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Publication Number: FHWA-HRT-06-066
Date: March 2006

Long-Term Pavement Performance Inventory Data Collection Guide

Chapter 2. Data Collection and Recording

2.1 Recording Data

Data for a particular LTPP test site may not be available for the specific 152-meter (m) (500-foot (ft)) section being monitored. Usually the data for a test site are available as part of a larger construction project that includes the 152-m (500-ft) test section being monitored. For example, an LTPP test site is within a long section of road that was constructed in 1.6-kilometer (km) (1-mile (mi)) increments, in which case the data items should be taken from the relevant records for the 1.6-km (1-mi) sections. When these records are not available, information for the sections should come from the State highway agency's (SHA) records, such as Project Notes, As-Built Plans, the Construction Diary, and Project Files (Design/Construction Plans, etc.). As a last resort, the State's standards or Standard Practices used at the time of construction should be consulted.

As shown in table 1, spaces are provided for a broad array of data elements, but much of the data will not be available. However, available data should be entered (even data that are not identified by an asterisk as minimum information), and every effort should be taken to obtain those data elements indicated by an asterisk (*). When the data element is not applicable to the test section or represents something that does not exist on the section (i.e., reinforcement data for a plain concrete pavement), enter an "N" to indicate that the data element is not applicable. If the data element is applicable, but the value is unknown (i.e., not available in project records), enter a "U" to indicate that the value is unknown. Many data items will require codes to be entered. Unless otherwise noted in the following instructions, the codes are listed or referenced on the data sheets.

2.1.1 Data Common for All Sheets

A common set of data elements appears in the upper right corner of every data sheet. These items provide the most basic identification of the data being provided and are defined below.

State-Assigned Identification (ID)

The State-assigned ID is an identification number assigned by the SHA used solely to facilitate filing of the projects for the SHA's convenience, and may be cross-referenced with the construction project number. A SHA can use any system for assigning these identification numbers.

State Code

The State code is a number used to identify the State or Canadian Province in which the pavement section is located (see appendix A, table A.1 for codes).

Strategic Highway Research Program (SHRP) ID

The SHRP section ID is a four-digit identification number assigned by LTPP. This number is used to facilitate the computer filing of the projects and will identify the section in the field. It will be cross-referenced with the State-assigned ID.

For SPS sections, the first two digits of the SHRP ID are the project ID, and the last two digits identify the individual section within the project. The first digit of the SHRP ID is the multiple site designator to differentiate between multiple projects for a specific SPS experiment in the same State. A 0 (zero) is assigned to the first project of a specific experiment selected in a State. An A, B, C, etc., is assigned to the second, third, fourth, etc., projects selected of a particular experiment in the same State. The second digit of the SHRP ID designates the SPS experiment number. The remaining two digits identify the individual test section. The test section number is specific to the experiment design. Project level data are specified using 00 as the test section number. For SPS projects, the inventory data are expected to apply to the entire project length. Therefore, the data should be entered for the project level section ID of 00.

2.2 Description of Individual Data Sheets

Following are descriptions of each data sheet used in collecting inventory data.

2.2.1 Project and Section ID (Sheet 1)

This data sheet is to be completed from project records for each GPS test section or project in SPS experiments SPS-3, SPS-4, SPS-5, SPS-6, SPS-7, and SPS-9.

Individual data elements include:

Date of Data Collection or Update (Item 1): A set of numbers to identify the month and year in which the inventory data have been collected or updated. The number to identify the month is in numerical sequence of the months as they occur during the year (e.g., enter 03 for March followed by the year).

SHA District Number (Item 2): A number used to identify the SHA district in which the pavement test section is located.

County or Parish (Item 3): A numeric code used to identify the county or parish where the pavement section is located. County codes may be found in Federal Information Processing Standards (FIPS) Publication 6, "Counties of the States of the United States," available at http://www.itl.nist.gov/fipspubs/co-codes/states.htm. Canadian agencies should write the county name on the sheet. Codes are available in the IMS to indicate this information.

Functional Class (Item 4): A numeric code used to identify the functional classification of the highway on which the test section is located (see appendix A, table A.2).

Route Signing (Item 5): A numeric code to identify the designation that precedes the number of the highway where the SHA project is located (e.g., an interstate highway would be coded as 1, using the codes provided on sheet 1).

Route Number (Item 6): The number assigned to the highway where the SHA project is located (e.g., 280 for I-280 or 23 for US-23).

Type of Pavement (Item 7): A numeric code identifying the general type of pavement structure (such as AC pavement with granular base, jointed plain concrete pavement, etc.). The pavement type codes are listed in appendix A, table A.3.

Number of Through Lanes (Item 8): A number indicating the total number of through lanes (exclusive of ramps and access roads) in the direction of travel on the test section.

Direction of Travel (Item 9): The general direction of traffic flow along the entire route, which includes the test section (e.g., traffic flow over the test section moving generally in a westbound direction would be coded as 2, per code on sheet 1).

Section Location Starting Point (Items 10 through 13): The locations of the starting point of the test section are to be identified by milepoint, elevation, latitude, and longitude.

Milepoints (Item 10): The milepoints are to be determined by adjusting the value posted on the milepost nearest to the starting point. For example, if the direction of travel (as noted in the preceding data element) is in the same direction as increasing mileposts for a given roadway, and the starting point was 0.29 miles from the preceding milepost (Mile 114), the milepoint for the starting point of the test section would be 114.29. Milepoints are to be given to the nearest hundredth of a mile (0.01 mi). Canadian agencies should convert kilometer points to milepoints.

Elevations (Item 11): Values are to be entered to the nearest foot. Survey measurements are not required. The intent is to obtain a reasonable estimate. In many cases, the elevations can be taken off the construction plans.

Latitude and Longitude (Items 12 and 13): Values are assumed to be in the northerly and westerly direction for latitude and longitude, respectively. Values are to be given in degrees, minutes, and seconds to the nearest hundredth of a second (0.01 s) when this type of accuracy is possible.

Location information for SPS projects should be referenced to the starting point of the first section encountered in the direction of travel.

Space is provided to enter Additional Location Information (Significant Landmarks) (Item 14). This entry should provide information that will be useful for field crews in locating the project during monitoring activities, including the name of the nearest town or city.

HPMS Sample Number (Item 15): This is the 12-digit "Section/Grouped Data Identification" assigned to any section of highway in the FHWA's Highway Performance Monitoring System (HPMS). It provides a unique identification for a test section and may be obtained from those SHA personnel servicing the HPMS.

HPMS Section Subdivision (Item 16): A single-digit code used to identify a further subdivision of an original HPMS section, generally included as a 13th digit to the HPMS sample number.

2.2.2 Global Positioning Measurements (Sheet 1A)

This data sheet is to be completed for each LTPP test section for which latitude and longitude measurements are made using one of the global positioning system receivers. Latitude and longitude data entered in this sheet will supersede those values stored in the IMS from Inventory Data Sheet 1, Project and Section Identification.

Individual data elements are:

Global Positioning System Instrument Type and Model Name (Item 1): Space is provided to enter the type and model of the global positioning system receiver used to measure latitude and longitude. This information is not entered into the IMS.

Measurement Date (Item 2): A set of numbers to identify the day, month, and year in which latitude and longitude measurements have been made with the global positioning system receiver. The format for this data element is dd/mm/yyyy; e.g., 03/04/1994 for global positioning system measurements made on April 3, 1994, or 20/12/1996 for global positioning system measurements made on December 20, 1996. This information is not entered into the IMS.

Latitude (Item 3): Latitude of the LTPP test section or project, as determined from the global positioning system measurement, in degrees, minutes, and seconds to the nearest tenth of a second (0.1 s). This information supersedes any that is currently stored in the LTPP IMS. (Note: North or south direction is not entered on this data sheet, since it is assumed to be north; however, direction will be included in the IMS at a future date to allow for sections in the Southern Hemisphere.)

Longitude (Item 4): Longitude of the LTPP test section or project, as determined from the global positioning system measurement, in degrees, minutes, and seconds to the nearest tenth of a second (0.1 s). This information supersedes that currently stored in the LTPP IMS. (Note: West or east direction is not entered on this data sheet since it is assumed to be west; however, direction will be included in the IMS at a future date to allow for sections in the Eastern Hemisphere.

Elevation (Item 5): Elevation of the LTPP section, as determined from the global positioning system measurement, in meters to the nearest meter. This information is not entered into the IMS, but should be used by the Regional Support Contractors (RSC) to check the reasonableness of the elevation data currently stored in the IMS.

Dilution of Precision (DOP) (Item 6): Measure of satellite geometry quality and relative accuracy of the global positioning system measurement. The DOP ranges from 1.0 (best) to 9.9 (worst), with the value entered to the nearest tenth (0.1). This information is not entered into the IMS, but is used by the RSCs for quality control purposes.

Estimated Position Error (EPE) (Item 7): Overall measure of position accuracy computed using the DOP, signal and data quality, receiver tracking status, and other factors. The EPE is expressed in meters, with the value entered to the nearest meter. This information is not entered into the IMS, but is used by the RSCs for quality control purposes.

