Results to date, as presented in this report, do indicate that CRC pavements have ...... Figure 1. Age as oflatest distress survey. I--. 35. 30. 25. ~ 20 ro. Q). >. ~ 15.
FOREWORD This report documents analysis of the continuously reinforced concrete (CRC) pavement test sections under study in the General Pavement Studies 5 (GPS-5) experiment of the Long Term Pavement Performance Program. Limitations of the data available when this work was undertaken precluded the production of definitive findings. However, the work does show that CRe pavements can perform well.
-7£~ (I \ T. Paul Teng, P.E. Director Office oflnfms.tructure Research and Devdopmz;nt
NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. This report does not constitute a standard, specification, or regulation. The United States Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear herein only because they are considered essential to the object of this document.
PROTECTED UNDER INTERNATIONAL COPYRIGHT ALL RIGHTS RESERVED. NATIONAL TECHNICAL INFORMATION SERVICE U.S. DEPARTMENT OF COMMERCE
1.
~
Report No.
\11~'lll' 1111111'''\1\ 11\'" 11\ 1.'1
I
3.
Recipient's Catalog No.
P'd99 -162 77H
FHWA-RD-99-086
5. Report Date
4. Title and Subtitle
PRELIMINARY EVALUATION OF LTPP CONTINUOUSLY REINFORCED CONCRETE (CRC) PAVEMENT TEST SECTIONS 7.
Technical Report Documentation Page
Author(s)
Julv 1999 6.
Performing Organization Code
8.
Performing Organization Report No.
Shiraz D. Tayabji, Olga Selezneva, and Y. Jane Jiang 9.
10. Work Unit No. (TRAIS) C6B
Performing Organization Name and Address
ERES Consultants, Inc. 9030 Red Branch Road, Suite 210 Columbia, Maryland 21045
11. Contract or Grant No.
DTFH61-95-C-00028 13. Type of Report and Period Covered
12. Sponsoring Agency Name and Address
Office of Infrastructure Research & Development Federal Highway Administration 6300 Georgetown Pike McLean, Virginia 22101-2296
Final Report Feb. 1995 - Oct 1998 14. Sponsoring Agency Code
15. Supplementary Notes
Contracting Officer's Technical Representative (COTR): Cheryl Allen Richter Consultant: Dr. Dan G. Zollinger, P.E. served as technical consultant 16. Abstract
As part of the study reported here, analysis of data from the LTPP GPS-5 test sections was conducted to identify factors that influence long-term crack spacing in continuously reinforced concrete (CRe) pavements and to determine the effect of crack spacing on pavement performance. Data from the 85 test sections from the GPS-5 experiment were analyzed. Due to the limitations of the available data and the lack of certain key data, the study was not able to produce definitive findings on factors that affect long-term crack spacing and CRC pavement performance. Lack of early-age cracking due to ambient weather conditions at the time of construction will continue to limit the value of GPS-5 to produce meaningful data on factors affecting early-age cracking. Continued monitoring of GPS-5 sites and subsequent data analysis should yield information on how CRC pavement cracking and performance changes with time, loading, and other factors. It is expected that as additional data from the GPS-5 experiment become available, it will be possible to perform more in-depth analysis of the test data to derive definitive results. Results to date, as presented in this report, do indicate that CRC pavements have the potential to provide long-term, low-maintenance service life as evidenced by the many wellperforming sections in the LTPP GPS-5 experiment. 18. Distribution Statement
17. Key Words
Concrete pavements, continuously reinforced concrete pavement, CRCP, LTPP, pavement distress, pavement performance, pavement testing, punchouts. 19. Security Classification (of this report)
Unclassified Form DOT F 1700.7
(8-72)
No restrictions. This document is available to the public through the National Technical Information Service, Springfield, VA 22161.
20. Security Classification (of this page)
21. No. of Pages
Unclassified Reproduction of completed page authorized
61
22. Price
_.
fluidounces gallons cubic feet cubic yards
miles
inches feet yards
29.57 3.785 0.028 0.765
VOLUME
645.2 0.093 0.836 0.405 2.59
AREA
25.4 0.305 0.914 1.61
LENGTH
Multiply By
foot-candles foot-Lamberts
fc
Ibf Ibflin2
10.76 3.426
ILLUMINATION
5(F-32)/9 or (F-32)/1.8
lux candelalm 2
Celcius temperature
grams kilograms megagrams (or "metric ton")
m3 •
milliliters liters cubic meters cubic meters
square millimeters square meters square meters hectares square kilometers
millimeters meters meters kilometers
To Find
poundforce poundforce per square inch 4.45 6.89
newtons kilopascals
FORCE and PRESSURE or STRESS
Fahrenheit temperature
fI
28.35 0.454 0.907
TEMPERATURE (exact)
ounces pounds short tons (2000 Ib)
of
oz Ib T
MASS
NOTE: Volumes greater than 1000 I shall be shown in
yd3
ft"
fI oz gal
square square square acres square
inches feet yards miles
When You Know
• SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380.
III
ac mi2
yd2
ft2
in 2
yd mi
ft
in
Symbol
APPROXIMATE CONVERSIONS TO SI UNITS
• I
N kPa
Ix cdlm 2
°C
g kg Mg (or "to)
mL L m3 m3
mm2 m2 m2 ha km 2
mm m m km
Symbol
N kPa
Ix cdlm 2
°C
g kg Mg (or "to)
mL L m3 m3
mm 2 m2 m2 ha km 2
mm m m km
Symbol
•
Celcius temperature
0.0929 0.2919
ILLUMINATION
1.8C + 32
newtons kilopascals
0.225 0.145
yd3
ft3
fI oz gal
yd2 ac mi 2
ft2
in 2
yd mi
ft
in
Symbol
foot-candles foot-Lamberts
Fahrenheit temperature
Ibf Ibflin2
(Revised September 1993)
poundforce poundforce per square inch
fI
fc
of
ounces oz Ib pounds short tons (2000 Ib) T
fluid ounces gallons cubic feet cubic yards
square inches square feet square yards acres square miles
inches feet yards miles
To Find
FORCE and PRESSURE or STRESS
lux candelalm 2
0.035 2.202 1.103
MASS
0.034 0.264 35.71 1.307
VOLUME
0.0016 10.764 1.195 2.47 0.386
AREA
0.039 3.28 1.09 0.621
LENGTH
MUltiply By
TEMPERATURE (exact)
grams kilograms megagrams (or "metric ton")
milliliters liters cubic meters cubic meters
square millimeters square meters square meters hectares square kilometers
millimeters meters meters kilometers
When You Know
APPROXIMATE CONVERSIONS FROM SI UNITS
TABLE OF CONTENTS
CHAPTER 1. INTRODUCTION Scope of Work Report Organization
1 2 2
CHAPTER 2. GPS-5 DATA CHARACTERISTICS 3 Inventory and Monitoring Data Summary 7 Climatic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Traffic Data 18 Summary 24 CHAPTER 3. EVALUATION OF CRACK SPACING DATA Introduction Bi-Variate Plots Effect of Cracking on Ride Effect of Crack Spacing on Deflections Summary
25 25 25 33 34 34
CHAPTER 4. ANALYSIS OF WELL AND POORLY PERFORMING SECTIONS Summary
37 51
CHAPTER 5. SUMMARY AND RECOMMENDATIONS
53
REFERENCES
55
111
LIST OF FIGURES
Fieure
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
Paee
Age as of latest distress survey 14 Age as of December 31, 1997 14 Design slab thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Design percent longitudinal steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Depth to longitudinal reinforcement 16 Longitudinal bar spacing 16 Transverse bar spacing 17 Annual freezing index summary 19 Annual precipitation summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Average daily temperature range 20 Cumulative ESAL summary 21 Average IRI summary 21 Average crack spacing 23 Typical crack spacing distribution plot for a CRC pavement 26 Typical plot of ASCFC for a CRC pavement 26 Crack spacing versus age 27 Crack spacing versus cumulative ESALs 28 Crack spacing versus slab thickness 28 Crack spacing versus concrete modulus of elasticity, Es1ab ••••••••••••••••••••••• 29 Crack spacing versus percent longitudinal steel 29 Crack spacing versus percent longitudinal steel (age < 10 years) 30 Crack spacing versus percent longitudinal steel (age> 10 years) 30 Crack spacing versus depth to longitudinal reinforcement 31 Crack spacing versus annual air freezing index 31 Crack spacing versus annual precipitation 32 Crack spacing versus average daily temperature range 32 Crack spacing versus longitudinal bar spacing 33 Effect of crack spacing on IRI 34 Average load transfer efficiency at cracks versus crack spacing 35 Ratio of maximum edge and interior deflections versus crack spacing 35 Comparison of design percent longitudinal steel. 41 Comparison of depth to reinforcement. 41 Comparison of longitudinal bar spacing 42 Comparison of transverse bar spacing 42 Comparison of slab thickness 43 Comparison of concrete modulus of elasticity as tested, Es1ab ••••••••••••••••••••• 43 Comparison of base thickness. . 44 Comparison of base modulus of elasticity, Ebase , as backcalculated 44 Comparison of subgrade k-value as backcalculated. . 45
IV
LIST OF FIGURES (Continued) Fie;ure
40 41 42 43 44 45 46 47 48 49 50
Pae;e
Comparison of annual air freeze index. . Comparison of annual precipitation. . Comparison of daily temperature range Comparison of crack spacing Comparison ofIRI values Comparison of age. . Effect of climatic region. . Effect of reinforcement placementtype Effect of base type Effect of subgrade type. . Effect of shoulder type. .
