Distress Identification Manual for The Long-Term Pavement Performance Program (Fifth Revised Edition)

CHAPTER 3. DISTRESSES FOR PAVEMENTS WITH CONTINUOUSLY REINFORCED CONCRETE SURFACES

This section covers continuously reinforced concrete-surfaced pavements (CRCP), including continuously reinforced concrete overlays on PCC pavements. Each of the distresses has been grouped into one of the following categories:

Cracking. Surface defects. Miscellaneous distresses.

 

 

 

 

Table 3 summarizes the various types of distress and unit of measurement. Some distresses also have defined severity levels.

Table 3. CRCP Distress Types.

A. CRACKING

This section includes the following distresses:

    1. Durability cracking ("D" cracking).

    2. Longitudinal cracking.

    3. Transverse cracking.

1. Durability Cracking ("D" Cracking)

Description

Closely spaced crescent-shaped hairline cracking pattern.

Occurs adjacent to joints, cracks, or free edges. Initiates at the intersection (e.g., cracks and a free edge).

Dark coloring of the cracking pattern and surrounding area.

Severity Levels

Low:

"D" cracks are tight, with no loose or missing pieces, and no patching is in the affected area.

Moderate:

"D" cracks are well- defined, and some small pieces are loose or have been displaced.

High:

"D" cracking has a well-developed pattern, with a significant amount of loose or missing material. Displaced pieces up to 0.1 m² may have been patched.

Figure 90. Distress Type CRCP 1- "D" Cracking

How to Measure

Record the number of affected transverse cracks at each severity level and the square meters of area affected at each severity level. The transverse crack and affected area severity rating is based on the highest severity level present for at least 10 percent of the area affected.

Figure 91. Distress Type CRCP 1-Moderate Severity "D" Cracking at Transverse Crack

Figure 92. Distress Type CRCP 1-High Severity "D" Cracking at Longitudinal Joint

2. Longitudinal Cracking

Description

Cracks that are predominantly parallel to the pavement centerline.

Severity Levels

Low:

Crack widths < 3 mm, no spalling, and there is no measurable faulting; or well-sealed and with a width that cannot be determined.

Moderate:

Crack widths ≥ 3 mm and < 13 mm; or with spalling < 75 mm; or faulting up to 13 mm.

High:

Crack widths ≥ 13 mm; or with spalling ≥ 75 mm; or faulting ≥ 13 mm.

How to Measure

Record the length of longitudinal cracking at each severity level. Also record the length of longitudinal cracking with sealant in good condition at each severity level. Sealant is not considered to be in good condition unless at least 1 m of continuous sealant in good condition is present. In cases where a crack is less than 1 m in length, the sealant must be present and in good condition over the entire length of the crack.

Figure 93. Distress Type CRCP 2-Longitudinal Cracking

Figure 94. Distress Type CRCP 2-Low Severity Longitudinal Cracking

Figure 95. Distress Type CRCP 2-High Severity Longitudinal Cracking

3. Transverse Cracking

Description

Cracks that are predominantly perpendicular to the pavement centerline. This cracking is expected in a properly functioning CRCP. All transverse cracks that intersect an imaginary longitudinal line at mid-lane and propagate from the pavement edges (centerline joint or the edge joint) shall be counted as individual cracks, as illustrated below. Cracks that do not cross the mid-lane are not counted.

Severity Levels

Low:

Cracks that are not spalled or with spalling along ≤ 10 percent of the crack length.

Moderate:

Cracks with spalling along > 10 percent and ≤ 50 percent of the crack length.

High:

Cracks with spalling along > 50 percent of the crack length.

Figure 96. Distress Type CRCP 3-Transverse Cracking

Figure 97. Distress Type CRCP 3-Transverse Cracking Pattern

How to Measure

Record separately the number and length in meters of transverse cracking at each severity level. The sum of all the individual crack lengths shall be recorded. Then, record the total number of transverse cracks within the survey section.

Note: Cracks that do not cross mid-lane, although not counted, should be drawn on the map sheets.

