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• Structural Factors of Jointed Plain Concrete Pavements: SPS-2—Initial Evaluation and Analysis

Structural Factors of Jointed Plain Concrete Pavements: SPS-2—Initial Evaluation and Analysis

Chapter 3. Assessment of Data Availability and Completeness

The second step in the SPS-2 review and evaluation study is to assess the key data availability and completeness. LTPP data availability and quality control (QC) checks are discussed first. Then, key data elements are assessed for their quality level and completeness. The data reviews are divided into the following categories:

• General site information.
• Pavement structure data.
• Construction data.
• Material testing data.
• Traffic data.
• Climate data.
• Monitoring data.
• Dynamic load-response data.

IMS data release 9.8, obtained on August 10, 1999, was used for the majority of the study; however, the distress, profile, and materials testing data are from IMS release 10.1, obtained on February 1, 2000.

LTPP Data Availability and Quality Control Checks

The quality of the data is the most important factor in any type of analysis. From the outset of the LTPP program, data quality has been considered of paramount importance. Procedures for collecting and processing data were defined (and are modified as necessary) to ensure consistency across various reporting contractors, laboratories, equipment operators, and so forth. Although these procedures formed the foundation of quality control/quality assurance (QC/QA) and data integrity, many more components of a QC/QA plan were necessary to ensure that the data sent to researchers were as error-free as practical.

LTPP has developed and implemented an extensive QC program that classifies each of the data elements into categories depending upon the location of the data in this QC process. Several components or steps comprise the overall QC/QA plan used on LTPP data, as are discussed in the following paragraphs.

1. Collect Data: Procedures for collecting data are documented for each module in the IMS. These procedures are intended to ensure that data are collected in similar format, amounts, conditions, etc. Documentation references include the Data Collection Guide for Long-Term Pavement Performance Studies⁽²⁾ and various module-specific guides.
2. Review Data: Regional engineers review essentially all data input into regional IMS (RIMS) to check for possible errors related to keystroke input, field operations, procedures, equipment operations, and other variables. The regional review is intended to catch obvious data collection errors. In addition, some data are preprocessed before they are entered into the IMS. For example, PROFCAL™ software is used on SHRP profilometers to provide a system check by comparing measurements taken at different speeds. PROFSCAN™ is a field QA tool that allows an operator to identify invalid data while still in the field, thus avoiding costly revisits to the site.
3. Load Data in IMS: Some checks are programmed into the IMS to identify errors as data are entered. The IMS contains mandatory logic, range, data verification, and other miscellaneous checks that are invoked during input.
4. QC/QA: Once data are input into the IMS and reviewed by regional engineers, formal QC/QA software programs are run on the data.
   • Level A-Random checks of data are performed to ensure correct RIMS to IMS data transfer.
   • Level B-A set of dependency checks is performed to ensure that essential section information has been recorded in the IMS. In addition, experiment types are verified based on inventory data. These checks are currently being incorporated into the level E checks for all modules.
   • Level C-A minimum data search is performed for critical elements. For example, inventory data should contain the coordinates of the section, friction data should contain the skid number, and rehabilitation data should have a code entered to identify each work type activity.
   • Level D-Expanded range checks are applied to certain fields to identify data element values that fall outside an expected range. These checks are more stringent than the input range checks reviewed by the regional engineers.
   • Level E-Intramodular checks are employed to verify the consistency of data within a data module. For example, if an overlay is identified in the inventory layer structure, the data of the overlay should be recorded in the inventory table that includes major improvements to the pavement structure.

Once the QC/QA programs are completed, the regional engineers review the output and resolve any data errors whenever possible. Often the data entered are accurate and legitimate, but do not pass a QC/QA check. When this occurs, the regional engineer can document that the data have been confirmed using a comments table in the IMS and manually upgrade the record to Level E.