v
45 46 46 47 47 48 48 49 49 50 50
LIST OF TABLES
1 2 3 4 5 6 7 8 9 10
Distribution of GPS-5 sections by climatic regions Distribution of GPS-5 sections by state. . List of sections List of overlaid sections. . GPS-5 data summary Percentage distribution of AASHTO subgrade types for GPS-5 sections Severity of transverse cracking Criteria for identification of well and poorly performing sections Lists of well performing sections and complementary data for sections Lists of poorly performing sections and complementary data for sections
VI
3 4 5 7 8 18 22 37 39 40
CHAPTER 1. INTRODUCTION A continuously reinforced concrete (CRC) pavement is a portland cement concrete (PCC) pavement with continuous longitudinal steel reinforcement and no intermediate expansion or contraction joints. The continuous joint-free length ofCRC pavement can extend to several miles (kilometers), with breaks provided only at structures. CRC pavements develop a transverse cracking pattern, with cracks generally spaced at about 0.6 to 1.8 m (2 to 6 ft). The cracking pattern is governed by the environmental conditions at the time of construction, the amount of steel reinforcement, and concrete strength. The steel reinforcement restrains the opening of the cracks. Also, the higher the amount of steel reinforcement used, the more closely spaced the cracks will be. Most of the cracks develop shortly after concrete placement; however, additional cracking may develop over several years as a result of continued drying shrinkage of concrete, temperature variations, and traffic loading. A major concern with CRC pavement is punchout distress. The definition of punchout distress is the area enclosed by two closely spaced (usually less than 0.6 m [2 ftD transverse cracks, a short longitudinal crack, and the edge of the pavement or a longitudinal joint. It also includes "Y" cracks that exhibit spalling, breakup, and faulting. The punchout distress is related to crack spacing, pavement thickness, poor foundation support, and heavy truck loadings. The repair of punchout distress typically consists of full-depth PCC patches. With time and as the number of full-depth patches increases, the pavement may be resurfaced with asphalt concrete (AC) or PCC, or it may be reconstructed. It should be noted that CRC pavements with smaller crack spacing (e.g., 0.6 m [2 ftD do exhibit good performance provided the support condition is very good. Other distresses associated with punchouts include spalling along transverse cracks and faulting at cracks. Other leading causes of CRC failure are wide (and spalled) transverse cracks due to steel rupture and spalling of concrete due to steel corrosion in the presence of heavy deicing salt applications in the northern states. Over the years, many studies have been conducted to explore the behavior and performance of CRC pavements. Many of these studies have focused on the mechanism of transverse crack development. Mechanistic procedures have been developed to predict crack spacing (e.g., CRCP-7(1»); however, these procedures require a fairly accurate knowledge of ambient climatic conditions and concrete's early-age properties. Other studies have focused on understanding the mechanism of punchout development. For this case also, mechanistic procedures have been proposed (e.g., Zollinger and Barenberg(2»). However, these mechanisticbased procedures require a fairly detailed knowledge of traffic loading (by specific axle loading) and climatic conditions (for computing curling and warping stresses and changes in the shape of the pavement as a result of temperature variation within the concrete), especially climatic (ambient) conditions during the first few days after concrete placement. The availability of the General Pavement Studies (GPS)-5 CRC pavement test sections in the Long Term Pavement Performance (LTPP) program provides an opportunity to evaluate factors affecting the cracking of CRC pavements and to identify how the cracking pattern and other CRC pavement attributes affect CRC pavement behavior under traffic loading. As part of a Federal Highway Administration (FHWA)-sponsored project, work was undertaken to use test
1
data from the LTPP program to study the transverse cracking pattern at the GPS-5 test sections and to evaluate the structural behavior of these sections. As part of the LTPP program, an extensive data collection effort has been underway since about 1989. These data types are classified within the LTPP program as follows: 1. 2. 3. 4. 5. 6.
Inventory Materials Testing Climatic Monitoring Traffic Seasonal
In addition, as appropriate, maintenance, rehabilitation, and construction data are also collected. Scope of Work The overall objective of the study reported here was to evaluate key factors affecting the development of crack spacing in CRC pavements and to determine the effect, if any, of the crack spacing on the structural response as well as the performance of the pavements. Because of lack of construction-time ambient condition data, no attempt was made to verify/validate mechanisticbased crack spacing development models such as CRCP-7 and TTICRCP. As part of the study, an attempt was also made to evaluate the structural performance of the CRC pavements using procedures developed by Professor Dan Zollinger of the Texas Transportation Institute (TTl). Report Organization Chapter 1 provides the background for the study. Chapter 2 provides a summary of the GPS-5 test section characteristics. Chapter 3 provides an evaluation of the crack spacing data. Chapter 4 presents an analysis of well and poorly performing test sections and chapter 5 presents a summary of findings and provides a discussion on improvements needed to be made to further advance the CRC pavement technology using LTPP data.
2
CHAPTER 2. GPS-5 DATA CHARACTERISTICS The LTPP data used in this report were obtained initially from the Information Management System (IMS) during February 1996 (IMS Release 6.0 data). These data were subsequently supplemented using DataPave97, version 1.0. The total number of GPS-5 sections available through DataPave97 was 85, with sections located in 4 climatic regions and 29 different states, as presented in tables 1 and 2. Texas has the largest number oftest sections, which constitute 22 percent of all GPS-5 sections. A list of the 85 test sections is given in table 3. Each test section is also identified with a reference number (from 1 to 85) to facilitate the plotting of charts presented later. In subsequent discussion and in tables and charts, the test sections are identified by these reference numbers. At the time of DataPave97's release (data as of October 1997), 9 ofthe 85 sections were overlaid, as indicated in table 4. For the overlaid sections, only data for the period prior to overlay were used in this study. The LTPP database for the GPS-5 sections consists of the following modules: inventory, environment, material testing, monitoring, and traffic. Each module contains data collected and stored at different times for different sections. The monitoring data used in the analysis are from the latest measurements available for each section for each data type.
Table 1. Distribution of GPS-5 sections by climatic regions. No. of Sections
Climatic Region Wet-Freeze Region
40
Wet-No Freeze Region
35
Dry-Freeze Region
6
Dry-No Freeze Region
4
Total
85
3
Table 2. Distribution of GPS-5 sections by state. State AL AZ AR CA CT DE GA ID IL IN IA MD MI MN MS MO NE NC ND OH OK OR PA SC SD TX VA WV WI TOTAL
Number of GPS-5 Sections 2 1 2 1 1 2 1 1 8 3 3 1 1 1 5 1 1 3 1 2 3 6 3 3 3 19 4 1 2 85 Sections
State ID 01 04 05 06 09 10 13 16 17 18 19 24 26 27 28 29 31 37 38 39 40 41 42 45 46 48 51 54 55 29 States
4
Table 3. List of sections. Reference No.
Section
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
013998 015008 047079 055803 055805 067455 095001 105004 105005 135023 165025 175020 175151 175843 175849 175854 175869 175908 179267 185022 185043 185518 195042 195046 199116 245807 265363 275076 283099 285006 285025 285803 285805 295047 315052 375037 375826 375827 385002 395003 395010 404158 404166 405021 415005
.
Current Status
Climatic Region
WNF WNF WNF WNF ONF WF WF WF WNF OF WF 78
WF WF WF WF WF WF WF WF WF WF WF WF WF WF WF WNF WNF WNF WF WNF WF WF WNF WF WF WF WF WF WF WNF WF WNF
78 78 78 78 78
78
78
5
..
Open-to-Traffic Date 03/01174 12/01177 08/01189 07/01173 11101175 12/01171 11/01181 06/01177 06/01171 06/01174 09/01172 10101/86 10101166 09/01182 11101171 01101182 12/01179 04/01171 10101/66 01101172 01101/69 12/01170 12/01175 11101175 08/01172 06101/90 12/01176 10/01170 11101170 04/01179 07/01177 09/01179 06101175 07/01172 12/01/69 10101172 06101177 03/01173 11/01173 09/01/88 07/01175 06101189 06101190 10101187 10101185
Table 3. List of sections (continued) . Reference No.
Section
46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71
415006 415008 415021 415022 417081 421598 421617 425020 455017 455034 455035 465020 465025 465040 483719 483779 485024 485026 485035 485154 485274 485278 485283 485284 485287 485301 485310 485317 485323 485328 485334 485335 485336 512564 515008 515009 515010 545007 555037 555040
72
73 74 75 76 77 78 79 80 81 82 83 84 85
7B = GPS Experiment 7B WF = wet-freeze region, WNF dry-no freeze region. Note: Data as of October 1997.
••
Current Status
.
7B
taken out of study
=
Climatic Region
DF DF WNF WNF DF WF WF WF WNF WNF WNF DF DF WF WNF DNF WNF WNF WNF WNF WNF DNF WNF WNF WNF WNF WNF WNF WF WNF WF WF WF WNF WNF WNF WNF WF WF WF
..
Open-to-Traffic Date
06/01173 06/01172 07/01186
10/01184 09/01188 01101/75 06/01172 05/01180 03/01/79 06/01/75 11101/75
08/01/73 11101/74 07/01163 01101165
06/01/78 01101182 06/01188 09/01/79
08/01/71 03/01/73
06/01/75 04/01188 03/01188
08/01/73 02/01/82 07/01187
04/01/82 10/01180 09/01/75
04/01/70 10/01180 12/01186 02/01169 08/01177
06/01/80 10/01188 06/01/77
11/01/73 11101/80
wet-no freeze region, DF = dry-freeze region, DNF
6
=
Table 4. List of overlaid sections. State
State ID
SHRPID
Year Constructed
Current Status
Year Overlaid
IL
17
5151
1966
GPS-7B Section
1990
IN
18
5022
1972
GPS-7B Section
1993
IN
18
5518
1970
GPS-7B Section
1993
IA
19
9116
1972
GPS-7B Section
1989
MN
27
5076
1970
GPS-7B Section
1990
MS
28
3099
1970
GPS-7B Section
1992
NC
37
5826
1977
GPS-7B Section
1995
OH
39
5010
1975
GPS-7B Section
1990
PA
42
1617
1972
GPS-7B Section
1991
Inventory and Monitoring Data Summary
The inventory and monitoring data available for GPS-5 sections are summarized in table 5. The characteristics of the key data are discussed next. Age The age for the GPS-5 sections was determined as the difference between the date of the last crack survey and the traffic opening date. Based on this calculation, the age of the test sections ranged from 1 to 30 years. The age summary is given in figure 1. Also, another age calculation was made as of December 31, 1997, as presented in figure 2. As of December 31, 1997, there were 59 sections that were 15 years of age or older and 42 of these sections were 20 years of age or older. With respect to the age at the time of the last distress survey, there were 23 sections that were 20 years of age or older. Slab Design Data The pavement slab design data include mean slab thickness, design percent of longitudinal steel, depth to reinforcement, spacing of longitudinal and transverse reinforcing bars, and reinforcement placement method. Design parameter summaries are given in table 5 and presented in figures 3 through 7. The following observations are made: 1.
