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MISSOURI COOPERATIVE HIGHWAY RESEARCH PROGRAM 92-5 REPORT
PERFORMANCE OF POLYMER CONCRETE WEARING SURFACE SYSTEM ON THE POPLAR STREET BRIDGE
INSPECTION REPORT III
Prnn.ertv of
MoDOT TRANSPORTATION LIBRARY
MISSOURI HIGHWAY AND TRANSPORTATION DEPARTMENT UNIVERSITY OF MISSOURI, COLUMBIA FEDERAL HIGHWAY ADMINISTRATION
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PERFORMANCE OF POLYMER CONCRETE WEARING SURFACE SYSTEM ON THE POPLAR STREET BRIDGE
Inspection Report m Tests conducted on the Poplar Street Bridge during September 16-17, 1994
Prepared for
Missouri Highway and Transportation Department
by
Vellore S. Gopalaratnam James W. Baldwin, Jr.
Bryan A. Hartnagel and
Zeyad El-Shakra
Department of Civil Engineering University of Missouri-Columbia
in cooperation with
Federal Highway Administration
The opinions, findings, conclusions and recommendations expressed in this report are those of the authors and are not necessarily those of the Federal Highway Administration, the Missouri Highway and Transportation Department or the University of Missouri-Columbia.
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• INTRODUCTION
The inspection project jointly sponsored by the Missouri Highway and Transportation
Department (MHTD) and the Federal Highway Administration (FHW A) is being conducted by
the Department of Civil Engineering, University of Missouri-Columbia (MU). Dr. Vellore S.
Gopalaratnam and Dr. James W. Baldwin, Jr., are the Principal Investigators. Mr. Bryan A.
Hartnagel, and Mr. Zeyad El-Shakra, both MU Graduate Research Assistants assisted the
principal investigators with the tests, results of which are reported and discussed here.
The first inspection was conducted during September 18-19, 1992, approximately one
month after the polymer concrete wearing surface was placed on the Poplar Street Bridge. No
noticeable aggregate loss, cracking or other damage to the wearing surface was observed during
Inspection I [1]. The second inspection was completed during June 25-27, 1993. Profiles and
other information related to the two visible cracks, one at each end (west-end and east-end) of the
right eastbound lane (Lane 4) were detailed in Inspection Report II [2]. Both cracks originated at
the expansion joint device in the vicinity of the lane boundary (boundary between eastbound
Lanes 3 and 4). These cracks were repaired on October 14, 1993. Details of the crack repair
procedure are described in the next section. This inspection (Inspection III) conducted during
September 16-17, 1994, included in addition to the routine general inspection of the wearing
surface performance, a closer look at the two repaired cracks to assess the effectiveness of the
repair procedure.
CRACK REPAIR PROCEDURE
The University of Missouri research team was not involved in the repair of the cracks.
The repair procedure reported here for informational purposes and because of its relevance to
the discussions to follow, was pieced together from discussions and correspondence with
Missouri Highway and Transportation Department Personnel (District VI Maintenance and
Annual Inspection Report of the Poplar Street Bridge [3]).
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The cracks were prepared for repair by sandblasting the exposed crack faces and
surfaces adjoining the crack (Fig. 1). Compressed air was blown into the crack along its entire
length so as to blow out loose particles and trapped water (Fig. 2). Water flushed out of the
crack can be seen in Fig. 2. The repair was reportedly undertaken one week after ·the last rain.
Once the crack faces and adjoining surfaces were clean and dry, neat epoxy (Transpo T-48,
identical to the epoxy used for the original wearing surface placed in 1992) was injected into
the crack through plastic injection ports. The injection ports were drilled into place on the
wearing surface at requisite locations along the crack length, Fig. 3. Holes were also drilled at
the tip of the two cracks to promote crack arrest through blunting action. The surface of the
crack was sealed with a regular epoxy (white paste-like material in Figs. 3 and 4) before
Transpo T-48 was injected.
