ST9302-SY010102PAVEMENT DISTRESS EVALUATION
on
"RE- CONSTRUCTED"
SANDY LAKE ROAD
West -Bound Lanes
Moore Road to Denton Tap Road
Coppell, Texas
ALPHA Report No. 00723
Prepared for:
CITY OF COPPELL
255 Parkway Boulevard
Coppell, Texas 75019
Attention: Mr. Ken Griffin, P.E.
January 2, 2001
Prepared By:
ALPHA TESTING, INC.
2209 Wisconsin Road, Suite 100
Dallas, Texas 75229
A
ALPHA TESTING, INC.
2209 Wisconsin St., Suite 100
Dallas, Texas 75229
9721620 -8911 - 9721263 -4937 (Metro)
FAX 9721406 -8023
January 2, 2001
CITY OF COPPELL
255 Parkway Boulevard
Coppell, Texas 75019
Attention: Mr. Ken Griffin, F.E.
Re: Pavement Distress Evaluation
"RE- CONSTRUCTED"
SANDY LAKE ROAD
West -Bound Lanes
Moore Road to Denton Tap Road
Coppell, Texas
ALPHA Report No. 00723
Attached is the report of the pavement distress evaluation performed for the project referenced
above. This study has been authorized by Mr. Ken Griffin on October 4, 2000 and performed in
accordance with ALPHA Proposal No. GT 7655 dated September 29, 2000.
This report contains results of field observations, in -place concrete pavement sampling,
laboratory testing and an engineering interpretation of these with respect to available project
characteristics. The results and analyses have been used to evaluate the most probable cause of
pavement distress. Recommendations for limiting future distress and repair of distressed areas
(where applicable) will be addressed in a subsequent report pending results of additional field
testing (i.e., impact echo survey) to be performed at a later date.
ALPHA TESTING, INC. appreciates the opportunity to be of service on this project. If we can
be of further assistance, such as performing the recommended impact echo survey, please contact
our office.
Sincerely yours,
ALPHA TESTING, INC.
Pi( A. Lewis, P_. E.
leer of Engineering Services
3iIEL. Hillhouse, P.E.
President
DAL /JLH /hva
Copies: (3) Client
Geoteci !niccrl F_ngineerinq ,v Construction Materials Testing n Environmental Engineering ff Consufhng
TABLE OF CONTENTS
111 - fl
"RE- CONSTRUCTED"
SANDY LAKE ROAD
West -Bound Lanes
Moore Road to Denton Tap Road
Coppell, Texas
ALPHA Report No. 00723
1 .0 PURPOSE AND SCOPE ..................................................................... ............................... l
2.0 PROJECT CHARACTERISTICS ........................................................ ..............................2
3.0 CONCRETE SAMPLING ..................................................................... ..............................2
4.0 CONCRETE DISTRESS SURVEY ..................................................... ...............................
5.0 OBSERVATION OF CONCRETE PLACEMENT ............................. ............................... ti
6.0 CONCLUSIONS AND OPINIONS ................................. ...............................
APPENDICES
APPENDIX A
Photographs of Concrete Cores — Pages 1 -5
APPENDIX B
Photographs of 50 -ft. Section Survey beginning at Station No. 26 +80 — Pages 1 -10
Photographs of 50 -ft. Section Survey beginning at Station No. 48 +70 — Pages 11 -20
APPENDIX C
Photographs of Aggregate Stockpiles, Concrete Placement and Finishing Methods — Pages 1 -5
ALPHA Report No. 00723
1.0 PURPOSE AND SCOPE
The initial purpose of this pavement distress evaluation is to evaluate some of the physical and
engineering properties of the in -place concrete at the subject site with respect to evaluation of the
most probable cause of pavement distress, methods of limiting future distress and repair of the
distressed pavement. However, in view of results of this study concerning the most probable
cause of pavement distress, recommendations for limiting future distress and repair of distressed
pavement will be provided pending results of subsequent impact echo surveys discussed later in
this report. In addition, two 50 -ft sections of the existing concrete pavement were surveyed to
document the location, size, frequency and depth of existing voids in the surface of the existing
concrete pavement. Finally, the investigation also included field observations of a typical concrete
placement for the east -bound lanes (currently under construction) to evaluate concrete
production, placement, finishing methods and procedures during a single day to aid in identifying
if the current pavement distress in the west -bound lanes can be related to methods or materials
used in concrete placement. Engineering analyses have been performed from results of the
concrete core samples and field observations. The analyses have been used to develop
engineering conclusions and recommendations regarding the cause of observed distress for the
pavement in the study area.