Figure 98. Distress Type CRCP 3-Low Severity Transverse Cracking

Figure 99. Distress Type CRCP 3-Moderate Severity Transverse Cracking

Figure 100. Distress Type CRCP 3-High Severity Transverse Cracking

B. Surface Defects

4. Map Cracking and Scaling

This section includes the following:

    4. Map cracking and scaling.

        4a. Map cracking.

        4b. Scaling.

    5. Polished aggregate.

    6. Popouts.

4a. Map Cracking

Description

A series of cracks that extend only into the upper surface of the slab. Larger cracks frequently are oriented in the longitudinal direction of the pavement and are interconnected by finer transverse or random cracks.

Severity Levels

Not applicable.

How to Measure

Record the number of occurrences and the square meters of affected area. When an entire section is affected with map cracking, it should be considered one occurrence.

Figure 101. Distress Type CRCP 4a-Map Cracking Attributable to Alkali-Silica Reactivity

4b. Scaling

Description

Scaling is the deterioration of the upper concrete slab surface, normally 3 to 13 mm, and may occur anywhere over the pavement.

Severity Levels

Not applicable.

How to Measure

Record the number of occurrences and the square meters of affected area.

Figure 102. Distress Type CRCP 4b-Scaling

5. Polished Aggregate

Description

Surface mortar and texturing worn away to expose coarse aggregate.

Severity Levels

Not applicable. However, the degree of polishing may be reflected in a reduction of surface friction.

How to Measure

Record square meters of affected surface area.

Note: Diamond grinding also removes the surface mortar and texturing; however, this condition should not be recorded as polished aggregate but instead should be noted by a comment.

Figure 103. Distress Type CRCP 5-Polished Aggregate

6. Popouts

Description

Small pieces of pavement broken loose from the surface, normally ranging in diameter from 25 to 100 mm and in depth from 13 to 50 mm.

Severity Levels

Not applicable. However, severity levels can be defined in relation to the intensity of popouts as measured below.

How to Measure

Not recorded in LTPP surveys, but should be noted.

Figure 104. Distress Type CRCP 6-Popouts

Figure 105. Distress Type CRCP 6-Popouts

C. MISCELLANEOUS DISTRESSES

This section includes the following distresses:

     7. Blowups.

     8. Transverse construction joint deterioration.

     9. Lane-to-shoulder dropoff.

     10. Lane-to-shoulder separation.

     11. Patch/patch deterioration.

     12. Punchouts.

     13. Spalling of longitudinal joints.

     14. Water bleeding and pumping.

     15. Longitudinal joint seal damage.

7. Blowups

Description

Localized upward movement of the pavement surface at transverse joints or cracks; often accompanied by shattering of the concrete in that area.

Severity Levels

Not applicable. However, severity levels can be defined by the relative effect of a blowup on ride quality and safety.

How to Measure

Record the number of blowups.

Figure 106. Distress Type CRCP 7-Blowups

Figure 107. Distress Type CRCP 7-A Blowup

Figure 108. Distress Type CRCP 7-Close-up View of a Blowup

Figure 109. Distress Type CRCP 7-Exposed Steel in a Blowup

8. Transverse Construction Joint Deterioration

Description

A series of closely spaced transverse cracks or a large number of interconnecting cracks occurring near the construction joint.

Severity Levels

Low:

No spalling or faulting within 0.6 m of construction joint.

Moderate:

Spalling < 75 mm exists within 0.6 m of construction joint.

High:

Spalling ≥ 75 mm and breakup exists within 0.6 m of construction joint.

How to Measure

Record number of construction joints at each severity level.

Figure 110. Distress Type CRCP 8-Transverse Construction Joint Deterioration

Figure 111. Distress Type CRCP 8-Low Severity Transverse Construction Joint Deterioration

Figure 112. Distress Type CRCP 8- Moderate Severity Transverse Construction Joint Deterioration

Figure 113. Distress Type CRCP 8- Low Severity Transverse Construction Joint Deterioration

9. Lane-to-Shoulder Dropoff

Description

Difference in elevation between the edge of slab and outside shoulder; typically occurs when the outside shoulder settles.

