comment code 83 was used in reporting the test results for P44 and P46.

Sample for Storage. The sample used for the P46 test was saved and stored after completing the test for possible future use by LTPP. The comment code 84 was used in reporting the test results for P46.

Rule #5: For 3-inch (76-mm) maximum size aggregates, a separate test sample for the classification test (P47) was not obtained from the bulk sample. The classification test was performed based on the test sample for gradation as described in Protocol P47. The comment code 82 was used in reporting the test results for P47.

Rule #6: For 3-inch (76-mm) maximum size aggregates, separate test samples were obtained for Protocols P41, P43, P44 and P46 if the bulk sample was more than 140 lbs (64 kg). Approximate 50-lb (23-kg) test samples were taken for gradation tests (Protocol P41) in accordance with Table 3.6.

Sample for Storage. An additional 65-lb (29-kg) sample was taken and stored for possible future used by LTPP if available in the remaining bulk sample. Otherwise, the sample used for P46 was saved after completing the test for future possible use by LTPP and the comment code 84 was used in reporting the test results for P46.

Rule #7: For 3-inch (76-mm) maximum size aggregates, separate test samples were obtained for performing tests according to Protocols P41, P43, and P44 if the bulk samples weighed 80 to 140 lbs (36 to 64 kg). Only 40-lb (18-kg) test samples were taken for the gradation test (Protocol P41).

Only dry sieving was used in the gradation test (Protocol P41) if the weight of the bulk sample was within a range of 80 to 140 lbs (36 to 64 kg). The gradation test sample was reused for performing the resilient modulus testing (Protocol P46). The comment code 85 was used in reporting the test results for P41 and P46.

Sample for Storage. The sample used for P46 testing was saved and stored after completing the test for possible future use by LTPP. The comment code 84 was used in reporting the test results for P46.

Rule #8: If the total bulk sample for 2- and 3-inch (51- and 76-mm) maximum size aggregates was 40 lbs (18 kg) or more but less than 80 lbs (36 kg) then, (i) only dry sieving for the gradation test (Protocol P41) was performed on a test sample weighing 40 lbs (18 kg), (ii) the gradation test sample was reused for other tests (Protocols P43, P47, P44, and P46), (iii) the sample from the last test was saved and stored for possible future use by LTPP, and (iv) the comment code 86 was added in reporting each test result to indicate this significant deficiency in the sample size.

Rule #9: If the total bulk sample for 1-inch (25-mm) maximum size aggregate was 40 lbs (18 kg) or more but less than 80 lbs (38 kg) then, (i) the sample from the P44 test was reused for P46 test, (ii) the sample from P46 test was saved and stored for possible future use by LTPP, and (iii) the comment code 86 was added in reporting the test results.

3.2.4 Untreated Subgrade Soils

Table 3.6 shows the test sample weights as required by the respective LTPP Protocol and/or pertinent AASHTO and ASTM standards. These weights are shown for samples of 1-inch (25-mm), 2-inch (51-mm), and 3-inch (76-mm) maximum size aggregates. The required tests are listed in this table in the sequence in which the tests were to be performed in the laboratory. The mixed and dried bulk sample was reduced to the appropriate test sizes as shown in Table 3.6 using the procedures described in AASHTO T248-83, Reducing Field Samples of Aggregate to Testing Size. The test samples were representative of the total bulk sample.

If the total bulk sample weight, as received from the field and as determined above, was less than the total required weight shown in Table 3.6 then the test samples was obtained from the bulk sample using the following rules.

Rule #1: For 1-inch (25-mm) maximum size aggregates, separate test samples were obtained if the bulk sample from near one end of the section weighed 80 lbs (36 kg) or more. Separate test samples, in the quantities shown in Table 3.6, as appropriate, were obtained for performing the tests using Protocols P51, P43, P42, P52, P55 and P46.

Sample for Storage. A representative 30-lb (14-kg) sample was taken and stored for possible future use by LTPP. Any excess material was discarded after completing the designated tests and obtaining approval.

Rule #2: For 2-inch (51-mm) maximum size aggregates separate test samples were obtained if the bulk sample from near one end of the section weighed more than 140 lbs (64 kg). Separate test samples in the quantities shown in Table 3.6, as appropriate, were obtained for performing the tests using Protocols P51, P43, P42, P52, P55, and P46.

Sample for Storage. A representative 30-lb (14-kg) sample was also taken if the total bulk sample was more than 140 lbs (64 kg) or more and stored for possible future use by LTPP.

The laboratory may have reused material from the P46 testing, if necessary. Any excess material was discarded after completing the designated tests and obtaining approval.

