U.S. Department of Transportation
Federal Highway Administration
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Washington, DC 20590
202-366-4000
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
| REPORT |
| This report is an archived publication and may contain dated technical, contact, and link information |
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| Publication Number: FHWA-HRT-13-092 Date: May 2014 |
Publication Number: FHWA-HRT-13-092 Date: May 2014 |
APPENDIX A. MANUAL FOR DISTRESS SURVEYS
TABLE OF CONTENTS
This appendix provides instructions, data sheets, and distress maps for use in visual surveys for the collection of distress information for ACP, JCP, and CRCP surfaces. Visual distress survey procedures have been used in the LTPP program as the primary distress data collection method since 1995. The Distress Identification Manual for the Long-Term Pavement Performance Program (DIM) is the basis for all distress surveys performed for the LTPP program.
During the visual distress survey, safety is the first consideration, as with all field data collection activities. All raters must adhere to the practices and authority of the State or Canadian Province and follow the guidelines in LTPP directive D-42 or its latest version.
EQUIPMENT FOR DISTRESS SURVEYS
The following equipment is necessary for performing field distress surveys of any pavement surface type:
INSTRUCTIONS FOR COMPLETING DISTRESS MAPS
The distress maps show the exact location of each distress type existing on the test section. The distress types and severity levels should be identified by using the DIM. A total of five sheets are used to map; each sheet contains two 15.25-m maps which represent 30.5 m of the test section (with the exception of SPS-6 sections 2 and 5, which are 305 m).
Each test section must be laid out consistently each time a survey is conducted. Sections begin and end at the stations marked on the pavement. Lateral extent of the section, for survey purposes, will vary depending on the existence of longitudinal joints and cracks and the relative position of the lane markings. Figure 134 and figure 135 illustrate the rules to follow when determining the lateral extent of the section for a distress survey. The lateral extent of the test sections should be consistent with prior distress surveys. On widened PCC sections, the lateral extent of the test section includes the full width (4.3 m) of the slab measured from the centerline longitudinal joint to the shoulder joint.
The lateral extent of an ACP test section will vary depending on the existence of longitudinal construction joints, longitudinal cracks, and the edge of the pavement or the relative position of the lane marking. Generally the lateral extent of the test section on ACP is from the outside edge of the edge stripe to the outside edge of the centerline stripe (see figure 134). The lateral extent of ACP test sections with double yellow lines on the centerline are determined by using the inside yellow line. If a longitudinal construction joint or a longitudinal crack or the edge of the pavement exists outside the stripes within 0.3 m of the stripes, the lateral extent of the test section is extended to the longitudinal construction joint or the longitudinal crack or the edge of the pavement. The lateral extent of a CRCP or JCP test section is defined by the centerline and edge longitudinal joints. All distresses within the lateral extent of the survey are rated. The lateral extent of the test section (test section width) shall be recorded in the comments on map sheet 1. Test sections begin and end at the stations marked on the pavement. All distresses within the test section limits are to be recorded on distress map forms and data sheets. In cases where a transverse crack, or any other distress, falls directly on one of the beginning or ending pavement markings, the rater shall record it consistent with previous surveys.
Figure 134. Test Section Limits for Surveys-Asphalt Surface
Figure 135. Test Section Limits for Surveys-Concrete Surface
To map the test section, place the tape measure on the shoulder adjacent to the test section from Station 0+00 to Station 1+00. It may be necessary to secure the tape onto the pavement with adhesive tape or a heavy object. After the tape is in place, the distresses can be mapped with the longitudinal placement of the distresses read from the tape. The transverse placement and extent of the distresses can be recorded using the additional tape measure. After the first 30.5-m subsection is mapped, the tape measure should be moved to map the second 30.5-m subsection. The process is repeated throughout the test section. A calibrated measuring wheel can be used as an alternative under the conditions outlined in LTPP directive D-28 or its latest version.
The distresses are drawn on the map at the scaled location using the symbols appropriate to the pavement type. In general, the distress is drawn and is labeled using the distress type number and the severity level (L, M, or H) if applicable. For example, a high severity longitudinal crack in the wheel path of an ACP would be labeled "4aH." An additional symbol is added beside the distress type and severity symbol in cases where the crack or joint is well-sealed. Figures specifying the symbols to be used for each pavement type are presented in the following chapters. In addition, example maps are provided to illustrate properly completed maps.
Photographs are an important component of LTPP manual distress surveys and must be taken during each survey in accordance with LTPP directive D-54 or its latest version. Any observed distresses that are not described in the DIM should be photographed and described on the comments line of the map sheet. The location and extent of the distress should be shown and labeled on the map. Crack sealant and joint sealant condition is to be mapped only for those distresses indicated in figure 137, figure 138, and figure 141. The specific distress types that are not to be included on the maps are to be recorded as follows.
If raveling, polished aggregate, or bleeding occur in large areas over the test section, do not map the total extent. Instead, note the location and extent in the space for comments underneath the appropriate map(s). These distresses should be mapped only if they occur in localized areas. The extent of these distresses must be summarized on the data summary sheets.
If map cracking/scaling, or polished aggregate occur in large areas over the test section, do not map the total extent. Instead, note the location, extent, and severity level if applicable in the space for comments underneath the appropriate map(s). These distresses should be mapped only if they occur in localized areas. The extent of these distresses must be summarized on the data summary sheets.
In the common data section appearing in the upper right-hand corner of each of the distress survey data sheets the six-digit SHRP ID (two-digit State code plus four-digit SHRP Section ID) is entered. The date the survey was conducted, the initials of up to two raters, before and after pavement surface temperature readings, and the code indicating whether photographs and/or video tape were obtained at the time of the survey are entered in the appropriate spaces.
INSTRUCTIONS FOR COMPLETING ACP DISTRESS SURVEY SHEETS
Location of the vehicle wheel paths is critical for distinguishing between types of longitudinal cracking in ACP. Figure 136 illustrates the procedure for establishing the location and extent of the wheel paths. Both wheel paths must be drawn and identified on the distress maps. The distresses observed are recorded to scale on map sheets. The individual distresses and severity levels depicted on the map are carefully scaled and summed to arrive at the appropriate quantities (e.g., square meters or number of occurrences) and are then recorded on sheets 1 through 3. It is important to carefully evaluate the distress map for certain distress types which have multiple methods of measurement because of orientation or location within the section. Longitudinal cracking, in the wheel path or elsewhere, are examples of these. Except where indicated otherwise, entries are made for all distress data elements. If a particular type of distress does not exist on the pavement, enter "0" as a positive indication that the distress was not overlooked in summarizing the map sheets. All data sheets are to be completed in the field prior to departing the site. Symbols to be used for mapping ACP sections are contained in figure 137, and an example mapped section is shown in figure 138.
Figure 136. Locating Wheel Paths in ACP
Figure 137. Distress Map Symbols for ACPs
Figure 138. Example Map of First 30.5 m of ACP Section
This data sheet provides space for recording measured values for the distress types identified in the left column. The units of measurement for each of the distress types are also identified in the left column. The extent of the measured distress for each particular level of severity is entered in the severity level columns identified as low, moderate, or high. Enter "0" for any distress types and/or severity levels not found.
This sheet is a continuation of the distress survey data recorded on sheet 1 and is completed as described under data sheet 1. In addition, space is provided to list other distress types found on the test section but not listed on data sheets 1 or 2.
This data sheet provides space to record rutting (using a straight edge 1.2 m long). Manual rutting measurements using a straight edge are only taken for visual surveys conducted on SPS-3 experiment sections. Measurements are taken at the beginning of the test section and at 15.25 m intervals. There should be a total of 11 measurements in each wheel path, for a total of 22 measurements on each test section.
INSTRUCTIONS FOR COMPLETING JCP DATA SHEETS
The distresses observed are recorded to scale on map sheets. This information is reduced by the rater in the field to summarize the results, which are then recorded on sheets 4 through 7. Except where indicated otherwise, entries are made for all distress data elements. If a particular type of distress does not exist on the pavement, enter "0" as a positive indication that the distress was not overlooked in summarizing the map sheets. Symbols to be used for mapping distresses in JCP sections are shown in figure 139, and an example mapped section is presented in figure 140.
This data sheet provides space for recording measured values for the distress types identified in the left column. The units of measurement for each of the distress types are also identified in the left column. The extent of the measured distress for each particular level of severity is entered in the severity level columns identified as low, moderate, or high. Enter "0" for any distress types and/or severity levels not found. The distress types and severity levels should be identified by using the DIM.
This sheet is a continuation of the distress survey data recorded on sheet 4 and is completed as described under data sheet 4. In addition, space is provided to list other distress types found on the test section but not listed on data sheets 4 or 5.
This data sheet provides space to record faulting information for each transverse joint and transverse crack. Distance from the beginning of the section and faulting measurements made at two transverse locations are recorded. The transverse locations are 0.3 and 0.75 m from the outside edge of the slab. For widened lanes, measure 0.3 m from the edge of the slab and 0.75 m from the outside edge of the lane edge stripe. At each location, three measurements are made, but only the approximate average of the readings is recorded to the nearest millimeter. The faultmeter identification number, which can be found on the meter, and the device code shall be entered on the form. The following codes shall be used:
Although no field is provided in the space to the left of the entry for measured faulting, there is room for a negative sign when negative faulting is observed. If the approach slab is higher than the departure slab, a positive sign is assumed, but no entry is required. If the approach slab is lower, a negative sign is entered.
This sheet is used to record lane-to-shoulder dropoff and lane-to-shoulder separation. Lane-to-shoulder dropoff is measured as the difference in elevation, to the nearest 1 mm, between the pavement surface and the adjacent shoulder surface. Measurements are taken at the beginning of the test section and at 15.25-m intervals (a total of 11 measurements) at the lane/shoulder interface or joint. Lane-to-shoulder dropoff typically occurs when the outside shoulder settles. However, heave of the shoulder may occur due to frost action or swelling soil. If heave of the shoulder is present, it should be recorded as a negative value. At each point where there is no lane-to-shoulder dropoff, enter "0."
Lane-to-shoulder separation is measured as the width of the joint (to the nearest 1 mm) between the outside lane and the adjacent shoulder surface. Measurements are taken at the beginning of the test section and at 15.25-m intervals (a total of 11 measurements). At each point where there is no lane-to-shoulder separation, enter "0." When the surveyor is unable to take a measurement due to an anomaly such as sealant or patch material, a null value should be recorded and entered into the database.
Figure 139. Distress Map Symbols for JCPs
Figure 140. Example Map of First 30.5 m of a JCP Section
INSTRUCTIONS FOR COMPLETING CRCP DATA SHEETS
The results of distress surveys on CRCP surfaces are recorded on sheets 8 through 10. Except where indicated otherwise, entries are made for all distress data elements. If a particular type of distress does not exist on the pavement, enter "0" as a positive indication that the distress was not overlooked in summarizing the map sheets. All data sheets are to be completed in the field prior to departing the site. Symbols to be used for mapping CRCP distresses are contained in figure 141, and an example mapped section is presented in figure 142.
Figure 141. Distress Map Symbols for CRCPs
Figure 142. Example Map of First 30.5 m of a CRCP Section
This data sheet provides space for recording measured values for the distress types identified in the left column. The units of measurement for each of the distress types are also identified in the left column. The extent of the measured distress for each particular level of severity is entered in the severity level columns identified as low, moderate, or high, except as indicated on the form. Enter "0" for any distress types and/or severity levels not found. The distress types and severity levels should be identified by using the DIM.
This sheet is a continuation of the distress survey data recorded on sheet 8 and is completed as described under data sheet 8. In addition, space is provided to list "Other" distress types found on the test section but not listed on data sheets 8 or 9.
This data sheet provides space to record lane-to-shoulder dropoff and lane-to-shoulder separation. Measurements are taken at the beginning of the test section and at 15.25-m intervals (a total of 11 measurements for each distress) at the lane/shoulder interface or joint.
Lane-to-shoulder dropoff is measured as the difference in elevation (to the nearest 1 mm) between the pavement surface and the adjacent shoulder surface. Lane-to-shoulder dropoff typically occurs when the outside shoulder settles. However, heave of the shoulder may occur due to frost action or swelling soil. If heave of the shoulder is present, it should be recorded as a negative value.
Lane-to-shoulder separation is measured as the width of the joint (to the nearest 1 mm) between the outside lane and the adjacent shoulder surface.
When the surveyor is unable to take a measurement due to an anomaly such as a sealant or patch material, a null value is recorded and entered into the database.
At each point where there is no lane-to-shoulder dropoff or lane-to-shoulder separation, enter "0."
The faultmeter identification number, which can be found on the meter, and the device code shall be entered on the form. The following codes shall be used:
EXAMPLE SURVEY MAPS AND COMPLETED SHEETS
This part of the appendix shows completed maps and survey forms for a JCP 60 m long. The rater uses the definitions from the DIMand the symbols from this appendix when mapping the section. The rater then quantifies each distress (and severity levels for the appropriate distresses) on the map. The rater then uses the right margin of the map sheets to tally the quantities of each distress type. This method is required because it simplifies totaling the various distress types, and reduces errors. The rater then uses the tallies from each map sheet to add the distress quantities. The section totals are entered in the left margin of the first map sheet.
The rater then writes in the totals in the appropriate blanks on the survey forms. All blanks are filled in. Zeros are entered if no distress was found. These forms provide a summary of the distresses found in the JCP section.
BLANK DISTRESS MAP FORMS AND DATA SHEETS
These map forms and data sheets may be photocopied from this book for field use. Note that each type of pavement has its own data sheets.
ACP: |
Sheets 1, 2, 3 |
Pages 110, 111, 112 |
JCP: |
Sheets 4, 5, 6, 7 |
Pages 113, 114, 115, 116 |
CRCP: |
Sheets 8, 9, 10 |
Pages 117, 118, 119 |