Comments (Item 8): Space is provided to enter any pertinent comments related to the latitude and longitude measurements using the global positioning system receiver. This information is not entered into the IMS.

2.2.3 Geometric, Shoulder, and Drainage Information (Sheet 2)

The data to be entered on this sheet provide basic information regarding the geometry of the pavement section, subsurface drainage incorporated in the pavement structure (if any), and the shoulder geometry and pavement structure. These data can be obtained from as-built plans and/or project files, but values should be checked at the site whenever possible through visual observation.

Individual data elements are:

Lane Width (Item 1): The width of the lane to be monitored, to the nearest whole number of feet.

Monitoring Site Lane Number (Item 2): A number that identifies which lane is to be monitored. The lane numbering methodology is identified on the data sheet. Lanes should be numbered starting with the outside lane as lane 1 and increasing toward the centerline of the roadway. Although a highway agency may wish to monitor more than one lane, each lane should be considered as a separate test section, with its own data (although much data may actually be common, such as environmental, materials, and thickness design data). For the LTPP studies, only the outside lane will be studied, so the code "1" should be entered for all test sections and projects in this study.

Subsurface Drainage Location (Item 3): A code indicating whether the subsurface drainage is continuous along the section or is provided at intermittent locations. Codes are provided on data sheet 2.

Subsurface Drainage Type (Item 4): A code indicating the type of system used to provide subsurface drainage, ranging from no subsurface drainage to a well system or a drainage blanket with longitudinal drains. Codes for each type of subsurface drainage are provided on data sheet 2. A code and space are provided for describing another type of subsurface drainage if different from those listed on data sheet 2.

Shoulder Data (Items 5 through 10): Spaces are provided to enter data describing both the outside and inside shoulder. If there are no inside shoulders, enter "N" for those spaces pertaining to inside shoulders.

Shoulder Surface Type (Item 5): A code indicating the type of material used for the surface of the shoulder for the outside and inside shoulders. Codes are provided on data sheet 2. If the full width of the shoulder is only partially paved, enter the code for the material used in the paved portion of the shoulder.

Total Width (Item 6): The total paved and unpaved width of the outside shoulder. A separate space is provided for the total paved and unpaved width of the inside shoulder to the nearest whole number of feet.

Paved Width (Item 7): The paved widths of the outside and inside shoulders to the nearest whole number of feet.

Shoulder Base Type (Item 8): Codes identifying the types of material used as the base of the pavement structure on the shoulders. See appendix A, table A.5 for codes.

Shoulder Surface Thickness (Item 9): The average thicknesses of the inside and outside shoulder surfaces to the nearest tenth of an inch (0.1 inch) (2.54 millimeters (mm)).

Shoulder Base Thickness (Item 10): The average base thicknesses along the shoulders to the nearest tenth of an inch (0.1 inch) (2.54 mm).

Additional Data for PCC Shoulders (Items 11 through 14): Spaces are provided for entering joint and reinforcing data for shoulders with PCC surfaces.

Average Joint Spacing (Item 11): Average distance between joints for PCC shoulders to the nearest whole foot.

Skewness of Joints (Item 12): The average distance in feet of the contraction joint from a normal right-angled joint at the opposite side of the shoulder. This is measured in feet to the nearest tenth of a foot (0.1 ft) (0.305 m).

Joints Match Pavement Joints? (Item 13): Codes are provided on data sheet 2 to indicate whether the joints in the shoulder have been constructed to match the spacing of the joints in the adjacent pavement slabs.

Reinforced? (Item 14): Codes are provided on data sheet 2 to indicate whether the PCC shoulder slab has reinforcing steel.

Diameter of Longitudinal Drainpipes (Item 15): The inside diameter to the nearest tenth of an inch (0.1 inch) (2.54 mm) of the longitudinal drainpipes used for subsurface drainage. If there is no longitudinal drainage, enter "N."

Spacing of Laterals (Item 16): The average spacing in feet between lateral drains from the pavement subdrainage system. Enter "N" if there are no subdrainage laterals.

2.2.4 Layer Descriptions (Sheet 3)

The data on this form provide key information as to the structure of the pavement at the time it is admitted to study in the LTPP program. This data sheet is to be completed from project records for each test section or project for which LTM is planned. As all subsequent data sheets refer back to this one, special care should be taken in completing it.

Individual data elements are:

Layer Numbers: Nine or fewer layers may be identified. Layer numbering begins at the bottom of the structure and increases moving to the top of the structure. Therefore, the subgrade is always layer number 1, and the last (and largest) number identifies the surface layer.

Layer Description: A layer description code identifying the function of the layer within the pavement structure is to be entered for each of the layers in the system. Codes are provided on data sheet 3. For hot-mix asphalt concrete (HMAC) layers, separate lifts of the same mixture are not to be identified as separate layers. Where HMAC is used as a base for PCC pavement, it should be described by code 05.

Many highway agencies cover poor subgrade soils with 0.3 to 1 m (1 to 3 ft) of select material. Such an embankment should be reported as a subbase with a layer description code 06.

Material Type Classification: A code identifying the type of material used in each layer of the pavement structure, including the subgrade, should be entered for material type classification. Codes for surfacing materials, base and subbase materials, subgrade soils, and thin seals and interlayers are identified in appendix A in tables A.4, A.5, A.6, and A.7, respectively. Embankment fill (layer description code 11) refers to nonselect or select fill greater than 1 m (3 ft) thick used to build up the roadbed, and appropriate codes are to be used to identify the materials.

Layer Thickness: Four numbers can be provided to indicate the mean, minimum, maximum, and standard deviation of thickness for each specific layer in inches. Enter to the nearest tenth of an inch (0.1 inch) (2.54 mm). If only a single specified design value for thickness is available from project records, enter it as the "mean value." (Detailed data is not to be filled out on subsequent data sheets for seal coats, interlayers, porous friction courses, or HMAC layers that are 19 mm (0.75 inch) thick or less.)

Layer Type: A letter code that helps identify the set of data sheets that must be completed for a particular layer. This data item is meant to be used purely for the convenience of the person(s) filling out the data forms to avoid potential confusion over which data sheets are required for a given project. Layer type codes and the required sheets for each layer type are shown in note 4 on the data sheet.

Depth Below Surface to "Rigid" Layer: A number should be entered to indicate the mean depth from the pavement surface to the top of a relatively rigid rock, stone, or dense shale formation. Enter to nearest tenth of a foot (0.1 ft) (0.305 m). If such a formation does not exist, enter "N" in the space provided. If such a layer has not been encountered at the depths bored, or it is not known whether it exists, enter a "U" for unknown.

2.2.5 Age and Major Pavement Improvements (Sheet 4)

This data sheet provides information regarding dates of construction for the primary pavement structure and any major improvements or rehabilitation that has occurred since that construction. This sheet is to be completed from project records for each test section or project for which LTM is planned.

Individual data elements are:

Date of Latest (Re)Construction (Item 1): Month and year in which construction or reconstruction (if any, not including overlay or mill and overlay) of the pavement to be monitored was completed. The first two digits represent the numerical sequence of the month as it occurs during the year, and the remaining four digits are the year.

Date Subsequently Opened to Traffic (Item 2): The month and year that the pavement originally was opened to traffic (not the date when the project was accepted). The first two digits represent the numerical sequence of the month as it occurs during the year, and the remaining four digits are the year.

Latest (Re)Construction Cost per Lane-Mile (Item 3): The total average original construction or reconstruction cost in thousands of dollars per lane-mile for the project that includes the test section exclusive of nonpavement costs such as bridges, culverts, lighting, and guard rails. This cost is to be reported as a cost indexed to the year reported in the data entry for "Date of Latest (Re)Construction."

Major Improvements Since Latest (Re)Construction (Items 4 through 8): Space is provided for identifying six major improvement activities by the year in which they were accomplished. This does not include bridges, culverts, lighting, etc. Major improvements do include overlays and associated pretreatments (patching, milling, joint repair, etc.), inlays (mill and fill), pressure relief joints in PCC pavements, subsealing or undersealing, retrofitted subdrainage, joint load transfer restoration, and shoulder restoration.

Year (Item 4): The year in which the major improvement was constructed.

Work Type Code (Item 5): A code to identify the type of maintenance work performed. Codes are provided in appendix A, table A.16.

Work Quantity (Item 6): The quantity of work applied to the section in appropriate units (refer to appendix A, table A.16 for determining appropriate units).

Thickness (Item 7): For improvements that increase the thickness of the pavement structure (such as "surface treatment, single layer" or "surface treatment, double layer," etc.), enter the thickness of the improvement to the nearest tenth of an inch (0.1 inch) (2.54 mm).

Total Cost (Item 8): The cost for the major improvements, exclusive of nonpavement costs, reported in thousands of dollars per lane-mile.

Additional Roadway Widening Information (Items 9 through 12): The following data items are applicable only if the roadway has been widened.