Figure 3 is a flowchart that shows the movement of data elements and quality checks completed on the data prior to release to the public. Only a fraction of the data fields are checked. A value of "A" is automatically assigned to a record on entry in the database. A value of "B" indicates that the QC process was executed and a level C check was failed. Any record for which correct section information is stored in the database is available after the QC is completed. A record of the QC processing is included with the record. Since the checks are run in sequence from A to E, the last successful check is identified on the record as the record status variable. A value of B or C does not necessarily indicate that higher level QC was unsuccessful, merely that a necessary data element was not available when the QC was done.

Figure 3. LTPP data collection and data movement flowchart.

There are numerous reasons why some important data may not be available from publicly released IMS database at the time of analysis. The following are some possible examples:

• Data are yet to be collected or the laboratory tests have not been performed yet.
• Data are under regional review.
• Data have failed one of the quality checks and are to be reviewed.
• Data have failed one of the quality checks and were identified as anomalies.
• Data are yet to be quality checked.

As such, the unavailable data identified in this report do not necessarily mean that the data were not collected or submitted by the States. There are several places where data may get held up and not reach level E. Note that the results reported in this report are based upon level E data only.

The LTPP program is embarking on a systemwide effort to resolve all unavailable data so that information will be available to future researchers. Some data have already been located during the course of this study.

General Site Information

General site-related information availability for SPS-2 projects is discussed in this section. This includes site identification and location, key equipment installed, report availability, and important dates associated with each SPS-2 site. The information was obtained from the site construction reports and deviation reports, or from the following IMS tables:

• EXPERIMENT_SECTION
• SPS_ID

The EXPERIMENT_SECTION table contains records for all the SPS-2 sites and sections. All the site-level records (0200) for the 13 constructed SPS-2 projects are at level E. The section-level records are at level E except for the 12 sections at the newly constructed Wisconsin SPS-2 site. The SPS_ID tables contain records for all 13 SPS-2 sites, and the site data are all at level E.

Since this site-level information is fundamental to the SPS-2 sites and is very important for an overall understanding of the sites, actual key data are presented, in addition to the data availability assessment. General State identification, equipment installation, and report availability information about the SPS-2 sites are provided in table 7. The construction reports were prepared and submitted by LTPP regional coordination office contractors (RCOCs) for all SPS-2 projects.

The site location and functional class information are provided in table 8. Table 9 presents the significant dates such as the approximate construction complete date, traffic opening date, and the LTPP assign and deassign dates. The oldest SPS-2 site is 7.5 years old. As indicated in both tables, all the important site-level information is available for the 13 SPS-2 sites. The only exception is that the approximate construction completion date for the North Dakota site was not available at the time of analysis in the SPS_ID table.

Table 7. SPS-2 site general information and report availability.

State Information				Equipment Installed			Report Availability
Abbr.	Code	Name	SHRP Region	AWS	WIM	AVC	Construction	Deviation
AZ	04	Arizona	W					-
AR	05	Arkansas	S			-
CO	08	Colorado	W					-
DE	10	Delaware	NA
IA	19	Iowa	NC
KS	20	Kansas	NC
MI	26	Michigan	NC
NV	32	Nevada	W					-
NC	37	North Carolina	NA					-
ND	38	North Dakota	NC
OH	39	Ohio	NC
WA	53	Washington	W					-
WI	55	Wisconsin	NC

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

Pavement Structure Data

Pavement structure data are further divided into two categories: pavement layer data and pavement design features.

Pavement Layer Data

Pavement layer data for SPS-2 sections are available from two sources: rod and level measurements (IMS table SPS2_Layer) and core measurements (IMS table TST_L05B). Both tables were examined for the following pavement structure layers:

• PCC slab thickness.
• Base type and thickness.
• Subgrade type.

The data availability and QC levels for these data elements are summarized in table 10.

The TST_L05B table contains records with all layer data for 143 core sections at 12 SPS-2 sites. Layer information from the Wisconsin SPS-2 site is not available from the database at the time of analysis.

The SPS2_LAYER table contains all layer data for all 155 sections from all 13 SPS-2 sites, and 143 sections are at QC level E. The remaining 12 records, all from the same site in Wisconsin, are at level A.