Rule #3: For 2-inch (51-mm) maximum size aggregates, separate test samples were not taken for performing the classification test (Protocol P52 for the subgrade), if the bulk sample weight was within a range of 80 to 140 lbs (36 to 64 kg). Approximate 40-lb (18-kg) test samples were taken for the gradation test (Protocol P51). The classification tests were performed on the test samples for gradation as described in Protocol P52. The comment code 82 was used in reporting the test results for P52 on Form T52.

Rule #4: For 2-inch (51-mm) maximum size aggregates, separate test samples were obtained for Protocols P51, P43, P42, P55 and P46 if the bulk sample was 140 lbs (64 kg) or less but more than 95 lbs (43 kg). If the bulk sample weight was within a range of 80 to 95 lbs (36 to 43 kg) then separate test samples were taken for only Protocols P51, P43, P42, and P55. The P55 test sample was reused for the P46 test. The comment code 83 was used in reporting the test results for P55 and P46.

Sample for Storage. The sample used for the P46 test was saved and stored after completing the test for possible future use by LTPP. The comment code 84 was used in reporting the test results for P46.

Rule #5: For 3-inch (76-mm) maximum size aggregates, a separate test sample for the classification test (Protocol P52) was not obtained from the bulk sample. The classification test was performed based on the test sample for gradation as described in Protocol P52. The comment code 82 was used in reporting the test results for P52.

Rule #6: For 3-inch (76-mm) maximum size aggregates, separate test samples were obtained for Protocols P51, P43, P42, P55, and P46 if the bulk sample was more than 140 lbs (64 kg). Approximate 50-lb (23-kg) test samples were taken for gradation test (Protocol P51) in accordance with Table 3.6.

Sample for Storage. An additional 65-lb (29-kg) sample was taken and stored for possible future use by LTPP if available in the remaining bulk sample. Otherwise, the sample used for P46 was saved after completing the test for future possible use by LTPP and the comment code 84 was used in reporting the test results for P46.

Rule #7: For 3-inch (76-mm) maximum size aggregates, separate test samples were obtained for performing tests according to Protocols P51, P43, P42, and P55 if the bulk sample weighs 80 to 140 lbs (36 to 64 kg). Only 40-lb (18-kg) test samples were taken for gradation test (Protocol P51).

Only dry sieving was used in the gradation test (Protocol P51) if the weight of the bulk sample was within a range of 80 to 140 lbs (36 to 64 kg). The gradation test sample was reused for performing the resilient modulus testing (Protocol P46). The comment code 85 was used in reporting the test results for P51 and P46.

Sample for Storage. The sample from the P46 test was saved and stored after completing the test for possible future use by LTPP. The comment code 84 was used in reporting the test results for P46.

Rule #8: If the total bulk sample for 2- and 3-inch (51- and 76-mm) maximum size aggregate was 40 lbs (18 kg) or more but less than 80 lbs (36 kg) then, (i) only dry sieving was performed for the gradation test (Protocol P51) on a test sample weighing 40 lbs (18 kg), (ii) the gradation test sample was reused for other tests (Protocols P43, P42, P52, P55, and P46), (iii) the sample from the last test was saved and stored for possible future use by LTPP, and (iv) the comment code 86 was added in reporting each test result to indicate this significant deficiency in the sample size.

Rule #9: If the total bulk sample for 1-inch (51-mm) maximum size aggregates was 40 lbs (18 kg) or more but less than 80 lbs (36 kg) then (i) the sample from P55 testing was reused for P46 testing, (ii) the sample from P46 testing was saved and stored for possible future use by LTPP, and (iii) comment code 86 was added in reporting the test results.

Resilient modulus testing of the "undisturbed" thin-walled tube sample may have been performed by the laboratory without waiting for the entire sequence of testing shown in Table 3.6, provided that the thin-walled tube sample was suitable for testing. If the thin-walled tubes were available and acceptable for the resilient modulus test then no bulk sample was needed to reconstitute the test sample for Protocol P46. The comment code 87 was used in reporting the test results for P46 in this case.

If the thin-walled tube sample was not acceptable as described in Protocol P46, then all rules described above were followed to reconstitute the test sample for the resilient modulus testing. The comment code 88 was used in reporting the test results for P46.

If the thin-walled tube samples were not available then all rules described above for the resilient modulus test sample (Protocol P46) were applicable. The test sample was reconstituted from a representative portion of the bulk sample. The comment code 89 was used in reporting the test results for P46.

If available, the untested thin-walled tube sample was marked and stored for possible future use by LTPP. The comment code 90 was used in reporting the test results for P46.