Year when Roadway Widened (Item 9): The year when the roadway was widened. If the roadway has not been widened, enter "N."

Original Number of Lanes (Item 10): The original number of lanes in the survey direction before roadway widening. If the roadway has not been widened,

enter "N."

Final Number of Lanes (Item 11): The final number of lanes after the roadway has been widened. If the roadway has not been widened, enter "N."

Lane Number of Lane Added (Item 12): Lane number added when roadway has been widened. The outside lane is lane 1; the next lane is lane 2, etc. If the roadway has not been widened, enter "N."

2.2.6 Portland Cement Concrete Layers, Joint Data (Sheet 5)

This sheet provides information regarding the contraction joints in the PCC pavement as well as any expansion joints in the section. The sheet is completed from project records for each PCC layer identified on sheet 3, except for continuously reinforced concrete pavements (CRCP) without joints. Where dowels or other mechanical load transfer devices are not provided at joints, enter "N" in the spaces for describing these devices.

Individual data elements are:

Layer Number (Item 1): The number of the PCC layer for which a description is provided (from sheet 3).

Average Contraction Joint Spacing (Item 2): The average spacing in feet (to the nearest tenth of a foot (0.1 ft) (0.305 m) between consecutive contraction joints (length of the concrete slab) of the pavement under survey. A space is provided to write in a description of any Random Joint Spacing (Item 3).

Built-in Expansion Joint Spacing (Item 4): The mean spacing in feet between consecutive expansion joints of the pavement under survey. If there are no expansion joints in the original construction, enter "N."

Skewness of Joints (Item 5): The average distance in feet of the contraction joint from a normal right-angled joint at the opposite side of the lane. This is measured in feet to the nearest tenth (0.1 ft) (0.305 m). If joints are not skewed, enter "N."

Transverse Contraction Joint Load Transfer System (Item 6): The mechanism by which a portion of the moving load is transferred across the transverse contraction joint to the adjacent slab. A space is provided to write in a description of another load transfer system if different from those for which codes are provided on data sheet 5. Where dowels or other mechanical load transfer devices are not provided at joints, enter "N" in the spaces for describing these devices.

Round Dowel Diameter (Item 7): The outer diameter of the round dowel bars used as the load transfer device across a contraction joint of the pavement under survey, assuming that round dowel bars are used as the joint load transfer system. This number is to be entered to the nearest hundredth of an inch (0.01 inch) (0.254 mm). If round dowel bars are not used, enter "N."

Dowel or Mechanical Load Transfer Device Spacing (Item 8): The average center-to-center distance in inches between mechanical load transfer devices (round or I-beam dowels, star lugs, etc.) across the contraction joint of the PCC layer being described.

Average Intermediate Sawed Joint Spacing (Item 9): The average distance between joints sawed at intervals between contraction joints (called "warping joints" by some SHAs). The distance is to be entered to the nearest tenth of a foot (0.1 ft) (0.305 m). If no intermediate sawed joints are provided, enter "N."

Dimensions for I-Beam Dowel Bars (Items 10 and 11): The height and width of I-beam dowel bars to the nearest hundredth of an inch (0.01 inch) (0.254 mm) assuming that

I-beam dowel bars are used as the joint load transfer system. If I-beam dowel bars are not used, enter "N."

Distance of Nearest Dowel (or Mechanical Load Transfer Device) from Outside Lane-Shoulder Edge (Item 12): The distance between the outside lane-shoulder edge and the dowel or mechanical load transfer device nearest to the outside lane-shoulder edge to a tenth of an inch (0.1 inch) (2.54 mm).

Dowel Length (Item 13): The mean length in inches of the round or I-beam dowel bars used for mechanical load transfer across contraction joints in the PCC layer being described.

Dowel Coating (Item 14): The material covering the dowel bar surfaces when installed in the concrete slab. A space is provided to write in a description if the dowel coating used differs from those for which codes are provided on data sheet 5.

Method Used to Install Mechanical Load Transfer Devices (Item 15): A code identifying the method used to install the dowels, I-beams, or other mechanical load transfer device. Space is provided for describing another method if the method used differs from those for which codes are provided on data sheet 5.

2.2.7 Portland Cement Concrete Layers, Joint Data (Continued) (Sheet 6)

This sheet is for continuation of sheet 5 to provide additional information on the joints in a PCC layer, and is filled out for each PCC layer identified on sheet 3, except for CRCP pavements without joints. These additional data items are described below.

Layer Number (Item 1): The number of the PCC layer for which a description is being provided (from sheet 3).

Method Used to Form Transverse Joints (Item 2): A code as defined on sheet 6 is entered that describes whether the contraction joints have been constructed by sawing the hardened slab at the proper time, by placing an insert into the slab surface while the concrete was plastic, or by any other construction method used to form the joint. Space is provided for describing another method if none of the other codes provided on sheet 6 are applicable.

Type of Longitudinal Joint (Item 3): A code as defined on sheet 6 is entered that indicates how the longitudinal joint between the lanes was formed. Space is provided for describing another way of forming the joints if none of the other codes provided on sheet 6 are applicable.

Type of Shoulder-Traffic Lane Joint (Item 4): A code is entered, as provided on data sheet 6, that describes how the joint between the concrete shoulder and the traffic lane was formed. "Tied concrete curb" indicates that a curb is provided in lieu of a shoulder. Space is provided for describing another way of forming the joints if none of those for which codes are provided has been used.

Transverse Joint Sealant Type (Item 5): A code provided on data sheet 6 defines the type of material used as joint sealant in the transverse joints. Space is provided for describing another type of sealant if none of the other codes provided on data sheet 6 is used.

Transverse Joint Sealant Reservoir (Items 6 and 7): The mean as-constructed width

and depth of the transverse joint sealant reservoir to the nearest hundredth of an inch (0.01 inch) (0.254 mm).

Longitudinal Joint Sealant Reservoir (Items 8 and 9): The average width and depth of the as-built longitudinal joint sealant reservoir to the nearest hundredth of an inch (0.01 inch) (0.254 mm). If butt or keyed joints have been used without a sealant reservoir, enter "0.00" in both of the spaces provided.

Between Lane Tie Bar (Items 10, 11, and 12): The nominal diameter to the nearest hundredth of an inch (0.01 inch) (0.254 mm) and the mean length in inches of the tie bars used across the longitudinal joints between the lanes entered to the nearest hundredth of an inch (0.01 inch) (0.254 mm). The mean center-to-center spacing between consecutive tie bars across the longitudinal joint between the lanes to the nearest tenth of an inch

(0.1 inch) (2.54 mm).

Shoulder-Traffic Lane Joint Sealant Reservoir (Items 13 and 14): The average width and depth of the as-built joint sealant reservoir between the shoulder and traffic lane. If butt or keyed joints are used without a sealant reservoir, enter "0.00" in both of the spaces provided.

Shoulder-Traffic Lane Joint Tie Bars (Items 15, 16, and 17): The outer diameter of the tie bars used across the joint between the shoulder and the traffic lane to the nearest hundredth of an inch (0.01 inch) (0.254 mm), the mean length of the tie bars to the nearest inch (1.0 inch) (25.4 mm), and the average center-to-center distance (spacing) in inches between consecutive tie bars across the concrete shoulder-traffic lane joint. If no concrete shoulder exists, enter "N" for these data entry spaces.

2.2.8 Portland Cement Concrete Layers, Reinforcing Steel Data (Sheet 7)

This data sheet provides a description of the type of reinforcement used in the PCC layer. It is filled out from project records for each reinforced PCC layer identified on sheet 3.

Individual data elements are:

Layer Number (Item 1): The number of the reinforced PCC layer for which a description is being provided (from sheet 3).

Type of Reinforcing (Item 2): The type of material used in reinforcing the PCC layer being described. A space is provided for entering a written description of a reinforcing type other than deformed bars or welded wire fabric as coded on data sheet 7.

Transverse Bar Diameter (Item 3): The nominal diameter of the transverse bars to the nearest hundredth of an inch (0.01 inch) (0.254 mm).

Transverse Bar Spacing (Item 4): The mean center-to-center spacing between transverse bars to the nearest tenth of an inch (0.1 inch) (2.54 mm).

Longitudinal Bar Diameter (Item 5): The nominal diameter of the longitudinal bars to the nearest hundredth of an inch (0.01 inch) (0.254 mm).

Design Percentage of Longitudinal Steel (Item 6): The percentage of reinforcing steel relative to the PCC cross section as required by the design to the nearest hundredth of one percent (0.01 percent).

Depth to Reinforcement from Slab Surface (Item 7): The mean depth, to the nearest tenth of an inch (0.1 inch) (2.54 mm), of the concrete cover over the top of the reinforcing steel.

Longitudinal Bar Spacing (Item 8): The mean center-to-center spacing between longitudinal bars to the nearest tenth of an inch (0.1 inch) (2.54 mm).

Yield Strength of Reinforcing (Item 9): The mean yield strength of the reinforcing steel to the nearest tenth of a kip per square inch (0.1 ksi (7 kg/cm2)). If tests have not been conducted for the steel used, enter the minimum yield strength allowed for the grade of steel used.