Fifty sections had 203-mm-thick slabs, 18 sections had 228-mm-thick slabs, and 10 sections had 254-mm-thick slabs. Only five sections had slabs thicker than 270 mm and only three sections had slabs thinner than 200 mm. This represents a very biased sample. 7
00
Section ID
1 01-3998 2 01-5008 304-7079 4 05-5803 505-5805 6 06-7455 7 09-5001 8 10-5004 9 10-5005 10 13-5023 11 16-5025 12 17-5020 13 17-5151 14 17-5843 15 17-5849 16 17-5854 17 17-5869 18 17-5908 19 17-9267 20 18-5022 21 18-5043 22 18-5518 23 19-5042 24 19-5046 25 19-9116 26 24-5807 27 26-5363 28 27-5076 29 28-3099 30 28-5006 31 28-5025 3228-5803 33 28-5805 34 29-5047 35 31-5052 36 37-5037 37 37-5826 38 37-5827 39 38-5002 4039-5003 41 39-5010 4240-4158 4340-4166
Section No.
78/1990
78/1995
78/1990 78/1992
78/1989
78/1993
78/1993
78/1990
Current Status
WN WN
WF WF WF WF WF
WN
Climatic Region WN WN DN WN WN DN WF WF WF WN DF WF WF WF WF WF WF WF WF WF WF WF WF WF WF WF WF WF WN WN WN WF WN WF WF
162
OS/21/93
82 161 141 90 144
12117/96
07/13/94 11/29/88 11/04/92 11/01/94
03/07/91 03/04/91 07/13/93 11/29/95 03/07/91 08/19/88 04/19/93 01/29/96
238 172 129 124 154 99 118 120
165 140 81 210
12101/89
09/07/89 08/30/94 07/28/89
76 215 125 107 86 212 77
80 182 19
159 213 221 115 113
08/02188 08/04/88 08/04/88 08/04/88 03/24/93 07/07/89 07/13/88
10/27/94 08/01/95 07/15/91
04/09/96 03/16/93
12117/91
11/28/94
11129/94
Manual Survey Date
1.86 0.95 1.08 1.69 1.06 0 0 0 0
0.64 0.89 1.18 1.23 0.99 1.54 1.29 1.27
0.94
0.92 1.09 1.88 0.73
2.01 0.71 1.22 1.43 1.77 0.72 1.98
1.91 0.84 8.03
0.96 0.72 0.69 1.33 1.35
0
0 0 0 0 0 0 0 0
0
0 0 0 0
0 0 0 0 0 0 0
0 0 0
0 0 0 1 0
Manual Manual Manual Total High Average Total Severity Crack Trans. Trans. Spacing, m Crack No. Crack No.
03/14/91 10/30/90
03/03/91 01/14/91 01/10/90 01/15/91 06/20/90 05/15/89 03/10/91 03/11/91 03/19/91 12106/90 10/03/90
02114/91
10/11/89 07/18/90 06/09/89
05/18/91 05/18/91
10/15/90 06/24/89 06/24/89 06/24/89 05/10/91 05/07/90 09/25/89 05/09/91
09/04/90 03/21/91 03/21/91 02109/91 09/20/89 05/13/91
11/14/89
02127/91
01115/91
02112190
04/16/90
PADIAS Survey Date
67 26
132 116 80 143 88 127 96 107 66 228
13 67 227
132 15
64 231 127 96 82 184 75 119
99 52 99 66 121 134
61 118 83 153 123
0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 1
1 O. 0 0 0 0 2 0
0 0 0 0 0 0
0 0 0 0 0
2.28 5.87
1.16 1.31 1.91 1.07 1.73 1.20 1.59 1.43 2.31 0.67
11.73 2.28 0.67
1.16 10.17
2.38 0.66 1.20 1.59 1.86 0.83 2.03 1.28
1.54 2.93 1.54 2.31 1.26 1.14
2.50 1.29 1.84 1.00 1.24
PADIAS PADIAS PADIAS Total High Average Severity Crack Total Trans. Trans. Spacing, Crack No. Crack No. m
Table 5. GPS-5 data summary.
0.94 0.67 0.64 0.89 1.18 1.23 0.99 1.54 1.20 1.27 1.43 1.86 0.67 0.95 1.08 1.69 1.06
2.01 0.66 1.20 1.43 1.77 0.72 1.98 1.28 0.92 1.09 1.88 0.73
2.50 1.29 1.84 0.96 0.72 0.69 1.33 1.35 1.54 1.91 0.84 1.14
Least Average Crack Spacing from Manual and PADIAS surveys, m
12106/90 07/13/94 11/29/88 11/04/92 11/01/94
12117/96
08/19/88 05/15/89 01/29/96 03/11/91
03107/91
06/24/89 06/24/89 08/04/88 03/24/93 07/07/89 07/13/88 05/09/91 12/01/89 09/07/89 08/30/94 07/28/89 10/11/89 OS/21/93 06/09/89 03/07/91 03/04/91 07/13/93 11/29/95
08/02188
04/16/90 02/12/90 01/15/91 11/29/94 11/28/94 12/17/91 04/09/96 03/16/93 03/21/91 10/27/94 08/01/95 05/13/91
Date Tested for Least Average Crack Spacing
06/01/89 06/01/90
07/01175
09/01/88
12101176 10/01170 11/01170 04/01179 07/01177 09/01179 06/01175 07/01172 12101/69 10/01172 06/01177 03/01173 11/01173
06/01/90
12101170 12101175 11/01175 08/01172
01/01/69
01/01172
10/01/66
12101179 04/01171
01/01/82
11/01171
10/01/86 10/01/66 09/01/82
06/01177 06/01171 06/01174 09/01172
11/01/81
07/01173 11/01175 12101171
08/01/89
Open-toTraffic Date 03/01174 12101177
6 18 7 9 22 23 16 22 19 14 19 17 1 17 19 21 12 16 16 16 16 20 24 14 23 17 6 13 3 4
16 13 2 21 19 20 15 16 20 20 23 5
Age as Tested, years
23 20 8 24 22 26 16 20 26 23 25 11 31 15 26 15 18 26 31 25 28 27 22 22 25 7 21 27 27 18 20 18 22 25 28 25 20 24 24 9 22 8 7
3 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 3 0 0 0 0 3 0 0 0 0 0 1 0 0 0 0 0
Total Age as of Punchouts 1/1/98, and years Patches
'"
Section ID
44 40-5021 45 41-5005 46 41-5006 47 41-5008 48 41-5021 49 41-5022 50 41-7081 51 42-1598 52 42-1617 53 42-5020 54 45-5017 55 45-5034 56 45-5035 57 46-5020 58 46-5025 59 46-5040 60 48-3719 61 48-3779 62 48-5024 63 48-5026 64 48-5035 65 48-5154 66 48-5274 67 48-5278 68 48-5283 69 48-5284 7048-5287 71 48-5301 7248-5310 7348-5317 7448-5323 7548-5328 7648-5334 77 48-5335 7848-5336 7951-2564 80 51-5008 81 51-5009 8251-5010 83 54-5007 84 55-5037 85 55-5040
Section No.
7B/1991
Current Status
WF WN DN WN WN WN WN WN DN WN WN WN WN WN WN WF WN WF WF WF WN WN WN WN WF WF WF
DF DF
1 0 2 0 0 0 0 0 0 0 0 6 0 0 1 0 0 0 0
2
0 0
125 131 129 144 139 108 75 176 117 83 143 123 86 74 235 133 219 209 162
128
85 118
12118/96
08/24/88 11/07/94
0 0 0 0 0
0
82
101 101 224 249 246
16 0 1 0
0
137 166 226 137
132
06/08/95 11/07/95 07/10/95 06/06/95 06/30/95 07/10/95 02111/97 06/05/95 02113/97 02113/97 02114/97 02113/97 02111/97 02111/97 08/10/95 08/05/93 08/11/95 08/10/95 08/08/95
06/07/93 03/17192 06/08/93 10/05/93 05/02189
07/27/95
04/30/96 04/29/96 06/27/94 05/23/96
DF DF DF WN WN DF
WF WF WF WN WN WN
11/01/94
WF
Climatic Region
Manual Survey Date
Manual Manual Total High Total Severity Trans. Trans. Crack No. Crack No.
1.79 1.29
1.19
1.22 1.16 1.18 1.06 1.10 1.41 2.03 0.87 1.30 1.84 1.07 1.24 1.77 2.06 0.65 1.15 0.70 0.73 0.94
1.51 1.51 0.68 0.61 0.62
1.86
1.11 0.92 0.67 1.11
1.16
Manual Average Crack Spacing, m
09/12190 03/05/91 03/05/91 06/05/90 12111190 12117/90 12115/90 02127191 09/11/90 10/12190 02126191 10/27/90 10/12190 10/29/90 01/24/91 10/27/90 10/27/90 10/27/90 10/27/90 03/11/91 03/21/89 04/24/89 03/11/91 04/25/89 04/24/89 01/11/90 03/20/91 03/20/91 03/20/91 03/20/91 05/01/91 10/19/90 09/12189
10/30/90 09/18/89 09/18/89 09/18/89 07/26/89 09/08/89 09/18/89 03/25/90
PADIAS Survey Date
104 88 100 160 226 236 330 95 112 83 94 86 94 60 156 45 21 101 89 55 58 190 104 215 184 87 166 156 79 25 212 109 90
83 33 112 178 148 93 3 79 0 0 0 0 0 0 0 1 0 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0
0 0 67 0 0 0 0 0 07/27/95
11/01/94 09/18/89 04/30/96 09/18/89 06/27/94 05/23/96
Date Tested for Least Average Crack Spacing
0.72 1.40 1.29
03/20/91 05/01/91 10/19/90 11/07/94
1.47 09/12190 1.51 06/07/93 1.51 03/17192 0.68 06/08/93 0.61 10/05/93 0.62 05/02189 0.46 12115/90 1.22 06/08/95 1.16 11/07/95 1.18 07/10/95 1.06 06/06/95 1.10 06/30/95 1.41 07/10/95 2.03 02111197 0.87 06/05/95 1.30 02113/97 1.84 02113/97 1.07 02114/97 1.24 02/13/97 1.77 02111197 2.06 02111197 0.65 08/10/95 1.15 08/05/93 0.70 08/11/95 0.73 08/10/95 0.94 08/08/95 0.92 03/20/91 0.98 03/20/91 1.19 12118196
1.86
1.93 1.47 1.73 1.53 0.95 0.67 0.65 0.46 1.61 1.36 1.84 1.62 1.77 1.62 2.54 0.98 3.39 7.26 1.51 1.71 2.77 2.63 0.80 1.47 0.71 0.83 1.75 0.92 0.98 1.93 6.10 0.72 1.40 1.69
1.11 0.86 0.67 1.11
1.16
Least Average Crack Spacing from Manual and PADIAS surveys, m
1.84 4.62 1.36 0.86 1.03 1.64
PADIAS PADlAS PADIAS Total High Average Severity Crack Total Spacing, Trans. Trans. Crack No. Crack No. m
Table 5. GPS-5 data summary (continued).