The condition of the two repaired cracks at the time of this inspection (almost one year
since repair) is described in the section summarizing results from this inspection.
TEST SECTIONS
The test sections used for the routine inspection during Inspection ill were identical to
those used during the earlier inspections [l, 2]. These are listed here for completeness of this
report.
Test Section A: Right eastbound lane (lAne 4) from Station 21 +00 to Station 23+00 Test Section B: Right middle eastbound lane (Lane 3)from Station 35+00 to Station 37+00 Test Section C: Left westbound lane (Lane ])from Station 37+00 to Station 35+00 Test Section D: Right middle westbound lane (Lane 3) from Station 27+00 to Station 25 +00
TEST PROGRAM AND PROCEDURES
The test program during each routine general inspection of the wearing surface
comprises: (i) pull-out tests to reco~d the adhesion strength in tension of the wearing surface
system to the deck-plate, (ii) resistivity tests to monitor cracking in the wearing surface, (iii)
chain drag/sounding tests to monitor delaminations of the wearing surface from the deck-plate,
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Fig. 1 The crack at the east-end of the right eastbound lane is being sandblasted.
Fig. 2 Compressed air is being blown into the crack to clean and dry it for epoxy injection. Note the water coming out of the crack. The repair was undertaken one week after the I last rain.
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Fig. 3 Plastic injection ports are fixed in place approximately every 6 in. along the length of the crack (west-end, right eastbound lane) while preparing the crack for the epoxy injection.
Fig. 4 Epoxy (Transpo T-48) is being injected into the crack at the west-end of the right eastbound lane.
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(iv) miscellaneous observations to record wearing surface thickness, aggregate loss, visible
cracks and cracking patterns. The typical layout used for the pull-out and resistivity tests for
Inspection III is illustrated in Fig. 5. It should be noted that the resistivity test locations used
for this inspection are identical to those used during Inspections I and IT.
Details of the procedures used for these tests have been included in Inspection Report I
[l] and will not be duplicated here. Results from this inspection are summarized in the
following section.
40' 25'
x6 x63 x62 x61
30' 30'
X5 XS3 XS2 XS!
30' 30'
X4 x43 x42 x4J
30'
X3 x33 x32 ~I
30' 30'
x2 x23 x22 "21
30' 30'
Xl x13 x12 ~I
10' 25'
I· ·I· ·I· ·I l··I· ·I· ·1°1 4' 4' 4' 2' 4'+4' 2'
+ Traffic di=:tion Traffic direction
(a) Pull-out test locations (b) Rt:sGlivity test locations
Fig. 5 Typical layout of a test section (not to scale).
SUMMARY OF RESULTS
A summary of the test results from the core pull-out test is presented in Table 1. As
observed from this and the previous inspections, the failure loads recorded are sensitive to the
deck temperature at gluing as well as at pull-out testing. The curing time, tensile strength and
adhesive strength of the glue used to bond the pipecaps to the wearing surface are all
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- - -Core Depth Diameter
(in.) (in.)