Method Used to Place Reinforcement (Item 10): The method used to install the reinforcing steel bars or wire fabric during pavement construction. Codes are provided on data sheet 7 for these methods including presetting the reinforcement on chairs, placing it mechanically by means of special equipment used for that purpose, or placing it between layers of concrete. A space is also provided to describe another method of placement if a code is not provided on data sheet 7 for the method used.

Lap Length of Longitudinal Steel Splices (Item 11): The length to the nearest inch

(1.0 inch) (25.4 mm) of the longitudinal reinforcing steel overlap at a CRCP construction joint. If the rigid pavement is not CRCP, enter "N."

2.2.9 Portland Cement Concrete Layers, Mixture Data (Sheet 8)

This data sheet provides information regarding the mixture proportions used for the PCC layer.

It is to be filled out from project records for each PCC layer identified on sheet 3.

Individual data elements are:

Layer Number (Item 1): The number of the PCC layer from sheet 3 for which a description is provided.

Mix Design (Items 2 through 5): The oven dry weights in pounds of coarse aggregate, fine aggregate, and cement; and the weight of water provided by the mix design for a cubic yard of concrete.

Type Cement Used (Item 6): The type of cement used in the slab concrete. These cement type codes appear in appendix A, table A.10. Additionally, if none of the codes provided are applicable to the type used, space is provided for identifying another type.

Alkali Content of Cement (Item 7): The alkali content of the cement to the nearest tenth of a percent (0.1 percent).

Entrained Air Content (Items 8 through 10): The mean, minimum, and maximum values of entrained air (as a percent of mixture volume) as measured during construction to the nearest tenth of a percent (0.1 percent). Any of the following test methods may be used to measure the amount of entrained air: American Association of State Highway and Transportation Officials (AASHTO) T121, American Society for Testing and Materials (ASTM) C138, AASHTO T152 (ASTM C231), or AASHTO T196 (ASTM C173).

Admixtures (Items 11 through 13): The types and amounts, in percent by weight of cement to the nearest thousandth (0.001 percent), of admixtures used in the concrete. The codes for concrete admixture types appear in appendix A, table A.11, and space is provided for identifying an admixture type for which a code is not provided.

Slump (Items 14 through 18): The mean of the slump measurements made for quality control purposes during construction of the PCC layer. In addition, space is provided for the maximum and minimum values and the standard deviation from the mean, all to the nearest tenth of an inch (0.1 inch) (2.54 mm). Space is also provided for the number of tests from which the values are obtained. The slump test is described in AASHTO T119 (ASTM C143). The maximum, minimum, and standard deviation of slump should be left blank if only one test result is available.

2.2.10 Portland Cement Concrete Layers, Mixture Data (Continued) (Sheet 9)

This data sheet is a continuation of the information provided on sheet 8 and is filled out from project records for each PCC layer identified on sheet 3.

Individual data elements are:

Layer Number (Item 1): The number of the PCC layer for which a description is provided (from sheet 3).

Composition of Coarse Aggregate (Items 2 through 4): The types and percentages by weight of coarse aggregate materials (that portion of an aggregate retained on the No. 4 (4.75-mm) sieve as defined by the Portland Cement Association (PCA)) for up to three separate materials in the coarse aggregate used in the concrete mix. Codes are provided on data sheet 9 for various types of aggregate. Space also is provided for the description of another type if none of the types for which codes are provided are used. Where only one type of material was used, enter its type code and 100 in the top set of data spaces, leaving the others blank.

Geologic Classification of Coarse Aggregate (Item 5): The geologic classification of the natural stone used as coarse aggregate in the concrete. These codes appear in appendix A, table A.8, and provide identification as to which of the three major classes of rock the coarse aggregate belongs, and the type of rock within those classes. If a blend is used, enter the code for the geological classification for the material representing the majority of the coarse aggregate. If a crushed slag, manufactured lightweight, or recycled concrete is used as coarse aggregate, enter "N."

Composition of Fine Aggregate (Items 6 through 8): The types and percentages by weight of fine aggregate materials (passing the No. 4 (4.75-mm) sieve and retained on the No. 200 (75-µm) sieve) for up to three separate fine aggregates used in the concrete mix. Codes are provided on data sheet 9 for various types of fine aggregate. Space is provided for identifying another type if none of those for which codes are provided are used. Where only one type of material was used, enter its type code and 100 in the top set of data spaces, leaving the others blank.

Insoluble Residue (Item 9): The percentage of insoluble residue (noncarbonate material) as determined using ASTM D3042.

Gradation of Coarse Aggregate (Item 10): The percent of coarse aggregate passing various standard sieve sizes to the nearest one percent (1.0 percent). It is not expected that values will be available for all of the sieve sizes shown. The objective is to provide space for a sufficient number of sieve sizes to accommodate testing and specification practices for most agencies.

Gradation of Fine Aggregate (Item 11): The percent of fine aggregate passing various standard sieve sizes to the nearest one percent (1.0 percent). It is not expected that values will be available for all sieve sizes shown. The objective is to provide space for a sufficient number of sieve sizes to accommodate testing and specification practices for most agencies.

Bulk Specific Gravities (Items 12 and 13): The mean bulk specific gravities, to the nearest thousandth (0.001), for coarse aggregate and fine aggregate. The bulk specific gravities for the aggregate fractions are measured using these laboratory procedures:

1) coarse aggregate—AASHTO T85 (ASTM C127), and 2) fine aggregate—AASHTO T84 (ASTM C128).

2.2.11 Portland Cement Concrete Layers, Mixture Data (Continued) (Sheet 10)

This data sheet is for continuation of the data on sheets 8 and 9, and is completed for each PCC layer identified on sheet 3. These additional data entries are discussed below.

Layer Number (Item 1): The number of the PCC layer for which a description is provided (from sheet 3).

Type of Paver Used (Item 2): A code to indicate whether a slip-form or side-form paver has been used to place the concrete. The codes appear on the data sheet along with a space to describe a different type not listed. Enter "N" if a paver has not been used (i.e., roller compacted concrete).

Aggregate Durability Test Results (Items 3 through 6): The type of tests used for evaluating the durability of the aggregate and the results in tenths (0.1) recorded in units specified for the particular test. Three of these sets are for coarse aggregates, and one is for the combination of coarse and fine aggregates. The durability test type codes and the units for reporting appear in appendix A, table A.12.

Method Used to Cure Concrete (Item 7): The method used to cure the concrete pavement. Codes are provided on data sheet 10 for various methods. Space is provided for identifying another curing method if none of those with codes listed has been used.

Method Used to Texture Concrete (Item 8): A code to indicate how the concrete surface has been textured. Codes are provided on data sheet 10 for various methods. Space is provided for identifying another texturing method if none of those with codes has been used.

Elastic Modulus (Items 9 through 13): The mean, minimum, maximum, and standard deviation of elastic moduli of the concrete in kips per square inch and the number of tests performed. The elastic moduli are obtained either through compression testing of cylindrical samples collected and tested during construction, or through relationships published by the American Concrete Institute (ACI) and others relating elastic modulus to compressive strength. In the event that only one test result is available, enter it as the "mean value." The standard deviation is to be left blank unless at least four test results are available. The ACI formula in general use (ACI 318-83, section 8.5) is:

Equation 1 (1)

where:

EC = Modulus of elasticity, psi

fC = 28-day compressive strength, psi

Method for Determination of Elastic Modulus (Item 14): The test method for measuring the elastic modulus of the mix; ASTM test method C469 (drilled core specimens), ASTM C469 (molded cylinders), ACI (equation 1 above), or some other test procedure as indicated in the space provided. Codes are provided for these methods on data sheet 10.

2.2.12 Portland Cement Concrete Layers, Strength Data (Sheet 11)

This data sheet is used to provide strength data on cylinders or beams molded from plastic concrete during construction, and is to be completed for each PCC layer identified on sheet 3. These data entries are discussed below.

Layer Number (Item 1): The number of the PCC layer for which a description is provided (from sheet 3).

Flexural Strength (Items 2 through 8): The type of test (third-point or center-point loading as coded on sheet 11), the age of the sample at testing, the number of tests performed, and the mean, minimum, maximum, and standard deviation of flexural strength tests, in psi. Testing for LTPP test sections built after 1988 should be done using third-point loading (AASHTO T97 (ASTM C78)).

Compressive Strength (Items 9 through 14): The age of the sample at testing, the number of tests performed, and the mean, minimum, maximum, and standard deviation of compressive strength in psi, measured according to the test procedures as established by AASHTO T22 (ASTM C39).

Splitting Tensile Strength (Items 15 through 20): The age of the sample at testing, the number of tests, and the mean, minimum, maximum, and standard deviation of splitting tensile strength in psi, measured according to AASHTO T198 (ASTM C496).