Key Design Feature Data

Important general design features, such as drainage, lane width, and shoulder type data, are included in table SPS_GENERAL. The data availability assessment for these data elements is provided in table 11.

As indicated in table 11, information is available for 133 SPS-2 sections, and the data are all at level E. The key design feature data for 24 SPS-2 core sections in Kansas and Wisconsin were not available at the time of analysis.

Construction Data

SPS-2 construction data include information pertaining to the pavement layers constructed according to the requirements stipulated for the experiment. The following key SPS-2 construction tables were evaluated for the data completeness and QC levels:

• SPS2_PCC_JOINT_DATA-PCC layers: Joint data (sheets 15, 16).
• SPS2_PCC_MIXTURE_DATA-PCC layers: Mixture data (sheets 18, 19).
• SPS2_PCC_PLACEMENT_DATA-PCC layers: Placement data. (sheets 20, 21).
• SPS2_PROJECT_STATIONS-Test section information (sheet 3).
• SPS2_SUBGRADE_PREP-Subgrade preparation (sheet 6).
• SPS2_UNBOUND_AGG_BASE -Unbound aggregate base material placement data (Sheet 9).

Data availability assessment and QC levels summary for these tables are provided in tables 12 and 13.

Over 90 percent of the existing pavement structure data are at level E, but some data for several SPS-2 core sections were not available at the time of analysis. However, the supplemental sections were missing a lot of data at the time of analysis, as shown in these tables. The Wisconsin SPS-2 site represents most of the missing data, as it was a new site at the time of analysis.

Material Testing Data

Field and laboratory tests are conducted to establish material properties and characteristics for LTPP sections. Characterization of material properties and the variations in these properties between and within the test sections is required to evaluate causes of performance differences between test sections. The materials characterization includes parameters used in current pavement design and mechanical analysis models.

Material sampling and testing requirements are documented in the SPS-2 Material Sampling and Testing Requirements report.⁽³⁾ This report includes the development of SPS-2 sampling and testing plans, field material sampling and testing requirements, and laboratory material testing requirements for each SPS-2 site. The SPS-2 material sampling and testing plans for subgrade and bases are provided in table 14, while the material sampling and testing plans for PCC surface are presented in table 15.

The sampling and testing plan specified methods for material sampling and testing at the site level for similar material and structure layers. Therefore, the evaluation of the material testing data should also be conducted at the SPS-2 site level.

Since there is a comprehensive LTPP material data review study underway, only the key data elements for the PCC surface from the SPS-2 sampling and testing plan were evaluated in this study.

For the SPS-2 experiment, the following materials testing tables were evaluated for data availability and completeness:

• TST_PC01-Compressive strength of in-place concrete test results for PCC layers.
• TST_PC02-Split tensile strength test results for PCC layers.
• TST_PC09-Flexural strength.
• TST_PC06-Core examination and thickness.

There are currently no data available on coefficient of thermal expansion for SPS-2 sections; such data are an essential variable for any mechanistic analysis.

The data availability and completeness assessment results for these key PCC materials testing tables are presented in table 16. As shown, 9 of 13 projects have good to excellent data availability for these tables, ranging from 81 to 100 percent tests completed. Three sites-Arkansas, Kansas, and Wisconsin-have a fair amount of PCC testing data available, ranging from 66 to 71 percent. The North Carolina SPS-2 project is missing much PCC testing data at the time of analysis, with only 33 percent available.

Traffic Data

Traffic data provide estimates of annual vehicle counts by vehicle classification, and distributions of axle weights by axle type. Annual traffic summary statistics are stored in the IMS traffic module. Data are provided for each year since the road was opened to traffic. With few exceptions (such as annual average daily traffic (AADT)-based values), the information applies only to the lane being studied. Traffic data are collected by the individual States/Provinces using a combination of permanent and portable equipment.

For the SPS-2 experiment, traffic data are generally obtained at the site level. In places where an intersection is located within the test site (thus resulting in different traffic levels on the test sections), measurements of the traffic level on the different groups of sections on each side of the intersection should be obtained. For simplicity and consistency, a traffic data availability assessment is conducted on a section-by-section basis.