Atla 0.647 1.950 A2la 0.545 1.945 A3la 0.560 1.955 A4lb 0.660 1.950 A5lb 0.656 1.959 A6lb 0.593 1.960 B7 0.535 1.945 B8 0.603 1.950 B9 0.546 1.945
BlO 0.564 1.945 Bll 0.480 1.950 B12 0.433 1.945 Cl3 0.680 1.945 Cl4 0.658 1.945 Cl5 0.737 1.962 Cl6 0.587 1.959 Cl? 0.784 1.948 C18 0.590 1.954 019 0.544 1.960 020 0.435 1.955 021 0.620 1.961 022 0.550 1.950 023 0.670 1.945 024 0.568 1.950
- - - - - -Table 1 : Summary of results from core pull-out tests - Inspection ill
(l'ests conducted on the Poplar Street Bridge during September 16-17, 1994)
Time glued Air temp. Time Air temp. Peak (at gluing) tested (at testing) load
(OF) (°F) Obs) 8:40 a.m 70 10:20 a.m. 72 650 8:45 a.m 70 10:45 a.m. 80 1285 8:50 a.m. 70 10:50 a.m. 80 438 8:55 a.m. 70 10:25 a.m. 75 1100 9:00 a.m. 70 10:30 a.m. 78 760 9:05 a.m. 70 10:35 a.m. 78 1396 1:30 p.m. 90 4:05 p.m. 84 927 1:35 p.m. 90 4:08p.m. 84 1175 1:42 p.m. 90 4:12 p.m. 84 1484 1:50 p.m. 90 4:17 p.m. 84 1454 2:00 p.m. 90 4:22p.m. 84 1011 2:10 p.m. 90 4:26p.m. 84 1372 8:35 p.m. 78 11:10 p.m. 72 1325 8:45 p.m. 77 11:20 p.m. 72 1333 8:55 p.m. 77 11:30 p.m. 72 1801 9:00 p.m. 76 11:35 p.m. 70 1461 9:05 p.m. 76 11:48 p.m. 70 1784 9:15 p.m. 76 11:55 p.m. 70 1944 6:05 p.m. 78 8:05 p.m. 74 2090 6:10 p.m. 78 8:10 p.m. 74 1467 6:20 p.m. 78 8:15 p.m. 74 1654 6:30 p.m. 78 8:20 p.m. 72 1544 6:40p.m. 78 8:25 p.m. 72 2090 6:45 p.m. 78 8:30 p.m. 72 1696
- -Peak Failure type2
. st~ (psi) 218 2 - 45 % • 3 - 55 % 433 3 - 100% 146 2 - 20 % , 3 - 80 % 368 2 - 70%, 3 -'30% 252 3 - 100% 463 2 - 85 % , 3 - 15 % 312 2 - 5%, 3 - 95% 393 3 - 100% 499 2 - 65 % • 3 - 35 % 489 2 - 5%. 3 - 95% 339 2 - 50%. 3 - 50% 462 3 - 100% 446 1 - 100% 449 1 - 45%, 3 - 55% 596 1 - 55%, 3 - 45% 485 1 - 30 % , 3 - 70 % 599 3 - 100% 648 1 - 5%, 3 - 95% 693 1 - 100% 489 1 - 100% 548 1 - 90%, 3 - 10% 517 1 - 100% 703 1 - 40%, 3- 60% 568 1 - 90%, 3 - 10%
Note: J. a. Pipecaps were glued with Devcon 5-minute epoxy, b. Pipecaps were glued with Devcon epoxy with a silica sand filler. A.ll other pipecaps were glued with Transpo T-371 MM.A..
2. See Fig. 6 for legend to failure types. Percentages besides failure type notations indicate approximate areas of the failure of each type as observed from the pulled-out pipe caps.
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(D Adhesive failure at the pipe cap
a) Cohesive failure in the glue
Q) Adhesive failure at the wearing surface
© Cohesive failure in the wearing surface
0 Adhesive failure at the deck plate
Fig. 6 Legends used for the pull-out failure descriptions in Table 1
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temperature sensitive. Colder temperatures at gluing and testing typically result in higher pull
out loads. No cohesive failures in the wearing surface or adhesive failure at the deck plate
were observed (see Fig. 6 for definitions of failure) in this inspection just as in the earlier two
inspections. Since failures were due to those observed in the glue used to bond the pipecap to
the wearing surface and not in the wearing surface itself, the stress values reported in Table I
merely represent the lower bound of the tensile strength of the wearing surface material and of
the adhesion strength in tension of the wearing surface to the deck plate.
The average peak pull-out stress recorded was 463 psi. When results from one test
section (Test Section A) for which Devcon 5-Minute Epoxy was used to glue the pipecaps are
excluded, the average peak pull-out stress recorded was 513 psi. The corresponding range of
pull-out stress values equals 312-703 psi. All of these numbers correlate well with those
observed in the previous two inspections.