2.2.13 Plant Mixed Asphalt Bound Layers, Aggregate Properties (Sheet 12)

This sheet is filled out from project records for each AC layer identified on sheet 3 that is thicker than 19 mm (0.75 inches). Detailed mixture data is not considered necessary for thin seal coats, porous friction treatments, etc. Although various SHAs discriminate between fine and coarse aggregates on the basis of different sieve sizes, the following definition is applied for LTPP studies: All aggregate retained on the No. 8 (2.36-mm) sieve is coarse aggregate as defined by the Asphalt Institute and all aggregate passing the No. 8 (2.36-mm) sieve is fine aggregate. "Mineral filler" as used in the LTPP program is defined by ASTM D242 as that portion passing the No. 30 (0.600-mm) sieve. At least 95 percent must pass the No. 50 (0.300-mm) sieve, and at least 70 percent must also pass the No. 200 (75-µm) sieve.

Individual data elements are:

Layer Number (Item 1): The number of the AC layer for which a description is provided (from sheet 3).

Composition of Coarse Aggregate (Items 2 through 4): The type and percentage by weight of materials in the coarse aggregate (aggregate retained on the No. 8 (2.36-mm) sieve) for up to three types of aggregate used in the AC mix. Codes for identifying the type are provided on sheet 12. Space is provided for identifying a type of coarse aggregate other than those with codes. Where only one type of material is used, enter the type code and 100 in the top set of data spaces, leaving the others blank.

Geologic Classification of Coarse Aggregate (Item 5): The geologic classification of the natural stone used as coarse aggregate (aggregate retained on the No. 8 (2.36-mm) sieve) in the AC. These codes appear in appendix A, table A.8, and help identify to which of the three major classes of rock the coarse aggregate belongs and the type of rock within those classes. If a blend is used, enter the code for the geological classification for the material representing the majority of the coarse aggregate. If a crushed slag, manufactured lightweight, or recycled concrete is used as coarse aggregate, enter "N."

Composition of Fine Aggregate (Items 6 through 8): The type and percentage by weight of materials in the fine aggregate (passing the No. 8 (2.36-mm) sieve and retained on the No. 200 (75-µm) sieve) for up to three types of aggregate used in the AC mix. Space is provided for identifying another type if none of those for which codes are provided on sheet 12 is used. Where only one type of material is used, enter its type code and 100 in the top set of data spaces, leaving the others blank.

Type of Mineral Filler (Item 9): The type of mineral filler used in the AC mix. The codes appear on the data sheet, including space for entering some other type for which a code is not provided.

Aggregate Durability Test Results (Items 10 through 13): The type of tests used to evaluate the durability of the aggregate and the results in tenths recorded in units specified for the test. Three of these sets are for coarse, and one is for the combination of coarse and fine aggregates. The durability test type codes appear in appendix A, table A.12.

Polish Value of Coarse Aggregates (Item 14): The accelerated polish value of the coarse aggregates used in the surface layer, as determined by AASHTO T279 (ASTM D3319).

2.2.14 Plant Mixed Asphalt Bound Layers, Aggregate Properties (Continued) (Sheet 13)

This data sheet is a continuation of the aggregate property data on sheet 12, and is filled out for each AC layer identified on sheet 3 that is thicker than 19 mm (0.75 inches). These additional data items are described below.

Layer Number (Item 1): The number of the AC layer for which a description is provided (from sheet 3).

Gradation of Combined Aggregates (Item 2): The percent passing on various standard sieve sizes, to the nearest one percent (1.0 percent). It is not expected that values will be available for all 18 sieve sizes; the objective is to provide space for a sufficient number of sieve sizes to accommodate testing and specification practices for most agencies.

Bulk Specific Gravities (Items 3 through 6): The mean bulk specific gravities (to the nearest thousandth—0.001) for coarse aggregate (aggregate retained on the No. 8 (2.36-mm) sieve), fine aggregate (aggregate passing the No. 8 (2.36-mm) sieve and retained on the No. 200 (75-µm) sieve), mineral filler, and the value for the combined aggregate. The bulk specific gravities for the aggregate fractions are measured using the laboratory procedures indicated below:

  • Coarse aggregate—AASHTO T85 (ASTM C127)
  • Fine aggregate—AASHTO T84 (ASTM C128)
  • Mineral filler—AASHTO T100 (ASTM D854)

The bulk specific gravity of the combined aggregate (usually called simply "bulk specific gravity of aggregate") is calculated using equation 2 below.

Equation 2 (2)

where:

Gsb = Bulk specific gravity for the total aggregate

P1, P2, P3 = Percentages of weight of coarse aggregate, fine aggregate, and mineral filler

G1, G2, G3 = Specific gravities of coarse aggregate, fine aggregate, and mineral filler

Effective Specific Gravity of Aggregate Combination (Item 7): The mean calculated effective specific gravity to the nearest thousandth (0.001). This calculation requires the maximum specific gravity (no air voids) of the paving mixture, which is obtained by test method AASHTO T209 or ASTM D2041. The effective specific gravity of the aggregate is calculated as shown in equation 3 below.

Equation 3 (3)

where:

Gse = Effective specific gravity of aggregate

Pb = Asphalt cement, percent by total weight of mixture

Gb = Specific gravity of asphalt

Gmm = Maximum specific gravity of paving mixtures (no air voids)

2.2.15 Plant Mixed Asphalt Bound Layers, Asphalt Cement Properties (Sheet 14)

This data sheet provides information regarding the properties of the asphalt cement used in the AC mixture. This sheet is filled out from project records for each AC layer identified on sheet 3 that is thicker than 19 mm (0.75 inches).

Individual data elements are:

Layer Number (Item 1): The number of the AC layer described on this sheet

(from sheet 3).

Asphalt Grade (Item 2): The grade of asphalt cement used (see appendix A, table A.15). Space is provided on the data sheet for identifying another grade of asphalt cement not appearing in table A.15.

Source (Item 3): The source refinery for the asphalt cement used in the AC layer being described. A list of asphalt refiners and processors is provided in appendix A, table A.13. Space is provided to specify other sources that may not be included in the table provided.

Specific Gravity of Asphalt Cement (Item 4): The mean specific gravity of the asphalt cement (to the nearest thousandth—0.001) when it is available. If the precise value for that material is unavailable, a typical specific gravity for asphalt cements produced at the source refinery may be entered. If the source refinery is unknown, enter 1.010 as a reasonable estimate. This specific gravity is measured as specified by AASHTO T228 (ASTM D70).

Original Asphalt Cement Properties (Items 5 through 7): The following data items should be provided when available for the original asphalt cement, tested before its use in the construction.

Viscosity of Asphalt at 140 °F (60 °C) (Item 5): The results, in poises, for absolute viscosity testing using test method AASHTO T202 (ASTM D2171) on samples of the original asphalt cement before its use in construction of the pavement section.

Viscosity of Asphalt at 275 °F (135 °C) (Item 6): The results to the nearest hundredth centistokes (0.01 centistokes) for kinematic viscosity testing using test method AASHTO T201 (ASTM D2170) on samples of the original asphalt cement.

Penetration at 77 °F (25 °C) (Item 7): The penetration, in tenths of a millimeter (0.1 mm (0.039 inch)), from testing the original asphalt cement in the mixture at 77 °F (25 °C), using a 100-gram load and a 5-second load duration with test method AASHTO T49 (ASTM D5) on samples of the original asphalt cement material.

Type and Quantity of Asphalt Modifiers (Items 8 and 9): Codes to identify up to two modifiers added to the asphalt cement for whatever purpose. A list of possible asphalt cement modifiers and codes for data entry are provided in appendix A, table A.14. If a material other than those listed in table A.14 is used, space is provided to record the pertinent information. If no modifier is used, enter "N." Enter the quantity of asphalt modifier in percent by weight of asphalt cement. Some modifiers (such as lime) may be specified in terms of percent of aggregate weight, but they must be converted to percent by weight of asphalt cement for uniformity. Space is provided for up to two types of modifiers. If no modifier is used, enter "N."

Ductility at 77 °F (25 °C) (Item 10): The ductility in centimeters of the original asphalt cement material as measured by test method AASHTO T51 (ASTM D113) at 77 °F (25 °C).

Ductility at 39.2 °F (4 °C) (Item 11): The ductility in centimeters of the original asphalt cement material at 39.2 °F (4 °C), using the procedures of test method AASHTO T51 (ASTM D113).

Test Rate for Ductility Measurement at 39.2 °F (4 °C) (Item 12): The test speed in centimeters per minute (0.1 cm/min) for the ductility measurement taken at 39.2 °F (4 °C).

Penetration at 39.2 °F (4 °C) (Item 13): The penetration value at 39.2 °F (4 °C) using a 200-gram weight and 60-second loading duration, tested in accordance with test method AASHTO T49 (ASTM D5) on samples of the original asphalt cement, before its use as a construction material.

Ring and Ball Softening Point (Item 14): The softening point of the asphalt cement in degrees Fahrenheit as measured with the ring-ball apparatus used in test method AASHTO T53 (ASTM D36), on samples of the original asphalt cement before its use as a construction material.