The SPS-2 experiment design calls for continuous weigh-in-motion (WIM) monitoring, as permitted by WIM scale operating conditions. Table TRF_MONITOR_BASIC_INFO was examined to identify SPS-2 records containing WIM records, automatic vehicle classifier (AVC) data, and annual ESAL estimates. The WIM and AVC data were further classified into "at least 1 day" and "continuous" monitoring frequency categories. Continuous AVC monitoring was defined as over 300 AVC monitoring days in a given year. Continuous WIM monitoring was defined as over 210 WIM monitoring days in a given year.

Table 17 summarizes the data availability and completeness for SPS-2 traffic data. As shown, very few sections have continuous WIM or AVC monitoring data stored in the IMS database. Non-zero computed annual ESALs were found for 84 core SPS-2 sections at 8 sites with 83 records at level E status. A total of 71 core sections (nearly half of the core sections) have neither WIM monitoring data nor annual ESAL estimates data in the table TRF_MONITOR_BASIC_INFO. Additional annual ESAL estimates were available for 15 supplemental sections located in 6 different States.

*Note: Min. req'd refers to the minimum number of tests required for the PCC layer.

Climate Data

There are three types of climatic information: general environmental, automated weather station (AWS), and seasonal monitoring. General environmental and AWS data for the SPS-2 project are obtained at a project or site level.

The general environmental information includes actual measurements from at least one nearby weather station for each LTPP site. In addition, a site-specific statistical estimate based on as many as five nearby weather stations is available. The estimates are called virtual weather stations. The IMS contains monthly and annual summary statistics. Daily data for both the virtual weather stations and actual weather stations are kept offline. General environmental data available in the IMS are derived from weather data originally collected from the National Climatic Data Center and the Canadian Climatic Center.

AWSs have been installed at nearly all of the SPS-2 project sites. The equipment provides site-specific information for the same parameters as the general environmental tables. AWS tables are available with monthly, daily, or hourly statistics.

The availability of both types of climatic data is shown in table 18. As noted, historic climatic data are available for all SPS-2 sites except Wisconsin. AWS data are available for 10 of 13 SPS-2 sites; Arkansas, Delaware, and Wisconsin have no data. The time periods covered by the AWS data at these sites range from 3 to 6 years.

Monitoring Data

Seven types of monitoring data are included in the LTPP IMS: automated distress, manual distress, friction, longitudinal profile, cross profile, deflection, and dynamic load response. The monitoring data reviewed for the SPS-2 project are broken into the following categories for discussion:

• Longitudinal profile data.
• Deflection data.
• Manual and photographic distress data.
• Friction data.

In this section, the monitoring frequency requirement is discussed first, followed by the data availability and completeness assessment of all the categories.

Monitoring Frequency

During the life of these pavement sections, multiple directives have been issued regarding the testing frequency for each type of monitoring data collected. Some of these directives have slightly adjusted the testing intervals during the life of the program. The following is a list of the key documents and directives that affect the monitoring frequency requirement for the SPS-2 project:

1. Data Collection Guide for Long-Term Pavement Performance Studies.⁽²⁾

2. LTPP Directive D-02: Quality Assurance of PASCO Products.⁽⁴⁾

3. LTPP Directive D-05: Measurement Frequency and Priorities of Manual Distress Surveys.⁽⁵⁾

4. LTPP Directive FWD-03: Deflection Monitoring Frequency Priorities and Use of FWDs Owned by Other Agencies.⁽⁶⁾

5. LTPP Directive FWD-10: Deflection Monitoring Frequencies and Priorities.⁽⁷⁾

6. LTPP Directive P-02: Profile Monitoring Frequencies and Priorities.⁽⁸⁾

7. LTPP Directive GO-20: Revised Friction Measurement Requirements.⁽⁹⁾

8. LTPP Directive GO-21: LTPP Test Section Monitoring Adjustments.⁽¹⁰⁾

These directives were used to identify all previous testing frequencies for each type of monitoring data collected, and are summarized in table 19. For supplemental sections, the monitoring frequencies are every 3 years for manual distress and joint faulting monitoring, every 2 years and responsive for photographic survey, and every 5 years and responsive for falling-weight deflectometer (FWD) testing.