Given the results from the three inspections thus far, the usefulness of the pull-out test
appears to be limited. However, this test may prove to be useful in providing support
information for the extent and type of delamination in situations where delamination of the
wearing surface is suspected. In situations where the wearing surface appears to be performing
well, the potential for damage to the deck-plate by the coring operations, and the needless
damage to the wearing surface due to the coring and re-patching can and should be avoided.
Summaries of results from the resistivity tests are reported in Tables 2-5 for Test
Sections A-D respectively. Resistivity values recorded in Inspection ill are comparable and
consistent with those reported in Inspection Report II, Fig. 7. The lowest resistance values
were recorded in Test Section B. The resistance values in this section range from 11 - 60 Mn.
The resistance values in this section are marginally higher than those measured during
Inspection II (which was in the range 9 - 26 Mn). The resistivity values from Inspection II
and Inspection ill are markedly different from that measured in Inspection I. The differences
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Table 2 : Results from the resistivity tests - Inspection ill (l'ests conducted on the Poplar Street Bridge during September 16-17, 1994)
Test Section: A (Eastbound Lane 4, Stations 21 +00 to 23 +00)
Initial wetting at: 8:02 a.m. First reading R1 at: 8: 16 a.m. Second reading R2 at: 8:36 a.m. Third reading R3 at: 9:00 a.m.
Air temperature: 69°F (8: 13 a.m.)
Location Resistance R1 Resistance R2 Resistance R3 (M!l) (Mn) (M!l)
All 60 80 80 A12 55 90 70 A13 200 150 100 A21 90 100 100 A22 300 250 200 A23 200 200 150
Initial wetting at: 8:57 a.m. First reading R1 at: 9:26 a.m. Second reading R2 at: 9:38 a.m. Third reading R3 at: 9:55 a.m.
Air temperature: 700F (9:37 a.m.)
Location Resistance R1 Resistance R2 Resistance R3 (M!l) (M!l) (M!l)
A31 150 125 150 A32 90 100 150 A33 150 125 200 A41 100 90 100 A42 150 100 200 A43 300 125 150
Initial wetting at: 9:57 a.m. First reading R1 at: 10:07 a.m. Second reading R2 at: 10:28 a.m. Third reading R3 at: 10:59 a.m.
Air temperature: 75°F (10:28 a.m.)
Location Resistance R1 Resistance R2 Resistance R3 (M!l) (Mn) (M!l)
A51 40 70 30 A52 50 100 35 A53 60 55 40 A61 35 60 27.5 A62 30 80 30 A63 40 40 30
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Table 3 : Results from the resistivity tests - Inspection m (Iests conducted on the Poplar Street Bridge during September 16-17, 1994)
Test Section: B (Eastbound Lane 3, Stations 35+00 to 37+00)
Initial wetting at: 1:33 p.m. First reading R1 at: 1:48 p.m. Second reading R2 at:2:03 p.m. Third reading R3 at: 2:31 p.m.
Air temperature: 9Q<>F (1:30 p.m.)
Location Resistance R1 Resistance R2 Resistance R3 (MO) (MO) (Mn)
B11 30 25 27.5 B12 45 35 30 B13 50 45 40 B21 27.5 22.5 27.5 B22 30 27.5 25 B23 25 25 25
Initial wetting at: 2:30 p.m. First reading R1 at: 2:47 p.m. Second reading R2 at: 3:03 p.m. Third reading R3 at: 3:28 p.m.
Air temperature: 84°F (2:51 p.m.)
Location Resistance R1 Resistance R2 Resistance R3 (MQ) (MO) (MQ)
B31 27.5 22.5 30 B32 60 30 35 B33 35 25 25 B41 50 30 35 B42 40 35 35 B43 27.5 25 22.5
Initial wetting at: 3:25 p.m. First reading R1 at: 3:41 p.m. Second reading R2 at:3:54 p.m. Third reading R3 at: 4:31 p.m.
Air temperature: 83°F (3:47 p.m.)