2.2.16 Plant Mixed Asphalt Bound Layers, Asphalt Cement Properties (Continued) (Sheet 15)

This data sheet is for continuation of the data on sheet 14, and is filled out for each AC layer identified on sheet 3 that is thicker than 19 mm (0.75 inches).

These additional data entries are discussed below.

Layer Number (Item 1): The number of the AC layer for which data are provided (from sheet 3).

Laboratory Aged Asphalt Cement Properties (Items 2 through 11): The following data items should be provided for laboratory aged asphalt cement samples, using virgin asphalt cement samples aged in accordance with the provisions of test method AASHTO T179 (ASTM D1754—Thin Film Oven Test) or test method AASHTO T240 (ASTM D2872—Rolling Thin Film Oven Test). Space is provided on the data sheet to describe the aging process used, if other than those stated above.

Test Procedure Used to Measure Aging Effects (Item 2): The test procedure used to age the asphalt cement in the laboratory, and to measure the effects of the aging. Codes to indicate the procedure are provided on data sheet 15.

Viscosity of Asphalt at 140 °F (60 °C) (Item 3): The mean of the results in poises from absolute viscosity testing on laboratory aged asphalt cement samples using test method AASHTO T202 (ASTM D2171).

Viscosity of Asphalt at 275 °F (135 °C) (Item 4): The mean of the results in centistokes, to the nearest hundredth (0.01), from kinematic viscosity testing using test method AASHTO T201 (ASTM D2170) on laboratory aged asphalt cement samples.

Ductility at 77 °F (25 °C) (Item 5): The mean ductility in centimeters at 77 °F (25 °C) as measured by test method AASHTO T51 (ASTM D113) on laboratory aged samples of the asphalt cement.

Ductility at 39.2 °F (4 °C) (Item 6): The mean ductility in centimeters of laboratory aged asphalt specimens at 39.2 °F (4 °C), using the procedures of test method AASHTO T51 (ASTM D113).

Test Rate for Ductility Measurement at 39.2 °F (4 °C) (Item 7): The test rate to the nearest tenth of a centimeter per minute (0.1 cm/min) for the ductility test performed at 39.2 °F (4 °C).

Penetration at 77 °F (25 °C) (Item 8): The mean penetration in tenths of millimeters (0.1 mm) from testing the laboratory aged asphalt cement used in the mixture at 77 °F (25 °C), using a 100-gram load and a 5-second load duration, in accordance with test method AASHTO T49 (ASTM D5).

Penetration at 39.2 °F (4 °C) (Item 9): The results in mean penetration in tenths of millimeters (0.1 mm) from testing the laboratory aged asphalt cement used in the mixture at 39.2 °F (4 °C), using a 200-gram load and 60-second load duration, in accordance with test method AASHTO T49 (ASTM D5).

Ring and Ball Softening Point (Item 10): The mean of the results in degrees Fahrenheit from the ring and ball softening point test for bitumen (AASHTO T53 (ASTM D36)) conducted on laboratory aged asphalt cement samples.

Weight Loss (Item 11): The mean weight loss resulting from the laboratory aging process to the nearest one-tenth of one percent (0.1 percent).

2.2.17 Plant Mixed Asphalt Bound Layers, Original Mixture Properties (Sheet 16)

The data on this sheet are derived from tests conducted on the mixture during or soon after construction. These values should represent the as-constructed values for the AC layer. Calculations for calculated values (i.e., percent air voids) should be made separately for individual samples, using data applicable to those samples. This data sheet is filled out from project records for each AC layer identified on sheet 3 that is thicker than 19 mm (0.75 inches).

The test samples can be obtained through laboratory compaction after sampling in the field, or by coring, cutting, or sawing after the mixture is compacted in place. In the event that both types of samples are tested, separate data sheets are filled out for those compacted in the laboratory and those compacted in the field. Although tests are conducted on core samples from the field for LTPP (and reported on other data sheets), data from project files are entered when available.

Data elements are:

Layer Number (Item 1): The number of the AC layer described on the sheet (from sheet 3).

Type of Samples (Item 2): A code to indicate whether the test samples have been sampled in the field and compacted in the laboratory or removed from the compacted pavement. The codes appear on the data sheet.

Maximum Specific Gravity (Item 3): The theoretical maximum specific gravity (no air voids) of a mixture sampled during or soon after construction, as an average from testing of several samples according to AASHTO 209 or ASTM D2041. When possible, several samples should be tested and the average entered. The resulting maximum specific gravity and the design asphalt content for the mixture are used to calculate the effective specific gravity of aggregate using equation 3. After the effective specific gravity of the aggregate is established, it is used to calculate other maximum specific gravities for the mixture at other measured asphalt contents using equation 4 below.

Equation 4 (4)

where:

Gmm = Maximum specific gravity of paving mixture (no air voids)

Ps = Aggregate, percent by total weight of mixture

Pb = Asphalt, percent by total weight of mixture

Gse = Effective specific gravity of aggregate

Gb = Specific gravity of asphalt

These other calculated values of maximum specific gravity (from equation 4) are not entered into the database, but are needed to calculate the percent air voids for measured asphalt contents for individual extractions on cores.

Bulk Specific Gravity (Items 4 through 6): The number of tests and the mean, minimum, maximum, and standard deviation of bulk specific gravities, to the nearest thousandth (0.001), of compacted mixtures measured on cores removed from the pavement during or right after construction. While the test method specified in ASTM D1188 is preferable, the results from nuclear density tests (ASTM D2950), appropriately calibrated to measurements on cores, also can be used.

Asphalt Content (Items 7 through 9): The number of samples and the mean, minimum, maximum, and standard deviation of percent by weight of the total asphalt cement (including that absorbed by the aggregate) in the AC mixture to the nearest one-tenth of a percent (0.1 percent). Asphalt contents measured by extraction tests (AASHTO T164 (ASTM D2172)) on field samples are preferred, but results from nuclear test methods may also be used. If no such test results are available, enter the specified asphalt content as the mean, and leave the other spaces blank.

Percent Air Voids (Items 10 through 12): The number of samples and the mean, minimum, maximum, and standard deviation of calculated air voids, to the nearest tenth of a percent (0.1 percent), as a percent of the material volume. This data is frequently not available, but can be calculated using other available data from reports on mix design and density measurements on samples from the pavement. Percent air voids is calculated as shown in equation 5.

Equation 5 (5)

where:

Pa = Air voids in compacted mixture, percent of total volume

Gmm = Maximum specific gravity of paving mixture (zero air voids) as determined by ASTM method D2041

Gmb = Bulk specific gravity of compacted mixture

Voids in Mineral Aggregate (Item 13): The mean void space between the aggregate particles of a compacted AC mixture, which includes air voids and the effective asphalt content, to the nearest one-tenth of a percent (0.1 percent). Percent of voids in mineral aggregate (VMA) is calculated as shown in equation 6.

Equation 6 (6)

where:

VMA = Voids in mineral aggregate (percent of bulk volume)

Gsb = Bulk specific gravity of aggregate

Gmb = Bulk specific gravity of compacted mixture (ASTM D2726)

Ps = Aggregate, percent by total weight of mixture

100 = Percent of asphalt cement by total weight of mixture

Effective Asphalt Content (Item 14): The mean effective asphalt content is the total asphalt content of the paving mixture minus the mean portion of asphalt that is lost by absorption into the aggregate particles, expressed by weight of total mixture to the nearest one-tenth of one percent (0.1 percent). The percentage of asphalt absorbed into the aggregate particles, expressed as a percentage of the weight of total mix, may be calculated as shown in equation 7.

Equation 7 (7)

where:

Pab = Absorbed asphalt, percent by total weight of mixture

Pba = Absorbed asphalt, percent by weight of aggregate

Ps = Aggregate, percent by total weight of mixture

Gse = Effective specific gravity of aggregate

Gsb = Bulk specific gravity of aggregate

Gb = Specific gravity of asphalt

Marshall Stability (Item 15): The mean Marshall stability measured on the mixture at optimum asphalt content during laboratory mix design using either test method AASHTO T245 (ASTM D1559), recorded in pounds.

Number of Blows (Item 16): The number of blows of the compaction hammer that are applied to each end of the specimen during laboratory compaction before Marshall stability and flow testing.

Marshall Flow (Item 17): The mean Marshall flow (average of measured results) as the whole number of hundredths of an inch (i.e., measure 0.15 inch—enter "15") measured by test method AASHTO T245 (ASTM D1559) for the mixture at optimum asphalt content during the laboratory mix design.

Hveem Stability (Item 18): The mean Hveem stability or "stabilometer value" as measured with the Hveem apparatus using test method AASHTO T246 (ASTM D1560).

Hveem Cohesiometer Value (Item 19): The cohesiometer value, in grams per 25-mm (1-inch) width (or diameter) of specimen, obtained by test method AASHTO T246 (ASTM D1560).