In addition, close-out monitoring consisting of FWD, profile, and manual distress surveys should be conducted on each section. According to LTPP Directive GO-21, this monitoring is performed "when it is determined that the test section will be taken out-of-study (due to a construction event or at the option of the highway agency) or at the end of the field monitoring portion of the LTPP program, whichever comes first." ⁽¹⁰⁾

The testing frequency requirements specified in LTPP Directive GO-21 are also listed in the table. This requirement has been in effect since October 1, 1999.

Monitoring Data Assessment

The following IMS monitoring tables are used in evaluating the data availability and completeness for SPS-2 monitoring:

• MON_PROFILE_MASTER-Monitoring profilometer master record.
• MON_DEFL_DROP_DATA-Peak and other drop-specific data values for Dynatest FWD.
• MON_DIS_JPCP_FAULT_SECT-Section faulting statistics for transverse joints and cracks.
• MON_DIS_JPCP_REV-Distress identification for jointed PCC surfaces.
• MON_DIS_PADIAS_JPCP-Distress identification for JPCP surfaces.
• MON_DIS_PADIAS42_JPCP-Distress identification for jointed PCC surfaces.
• MON_FRICTION-Friction-resistance measurements.

Tables 20 to 24 show summaries of the data availability assessment for longitudinal profile, deflection, faulting, manual, and photographic distress surveys, and friction-monitoring data for SPS-2. Using the minimum monitoring data collection requirement noted in these tables, an assessment of this data availability and completeness follows:

• Longitudinal profile data are acceptable for most sites, but some are seriously deficient (such as Arkansas and North Dakota) with very late initial longitudinal profile measurement.
• Deflection data are very complete. The only exception is the late initial survey at the Arkansas site.
• Faulting data are very deficient at the Kansas site. Data from Arizona, Arkansas, Colorado, and North Carolina are late. The other eight sites have adequate faulting data.
• Combined distress data satisfies the minimum requirement, except for the initial surveys of Arizona, Arkansas, and North Dakota.
• Friction monitoring data are deficient, with very few test visits, too-long survey intervals, and far too long to initial friction measurement.

Table 20. Summary of the number of the surveys for longitudinal profile data collection.

SPS-2 Project in State	Age as of Aug. 1999	No. of Test Visits			Long-Term Interval, year	Initial Survey Age, month	Meet Minimum Requirement? *
		Core Sections		Suppl. Sections
		Avg (min-max)	% At E		Avg (min-max)	Avg (min-max)
AZ	6.3	4.9 (4-5)	100	5.0 (5-5)	1.3 (1-2)	3.8 (4-4)
AR	4.3	1.0 (1-1)	100	N/A	N/A	16.2 (16-16)	Not the initial survey
CO	6.3	3.0 (3-3)	100	3.0 (3-3)	2.2 (2-2)	6.4 (6-6)
DE	3.7	6.0 (6-6)	100	6.0 (6-6)	0.3 (0-0)	7.2 (7-7)
IA	5.4	4.9 (4-5)	100	5.0 (5-5)	1.1 (1-1)	6.5 (7-7)
KS	7.5	7.9 (7-8)	100	7.0 (7-7)	0.9 (1-1)	2.0 (1-8)
MI	6.2	8.6 (7-9)	99	9.0 (9-9)	0.6 (1-1)	10.2 (10-10)
NV	4.4	3.6 (2-4)	100	4.0 (4-4)	0.7 (1-1)	10.9 (11-11)
NC	5.5	7.9 (7-8)	100	7.5 (7-8)	0.7 (1-1)	<0 (-3-3)
ND	5.3	2.0 (2-2)	100	2.0 (2-2)	2.0 (2-2)	31.0 (31-31)	Not the initial survey
OH	3.3	4.0 (4-4)	100	3.4 (3-4)	0.7 (1-1)	<0 (-1-1)
WA	4.2	4.0 (4-4)	100	4.0 (4-4)	1.2 (1-1)	0.6 (1-1)
WI	2.3	3.0 (3-3)	100	3.0 (3-3)	0.7 (1-1)	2.0 (2-2)

Note: * Minimum longitudinal profile data collection requirement: Within 12 months for the initial survey, and less than 3 years for all long-term monitoring intervals (i.e., biannually, but may be postponed up to 1 year).