3.2.5 Portland Cement Concrete

PCC cores from pavement sections included in GPS-3, GPS-4, and GPS-5, extracted from the PCC pavement surface, were marked with an arrow or symbol to show the direction of traffic. Any underlaying bonded layer of treated base and/or subbase (including asphalt treated base, lean concrete, econocrete, cement treated aggregate layers) were required to be removed from the PCC cores in the field or by sawing in the laboratory.

PCC cores from pavement sections included in the GPS-7 were retrieved with an overlaid AC core. If the AC core was bonded with the PCC core and/or the underlaying layer of treated base/subbase was bonded with the PCC core, then the PCC core was to be separated by sawing from the bonded layers in the laboratory. The laboratory was required to paint the same arrow or other traffic direction symbol on the top of the surface of each PCC core as that marked on the surface of the overlying AC core.

After assigning proper layer numbers for the GPS-9 experiment, PCC cores were used to obtain test specimens of the concrete overlay layer and the original concrete pavement layer from each specified location. The mark of the traffic direction was transferred to the underlying original concrete pavement layer surface.

The individual layers within the PCC core were separated using the following rules.

Rule #1: Sawing of the PCC core was not required if the specimen consisted of only one layer. The testing was conducted on the core(s) using the instructions in the designated protocol.

Rule #2: Two or more layers within a PCC core were not to be combined for any specified tests.

Rule #3: Any 1.5-inch (38-mm) or thicker PCC layer was separated from the PCC sample by carefully sawing the sample (see note 1). The sawing was performed with special care such that minimal disturbance was made on the sample. The sawing operation was performed on the interface of the layer to be separated so that the PCC would not be weakened by shock or by heating. The sawed surface of cores were to be smooth, plane, parallel, and free from steps, ridges and grooves. The specimens were dried in air at approximately room temperature (60–75°F [16–24°C]). Sample identification was assigned and the specimens were marked with the traffic direction using the procedure described above. The bottom layer was sawed and separated first, followed by the next layer over the bottom layer in ascending order until reaching the top layer.

Rule #4: If a portion of the PCC sample contained one or more layers less than 1.5 inches (38 mm) thick, then no sawing was required for those layers. No further testing of these (less than 1.5-inch [38-mm] thick) layers was required. However, all layers were required to be appropriately marked for sample identification as described above and appropriate layer numbers marked on the side of the sample for each layer.

Note 1: If a PCC core sample was received by the laboratory with a bituminous layer attached, the AC layer was removed from the core by sawing after performance of the visual examination and length measurement test (LTPP Protocol P66). If the thickness of the AC layer was less than 1.5 inches (38 mm), the AC layer was disposed of after the approval of the FHWA Contracting Officer’s Technical Representative (COTR). If the AC layer was more than 1.5 inches (38 mm) thick, then the bituminous layer was tested as required. Under SHRP supervision of the program, this testing required shipment of the AC material to the appropriate laboratory.

3.2.6 Sample Combination under the MAP

As might have been observed in the previous sections, it was quite common to combine samples from several locations to create the sample that was used in testing. Samples were identified from the field using a location number and a sample number. The location number (as identified under the description of the L04) was an alphanumeric code usually, but not always, consisting of three digits for the sample location obtained from field markings and Field Operations Information Form 1. This number designated the field location of the sample. If samples were combined from several field locations to form a representative sample for testing, an asterisk was placed in the third digit from the right for the location number (e.g., BA*). This specified that the laboratory test was conducted on a combined sample.

The sample number (as identified under the description of the L04 form) was an alphanumeric code usually containing four digits which identified the type of sample/specimen and the sampling location of the material sample. If samples were combined from several field locations to form a representative sample, asterisks were placed in the third and fourth digit of the LTPP Sample Number (e.g., BG**). The asterisk(s) specified that the laboratory test was conducted on a combined sample.

Unfortunately, the use of the asterisk did not allow for identification of the samples from which the combined sample was created. Therefore, for the MAP testing, a new naming convention was used for the location number and sample number of these samples.

The location number for the sample was designated with an 'LCS' for a laboratory combined sample or "FCS" for a field combined sample. These three letter designations were followed with a number beginning with "01" and increasing for each additional combined sample of that type for the test section.

The sample number designation followed the same criteria previously in place as described in the Field Sampling Guide.⁽²⁾ However, immediately following the first two letters of the sample number, an "X" was used to indicate that the sample had been combined from two or more other samples.

Additionally, a table was added to the PPDB to indicate the identity of the original samples that were used in creating the combined sample identified.