Severity Levels

Not applicable. Severity levels could be defined by categorizing the measurements taken. A complete record of the measurements taken is much more desirable, however, because it is more accurate and repeatable than are severity levels.

How to Measure

Measure at the longitudinal construction joint between the lane edge and the shoulder.

Record to the nearest millimeter at 15.25-m intervals along the lane-to-shoulder joint.

If the traveled surface is lower than the shoulder, record as a negative value.

Figure 114. Distress Type CRCP 9-Lane-to-Shoulder Dropoff

Figure 115. Distress Type CRCP 9-Lane-to-Shoulder Dropoff

10. Lane-to-Shoulder Separation

Description

Widening of the joint between the edge of the slab and the shoulder.

Severity Levels

Not applicable. Severity levels could be defined by categorizing the measurements taken. A complete record of the measurements taken is much more desirable, however, because it is more accurate and repeatable than are severity levels.

How to Measure

Record to the nearest millimeter at intervals of 15.25 m along the lane-to-shoulder joint and indicate whether the joint is well-sealed (yes or no) at each location.

Note: A null value should be recorded and entered into the database when the surveyor is unable to take a measurement due to an anomaly such as sealant or patch material.

Figure 116. Distress Type CRCP 10-Lane-to-Shoulder Separation

Figure 117. Distress Type CRCP 10-Close-up View of a Lane-to-Shoulder Separation

11. Patch/Patch Deterioration

Description

A portion greater than or equal to 0.1 m² or all of an original concrete panel that has been removed and replaced or additional material applied to the pavement after original construction.

Severity Levels

Low:

Patch has, at most, low severity distress of any type; no measurable faulting or settlement; and there is no loss of patching material. Pumping is not evident.

Moderate:

Patch has moderate severity distress of any type or has faulting or settlement up to 6 mm. Pumping is not evident.

High:

Patch has a high severity distress of any type or has faulting or settlement ≥ 6 mm, or the patch has additional material within it. Pumping may be evident.

Figure 118. Distress Type CRCP 11-Patch/Patch Deterioration

Figure 119. Distress Type CRCP 11-Small, Low Severity AC Patch

How to Measure

Record the number of patches and square meters of affected surface area at each severity level by material type-rigid versus flexible. Surface flexible patches are limited to those with patching material that contain aggregate. If a surface patch has worn away revealing an underlying distress or the underlying distress has reflected through the surface patch and the distress’ existence can be verified on prior surveys, then also rate the distress. Any new distress in the original pavement layer in the patched area should also be rated. Distresses in the patched area affect the severity level of the patch. Patches with no distress are rated low severity. Applications of sealant without aggregate are not to be recorded as patches. These should be drawn on the map sheets and recorded on the distress survey sheets as distress type 16 Other provided that they exceed 0.1 m².

Note: Panel replacement shall be rated as a patch. Any sawn joints shall be considered construction joints and rated separately. All patches are rated regardless of location.

Figure 120. Distress Type CRCP 11-Low Severity AC Patch

Figure 121. Distress Type CRCP 11-Moderate Severity AC Patch

Figure 122. Distress Type CRCP 11-Low Severity PCC Patch

12. Punchouts

Description

The area enclosed by two closely spaced (usually < 0.6 m) transverse cracks, a short longitudinal crack, and the edge of the pavement or a longitudinal joint. Also includes "Y" cracks that exhibit spalling, breakup, or faulting. An area that is enclosed by two distressed transverse cracks that are spaced between 0.6 m and 1 m, a short longitudinal crack, and the edge of the pavement or a longitudinal joint is also considered a punchout.

Severity Levels

Low:

Longitudinal and transverse cracks are tight and may have spalling < 75 mm or faulting < 6 mm with no loss of material and no patching. Does not include "Y" cracks.