Location Resistance R1 Resistance R2 Resistance R3 (MO) (MO) (MQ)
B51 20 16 25 B52 25 17 25 B53 15 11 14 B61 27.5 17 35 B62 30 16 30 B63 22.5 14 20
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Table 4 : Results from the resistivity tests - Inspection m . (J'ests conducted on the Poplar Street Bridge during September 16-17, 1994)
Test Section: C (Westbound Lane 1, StaJions 37+00 to 35+00)
Initial wetting at: 10:28 p.m. :. First reading R1 at: 10:44 p.m. Second reading R2 at: 11:07 p.m. Third reading R3 at: 11:40 p.m.
Air temperature: 74°F (10:28 p.m.)
Location Resistance R1 Resistance R2 Resistance R3 (Mn) (Mn) (Mfl)
Cll 90 100 125 Cl2 200 200 200 C13 125 100 150 C21 100 150 200 C22 80 100 200 C23 150 200 200
Initial wetting at: 9:20 p.m. First reading R1 at: 9:39 p.m. Second reading R2 at: 9:54 p.m. Third reading R3 at: 10:24 p.m.
Air temperature: 76°F (9:30 p.m.)
Location Resistance R1 Resistance R2 Resistance R3 (Mfl) (Mn) (Mfl)
C31 300 250 200 C32 200 250 200 C33 200 200 200 C41 90 100 90 C42 150 200 150 C43 200 200 150
Initial wetting at: 7:50 p.m. First reading R1 at: 8: 14 p.m. Second reading R2 at: 8:33 p.m. Third reading R3 at: 9:17 p.m.
Air temperature: 78°F (8:16 p.m.)
Location Resistance R1 Resistance R2 Resistance R3 (MQ) (MO) (MQ)
C51 75 150 175 C52 50 70 100 C53 80 200 300 C61 40 70 90 C62 70 150 200 C63 90 100 200
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Table S : Results from the resistivity tests - Inspection ill (Tests conducted on the Poplar Street Bridge during September 16-17, 1994)
Test Section: D (Westbound Lane 3, Stations 27 + 00 to 25 + 00)
Initial wetting at: 5:52 p.m. First reading R1 at: 6:06 p.m. Second reading R2 at: 6:24 p.m. Third reading R3 at: 6:52 p.m.
Air temperature: 78°F (6: 18 p.m.)
Location Resistance R1 Resistance R2 Resistance R3 (M!l) (Mn) (Mn)
Dll 80 150 200 D12 150 125 200 D13 70 100 150 D21 90 150 200 D22 100 150 200 023 60 100 150
Initial wetting at: 6:49 p.m. First reading R1 at: 7:04 p.m. Second reading R2 at: 7:20 p.m. Third reading R3 at: 7:49 p.m.
Air temperature: 78°F (6:49 p.m.)
Location Resistance R1 Resistance R2 Resistance R3 (M!l) (M!l) (M!l)
031 125 150 200 032 100 150 300 033 70 90 150 041 90 150 200 042 150 150 300 043 100 100 100
Initial wetting at: 7:37 p.m. First reading R1 at: 7:59 p.m. Second reading R2 at: 8: 19 p.m. Third reading R3 at: 8:39 p.m.
Air temperature: 74°F (7:41 p.m.)
Location Resistance R1 Resistance R2 Resistance R3 (M!l) (M!l) (M!l)
D51 300 150 150 052 300 200 150 D53 100 100 90 061 200 150 150 D62 300 200 . 200 D63 150 90 100
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-w
-1000
'c'900 6800 a:::_ 700 ~ 600 c Jg 500 U)
·en 400 Q)
-Section A
a::: 300 ~ A 200 " I '- I \ 100 -;:f~'.--~~~L_.._ -1
0
1000 'c'900 6800 a:::_ 700 ~ 600 c ro 500 ...... U)
·en 400
0 2 4 6 8 1 0 12 14 16 18 20
Location
Section C
Q) " a::: 300 I~ 200 "-<_ ---;;; "\., /\\.. ..,,.. .. 1 oo r .._ \ ____ ..-......-.....__~ --
o 0 2 4 6 8 1 0 12 14 16 18 20
Location
-Section B
1000 ~---------'c' 900 6800 a::: 700 ~- 600 c J9 500 U)
"en 400 Q)
a::: 300 200
Inspection I ..__. Inspection II --- .. Inspection Ill ,._ _,.
100 _ I O I t:==t-~ ?";;.:;-~':=:---~ ..
I I 1~-----r ~1
0 2 4 6 8 10 12 14 16 18 20
Location
1 ooo Section D
asoo 6800 a:::_ 700 ~ 600 c J9 500 U)
"en 400 Q)
a::: 300 200 100
O-r-r-i-r-r~+-~.::._:_J 0 2 4 6 8 10 12 14 16 18 20
Location
Fig. 7 Resistivity values recorded in the four test sections during each of the last three inspections. Location legend 11 - 1, 12 - 2, 13 - 3, 21 - 4, 22 - 5, 23 - 6, 31 - 7, 32 - 8, 33 - 9
41 - 10, 42 - 11, 43 - 12, 51 - 13, 52 - 14, 53 - 15, 61 - 16, 62 - 17, 63 - 18
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in resistivity between those measured during Inspection I and those measured during
Inspections II and ill can be attributed in part to the traffic related wear of the sealant coating
of methyl methacrylate. It should be noted that Inspection I was completed one month after the
wearing surface and sealant coat was applied to the deck. It is also possible that traffic related
surface contamination of the wearing surface also affects the resistivity values recorded. It is
hence understandable that no further drop (of any significance) in resistivity was observed ·
since Inspection II. The lowest resistivity value in the test sections recorded during Inspection
ill was 11 Mn (Location B53). This is far in excess of the 700,000 n value used in the past to
identify acceptable behavior of polymer concrete membranes.
No noticeable aggregate loss was detected in the test sections. The average wearing
surface thickness in the test sections recorded in conjunction with the pull-out tests was 0.594
in. Wearing surface thickness values were in the range 0.435-0.0.784 in. The average
thickness values in Test Sections A, B, C and D were 0.610 in., 0.527 in., 0.673 in. and
0.565 in. respectively.
Close-up photographs of the two repaired cracks are presented in Figs. 8-9 ( crack at the
west-end) and Figs. 10-11 (crack at the east-end). These repairs were in place for
approximately eleven months when this inspection was conducted. During this time these
cracks were subjected to normal service loads. The two cracks have not grown in length since
Inspection II. The original cracks are reflected in the repaired surface as can been seen in Figs.
8-11. The widths of these reflected cracks are smaller than the original crack-widths observed
in Inspection II. Larger pockets of damage to the sealed crack were observed at some locations
where the epoxy injection port inserts were left behind (star-shaped inserts seen in Figs. 9-11).
When water was ponded over these cracks, it did not run into the cracks as readily as they did
prior to the repair. However slowly but steadily water was able to infiltrate into the cracks.
This suggests that the repair technique is not successful in effectively sealing the crack under
service conditions. The potential for water infiltration is a cause for concern from two
I standpoints. It has the potential to contribute to crack growth and further delamination of the
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Fig. 8 Repaired crack at the west-end of right eastbound lane (approx. one year in service)
Fig. 9 Close-up of the repaired crack (west-end) showing reflective cracking and the injection port inserts used for the epoxy injection
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Fig. 10 Repaired crack at the east-end of the right eastbound lane showing wider crack widths than the crack at the west-end.
Fig. 11 Close-up of the repaired crack at the east-end showing the damage zone in the vicinity of the epoxy injection port inserts. Brown stains observed along the crack were attributed to dirt trapped in the crack (and not rust).
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wearing surface through freeze-thaw action, and it is also likely to contribute to the rusting of
the deck plate.