10/01/87 10/01/85 06/01173 06/01172 07/01/86 10/01/84 09/01/88 01/01175 06/01172 05/01/80 03/01179 06/01175 11/01175 08/01173 11/01174 07/01/63 01/01/65 06/01178 01/01/82 06/01/88 09/01179 08/01171 03/01173 06/01175 04/01/88 03/01/88 08/01173 02101182 07/01/87 04/01/82 10/01/80 09/01175 04/01170 10/01/80 12101186 02101169 08/01177 06/01/80 10/01/88 06/01177 11/01173 11/01/80
Open-toTraffic Date
10 14 17 18 20 15 27 30 17 13 7 16 24 24 20 9 9 24 15 10 15 15 18 25 15 9 22 14 16 3 14 17 14
20
7 4 23 17 8 12
Age as Tested, years
10 12 24 25 11 13 9 22 25 17 18 22 22 24 23 34 32 19 15 9 18 26 24 22 9 9 24 15 10 15 17 22 27 17 11 28 20 17 9 20 24 17
0 0
nla
0 0 0 0 0 0 0 2 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 2 1 6 2 23 1 0 6 0 0 0 4 0
Total Age as of Punchouts 1/1/98, and years Patches
o
.....
Section 10 1 01-3998 2 01-5008 304-7079 405-5803 505-5805 606-7455 7 09-5001 ·8 10-5004 9 10-5005 10 13-5023 11 16-5025 12 17-5020 13 17-5151 14 17-5843 15 17-5849 16 17-5854 17 17-5869 18 17-5908 19 17-9267 20 18-5022 21 18-5043 22 18-5518 23 19-5042 24 19-5046 25 19-9116 26 24-5807 27 26-5363 28 27-5076 29 28-3099 30 28-5006 31 28-5025 32 28-5803 33 28-5805 34 29-5047 35 31-5052 36 37-5037 37 37-5826 38 37-5827 39 38·5002 40 39·5003 41 39-5010 42 40-4158 43 40-4166
Section No.
IRI Date 05/04/90 12110/90 03/23/90 09/23/94 09/23/94 05/01/91 04/12196 10/17193 06/19/91 05/17/94 09112194 03/06/91 03/11/95 06/12190 03/12190 04/09/90 04/10/90 10/06/92 04/08/90 03/18/95 06113/91 07/25/90 06/19/90 09/16/94 04/08/90 12104/95 04/22193 OS/22190 10/09/91 12105/90 08/01/95 01/27/94 06/04/90 03/19/90 11/20/89 11/16/94 03/26/91 04/25/96 10/25/89 04/04/94 09/28/89 08/28/91 11/17/93
AvglRI, mlkm 1.32 0.94 1.03 1.45 1.32 1.23 1.80 1.18 1.07 1.26 2.39 1.22 1.15 1.18 1.58 2.13 1.70 2.02 1.10 0.94 2.41 1.32 1.70 1.55 0.84 1.48 1.83 0.77 1.47 1.45 1.41 1.55 1.30 1.59 1.05 1.07 1.22 0.99 1.26 1.15 1.84 1.03 0.95 0.61 0.72
0.61 0.59 0.59 0.59 0.59 0.60 0.75 0.60 0.65 0.60 0.60 0.96
0.60 0.60 0.61 0.65 0.65 0.65 0.53 0.70
Design % Long. Steel 0.59 0.68 0.57 0.61 0.61 0.56 0.60 0.60 0.60 0.60 0.61 0.73 0.69 0.71 0.70 0.61 0.72 0.57
Depth ReinforReinfor- Long. Bar Trans. Bar cement Spacing, Spacing, cement, Place mm mm mm Method 168 76 762 Chairs 185 114 965 Chairs 152 114 864 Chairs 102 102 406 Chairs 160 89 762 Chairs 165 102 1524 Chairs 160 102 864 Chairs 97 152 Chairs 97 152 Chairs 152 99 Mech 229 64 Other 76 193 1219 Chairs 76 165 1219 Chairs 58 185 1219 Mech Other 94 127 Mech 147 89 Mech 165 1219 Chairs 76 165 1219 Chairs 76 Mech Chairs Chairs 89 216 Mech 216 89 Mech 76 216 Mech 241 1372 Chairs 109 102 165 Other Other 165 102 1067 Chairs 97 165 914 Chairs 97 165 914 Chairs 97 165 914 Mech 76 165 762 Chairs 89 152 1219 BTW 64 152 914 Chairs 102 762 305 Chairs 152 76 762 Other 76 152 762 Other 102 165 1219 Mech 102 160 762 Chairs Other 185 127 1118 Mech 127 185 1118 Mech
Average Mean Split Slab Average Tensile Compressive Strength, Thick, Strength, MPa mm MPa 57.7 203 6.2 229 229 4.7 203 203 213 4.8 203 62.9 4.6 42.2 229 4.2 34.5 203 4.8 49.9 216 5.3 203 3.5 203 48.1 4.7 203 4.1 65.1 4.5 254 55.8 178 4.6 55.9 4.6 254 229 64.6 5.4 52.5 203 3.5 60.7 203 4.7 50.9 229 3.7 54.8 185 44.9 4.9 229 56.2 4.3 203 51.7 203 48.2 3.4 203 40.7 4.5 229 52.2 229 62.2 229 5.2 68.6 5.6 203 64.8 203 5.2 203 53.7 203 4.9 203 203 47.0 5.0 40.1 203 4.2 55.6 4.9 203 55.5 203 4.7 203 44.9 3.7 203 51.7 5.4 254 203 262 259 56.3 4.5
ESlab Base E Base Base E Lab Backcalc., Thickness, Backcalc., Material Tested, GPa GPa mm GPa Type 58.0 152 46.3 8.4 SC 55.8 152 8.1 ACM 102 27.2 ACM 152 ACM 53.7 178 7.8 ACM 54.0 137 7.8 CAM 32.0 44.9 254 36.7 6.5 G 102 21.9 30.4 4.4 SC 36.6 18.6 102 5.3 SC 43.2 152 6.3 CAM 33.2 32.0 102 29.6 4.6 CAM 23.6 37.4 102 5.4 PAM 33.6 102 G 28.9 40.7 102 4.2 CAM 48.7 102 7.1 ACM 27.6 53.6 102 7.8 CAM 34.3 29.1 102 4.2 LT 40.3 23.1 42.5 102 6.2 ACM 42.9 43.3 102 6.3 ACM 45.3 40.5 102 6.6 ACM 37.6 203 35.8 5.5 G 38.1 152 5.5 G 33.2 50.3 102 7.3 ACM 30.0 45.5 102 6.6 CAM 31.2 45.7 102 6.6 ACM 33.8 51.0 152 7.4 CAM 30.6 37.1 102 5.4 G 30.1 42.5 152 6.2 G 37.2 32.8 152 4.8 SC 39.1 152 4.6 CAM 32.0 34.6 47.8 102 6.9 ACM 28.5 152 31.5 4.1 ACM 70.2 102 10.2 ACM 55.5 102 34.8 8G 62.2 25.7 76 9 SC 34.6 102 5G 21.4 40.7 38 5.9 ACM 28.4 38.8 22.2 102 5.6 G 41.5 51 6 ACM 6ACM 26.2 41.2 102 102 CAM 40.0 114 5.8 ACM 45.3 102 33.4 6.6 CAM
Table 5. GPS-5 data summary (continued).
05/19/93 OS/28/93
07/30/90 11/13/89 05/02190 05/02190 03/24/93 09/19/90 07/21/90 05/17/90 04/30/92 04/18/90 08/30/94 07110/89 04/24/89 06/25/90 07/02190 10/10/91 10/08/90 10/31/94 11/29/95 11/23/92 10/24/89 08/11/89 01/29/96 10/16/89 12117/96 08/28/90 07/13/94
06/07/93 12101/89 04/09/96 03/16/93 07/26/91 03/15/95 08/01/95 11/01/90
Date Modulus Evaluated 09/13/90 09/17/90
...... ......