Sampling of the in -place concrete has been accomplished by coring the concrete pavement. Cores
were spaced at five different locations (3 cores per location) along the west -bound lane of "re-
constructed" Sandy Lake Road between Moore Road and Denton Tap Road in Coppell, Texas.
At the time this study was performed, construction was in progress for the east -bound lanes of the
subject `re- constructed" roadway.
Professional services provided in this distress evaluation have been performed, findings obtained,
and recommendations prepared in accordance with generally accepted engineering principles and
practices. ALPHA TESTING, INC. is not responsible for conclusions, opinions or
recommendations made by others based on this data. Information contained in this report is
intended for exclusive use of the Client (and their design representatives) and remedial design of
the specific pavement outlined in Section 2.0. Recommendations presented in this report should
not be used for design of any other pavement except that specifically described in this report.
Opinions and conclusions provided in this report are based on our understanding of information
provided by the Client about characteristics of the project. If the Client notes any deviation from
the facts about project characteristics, our office should be contacted immediately since this may
materially alter the conclusions.
2.0 PROJECT CHARACTERISTICS
The existing west -bound lanes of "re- constructed" Sandy Lake Road were constructed in about
December, 1999 between Denton Tap Road and Moore Road in Coppell, Texas. This portion of
Sandy Lake Road has experienced distress in the form of numerous relatively small, shallow
"voids" in the top surface of the pavement measuring about 1 to 8 inches in diameter. The
1
ALPHA Report No. 00723
distress is generally observable as sporadic and the voids are spread randomly although there
appears to be a slight increase in frequency of voids along vehicle wheel path lines. The depth of
the voids varies between less than about 0.25 inches to almost 6 inches. According to the City of
Coppell, the number of "voids" observed in the surface of the subject concrete pavement has
increased over time.
3.0 CONCRETE SAMPLING
Samples of the in -place concrete pavement were obtained at five different locations varying from
non - distressed to distressed areas. Core Location No. 2 (at Station No. 47 +24) was performed in
a non - distressed area while the remainder of the cores were performed in areas with slight distress
to heavy distress. Three (3) cores samples (each measuring about 4 inches in diameter) were
obtained at each selected test location. At each sample location in distressed areas, two cores
were performed within the void area while the third core was performed just outside the void..
The core holes were immediately patched using high strength grout material. The approximate
location of each concrete core location and the general outline of the cores at each location are
shown in the following photographs:
PA
2. At Station No. 47 +24
1. At Station No. 49+00 near Moore Road
ALPHA Report No. 00723
Based on results from the existing in -place concrete cores, the depth of the concrete varies from
about 8 inches to about 9 inches while the depth of the voids varies from about 2 inches to almost
5 inches in the core samples obtained. The width of the surface voids at the cored locations varies
from about 1.5 to at least 4 inches. Photographs of each core obtained are enclosed in Appendix
A at the end of this report.
4.0 CONCRETE DISTRESS SURVEY
A concrete distress survey was performed at two different locations along the existing west -bound
lanes of the `re- constructed" Sandy Lake Road. As part of the survey, two 50 -ft sections of the
west -bound lanes (beginning at Station No. 26 +80 and 48 +70) were surveyed by taking
photographic pictures to document the location, size and frequency of the existing surface
voids. The survey at each location included a section of pavement 50 ft long and 27 ft wide.
3
4. At Station No. 26 +36
3. At Station No. 34 +32
5. At Station No. 5 +50 near Denton Tap Road
ALPHA Report No. 00723
Each 50 -ft by 27 -ft section was divided into 60 panels, each measuring about 5 ft by 4.5ft.
Photographs of each 50 -ft section are enclosed in Appendix B. The general layout and the
numbering of the photographs for each 50 -ft section is outlined below:
51
50
31
30
11
10
52
49
32
29
12
9
53
48
33
28
13
8
54
47
34
27
14
7
55
46
35
26
15
6
56
45
36
25
16
5
57
44
37
24
17
4
58
43
38
23
18
3
59
42
39
22
19
2
60 1
41
40
21
20
1
4
ALPHA Report No. 00723
5.0 OBSERVATION OF CONCRETE PLACEMENT
Field observations of concrete placement were performed on November 30, 2000 for east -bound
lanes currently under construction and located generally west of Mockingbird Lane. Observations
of concrete placement were made by a Professional Engineer to aid in identifying if the current
pavement distress in the "re- constructed" west -bound lanes can be related to methods and
materials used in on -going concrete placement. Photographs taken during the field observations
are enclosed in Appendix C.
6.0 CONCLUSIONS AND OPINIONS
According to visual observations performed along the "re- constructed" portion of the west -bound
lanes for Sandy Lake Road between Moore Road and Denton Tap Road, surface voids were
noted sporadically and /or randomly along the subject pavement. Results of examination of
concrete cores performed in the subject pavement indicate the primary cause for the voids in the
concrete pavement is the presence of clayballs in the concrete mix at the time of concrete
placement. As noted in the photographs in Appendix A, the voids (filled with clayballs and
debris) extend down into the concrete core samples and then sometimes outward even beyond the
cored sample. It is our opinion clayballs were present in the aggregate stockpiles at the on -site
batch plant and then incorporated into the concrete mix for the subject pavement.
Observations performed during concrete placement for the eastbound lanes west of Mockingbird
Lane indicated clayballs were present in the aggregate stockpiles as shown in the photographs
enclosed in Appendix C. In addition, the exposed ground surface near the aggregate stockpiles
consist of natural clayey type soils. Therefore, it is possible equipment used to handle the
aggregate might have also co- mingled portions of the aggregate with the on -site soils before
placement in the on -site concrete mixing hopper. Also, it is possible the concrete aggregate was
hauled to the site containing clayballs. A third and somewhat less likely possibility of
incorporating clayballs into the concrete pavement was the finishing procedures used in the
concrete placement, such as scooping up excess concrete from outside the slip forms and placing
the excess concrete back into the concrete pavement. Photographs illustrating the above
mentioned situations are enclosed in Appendix C.
Visual observations of some concrete test cylinders from ALPHA Project No. 98881 (SANDY
LAKE ROAD) indicated a sparkling or shiny material present in the fractured surfaces of some of
the coarse aggregate particles. Results of a limited petrographic analysis performed on fragments
of concrete cylinder No. 157 (ALPHA Project No. 98881, Sandy Lake Road in Coppell) indicate
the limestone particles contained calcite crystals with large rhombohedral cleavage planes, giving
the sparkle or shiny appearance. These cleavage planes, when viewed microscopically under
reflective light, are often seen as tiny sparkles of light. These large cleavage fragments observed in
the test cylinders are somewhat the exception rather than the rule, but do not compromise the
general quality of the limestone, and should not affect future performance of the concrete.
5
ALPHA Report No. 00723
Concrete distress surveys performed at two different locations indicate the voids are sporadic
and/or randomly located. Results of the survey of two 50 -ft sections indicated the presence of
voids was slightly more pronounced in wheel path lanes. The width of the voids in the surveyed
area varies from less than about an inch to about 8 inches while the depth of the voids varies from
about 0.25 to 6 inches. Photographs provided in Appendix B of this report indicate the location,
size and frequency of the potholes at the time of the survey.
Review of the density tests and concrete compressive strength tests (ALPHA Job No. 98881)
indicated the compaction of the paving subgrade and the concrete strength for the pavement
conformed to project specifications. However, the existing voids reduce the thickness of concrete
pavement. Hence, these voids would limit the future load carrying capacity (and useful life) of the
concrete pavement. Further, it is likely rain water and other surface water sources would increase
the rate of deterioration of the concrete pavement from freeze -thaw action.
The extent and type of repairs recommended is dependent upon the extent and frequency of voids
in the existing pavement. Since it is our understanding the number of voids observed continues to
increase with time, adequate information is not currently available to support recommendations
for the method of repair. Hence, it is recommended an impact echo survey be performed on the
existing pavement to further evaluate the extent of distress (voids). This method allows for
evaluation of the presence of voids that might not yet be visible at the surface of the concrete
pavement. In areas where voids are numerous and extensive, complete removal of selected
concrete panels may be required. In other areas where voids are relatively minor, cleaning and
filling the voids with high strength grout might be an option. These and other remedial repair
methods would be explored more fully pending results of the impact echo survey.
P1
APPENDIX "A"
Photographs of Concrete Cores
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ALPHA Report No. 00723 CONCRETE CORE PHOTOGRAPHS
APPENDIX "B"
Photographs of 50 -ft. Section Survey
(Beginning at Station No. 26 +80 & 48 +70
GENERAL LAYOUT OF THE 50 -FT SECTION PHOTOGRAPHIC SURVEY
BEGINNING AT STATION NO. 26 +80
26 +80
26 +90
27 +00
27 +10
27 +20
27 +30
51
50
31
30
11
10
52
49
32
29
12
9
53
48
33
28
13
8
54
47
34
27
14
7
55
46
35
26
15
6
56
45
36
25
16
5
57
44
37
24
17
4
58
43
38
23
18
3
59
42
39
22
19
2
60
41
40
21
20
1
27 ft.
50 ft.
F'o I
-3
ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 26 +80
ALPHA Report No. 00723 50-FT. SECTION SURVEY beginning at STATION NO. 26+80
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 26 +80
ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 26 +80
ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 26 +80
ALPHA Report No. 00723
50 -FT. SECTION SURVEY beginning at STATION NO. 26 +80
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 26 +80
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 26 +80
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 26 +80
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 26 +80
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_ _ 1
GENERAL LAYOUT OF THE 50 -FT SECTION PHOTOGRAPHIC SURVEY
BEGINNING AT STATION NO. 48 +70
48 +70
48 +80
48 +90
49 +00
49 +10
49 +20
51
50
31
30
11
10
52
49
32
29
12
9
53
48
33
28
13
8
54
47
34
27
14
7
55
46
35
26
15
6
56
45
36
25
16
5
57
44
37
24
17
4
58
43
38
23
18
3
59
42
39
22
19
2
60
41
40
21
20
1
27 ft.
50 ft.
ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 48 +70
ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 48 +70
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13
ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 48 +70
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 48 +70
15
ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 48 +70
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 48 +70
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 48 +70
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 48 +70
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ALPHA Report No. 00723 50 -FT. SECTION SURVEY beginning at STATION NO. 48 +70
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APPENDIX "C"
Photographs of Aggregate Stockpiles,
Concrete Placement and Finishing Methods
ALPHA Report No. 00723
Vicinity of Stockpiles and Batch Plant Areas
ALPHA Report No. 00723 -_
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Vicinity of Stockpile and Batch Plant Areas
2
Aggregate Stockpile Showing Clayballs
ALPHA Report No. 00723
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Aggregate Stockpile Showing Clayballs
ALPHA Report No. 00723
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Aggregate Stockpile Showing Clayballs
4
ALPHA Report No. 00723
A-1
Finishing Procedures used in Concrete Placement