2.2.18 Plant Mixed Asphalt Bound Layers, Original Mixture Properties (Continued) (Sheet 17)

This data sheet provides for continuation of the data on sheet 16, and is filled out for each AC layer identified on sheet 3 that is thicker than 19 mm (0.75 inches).

These additional data entries are discussed below.

Layer Number (Item 1): The number of the AC layer for which a description is provided (from sheet 3).

Type Asphalt Plant (Item 2): The type of plant that produced the AC mixture. Codes are provided on the data sheet for a batch plant, a drum mix plant, or another type of plant as described by the person(s) completing the form.

Type of Antistripping Agent (Item 3): The type of antistripping agent used in the mixture. The codes are provided in appendix A, table A.20. Space is provided to identify an antistripping agent other than those shown in the table.

Antistripping Agent Liquid or Solid (Item 4): A code to indicate whether the antistripping agent used is a liquid or solid. Codes are provided on the data sheet.

Amount of Antistripping Agent (Item 5): The amount of antistripping agent used in the mixture by weight to the nearest tenth of a percent (0.1 percent) of weight of asphalt if the agent is liquid and weight of aggregate if the agent is solid.

Moisture Susceptibility Test Type (Item 6): The type of moisture susceptibility test used during the test program. Codes are provided on sheet 17. If a procedure other than those for which codes are provided was used, space is provided to specify a name or reference for the test.

Moisture Susceptibility Test Results (Items 7 through 10): The mean Hveem stability number or percent stripped and the tensile strength ratio or index of retained strength. Space is provided to record these results in varying forms, depending on the test procedure used.

2.2.19 Plant Mixed Asphalt Bound Layers, Construction Data (Sheet 18)

This sheet provides information about the construction of the AC layer. The sheet is completed from project records for each AC layer identified on sheet 3 that is thicker than 19 mm (0.75 inches).

Individual data elements are:

Layer Number (Item 1): The number of the AC layer for which the compaction data is described on this sheet (from sheet 3).

Mean Mixing Temperature (Item 2): The mean temperature of the mixture during mixing at the plant (i.e., the mix as discharged) in degrees Fahrenheit.

Laydown Temperatures (Items 3 through 5): The number of temperature measurements taken and the mean, minimum, maximum, and standard deviation of temperatures measured in degrees Fahrenheit.

Compaction Data (Items 6 through 31): Spaces are provided to enter data related to compaction of the asphalt cement.

Roller Data (Items 6 thru 22): Codes appear on the data sheet for steel-wheeled tandem, pneumatic-tired, single-drum vibratory, and double-drum vibratory rollers. For each type of roller, spaces are provided to describe significant characteristics of up to four different rollers (items 6 through 22). Steel-wheeled tandem rollers are described by their gross weights to the nearest tenth of a ton (0.1 ton). Pneumatic-tired rollers are described by their gross weight and mean tire pressure in psi. Vibratory rollers are described by their gross weight in tons to the nearest tenth (0.1 ton), frequency in vibrations per minute, amplitude in inches to the nearest thousandth (0.001 inch) (0.0254 mm), and roller speed in miles per hour (mi/h) to the nearest tenth of a mile (0.1 mi/h) (0.16 kilometers per hour (km/h)).

Description of the Roller (Items 23 thru 28): Spaces are provided for the description of the roller used (roller code from data sheet) and number of coverages for breakdown, intermediate, and final compactions for each lift placed. A "coverage" in this case is defined as one trip of the roller across the pavement.

Mean Air Temperature (Item 29): The air temperature in degrees Fahrenheit while compaction is performed. Space is provided to record data for each of up to four AC lifts.

Compacted Thick (Item 30): The mean thickness of the compacted lift in inches to the nearest tenth (0.1 inch) (2.54 mm). If coring is not performed, the planned thickness should be recorded. Space is provided to record data for each of up to four AC lifts.

Curing Period (Item 31): The mean curing period in hours before a new lift is placed or the roadway is opened to traffic. Space is provided to record data for each of up to four AC lifts.

If compaction data are unavailable, enter "U" in these spaces. If partial data are available, fill in the available data and enter a "U" where data are not available, but would be applicable. Enter "N" in spaces that are not applicable (i.e., if there was no fourth lift, enter "N" in the appropriate space). Use only the roller descriptions and codes required.

2.2.20 Unbound or Stabilized Base or Subbase Material Description (Sheet 19)

This data sheet is filled out from project records for each base or subbase layer identified on sheet 3. Note that a stabilized subgrade (treated with lime, cement, asphalt, etc.) is considered to be subbase, and entries for this layer should be made on this data sheet and the next.

Individual data elements are:

Layer Number (Item 1): The number of the base or subbase layer described on this sheet (from sheet 3).

AASHTO Soil Classification (Item 2): The AASHTO soil classification for the base or subbase material (before any stabilization). The code numbers appear in appendix A, table A.9 for the various AASHTO classifications.

Atterberg Limits (Item 3): The plasticity index (PI), liquid limit (LL), and plastic limit (PL) determined by AASHTO T90 and T89 or ASTM D4318.

Maximum Lab Dry Density (Item 4): The maximum laboratory dry density in pounds per cubic foot for the base or subbase material in the layer of interest.

Optimum Lab Moisture Content (Item 5): The optimum moisture content obtained in the laboratory to the nearest one-tenth of a percent (0.1 percent) for the base or subbase layer.

Test Used to Measure Maximum Dry Density (Item 6): The test method used to establish the maximum dry density and optimum moisture content. Codes are provided on data sheet 19 for the most commonly used test methods. Space also is provided for identifying another test method used, if different from the test methods listed.

Compactive Energy for "Other" Method (Item 7): The compactive energy in foot-pounds per cubic inch is applied if some test method was used other than those for which codes are provided under item 6. If the test method used already had a code under item 6, this space is to be left blank.

In Situ Dry Density (Items 8 through 10): The number of samples tested, and the mean, minimum, maximum, and standard deviation of field measurements of the in-place dry density in pounds per cubic foot for the base or subbase layer.

In Situ Moisture Content (Items 11 through 13): The number of samples tested, and the mean, minimum, maximum, and standard deviation of field measurements of the base or subbase in-place moisture content in percent of dry weight of the material. This moisture content data is to be based on the same tests as the dry density data in items 8 through 10.

Gradation of Base or Subbase Material (Coarse and Fine Aggregates) (Items 14 and 15): The percentage of material passing various standard sieve sizes to the nearest one percent (1.0 percent). It is not expected that values will be available for all 17 sieve sizes. The objective is to provide space for a sufficient number of sieve sizes to accommodate testing practices for most agencies.

2.2.21 Unbound or Stabilized Base or Subbase Material Description (Continued) (Sheet 20)

This data sheet is for continuation of the data on sheet 19, and is filled out for each base or subbase layer identified on sheet 3. Note that a stabilized subgrade (treated with lime, cement, asphalt, etc.) is considered to be a subbase, and entries for this layer should be made on this data sheet and the next.

These additional data entries are discussed below.

Layer Number (Item 1): The base or subbase layer for which a description is provided (from sheet 3).

Type and Percent Stabilizing Agent (for Stabilized Layers Only) (Items 2 and 3): The types of stabilizing agents and the average percent of each by dry weight of soil mixed into the base or subbase material in the layer of interest. Codes are provided on the data sheet for stabilizing agents commonly in use, and space is provided to identify an agent not listed. An average of measured percentages is used whenever available. If percentages have not been measured, the specified percentage should be entered. If neither measured nor specified data are available, but the layer is known to have been stabilized, a percentage should be estimated based on practice at the time the stabilized base or subbase layer was constructed. If only one stabilizing agent is used, leave the spaces for "Stabilizing Agent 2" blank. If the base or subbase material is not stabilized, enter "N."

Admixtures (Item 4): The type of admixture and the percent added by weight of the base or subbase material, as measured by ASTM D4373. Codes are provided on the data sheet for the type of admixture used, along with space for identifying a type other than those for which codes are provided.

Compressive Strength (Items 5 through 7): The number of tests performed and the mean, minimum, maximum, and standard deviation of the compressive strength in pounds per square inch (psi) of the stabilized or unstabilized material.

Type of Compression Test (Item 8): The type of test used to evaluate the compressive strength of the material. Codes are provided on the data sheet along with space to identify the test type if the appropriate type is not listed.

Confining Pressure (Item 9): The confining pressure applied during the compressive strength testing. If the test was unconfined, enter "0.0."

Calcium Carbonate Content (Item 10): The percent by weight of the base or subbase material that is composed of calcium carbonate, as determined by ASTM D4373.

California Bearing Ratio (CBR) (Item 11): The mean CBR-value of the material as determined by test method AASHTO T193 or ASTM D1883.

Resistance (R-Value) (Item 12): The mean R-value as determined by test method AASHTO T190 (ASTM D2844).

Modulus of Subgrade Reaction (k-Value) (Items 13 and 14): The mean k-value in psi (pounds per square inch per inch of deflection) measured at the top of the base or subbase after it is compacted in place, and the type of test used. Either the repeated load test (AASHTO T221 (ASTM D1195)) or the static load test (AASHTO T222 or ASTM D1196) may be used, and codes for these are provided on the data sheet.