Section Section 10 No. 44 40-5021 45 41-5005 46 41-5006 47 41-5008 48 41-5021 49 41-5022 50 41-7081 51 42-1598 52 42-1617 53 42-5020 54 45-5017 55 45-5034 56 45-5035 57 46-5020 58 46-5025 59 46-5040 60 48-3719 61 48-3779 62 48-5024 63 48-5026 64 48-5035 6548-5154 66 48-5274 67 48-5278 6848-5283 6948-5284 7048-5287 71 48-5301 72 48-5310 7348-5317 7448-5323 7548-5328 7648-5334 77 48-5335 7848-5336 79 51-2564 8051-5008 81 51-5009 82 51-5010 8354-5007 84 55-5037 85 55-5040
IRI Date 09/16/93 11/17/89 OS/20/97 10/20/89 03/31/93 11/18/89 OS/20/97 11/08/95 11/10/95 05/16/90 04/29/92 04/29/92 04/10/94 06/16/93 11/18/89 11/13/89 02103/95 10/13/94 01/31/95 02101/95 12107/94 01/30/95 12108/94 11/16/94 12107/94 12107/94 12106/94 12105/94 12/06/94 12112194 11/22194 04/21/93 01/12195 11/22194 11/21/94 06/21/91 06/21/91 12113/95 12107/89 11/15/91 09/17/95 07/14/94
Avg IRI, mlkm 0.94 1.32 1.43 0.93 1.09 0.94 0.82 1.81 0.84 1.81 2.05 1.42 1.22 0.97 1.31 1.99 2.29 2.23 2.32 1.72 1.86 1.66 1.66 1.67 1.18 2.43 2.02 1.69 2.01 2.34 1.79 1.59 1.10 2.01 1.42 0.97 2.07 2.17 1.55 2.35 1.14 2.39
Design % Long. Steel 0.59 0.51 0.51 0.51 0.51 0.51 0.70 0.65 0.64 0.65 0.57 0.64 0.64 0.59 0.59 0.65 0.51 0.51 0.60 0.56 0.61 0.52 0.51 0.61 0.52 0.50 0.51 0.60 0.50 0.51 0.61 0.61 0.51 0.61 0.61 0.60 0.60 0.60 0.65 0.65 0.61 0.65
Depth ReintorReintor- Long. Bar Trans. Bar cement cement, Spacing, Spacing, Place mm mm mm Method 114 147 1118 Mech 122 147 1524 Chairs 102 1524 Chairs 165 1524 Chairs 102 165 109 165 1524 Mech 76 122 1524 Chairs 109 165 914 Chairs 89 864 Chairs 147 89 152 864 Chairs 89 203 864 Chairs 99 762 Chairs 152 89 762 Chairs 152 89 762 Chairs 152 64 1219 Chairs 165 64 1219 Chairs 165 64 1118 Chairs 152 102 191 610 Chairs 102 191 914 Chairs 127 185 914 Chairs 127 198 610 Mech 914 Chairs 102 160 914 Chairs 102 191 914 Chairs 102 191 914 Chairs 76 216 610 Chairs 127 216 610 Chairs 140 203 102 191 914 Chairs 127 185 914 Chairs 140 203 610 Chairs 102 914 Chairs 191 114 914 Mech 203 102 914 Chairs 160 97 191 762 Other 114 203 914 Mech 114 914 Mech 203 89 Mech 152 Mech 89 152 89 152 Mech 102 Mech 191 76 Chairs 76 229 Mech Other 76 216
Average Mean Split Slab Average Tensile Thick, Compressive Strength, mm Strength, MPa MPa 229 279 5.8 203 3.6 203 3.3 274 5.3 305 5.5 254 5.1 229 65.0 4.4 229 41.3 5.5 229 48.6 4.2 229 44.8 5.9 203 47.4 3.8 203 50.7 3.6 203 4.5 54.0 203 5.0 56.8 203 5.6 73.4 203 51.9 4.3 203 254 254 62.7 5.7 203 203 203 152 254 279 203 254 279 203 229 4.1 57.0 206 203 4.8 47.4 229 63.9 4.9 229 203 51.6 4.4 203 5.0 45.2 203 50.2 4.3 229 39.0 4.6 203 57.7 5.2 203 59.4 5.8 203 54.9 5.4
Table 5. GPS-5 data summary (continued).
24.8 25.1 25.3 31.0 21.9 34.6 42.7
35.0 35.0
29.3
37.7
31.5 28.4 31.3 22.9 24.3 26.0 43.1 40.0 43.8 20.8 21.5 24.3 27.6 29.8 33.2 44.1
E Lab Tested, GPa
Base EBase Base ESlab Backcalc., Thickness, Backcalc., Material Type mm GPa GPa 89 7.1 ACM 48.7 165 8.8 LC 60.4 10.7 CAM 73.7 152 5.5 CAM 37.8 102 6 CAM 41.5 229 33.3 508 4.8 G 51.0 203 7.4 LC 36.9 203 5.3 G 38.2 203 5.5 G 59.3 152 8.6 G 35.2 152 5.1 CAM 36.0 127 5.2 CT 5.9 CT 40.8 127 5ACM 34.5 51 76 6.6 G 45.6 76 5.7 G 39.4 102 6.7 CAM 46.5 51 5.2 ACM 35.5 102 9.4 ACM 65.1 152 7.1 CAM 48.7 152 5.2 ACM 36.0 66.9 102 9.7 ACM 5.3 ACM 102 36.6 8.7 ACM 59.9 102 5.6 ACM 38.6 51 5.7 ACM 51 39.0 102 4.2 ACM 29.0 51 6.8 ACM 46.6 102 5ACM 34.6 7.5 ACM 51.7 51 5.5 ACM 152 38.1 6.5 ACM 109 45.1 5.4 ACM 102 37.5 4.2 ACM 28.9 152 6.4 ACM 43.9 152 4.3 SC 152 29.6 5.3 SC 127 36.3 7.8 CAM 53.7 152 7.7 CAM 203 53.3 3.5 ACM 152 24.0 7.2 G 152 49.4 6.3 G 43.3 152
Date Modulus Evaluated 05/18/93 10/18/89 04/30/96 08/24/89 06/27/94 OS/23/96 04/19/96 07/27/95 04/25/90 04/24/90 08/31/92 09/02192 10/26/92 10/05/93 06/08/89 10/25/91 01/04/95 11/16/94 10/06/93 03/06/90 08/23/93 12103/91 08/19/93 01/27/95 08/25/93 08/24/93 02112196 08/20/93 08/30/93 08/18/93 01/23/95 08/31/93 01118/95 01/20/95 01/25/95 02127/90 02128/90 04/30/90 05/01/90 06/17/91 08/21/90 11107/94
N
......
Section ID 1 01-3998 201-5008 304-7079 405-5803 505-5805 606-7455 709-5001 8 10-5004 9 10-5005 10 13-5023 11 16-5025 12 17-5020 13 17-5151 14 17-5843 15 17-5849 16 17-5854 17 17-5869 18 17-5908 19 17-9267 20 18-5022 21 18-5043 22 18-5518 23 19-5042 24 19-5046 25 19-9116 26 24-5807 27 26-5363 28 27-5076 29 28-3099 30 28-5006 31 28-5025 32 28-5803 33 28-5805 34 29-5047 35 31-5052 3637-5037 3737-5826 38 37-5827 39 38-5002 40 39-5003 41 39-5010 4240-4158 4340-4166
Section No.
k-value AASHTO Soil Backcalc., Classif. Bond MPalmm 91 A-2-4 1.0 1.0 44 A-5 A-6 A-4 159 1.0 42 A-6 1.0 1.0 33 A-2-4 36 A-1-b 0.0 1.0 78 A-4 1.0 69 A-3 1.0 103 A-1-a 0.0 48 A-6 A-4 1.0 57 A-6 1.0 65 A-4 51 A-6 0.0 1.0 78 A-4 1.0 58 A-1-b 1.0 82 A-1-b 1.0 73 A-4 1.0 70 A-7-6 1.0 73 A-2-4 57 A-4 1.0 83 A-2-4 1.0 1.0 58 A-6 1.0 69 A-4 1.0 59 A-2-4 1.0 46 A-4 1.0 44 A-7-6 1.0 120 A-7-6 0.0 103 A-2-4 61 A-2-4 1.0 57 A-3 1.0 1.0 42 A-6 1.0 43 A-7-6 55 A-5 1.0 34 A-4 1.0 31 A-l-b 1.0 1.0 32 A-7-6 1.0 125 A-4 A-4 84 A-2-4 1.0 1.0 106 A-6 F C C F C C F C F F F F C C F F C F C F F C F F F C C C F F C F C F F F C F
Soil Type Coarse/Fine C F F F
Outside Shoulder Type PCC (JPCP) PCC (JPCP) PCC (JPCP) AC PCC(JPCP) AC AC AC PCC (JRCP) AC AC PCC (JPCP) PCC (JRCP) AC AC AC AC AC PCC(JRCP) AC AC AC AC AC AC PCC(JPCP) AC AC PCC(JRCP) AC PCC (JRCP) AC AC PCC(JRCP) AC AC AC AC PCC(JPCP) PCC(JPCP) AC PCC (JPCP) PCC(JPCP) 548 468 462 506 255 565 393 202 442 823 814 933 131 483 943 18 57 24 97 4 305 574 83 95 89 1299 364 429 80 55
Average Annual Freeze Index, degrees C days 30 41 0 69 73 1 397 197 125 2 543 196
Table 5. GPS-5 data summary (continued).