Table 21. Summary of the number of the surveys for deflection data collection.

SPS-2 Project in State	Age as of Aug. 1999	No. of Test Visits			Long-Term Interval, year	Initial Survey Age, month	Meet Minimum Requirement? *
		Core Sections		Suppl. Sections
		Avg (min-max)	% At E		Avg (min-max)	Avg (min-max)
AZ	6.3	6.1 (5-7)	100	2.3 (1-5)	1.1 (1-1)	<0 (-2-2)
AR	4.3	1.5 (1-2)	100	N/A	0.0 (0-0)	13.5 (13-14)	Not the initial survey
CO	6.3	4.2 (3-5)	100	3.0 (3-3)	1.6 (1-2)	0.5 (-2-6)
DE	3.7	2.2 (2-3)	100	2.0 (2-2)	1.2 (1-1)	0.2 (0-0)
IA	5.4	1.4 (1-2)	100	1.0 (1-1)	2.6 (3-3)	5.3 (3-35)	OK except for 0219
KS	7.5	5.3 (5-7)	100	2.0 (2-2)	1.1 (1-1)	1.1 (1-1)
MI	6.2	4.2 (3-5)	100	4.0 (4-4)	1.4 (1-2)	0.5 (0-1)
NV	4.4	4.0 (2-6)	100	2.0 (2-2)	0.7 (0-1)	<0 (-2-1)
NC	5.5	2.4 (2-5)	100	2.0 (2-2)	1.9 (1-2)	<0 (-2-2)
ND	5.3	1.3 (1-2)	100	1.3 (1-2)	0.8 (1-1)	1.1 (1-1)
OH	3.3	3.9 (3-5)	100	3.3 (2-4)	0.6 (0-1)	<0 (-14--12)
WA	4.2	4.7 (4-5)	100	4.0 (4-4)	0.9 (1-1)	<0 (-4-4)
WI	2.3	1.0 (1-1)	0	0.9 (0-1)	N/A	6.8 (7-7)

Note: * Minimum deflection data collection requirement: Within 12 months for the initial survey, and less than 3 years for all long-term monitoring intervals (i.e., biannually, but may be postponed up to 1 year).

Table 22. Summary of the number of the surveys for faulting data collection.

SPS-2 Project in State	Age as of Aug. 1999	No. of Test Visits			Long-Term Interval, year	Initial Survey Age, month	Meet Minimum Requirement? *
		Core Sections		Suppl. Sections
		Avg (min-max)	% At E		Avg (min-max)	Avg(min-max)
AZ	6.3	2.6 (2-3)	100	2.3 (0-3)	1.7 (1-2)	29 (17-49)	Not the initial survey
AR	4.3	1.0 (1-1)	100	N/A	N/A	14 (13-14)	Not the initial survey
CO	6.3	3.0 (3-3)	100	3.0 (3-3)	1.7 (2-2)	30.8 (31-31)	Not the initial survey
DE	3.7	3.2 (3-4)	100	3.0 (3-3)	1.5 (1-2)	0.2 (0-0)
IA	5.4	2.8 (2-3)	100	2.0 (2-2)	2.9 (2-5)	2.6 (3-3)
KS	7.5	1.9 (1-2)	100	1.0 (1-1)	4.1 (4-4)	13.4 (9-59)	No
MI	6.2	4.8 (3-6)	100	4.0 (4-4)	1.4 (1-1)	0.5 (0-1)
NV	4.4	2.2 (2-3)	100	2.0 (2-2)	2.1 (1-3)	7.9 (8-8)
NC	5.5	2.4 (1-6)	100	2.0 (2-2)	2.6 (1-3)	2.6 (0-33)	Not the initial survey for 0204, 0208, 0212
ND	5.3	2.1 (1-3)	100	1.7 (1-2)	3.9 (2-5)	0.8 (1-1)
OH	3.3	2.0 (2-2)	100	2.0 (2-2)	2.7 (3-3)	3.4 (3-3)
WA	4.2	3.0 (3-3)	100	3.0 (3-3)	1.5 (1-1)	0.0 (0-0)
WI	2.3	1.1 (1-2)	0	0.9 (0-1)	N/A	6.8 (7-7)