While the need for repairing the cracks may not be extremely urgent given the fact that
the cracks have not grown in size during the last eleven months of service, it is certain that
additional crack repair measures are necessary to ensure that the problem of water infiltration
is not aggravated. It is recommended that MHTD Maintenance monitor the cracks on a regular
basis so that deterioration at these locations can be spotted and acted upon in a prompt manner.
Further laboratory studies on more effective crack repair procedures may additionally be
useful.
During this inspection, a patch where the top layer broadcast aggregates had
delaminated (from the polymer concrete wearing surface) was located approximately 14 ft. east
of Test Section C (westbound Lane 1 between stations 37+00 and 38+00). The patch was
approximately shaped like a tear drop, 48" long and approximately 10" wide (at its widest
location), aligned in the direction of the lane, Fig. 12-13. In its vicinity (within 20") there also
is another circular patch almost 6" in diameter, Fig. 14. Acoustic tests (with a regular
hammer) revealed that there was delamination up to 20-30" from the patches between the top
layer of broadcast aggregates and the polymer concrete wearing surface. However the
smoothness of the exposed polymer concrete wearing surface in the patches indicated clearly
that there was no embedment of the broadcast aggregates in the wearing surface during the
original placement (August 1992). It is likely that the polymer concrete layer had cured in this
area before the top aggregates were broadcast. The problem appears to be local in nature. The
polymer concrete surface appears to be well bonded to the deck. The resistivity values
recorded on the patch was greater than 30 MO, suggesting there is no immediate concern
unless the patch grows rapidly in size, and loss of traction becomes a problem. It is
recommended that MHTD Maintenance also monitor this patch on a regular basis to spot
deterioration. Since bonding to cured epoxy is a problem, surface bonding of a traction layer
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Fig. 12 Patch on the westbound lane showing loss of top layer of broadcast aggregates.
Fig. 13 Patch (top end of the patch shown in Fig. 12) on the westbound lane showing loss of top layer of broadcast aggregates.
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may not offer an effective long-term remedy. More substantial rep~s may become necessary
if the deterioration becomes severe (a traffic hazard or potential damage to the overlay system
itself).
Fig. 14 Patch (same location as shown in Figs. 12 and 13) showing delamination type of failure between the polymer concrete wearing surface and the top layer of broadcast aggregates. Smooth surface on the polymer concrete patch indicates that the broadcast aggregates were not embedded in the polymer concrete.
ACKNOWLEDGMENTS
The authors would like to thank Mr. Pat Martens, District Maintenance Engineer,
MHTD and his crew for assistance with carrying out Inspection m. Photographs for Figs. 1-4
dealing with crack repair were obtained from Mr. Tom Anna, Field Bridge Inspector.
Discussions with Mr. Martens and Mr. Rich Brittin of Harris Specialties (formerly with
Transpo Industries, Inc.) on the crack repair procedures were helpful. Thanks are also due to
Mr. Al Lafoon, Mr. Fred Martin and Mr. Dan Salisbury of the MHTD Bridge Division for
their ongoing interest and participation in this experimental research project.
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REFERENCES
1.
2.
3.
Gopalaratnam, V.S., Baldwin, J.W., Hartnagel, B.A., and Krull, T., "Performance of Polymer Concrete Wearing Surface System on The Poplar Street Bridge - Inspection Report I,", Test Conducted during September 1992, Report prepared for the Missouri Highway and Transportation Department by the Department of Civil Engineering, University of Missouri-Columbia.
Gopalaratnam, V.S., Baldwin, J.W., Hartnagel, B.A., and Holder, M., "Performance of Polymer Concrete Wearing Surface System on The Poplar Street Bridge - Inspection Report II,", Test Conducted during June 1993, Report prepared for the Missouri Highway and Transportation Department by the Department of Civil Engineering, University of Missouri-Columbia.
Annual Inspection Report, Mississippi River Bridge at Poplar Street, Bridge No. A-1500R3, Route 1-70, St. Louis City, Illinois Structure No. 082-0004, September 29, 1994, Missouri Highway and Transportation Department.
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