Average Daily Annual Temp. precip., Range, KESAL_ mm degrees C 18k Total 1423 13.6 6912 1345 13.8 8840 706 1336 11.9 1820 1298 11.9 2723 270 15.1 8971 1243 12.2 15646 1094 10.5 40312 1160 11.6 5976 1266 11.2 21332 370 17.0 14502 1036 321 12.1 17451 820 11.4 4897 1000 11.8 10250 968 11.9 708 979 11.6 1136 58 12.4 2465 925 10.7 16311 1055 11.6 63112 1160 11.3 326 935 11.1 68028 828 5923 12.0 820 11.9 8451 821 11.4 6894 1075 11.0 860 10.6 3989 798 5488 11.1 1570 14.0 2490 1387 12.8 2369 1561 13.5 1502 1441 12.7 5115 1655 10.5 11144 958 12.3 5397 734 5263 11.5 1175 13.4 12365 1150 13.7 8239 1163 3117 12.3 510 12.0 4977 822 952 10.8 980 12.6 2272 1072 13.6 9229 1686 12.3 10481
V .l
-
Section No. Section ID 44 40-5021 45 41-5005 46 41-5006 47 41-5008 48 41-5021 49 41-5022 50 41-7081 51 42-1598 52 42-1617 53 42-5020 54 45-5017 55 45-5034 56 45-5035 57 46-5020 58 46-5025 59 46-5040 60 48-3719 61 48-3779 62 48-5024 63 48-5026 64 48-5035 65 48-5154 66 48-5274 67 48-5278 68 48-5283 69 48-5284 70 48-5287 71 48-5301 72 48-5310 7348-5317 7448-5323 75 48-5328 7648-5334 77 48-5335 7848-5336 79 51-2564 80 51-5008 81 51-5009 82 51-5010 8354-5007 84 55-5037 85 55-5040 Bond 1.0 0.0 1.0 1.0 1.0 1.0 0.0 1.0 1.0 1.0 1.0 1.0 0.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.0 1.0 1.0 0.0 1.0 1.0 1.0 1.0 1.0 0.0 0.0 0.0 0.0 0.0 1.0 1.0
AASHTO k-value Backcalc., Soil MPalmm Classif. 75 A-6 67 A-6 38 A-7-6 145 A-2-6 71 A-4 50 A-6 97 A-1-b 107 A-2-4 99 51 A-4 164 A-2-4 120 A-2-4 74 A-2-4 125 A-2-4 39 A-7-6 39 A-6 47 A-7-6 48 85 A-2-6 53 A-7-6 209 130 A-2-7 75 A-2-7 168 A-2-4 102 A-2-6 84 A-2-6 66 A-5 129 A-6 95 A-7-6 47 A-2-7 61 A-6 62 A-5 102 A-4 61 A-6 79 A-7-5 90 A-4 85 A-4 87 A-2-4 101 A-7-6 50 A-4 78 A-1-b 49 A-7-S C C C C C F F F C F F F F F F F C F F C F
C F
Soil Type Coarse/Fine F C F C F F C C C F C C C C F F F
Outside Shoulder Type PCC (JPCP) AC AC AC AC AC AC PCC(JRCP) AC AC AC AC AC AC AC AC PCC (JRCP) AC PCC (JPCP) PCC (JPCP) PCC (JPCP) AC AC AC PCC (JPCP) PCC (JPCP) AC PCC (JPCP) PCC (JRCP) PCC (JRCP) PCC (JPCP) PCC (JRCP) PCC(JRCP) PCC (JPCP) PCC (JPCP) AC AC AC PCC (JPCP) AC AC PCC (JPCP) 38 139 55 133 130 135 45 48 76 71 313 1086 523
44
Average Annual Freeze Index, degrees C days 141 12 210 212 27 26 124 240 202 216 20 16 15 620 576 910 3 11 15 9 35 8 38 33 48 48 37 52
Table 5. GPS-5 data summary (continued).
Annual precip., mm 1065 377 426 428 1117 1128 176 1033 1132 1116 1175 1147 1138 451 400 606 1518 264 999 1123 934 953 861 404 965 969 864 838 946 888 566 859 574 584 526 1178 1159 1077 1092 1219 811 845
Average Daily Temp. Range, KESAl_ degrees C 18k Total 6739 12.9 11.7 11026 13.5 13754 13.4 9958 12.7 11588 12.3 16927 11.8 1466 10.5 22826 6381 11.3 5118 11.5 8299 12.9 4972 13.3 13.0 6039 15.8 947 555 15.0 1343 12.5 9199 10.5 16.1 9325 14.1 1522 239 9.8 9492 12.0 10317 12.2 5929 12.4 15.2 1189 12.5 1551 12.6 1019 12.6 4538 1765 12.9 13.6 2238 4426 12.5 15.3 9748 7292 12.7 11754 15.0 8914 15.3 1486 15.9 10.2 11755 9.7 10505 2207 12.2 381 12.2 1751 13.0 2627 12.9 9.3 9118
32 28 24 ~
ro
20
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16
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12 8
4 0
Section Reference Number
Figure 1. Age as of latest distress survey. 35 30 25 ~ ro 20
Q)
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~ 15
oct:
10
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5 0 .....
LO
Ol
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Section Reference Number
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Figure 2. Age as of December 31, 1997. 14
~
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00
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Figure 4. Design percent longitudinal steel.
15
150.00 135.00 120.00
E E 105.00
... c:
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E
90.00
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75.00
.iii
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0 .-
..c: .-
0-
~
60.00 45.00 30.00 15.00 0.00 ~
m
~
~
N
~
~
~
M
~
~
~
~
~
ID
Section Reference Number
~
$
~
~
~
~
Figure 5. Depth to longitudinal reinforcement. 250.00,-
E E
-,
200.00
Ol
c: '0
ro
0-
150.00
...ro
W aJ
(i'j
c:
100.00
:a::J .-
'5> c: 0
-oJ
50.00
0.00
Section Reference Number
Figure 6. Longitudinal bar spacing. 16
1600.00
r-------------------------------.
1400.00 + - - - - 1 : . . - - - - - - - - - - - - -
E E
1200.00
~ 1000.00 '0 co coo 800.00
-/----1--
-/----1--
-I-Hf--III------
600.00
400.00
200.00
0.00
~ ~ ~ ~ ~ ~ ~ ~ Section Reference Number
w~
$
~
~
00 ~
Figure 7. Transverse bar spacing. 2.
3. 4. 5.
Most sections have 0.62 percent or less longitudinal steel. Only 10 sections had steel equal to or greater than 0.7 percent. Fifteen sections had steel equal to or less than 0.5 percent. Depth of longitudinal reinforcement was generally greater than 75 rom. Spacing of longitudinal bars was generally more than 150 rom. Where transverse bars were used, bar spacing was generally greater than 600 rom.
Base and Subgrade Inventory Data Base material was characterized by material type as presented in table 5. The material type codes used in table 5 are as follows:
G SC ACM CAM LC LT CT PAM
Gravel Soil Cement Dense-Graded, Hot-Laid, Central-Plant AC Mix Cement-Aggregate Mixture Lean Concrete Lime-Treated Subgrade Soil Cement-Treated Subgrade Soil Pozzolanic-Aggregate Mixture
17
Data for the subgrade includes American Association of State Highway and Transportation Officials (AASHTO) soil classification and classification by soil particle size as coarse-grained (C) and fine-grained (F) (given in table 5). The subgrade type for 43 percent of the GPS-5 sections was identified as coarse-grained and 57 percent were identified as fine-grained based on the inventory data. The actual percentage distribution for subgrade types according to AASHTO classification (based on field sampling and laboratory testing) is given in table 6. Table 6. Percentage distribution of AASHTO subgrade types for GPS-5 sections. AASHTO Classification
No. of Sections
A-l-a A-l-b A-2-4 A-2-6 A-2-7 A-3 A-4 A-5 A-6 A-7-5 A-7-6 Not Known
1 6 15 4 3 2 18 4 15 1 12 4
Percent Distribution 1.2 7.1 17.6 4.7 3.5 2.4 21.2 4.7 17.6 1.2 14.1 4.7
Shoulder Type Information on outside shoulder type is given in table 5. Forty percent of the GPS-5 sections have concrete shoulders and 60 percent of the sections have AC shoulders. The concrete shoulders are typically plain jointed concrete. However, there are a few jointed reinforced concrete shoulders. There are no CRC shoulders. Climatic Data Climatic data for GPS-5 sections include climatic region type, average annual freezing index, average annual precipitation, and average daily temperature range. The key climatic data for GPS-5 sections are given in table 5 and are presented in figures 8 through 10. The climatic data are based on values averaged over the years that each section has been in service. Traffic Data The cumulative 80-kN equivalent single-axle load (ESAL) was used to characterize traffic loading. The cumulative 80-kN ESALs to the date of the distress survey were evaluated by summing the estimated annual 80-kN ESALs over the years the sections were in service up to the time of the latest distress survey. In the cases where some ESAL values were missing for a few years, regression analysis was used to estimate the annual total ESALs for these years. 18
Figure 9. Annual precipitation summary. 19
18.00 16.00 () 0
a)
14.00
0
c::
~
~
12.00
i:5
~ ::l
+oJ
£!! Q) a. E ~ ~
'(6
0
10.00 8.00 6.00
Q) C)
£!!
~
4.00 2.00 0.00 ....
LO
0>
~
~
N
~
~
~ M ~ ~ ~ ~ ~ Section Reference Number
w
~
~
~
~
w
~
Figure 10. Average daily temperature range. Section 24-5807 had no traffic data and was therefore not considered in subsequent analyses. A summary of the ESAL data is given in figure 11. Profile Data International Roughness Index (IRI) is one of the indices used in the LTPP program for characterization of pavement section roughness. IRI values determined at different test times over the years are available in the database. Values at times that correspond to the latest distress survey dates were used for characterization of profile condition of pavement sections. A summary of IRI data is given in table 5 and figure 12. The IRI values for GPS-5 sections ranged from about 0.7 to 2.4 m/km, with a large number of sections exhibiting IRI values less than 1.8 m/km. Considering the service lives ofthe CRC sections in the GPS-5 experiment, the CRC pavements are exhibiting good ride characteristics. Crack Spacing Data The CRC pavement distress data under the LTPP program are available from two types of condition surveys: the manual distress survey and the photographic survey using the PADIAS system. For the purposes of the analysis presented in this report, the following guidelines were used:
20
70000.00.--
--,
60000.00 + - - - - - - + - 1 - - - - - - - - - - - - - - - - - - - - - 1
8' 50000.00 + - - - - - - + - 1 - - - - - - - - - - - - - - - - - - - - - - - 1 o .... L
~
40000.00 + - - - . - - - - + - 1 - - - - - - - - - - - - - - - - - - - - - - - 1
C/)
w
!!o! 30000.00 + - - - - + - - - + - 1 - - - - - - - - - - - - - - - - - - - - - 1
~ :;
§
U
20000.00 + - - - + - 1 - - - + - 1 - - - - - - - - - - - - - + - - - - - - - - - - - - \
10000.00 -l----II---II--I--tc--H----I---------I------I----=JI-
0.00 .....
LO
en
Section Reference Number
Figure 11. Cumulative ESAL summary. 2.50
2.00
E
~
1.50
E
Q; Q) C)
~ 1.00
l-
~
i-
0.50
0.00 LO
en
~
~
N
~
~
~
~
~
~
~
~
~
Section Reference Number
Figure 12. Average IRI summary. 21
w
~
m~
~
~
~
1.
If data from several survey dates were available, the information from the latest survey was used.
2.