Note: * Minimum faulting data collection requirement: Within 12 months for the initial survey, and less than 3 years for all long-term monitoring intervals (i.e., biannually, but may be postponed up to 1 year).

Table 23. Summary of the number of the surveys for manual and photographic distress data collection.

SPS-2 Project in State	Age as of Aug. 1999	No. of Test Visits			Long-Term Interval, year	Initial Survey Age, month	Meet Minimum Requirement? *
		Core Sections		Suppl. Sections
		Avg (min-max)	% At E		Avg (min-max)	Avg (min-max)
AZ	6.3	3.6 (3-4)	100	3.1 (0-4)	1.5 (1-2)	17.2 (17-18)	Not the initial survey
AR	4.3	1.0 (1-1)	100	N/A	N/A	13.5 (13-14)	Not the initial survey
CO	6.3	5.1 (5-6)	100	5.0 (5-5)	1.3 (1-1)	9.4 (9-9)
DE	3.7	3.2 (3-4)	100	3.0 (3-3)	1.5 (1-2)	0.2 (0-0)
IA	5.4	3.8 (3-5)	100	3.0 (3-3)	1.7 (1-2)	2.6 (3-3)
KS	7.5	3.8 (3-4)	100	4.0 (4-4)	1.5 (1-2)	9.2 (9-9)
MI	6.2	5.8 (4-7)	100	6.0 (6-6)	1.1 (1-1)	0.5 (0-1)
NV	4.4	3.2 (3-4)	100	3.0 (3-3)	1.1 (1-1)	7.9 (8-8)
NC	5.5	2.5 (2-6)	100	2.0 (2-2)	1.0 (1-1)	19.0 (17-19)	Not the initial survey
ND	5.3	3.3 (3-4)	100	3.0 (3-3)	2.1 (2-2)	0.8 (1-1)
OH	3.3	3.0 (3-3)	100	2.6 (2-3)	1.5 (2-2)	<0 (0-0)
WA	4.2	3.0 (3-3)	100	3.0 (3-3)	1.5 (1-1)	<0 (0-0)
WI	2.3	1.0 (1-1)	0	0.9 (0-1)	N/A	6.8 (7-7)

Note:* Minimum manual and photographic data collection requirement: Within 12 months for the initial survey, and less than 3 years for all long-term monitoring intervals (i.e., biannually, but may be postponed up to 1 year).

Table 24. Summary of the number of the surveys for friction data collection.

SPS-2 Project in State	Age as of Aug. 1999	No. of Test Visits			Long-Term Interval, year	Initial Survey Age, month	Meet Minimum Requirement? *
		Core Sections		Suppl. Sections
		Avg (min-max)	% At E		Avg (min-max)	Avg (min-max)
AZ	6.3	0	-	-	-	-	No Data
AR	4.3	0	-	-	-	-	No Data
CO	6.3	1.0 (1-1)	100	1.0 (1-1)	-	7.0 (7-7)	No
DE	3.7	0	-	0.0 (0-0)	-	-	No Data
IA	5.4	3.0 (3-3)	100	3.0 (3-3)	1.0 (1-1)	13.0 (13-13)	No
KS	7.5	2.0 (2-2)	100	2.0 (2-2)	1.1 (1-1)	46.0 (46-46)	No
MI	6.2	0.5 (0-1)	100	1.0 (1-1)	-	46.8 (47-47)	No
NV	4.4	0	-	0.0 (0-0)	-	-	No Data
NC	5.5	0	-	0.0 (0-0)	-	-	No Data
ND	5.3	0	-	0.0 (0-0)	-	-	No Data
OH	3.3	0	-	0.0 (0-0)	-	-	No Data
WA	4.2	2.0 (2-2)	100	2.0 (2-2)	0.5 (0-1)	10.5 (6-11)
WI	2.3	0	-	-	-	-	No Data

Note:* Minimum friction data collection requirement: Within 12 months for the initial survey, and less than 3 years for all long-term monitoring intervals (i.e., biannually, but may be postponed up to 1 year).

Dynamic Load-Response Data

Various PCC pavement sections of the SPS-2 project were selected for measuring pavement response under controlled loading conditions. Both deflections and strains at defined positions within the slab were recorded under loading by known vehicles. Deflections of the PCC surface were measured at six locations (corner, midslab edge, and midslab out wheel path) within two adjacent slabs. The pavement surface strains were measured using surface-mounted strain gauges located at midslab within the wheel path and midslab along the slab edge. Data from a total of 30 traces were obtained from each pass of the loaded vehicle, with multiple repetitions at multiple speeds collected at various times of the day. During the early life of the pavement, dynamic load-response data were collected on a quarterly basis. Data collection was terminated after 2 years.

The dynamic load-response data for PCC sections are stored in the DLR_* module in the following seven IMS tables:

• DLR_LVDT_CONFIG_PCC-LVDT gauge device, settings, and location information.
• DLR_LVDT_TRACE_SUM_PCC-LVDT trace summary information.
• DLR_MASTER-Dynamic load response site and instrumentation summary information.
• DLR_STRAIN_CONFIG_PCC-Sensor gauge device, settings, and location information.
• DLR_STRAIN_TRACE_SUM_PCC-Data load response strain trace summary information.
• DLR_TEST_MATRIX-Data load response test matrix summary information.
• DLR_TRUCK_GEOMETRY-Data load response truck geometry summary information.

The only dynamic load response data in the IMS database are from the North Carolina and Ohio SPS-2 sites. The data availability assessment of these tables is provided in table 25. All records in these tables are at level E. As shown in the table, significant amounts of stress and strain data are available on the instrumented sections. These data should be very useful for the analysis of the pavement dynamic load responses.

Summary of SPS-2 Data Availability and Completeness Assessment

Table 26 summarizes the data availability and completeness by key data types that are not subject to long-term monitoring, while table 27 summarizes the data availability and completeness for the key data types subject to long-term monitoring. Note that any rating of "fair" or "poor" means that these sites would not meet analysis needs and therefore must be improved as soon as possible. The SPS-2 data deficiencies are summarized below:

• Wisconsin-newly constructed, data processing underway.
• Arizona, Arkansas, and North Carolina-late initial survey for most monitoring types.
• Colorado and North Dakota-late initial survey for one monitoring collection activity, either longitudinal profile measurements, deflection testing, faulting, or distress data.
• Kansas SPS-2-very deficient faulting data.
• Traffic data are very deficient for 5 of 13 sites (40 percent).
• Joint faulting data are not being collected at the frequency specified by LTPP data collection guidelines, and this will limit the analyses that can be conducted.
• Friction data are completely deficient for most projects (11 out of 13).
• Arkansas, Kansas, North Carolina, and Wisconsin are missing significant PCC material testing data at the time of analysis.

A very good percentage of the SPS-2 data are at level E. More than 82 percent of the records are at level E for all data types, with many greater than 99 percent. The availability and completeness of data for the SPS-2 experiment is good overall. However, a significant amount of data was not available at the time of analysis, especially traffic, distress and faulting surveys, and key materials testing data. These deficiencies need to be addressed before serious data analysis can be undertaken. There is an active plan in place to address the deficient materials testing and traffic data.