2.2.22 Subgrade Data (Sheet 21)

This data sheet is for entering subgrade data from project records, and is filled out for each GPS test section or SPS project. If there are substantial variations in subgrade characteristics throughout the project, additional subgrade data sheets are provided for each subgrade type. Location information, such as station boundaries, is provided on these extra data sheets under the SHRP Section ID data item. Note that a portion of subgrade that is treated (or stabilized) with lime, cement, asphalt, or other such agents is considered a subbase layer. Its details should be reported on the other data sheets provided for bases and subbases.

As variations in soil type with depth are common (especially where a select fill has been used as an embankment), judgment is required in selecting subgrade soil samples for testing. Some considerations include: 1) relative thicknesses of soil strata that differ in general characteristics and 2) depth. Subgrade soils near the surface will generally have more of an effect on pavement performance than will soils at a greater depth.

For SPS projects, the properties of the predominant subgrade type encountered on the project should be entered on this data sheet. In cases where a known variation in the subgrade occurs during the project, this data sheet should be completed for each test section.

Individual data elements are:

AASHTO Soil Classification (Item 1): The AASHTO soil classification for the subgrade material. These codes are provided in appendix A, table A.9.

CBR (Item 2): The CBR for the subgrade soil (test method AASHTO T193 or ASTM D1883).

R-Value (Item 3): The mean resistance R-value as determined by test method AASHTO T190 (ASTM D2844).

k-Value (Items 4 and 5): The mean modulus of subgrade reaction in pci (pounds per square inch per inch of deflection) for the in situ subgrade, and the type of test used. Either the repeated load test (AASHTO T221 (ASTM D1195)) or the static load test (AASHTO T222 or ASTM D1196) may be used as coded on the data sheet.

Percent Passing No. 40 Sieve (Item 6): The average of percentages of material passing the No. 40 (0.425-mm) sieve from available sieve test results for samples from the first 5 feet (1.5 m) of the subgrade. Enter to the nearest one-tenth of one percent (0.1 percent).

Percent Passing No. 200 Sieve (Item 7): The average of percentages of material passing the No. 200 (75-µm) sieve from available sieve test results for samples from the first 5 feet (1.5 m) of the subgrade. Enter to the nearest one-tenth of one percent (0.1 percent).

Plasticity Index (Item 8): The average of plasticity indices measured for samples from the first 5 feet (1.5 m) of the subgrade (test methods AASHTO T90 or ASTM D4318).

Liquid Limit (Item 9): The average of the liquid limits measured for samples from the first 5 feet (1.5 m) of subgrade (test methods AASHTO T89 or ASTM D4318).

Maximum Laboratory Dry Density (Item 10): The maximum laboratory dry density in pounds per cubic foot for the subgrade material.

Optimum Laboratory Moisture Content (Item 11): The optimum moisture content obtained in the laboratory to the nearest tenth of a percent (0.1 percent) for the subgrade.

Test Used to Measure Maximum Dry Density (Item 12): A code, provided on data sheet 21, indicates whether standard AASHTO, modified AASHTO, or some other test method is used to establish the maximum dry density and optimum moisture content.

Compactive Energy for "Other" Method (Item 13): The compactive energy in foot-pounds per cubic inch applied if some test method is used other than the standard AASHTO or modified AASHTO. If the standard or modified AASHTO is used, leave this space blank.

In Situ Dry Density (Percent of Optimum) (Items 14 through 16): The number of tests conducted, and the mean, minimum, maximum, and standard deviation of field measurements of in-place dry density for the subgrade as a percentage of the maximum lab dry density. In situ dry density may be measured successfully by several procedures. These include the rubber-balloon method (AASHTO T205 (ASTM D2167)), the sand cone method (AASHTO T191 (ASTM D1556)), or nuclear methods (AASHTO T238).

In Situ Moisture Content (Percent of Optimum) (Items 17 through 19): The number of tests conducted, and the mean, minimum, maximum, and standard deviation of field measurements of in-place subgrade moisture content as a percent of the optimum moisture content obtained in the laboratory. This moisture content data is to be based on the same tests as for the dry density data above. Values should be recorded to the nearest tenth of a percent (0.1 percent).

In Situ Dry Density (pcf) (Items 20 through 22): The number of tests conducted, and the mean, minimum, maximum, and standard deviation of field measurements of in-place dry density in pounds per cubic foot for the subgrade. This data item need not be entered if both the maximum laboratory dry density and the in situ dry density as a percent of maximum dry density have been reported.

In Situ Moisture Content (Items 23 through 25): The number of tests conducted, and the mean, minimum, maximum, and standard deviation of field measurements of in-place subgrade moisture in percent of dry weight of the material. This moisture content data is to be based on the same tests used for the dry density data above, and need not be entered if the optimum laboratory moisture content and the in situ moisture content as a percent of optimum have been reported. Values should be recorded to the nearest tenth of a percent (0.1 percent).

2.2.23 Subgrade Data (Continued) (Sheet 22)

This data sheet is for continuation of the data on sheet 21 and is completed for each GPS test section. For SPS projects, the properties of the predominant subgrade type encountered on the project should be entered on this data sheet per the instructions for data sheet 21.

Individual data elements are:

Relative Density of Cohesionless Free-Draining Soil (Items 1 through 4): For cohesionless free-draining soils only. If more than 12 percent by weight of the subgrade is passing the No. 200 (75-µm) sieve or is otherwise known to not be free-draining, enter "N" in these spaces. Otherwise, the following values are requested: 1) minimum and maximum densities in pcf to the nearest tenth (0.1 pcf), as determined by test method ASTM D2049 (measured density); 2) mean relative density in percent to the nearest tenth (0.1 percent) and number of tests conducted; 3) minimum and maximum mean relative densities in percent to the nearest tenth (0.1 percent); and 4) standard deviation of relative density in percent to the nearest tenth (0.1 percent). The calculated relative densities and standard deviation of relative density are related to the in situ dry densities in pcf recorded on sheet 21, and are calculated using those field densities and the minimum and maximum densities from test method D2049.

Soil Suction (Item 5): A value for soil suction (negative pore water pressure) to the nearest tenth of a ton per square foot (0.1 tsf) determined by AASHTO T273.

Expansion Index (Item 6): The expansion index as determined by ASTM test method D4829. The expansion index has been included as a data element because it appears to offer high potential for explaining the effects of expansive soils on pavement performance in future predictive models.

Swell Pressure (Items 7 and 8): A value to the nearest pound per square inch (1.0 psi) for swell pressure, and a code to identify the test used. Codes are provided on data sheet 22.

Percent by Weight Finer than 0.02 mm (Item 9): The percent by weight, to the nearest tenth of a percent (0.1 percent), of the subgrade sample having soil grains finer in size than 0.02 mm (0.0008 inch). This value is generally obtained by hydrometer analysis (ASTM test method D422). This data item is only required in freeze zones where frost is expected to penetrate into the subgrade.

Average Rate of Heave During Standard Laboratory Freezing Test (Item 10): The average rate of heave in millimeters per day, to the nearest tenth (0.1 mm/day) (0.0039 inch), of the subgrade soil as measured by a standard laboratory freeze test.* This data item is only required in freeze zones where frost is expected to penetrate into the subgrade. (*Reference not available. Test used by U.S. Army Corps of Engineers.)

Frost Susceptibility Classification Code (Item 11): The frost susceptibility classification of the subgrade soil. The codes appear on the data sheet. A value for the average rate of heave is required for the classification, although percent by weight finer than

0.02 mm (0.0008 inch) is indicative and significant to the heave rate. This data item is only required in freeze zones where frost is expected to penetrate into the subgrade.

2.2.24 Snow Removal/Deicing (Sheet 23)

This data sheet provides information on the snow removal and deicing practices used by the SHA at the test section location.

Individual data elements:

Frequency of Snow Removal at Test Site? (Item 1): A code indicating the general number of times per year that snow removal is required at the section location. Codes are provided on the data sheet.

Frequency of Application of Deicing Chemicals on the Test Site? (Item 2): A code indicating the general number of times per year that deicing chemicals are applied to the test section. Codes are provided on the data sheet.

What Type of Deicers Have Been Used on This Test Section? (Item 3): A code indicating the type of chemicals used for deicing on the test section. Codes are provided on the data sheet.

Has the Use of Any of These Deicers Been Discontinued Since the Test Site was Open to Traffic? (Item 4): A code indicating any chemicals that were once used at the location for deicing but are no longer used on a regular basis. Codes are provided on the data sheet. In addition, space is provided to indicate the year that the deicing chemicals were discontinued.

FHWA-HRT-06-066

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The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT).
The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT). Provide leadership and technology for the delivery of long life pavements that meet our customers needs and are safe, cost effective, and can be effectively maintained. Federal Highway Administration's (FHWA) R&T Web site portal, which provides access to or information about the Agency’s R&T program, projects, partnerships, publications, and results.
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