If the manual and PADIAS surveys indicated a different number of cracks or local failures for the same section, the survey that recorded the maximum number of cracks was used.
Average transverse crack spacing was calculated by dividing the length of the section by the total number of cracks. The total number of localized failures was found as a summation of the total number of rigid and flexible patches and punchouts. Table 5 gives a summary of GPS-5 distress survey data. Generally, PADlAS surveys predicted larger crack spacings compared to the manual survey, as shown in figure 13. The crack spacing shown in figure 13 is based on the most recent surveys listed in table 5. Overall, the average crack spacing for the GPS-5 test sections was found to be about 1.2 m (4 ft) based on manual surveys. It appears that the photographic procedure fails to adequately identify all low-severity transverse cracking. Out of 85 sections, there were 2 sections without both manual survey data and PADIAS survey data (sections 17-5151 and 42-1617). These two sections were excluded from transverse cracking analysis. There were four other sections with unreasonably large crack spacing calculated from the PADIAS distress survey (sections 24-5807, 41-5005, 41-7081, and 51-5010). These four sections did not have manual surveys. These four sections were also excluded from the transverse cracking analysis. Both manual and automatic surveys indicate a very small percentage of high-severity transverse cracking and a moderate amount of medium-severity cracking in all the sections, as summarized in table 7. Table 7. Severity of transverse cracking. Percentage of Cracking Survey Type
Low-Severity Cracks
Medium-Severity Cracks
High-Severity Cracks
Manual
78.91
21.74
0.26
PADIAS
63.14
36.27
0.59
Note: Based on total amount of cracking. Punchout and Patching Data
The total number of punchouts and patches for each section is given in table 5. It is seen that localized failures have not been a serious problem to date at the GPS-5 sections. There were 16 sections exhibiting localized failure, as summarized below:
22
12.00
10.00
E d) c::::
.~
8.00
0-
W
.:Jt:.
u
6.00
l!!
(J Q)
~
4.00
~
I
2.00
0.00 ...
11~~n~~111 In~ ,. II~~ Iln~~ '" I~ ~~~ II)
en
...
('I")
~
N ~
re
~
~
~
~
~
f--
I~nnl ~
~
I~ ~
~
m~
Inn ~
~ ~ ~
~
Section Reference Number • PADIAS
0 M6.NUAL
Figure 13. Average crack spacing.
Total Number of Failures
Number of Sections
1 2 3 4 5 6
5 5 3 1
o 2
One section reportedly exhibited 23 punchouts/patches. This is considered an error in interpretation of the distress data. Twenty-three localized failures over a length of 152.4 m would equate to a rate of about 150 localized failures per kilometer. It is unlikely that any highway agency would permit such a high amount of localized failures to remain on a public highway. It should be noted that, as shown in table 5, none of the nine sections that have been overlaid and the one section that was taken out of the study exhibited no localized failures. Also, eight of the nine overlaid sections had IRI values less than 1.5 m/km. The section that was taken out of the study had an IRI value of2.35 m/km at the time of the last profile survey. It thus appears that the appropriate overall pavement projects are performing far worse than the overlaid test sections. It further appears that performance evaluation of CRC pavements should incorporate longer lengths of pavement to ensure that representative failure conditions in the pavement are reliably obtained. Thus, the visual condition survey should include a survey of 5- to 23
8-km lengths of the CRC pavement in addition to a detailed survey of the 152.4-m (500-ft) monitoring length of the test section. The longer visual condition survey should record at least the number and severity of punchouts, patches, and other localized failures. Summary
The small amount of localized failures observed at the GPS-5 test sections limits the type of analysis that can be carried out to evaluate the performance of CRC pavements. It appears that most ofthe CRC pavements are performing well, or rather, exceptionally well. This observation is also supported by the low lRI values determined for the GPS-5 test sections.
24
CHAPTER3. EVALUATION OF CRACK SPACING DATA Introduction
It is well established that transverse crack spacing in CRC pavements is influenced by the percent of longitudinal reinforcement, concrete strength, and slab/base interface friction. Recent efforts have also shown that the transverse crack spacing pattern is influenced significantly by the ambient weather conditions at the time of concrete placement and a few days thereafter. As such, the long-term crack spacing pattern is influenced by the conditions during the first few days after concrete placement. The LTPP database contains no data on ambient weather conditions during time of concrete placement. In addition, data on specific dates of construction of the test section portion of the roadways are not available. Thus, analysis of the crack spacing patterns for the GPS-5 sections have to rely on other attributes that relate to the properties of the CRC pavement and general climatic data. Another data type that is currently not available is the data on individual crack spacing. Without this data, analysis of the characteristics of the crack spacing pattern is not possible. Previous studies have shown that frequency distribution curves for crack spacing and plots of "average spacing ofthec1osest five cracks" (ASCFC) can be useful in understanding the behavior of CRC pavements and in determining potential areas of future localized failures. The ASCFC plots can identify poor crack spacing patterns within a section of CRC pavements. Cluster cracking areas and areas with large' crack spacings can be easily identified. Wide crack spacing can result in premature crack spalling and "companion" punchouts at the location of wide cracks. Typical frequency distribution curves and the plots of ASCFC are shown in figures 14 and 15. It is believed that in the future, the interpretation of distress data will also include data on individual crack spacing along the 152.4-m length of each GPS-5 test section. Future analysis of theCRC pavements will also benefit if actual distress survey maps are made available to the analysts. Then it would be possible to relate the locations of the failures to crack spacing characteristics at these locations. Another data type that is missing from the LTPP database is the crack width data. No attempt has been made to date to measure crack width at the GPS-5 test sections. Crack width data are needed to study the correctness of applying various crack width criteria as part of the design of CRC pavements. Bi-Variate Plots
The following independent variables were selected to analyze their effect on crack spacing: • • • • •
• • • •
Age at the time of distress survey. Cumulative ESALs. Slab thickness. Elastic modulus of the concrete. Design percent steel.
25
Depth to the reinforcement. Freeze index. Annual precipitation. Daily temperature range.
o ---- ._.-' .-., I' " , '
100
.., .,.,.."""" ..,_...... "...-.--
...",.,..-",. ...... ",,:" ;,,"
/
CD
> +:l
..
""....
ro 0~
,. " .
""...- ....
';"
/
/.
00
ca
//
''
":
"
,'~"
/
'
I'
I'
/
.. ""
/
.",- ..
.... "
.. ' -
.. ....
,-
""
..
".
.. - . -- ......... ..--_ .. --- .. --
• ""
-" -IL-1
",,-
-'-'IL-2 ..... ·IL-3
" ,' ""// /
.' ""..
l ,.,/
"S E 40 :::J
I
()
:'/'.;" ., .
--IL-4 r-- - - IL-5
I
.'. I • / ' ." I' I • I.' I .//
iF/ '"
/
~.
'I / l
o
~
J
20
I~'
/
I'
•
/. ~ flo""
o
1
r--
1ft=O.:n;
..
2
3
4
6
5
7
8
9
10
11
12
20
15
Figure 14. Typical crack spacing distribution plot for a CRC pavemenf.
Crack Spacing for IL-2 12 , - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ,
11 10 9
Acceptable Range
8 7
6-+---++:-----:--r------"""*"~-->OO'd____r__t:_-_tV_'lrt_"_Tf_+_----__t
5 4HLHKH-H-tor+--\f-T-ft~fPr;:r_71r_+-+_t_-_+__f-..l.M_ll----_t_-
---t
3-+At-~-----l~lHt---'I-'_+_--''_t_1I_'t1I---~t__JfI_-.L.-----;?4_----__t
Average
2
1
1 ft =0.305 m
o +-----f--------+-----+-----+------+-----j
o
200
400
600
800
1000
Location Within Site, ft
Figure 15. Typical plot of ASCFC for a CRC pavemenf.
26
1200
The bi-variate plots of transverse crack spacing with respect to the above-listed independent variables are presented as follows: Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 -
Crack spacing versus age. Crack spacing versus cumulative ESALs. Crack spacing versus slab thickness. Crack spacing versus concrete modulus of elasticity. Crack spacing versus percent longitudinal steel. Crack spacing versus percent longitudinal steel (age < 10 years). Crack spacing versus percent longitudinal steel (age> 10 years). Crack spacing versus depth to longitudinal reinforcement. Crack spacing versus annual air freezing index. Crack spacing versus annual precipitation. Crack spacing versus average daily temperature range. Crack spacing versus longitudinal bar spacing.
3.00
2.50
E
•
1i C/)
~
0
e u
1.50
••
•
.--.
• • • •* • • •
Q) C)
e ~
••
....
c'i 2.00 c: '0
1.00
0.50
·
•*
••
•
• ~ • •• • •• • • • • •• •• •••• •• •• • • • • •• •• • •• • : • • ....
•
*•
.
• •
0.00
o
4
8
12
16
20
Age, years
Figure 16. Crack spacing versus age.
27
24
28
32
3.00
2.50 E
ci 2.00
c: '0
•• •
1lI 0-
en
13
e
1.50
(,)
~
• •
1.00
0.50
'If
••
.. •••••
• . 1 :•....... .. -. ~.
CI)
Cl
e
...
•
•
~
•
• • .+: •• *..# • •
0.00 0.00
10000.00
20000.00
30000.00
40000.00
50000.00
60000.00
70000.00
80000.00
Cum ulative ESAL (*1000)
Figure 17. Crack spacing versus cumulative ESALs. 3.00
2.50
E
••*
ci 2.00 c:
'0
1lI 0-
en
13
•
1.50
l!!
•
(,)
CI)
Cl
e
~
1.00
•
0.50
0.00 100.00
•
150.00
•
•
•
*
•
~
I ~ •• I a • --.
••••
•
• •
250.00
200.00
Slab Thickness, mm
Figure 18. Crack spacing versus slab thickness.
28
300.00
350.00
3.00
2.50
E 2.00 Ci t::
••
'0
Cll Co
en ~
•
1.50
l!!
--.-
• •
•
•
• • • •• • •• •• • •• • • • •• • ••• •• • •• • • •• • •• • • • • •
..........
U
CD Cl
l!! 1.00
~
.