Moderate:

Spalling ≥ 75 mm and < 150 mm or faulting ≥ 6 mm and < 13 mm exists.

High:

Spalling ≥ 150 mm or concrete within the punchout is punched down by ≥ 13 mm, or is loose and moves under traffic, or is broken into two or more pieces, or contains patch material.

Figure 123. Distress Type CRCP 12-Punchouts

Figure 124. Distress Type CRCP 12-Low Severity Punchout

How to Measure

Record the number of punchouts at each severity level.

The cracks which outline the punchout are also recorded under "longitudinal cracking"(CRCP 2), and "transverse cracking" (CRCP 3).

Punchouts that have been repaired by completely removing all broken pieces and replacing them with patching material (rigid or flexible) should be rated as a patch. If the boundaries of the punchout are visible, then also rate as a high severity punchout.

Note: Areas between two transverse cracks spaced greater than 0.6 m but less than or equal to 1 m apart and bounded by the edge of pavement (or longitudinal joint) and a longitudinal crack, are rated as moderate or high severity punchouts if the cracks are exhibiting spalling or if the area is breaking up or faulting.

Figure 125. Distress Type CRCP 12-Moderate Severity Punchouts

Figure 126. Distress Type CRCP 12-High Severity Punchouts

13. Spalling of Longitudinal Joints

Description

Cracking, breaking, chipping, or fraying of slab edges within 0.3 m of the longitudinal joint.

Severity Levels

Low:

Spalls < 75 mm wide measured to the face of the joint with loss of material or spalls with no loss of material and no patching.

Moderate:

Spalls 75 to 150 mm wide measured to the face of the joint with loss of material.

High:

Spalls > 150 mm wide measured to the face of the joint with loss of material, or is broken into two or more pieces, or contains patch material.

Figure 127. Distress Type CRCP 13-Spalling of Longitudinal Joints

How to Measure

Record the length of longitudinal joint spalling at each severity level. Only record spalls having a length of 0.1 m or more. Spalls that have been repaired by completely removing all broken pieces and replacing them with patching material (rigid or flexible) should be rated as a patch. If the boundaries of the spall are visible, then also rate as a high severity spall.

Note: All patches meeting the size criteria are rated as patches.

Figure 128. Distress Type CRCP 13-Close-up View of Low Severity Spalling of a Longitudinal Joint

Figure 129. Distress Type CRCP 13- Low Severity Spalling of a Longitudinal Joint

Figure 130. Distress Type CRCP 13-Moderate Severity Spalling of a Longitudinal Joint

14. Water Bleeding and Pumping

Description

Seeping or ejection of water from beneath the pavement through cracks or joints. In some cases, it is detectable by deposits of fine material left on the pavement surface, which were eroded (pumped) from the support layers and have stained the surface.

Severity Levels

Not applicable. Severity levels are not used because the amount and degree of water bleeding and pumping changes with varying moisture conditions.

How to Measure

Record the number of occurrences of water bleeding and pumping and the length of affected pavement with a minimum length of 1 m.

Note: Water bleeding and pumping is measured longitudinally along the length of the test section. The combined quantity of water bleeding and pumping cannot exceed the length of the test section.

Figure 131. Distress Type CRCP 14-Water Bleeding and Pumping

Figure 132. Distress Type CRCP 14-Close-up View of Water Bleeding and Pumping

15. Longitudinal Joint Seal Damage

Description

Joint seal damage is any condition that enables incompressible materials or a significant amount of water to infiltrate into the joint from the surface. Typical types of joint seal damage include extrusion, hardening, adhesive failure (bonding), cohesive failure (splitting), or complete loss of sealant.

Intrusion of foreign material in the joint. Grass or weed growth in the joint.

Severity Levels

Not applicable.

How to Measure

Record the number of longitudinal joints that are sealed (0, 1, 2). Record the length of sealed longitudinal joints with joint seal damage. Individual occurrences are recorded only when at least 1 m long.

Figure 133. Distress Type CRCP 15-Longitudinal Joint Seal Damage