•
0.50
0.00 15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
Figure 19. Crack spacing versus concrete modulus of elasticity, Es1ab ' 3.00
2.50
E Ci 2.00 c
:
'lj Cll Co
en
is
•
1.50
••
l!!
U
CD Cl
l!! 1.00
~
0.50
0.00 0.45
I •
•
0.50
: i• • ..... • .... , • • • • ,I• • • ;1. • • •• • •• t •• • • 0.55
0.60
0.65
0.70
0.75
•
0.80
0.85
0.90
% Steel
Figure 20. Crack spacing versus percent longitudinal steel.
29
0.95
1.00
3.00
2.50
E.2.00
....
Cl
c
•
:
'u ClI
Q.
•
(J)
is I.! o
1.50
•
Q)
Cl
i 1.00
C(
•
•
• • ••
••
•
•
0.50
0.00 0.45
0.75 % Steel
0.65
0.55
0.85
0.95
Figure 21. Crack spacing versus percent longitudinal steel (age < 10 years). 3.0q
2.50
E c)
c '0
•
2.00
•
ClI
c-
oo ~
0
1.50
I.!
u
I
Q) C)
I.!
~
1.00
• •
0.50
0.00 0.45
0.50
....
• • 0.55
•
i
•
.'.
•
....
·'1
•• •
•• a ••
•
0.60
0.65
•
• • • 0.70
0.75
% Steel
Figure 22. Crack spacing versus percent longitudinal steel (age> 10 years).
30
0.80
3.00
2.50 E
.~ U
2.00
••
«l
Q.
Cf) ~
u
1.50
t
1.00
b Ql
>
••
•
.
0.00 0.00
, ..
200.00
400.00
•
• ••
•
•
600.00
800.00
1000.00
Freezing .,dex. °Cdays
Figure 24. Crack spacing versus annual air freezing index.
31
1200.00
1400.00
3.00
2.50
E
......
2.00
oj
c
'u III Q. en
•
~
1.50
0
III
0
Q)
Cl III
...
1.00
Q)
>
«
0.50
0.00 0.00
• • 200.00
•
... .•, ••
•
400.00
600.00
.... • •• • • • • •.. .......... •I • • • •• •••# • .~ •• t ... • .... •• • • • •• • • •
. .. - ..
800.00
1000.00
1200.00
1400.00
1600.00
Annual A"ecipitation, mn
Figure 25. Crack spacing versus annual precipitation. 3.00
2.50
~
E oj
.0~
....
....
2.00
• • ••• • •• • • ......... • • •• •• +;..••:: • • ...• •••• • t. • • .t • •
III
Q.
...... , .
en ~
0
1.50
III
0
Q)
Cl III
... Q)
i
....
1.00
>
«
~
0.50
0.00 5.00
7.00
9.00
11.00
13.00
• • • • ~: • 15.00
17.00
Daily Terrperature Range, OC
Figure 26. Crack spacing versus average daily temperature range.
32
19.00
1800.00
3.00
2.50
~
E ci 2.00
• • • ••• •
III
a.
(J)
.:JI:. 0
1.50
u
Q) C)
1.00
•
~
••
•
• 75.00
100.00
125.00
• • ••• • • ••
••
0.50
0.00 50.00
: •
•
,*. *, ; ·1
e!
...III
*
•
c:
'0
150.00
••
175.00
200.00
• •
• • • •
225.00
250.00
Longitudinal Bar Spacing, mm
Figure 27. Crack spacing versus longitudinal bar spacing. It is seen from a review of figures 16 through 27 that no clear trends are evident on the basis ofbi-variate analysis of the data. The long-term crack spacing pattern, as represented by average crack spacing, is dependent on the interactions of possibly all of the independent variables considered together with the ambient conditions during the first few days of construction. As such, an understanding of the effect of the variables noted would have to consider the interactions and the confounding effects of each of the variables. One method to account for these effects is to use multiple regression analysis. A limited effort was made to determine if robust explanatory models could be developed for crack spacing using linear regression analysis. However, the results were not promising (low coefficient of correlations) and no further effort was devoted to this activity. Use of empirical analysis was not part of the scope of the study and the results are therefore not reported here.
Effect of Cracking on Ride
The effect of transverse cracking on ride is shown in figure 28. No clear trends are apparent. This is possibly due to not considering the influence of initial roughness. It should be noted that previous studies have indicated that initially smooth (as-constructed) CRC pavements generally remain smooth, and rough (as-constructed) CRC pavements tend to become rougher with time.
33
3.00
2.50
~
.
2.00
•
•
•
• • • .... .... • • • • •• •••• • • •• # l • •• • ~ • • • •• • • •• • •
E
o!!!:
E 1.50
~ 1.00
••
•
0.50
0.00 0.00
....
0.50
....
•
•
... ... .. ... .. • •
•
1.00
1.50
2.00
2.50
3.00
Average Crack Spacing, m
Figure 28. Effect of crack spacing on JR!.
Effect of Crack Spacing on Deflections To determine the relationship between crack spacing and deflections as measured by the falling-weight deflectometer (FWD), average crack spacing was plotted versus load transfer efficiency and the ratio of the edge deflection and the corresponding interior deflection for sections having FWD data in the database, as shown in figures 29 and 30, respectively. No clear trends in the data can be observed. It is seen that most of the sections exhibited load transfer efficiency at cracks of 90 percent or more. The ratios of the edge deflection and the corresponding interior deflection ranged from 1 to about 2. The variability within the range is possibly due to the time of testing (curling effects), slab warping effects, and the type of shoulder.
Summary CRC pavement behavior is characterized by crack spacing (average crack spacing and other crack spacing-related statistics) and CRC pavement performance is characterized by the number oflocalized failures (patches and punchouts), ride quality, and structural capacity (as determined by FWD testing). For the GPS-5 experiment, it appears that cracking data must be obtained by manual surveys and actual crack mapping must be done to allow appropriate crack spacing statistics to be determined. Also, the GPS-5 monitoring plan must include a visual survey of 5- to 8-km lengths of the project to allow reliable determination of the number of localized failures per kilometer. Crack width data are also important and should be collected over a representative subsection of the monitored length. 34
~III
o
~
:
iii
~
ij' 0.95 I::
.\,1
iIi...
-
0.9
Q)
v
V
~
VI I::
¢¢
6
III
~
.3
.!I!
16
~.
0.85
Q)
Cl III
...
Q)
«>
0.8 0.0
2.0
1.5
1.0
0.5
2.5
3.0
Crack Spacing, m
Figure 29. Average load transfer efficiency at cracks versus crack spacing. 5
v ~
~ (l¢
~
~ ¢O A~
(/) 0.2
~
~
+--~
0.1 +---
~
9l O.O-J---
«
Well Performing Sections
Poorly Performing Sections
All Sections
Figure 31. Comparison of design percent longitudinal steel.
E E ~
c: Q)
E Q)
120.0 100.0
~
80.0
'w
60.0
.... .l:: ....a.
40.0
.Q c:
c::: 0
Q)
Cl Q)
20.0
C>
~
9l
«
0.0 Well Performing Sections
Poorly Performing Sections
All Sections
Figure 32. Comparison of depth to reinforcement.
41
~ 250.0 - . - - - - - - - - - - - - - - - - - - - - - - - - - , di
.~ ro 200.0
+---
0.
00
ffi 150.0
aJ
roc: '5
::l
+--
100. 0 +--------j
~
C)
c:
.:l
50.0
+-----j
0.0
+-~
Q) C)
~
~
«
Well Performing Sections
Poorly Performing Sections
All Sections
Figure 33. Comparison of longitudinal bar spacing.
r-------------
-~-------------- - - - - - - - - - ,
------~---------
I
~
I
.[
1200.0 - , - - - - - - - - - - - - - - - - - - - - - - - ,
g> 1000.0
Cf)
_
800.0 600.0 400.0 200.0 0.0 Well Performing Sections
Poorly Performing Sections
All Sections
_________________________~
_._J
Figure 34. Comparison of transverse bar spacing.
42
250.0
E E
ui 200.0 -
m c
..:.:: 0
~
150.0 -
.0
m
Ci5 100.0 c
m Q) ~ Q)
50.0 -
C>
~
~
0.0 -
Well Performing Sections
Poorly Performing Sections
All Sections
Figure 35. Comparison of slab thickness.
-----~-_._--_..
_------
.-
--_.-._--_ .. _------- .. _--
-----~~~~~~~~~~~---,
35 - r - - - - - - - - - - - - - - - - - - - - - - - - - , m a.. 30 C.9 "t:J Q)
-1-~~~~~---------_
25 -
.._.. _ - - - - - - - - - - - - - - - - - - - - I
-----------_.._--- ...- ----------~~~~~~-----I
+-'
Ul
~ 20 Ul m 15 J:J u; '"
L1J
10 -
Q)
Cl
~
~
«
5 0 Well Performing Sections
Poorly Performing Sections
All Sections
Figure 36. Comparison of concrete modulus of elasticity, E s1ab , as tested.
43
140 E E 120 iii III
100
c: ..lo:: u
80
Q)
~
Q)
III
ro co
Q)
60 40
Cl
~
~
20
«
0 Well Performing Sections
Poorly Performing Sections
All Sections
Figure 37. Comparison of base thickness.
ro 0.
7 ,--
C.9 -0 Q)
6
iii
:; u
---,
.
5
rou ..lo::
u
ro co III ro ~
I'll
2--
.c
W Q)
Cl
~ ~
«
0
-1----
Well Performing Sections
Poorly Performing Sections
All Sections
Figure 38. Comparison of base modulus of elasticity, Ebase , as backcalculated.
44
90.0 - r - - - - - - - - - - - - - - - - - - - - - - - , 80.0 +-~~~~~~~~~~~~ __~~~~~~_I 70.0 + - -
60.04---50.0 -
40.04---30. 0
-f-----~
20.0 + - 10.0 -
0.0 Well Performing Sections
Poorly Performing Sections
All Sections
Figure 39. Comparison of subgrade k-value as backcalculated.
en
~
250 , - - - - - - - - - - -
-,
'i'
u
o
~ '0
.£ Ql
200 --\--150 --\---
~ ~
LL
ro:::J c: c:
