James L. Brown, Larry J. Buttler and William P. Ezzell

Transcription

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2 ~.,_~w._'''... SURVEY OF STRUCTURAL FAILURES IN A CONTINUOUSLY REINFORCED CONCRETE PAVEMENT By James L. Brown, Larry J. Buttler and William P. Ezzell Special Study No.. Highway Design Division, Research Section TEXAS HIGHWAY DEPARTMENT October 969

3 PREFACE This report documents a survey made by Texas Highway Department personnel to locate and measure distressed areas in a Continuously Reinforced Concrete Pavement in Walker County, Texas. It is intended-that the application of procedures discussed herein will enable other THD field personnel to obtain similar data with a degree of statewide uniformity in operations and data presentation. A summary of the measurements obtained is indicated in the following table entitled "Summary of Percent Distress per Wheel Path Walker County", and is discussed further in the report.

4 Summary of Percent Distress per Wheel Path-Walker County (Rounded Values) Southbound Lane Northbound Lane *Wheel Path *Wheel Path Total Length of Failure, Feet 3,494',850' 432' 390' 2,278'.,78 ' 42' 344' Percent Failure *Wheel paths are numbered consecutively, increasing from the outer separation to the median

5 TO DALLAS END PROJECT Sta GENERAL SITE LOCATION Farm to Market Rd. Farm to Market Rd. BEG. PROJECT Sta TO HOUSTON-----I... L.OCATION AND LAYOUT OF WALKER COUNTY PROJECT

6 ct. Highway I 6'-a" 6-0" V4 in/ft, 24'-0" a" Continuously Reinforced Concrete Pavement WP#4 I WP#3 I WP#2,4, ': ':;' 4', ':': 4 '? f :-,' '::,::.0' " :.. ' 4 ',.,: : -: : ":', :, 0'- a" I" Asphaltic Concrete ~ i%t. Lime Stabilized Base 6" Lime Stabilized Soil 6" Flexible Base TYPICAL HALF SECTION FOR WALKER COUNTY PROJECT

7 TABLE OF CONTENTS Page No. Introduction. Definition of Failure and Data Collection Technique Discussion of Data Summary Tables and Figures Table Table 2 Summary of Percent Distress per Wheel Path-Walker County. Design Sections with Significantly Different Percentages of Distress in Wheel Path No. 2 3 Figure Profile Plot of Percent Failures Discussions and Conclusions References Appendices Appendix A Appendix B Sample Field Data Sheet and Definition of Coding Sample Photographs of Distressed Areas 8 Appendix C Location of Distressed Areas.. 9 Appendix D Tabulation of Percent Failures 39

8 SURVEY OF STRUCTURAL FAILURES IN A CONTINUOUSLY REINFORCED CONCRETE PAVEMENT Introduction A design procedure for determining the thickness of asphaltic concrete overlay to place on a deteriorating continuously reinforced concrete pavement has been developed (Ref. ). It became appar'ent during its development that the amount of structural failure or distressed areas now present in the CRCP would be required as a quantitative parameter to help define the pavement structure. Additionally, this measure of failure was to give the designer a "feel ll for the confidence level that should be used in the design procedure. Proper referencing of the failures observed was necessary so that future observations of the same failures could be made after the placement of an overlay. Definition of Areas of Distress and Data Collection Technique For this survey, areas of distress in the concrete pavement were defined by the following criteria (See Appendix B for example photographs).. Portland Cement Concrete Repairs (Patches) 2. Asphaltic Concrete Repairs (Patches) 3. Longitudinal cracks 4. Transverse cracks with spalling wider than ~" A previous field party measuring deflections with a Dynaflect instrument marked station numbers along the pavement edge every /0 of a mile (approximately) on both the southbound and northbound roadway. These Dynafect station numbers can be referenced to the center line station of the main lanes prior to the placement of an overlay as provided in Appendix C. A "Rolatype" measuring wheel four feet in circumference and calibrated to the nearest one-tenth of a foot was used to measure each failure occuring in the CRCP. The wheel was rolled along the outside shoulder parallel to the main lanes. The distance to the beginning and the ending of each distressed or failed area from the previous Dynafect station number was recorded; this distance was recorded on the prepared data sheet. (See Appendix A for explanation of the data sheet). The wheel path of each failure was also recorded as was the type of failure, i.e., concrete patch, asphalt patch, construction joint, etc. The original field data is in the files of the Research Section, Highway Design Division and is available upon request Discussion of Data Summary Tables and Figures Table depicts percent failure per wheel path for both the northbound and southbound roadway found by taking the total length of failure measured and dividing by the length of the roadway. The failure length for each isolated, spalled, transverse crack (See 4. above) was considered to be two feet.

9 Table. Summary of Percent Distress per Wheel Path-Walker County (Rounded Values) Southbound Lane Northbound Lane *Whee Path *Whee Path Total Length of Failure, Feet 3,494',850' 432' 390' 2,278',78' 42' 344' Percent Failure To satisfactorily accomplish the design of an overlay, the worst condition or the wheel path with the highest percentage of failure was taken as the governing criteria. This data was plotted by Dynafect station number as shown in Figure and this plot was used to divide the roadway into test sections of equal performance considering the failures as an indicator of performance. (See Appendix D for tabulation of data). Using the statistical analysis of variance tests (Ref. 2) the sections were compared and combined until the adjacent sections were sufficiently different at the 95% confidence level. The results of this study are presented in Table 2, in terms of the station limits, average failures for the outside wheel path of the outside lane, and the standard deviation of the failures for each section. *Whee paths are numbered consecutively, increasing from the outer separation to the median 2

10 Design Sections with Significantly Different Percentages Distress in Wheel Path No. (95% Confidence Level) Lane Limits (Dynaflect s) Average of Failure Linear Ft!Ft Wheel Path No. Standard Deviation North Bound South Bound Overlay 7.82 Overlay-l End.20 0-Overay 3.60 Overay-4l End Table 2 3

11 ~ , ,----- w 5 a: ::::>.J LL.I <i 0 A I o ~ OVERLAY 5.p- o I v v v tv". I "\ I o DYNAFLECT STATIONS (SBL) Iii ~ 38.0, 23.7 w Q: :::::> 5 ~.J 0 I I /\ ~ I I I:, /I OVERLAY ~ o 5 o DYNAFLECT STATIONS (NBU FIGURE I. PROFILE OF PERCENT FAILURES 55

12 :: ::::>...J 5 ~ I.L 0 ~ 0 5 VI ~OO 0 DYNAFLECT STATIONS (S8U :: ::J...J 0 'ff:. ~ , DYNAFLECT STATIONS (NBU FIGURE I CONTINUED

13 Discussion and Conclusions The percent failures per wheel path obtained from this survey quantified the results of a visual inspection of this section of IH 45. They indicate that the outside wheel paths of both the Southbound and Northbound Roadways which are traveled by the highest number of vehicles, including heavy trucks, are failing more rapidly than the adjacent wheel paths. With the percentages shown in Table, it is now possible to check the predicted failures obtained from the overlay design procedure. In future surveys of this type, if possible, one individual should estimate the failure areas throughout the entire survey. If more than one individual is used to survey a project then great care should be taken to insure that the different individuals are surveying with the same criteria for failure. For the location of failures the calibrated wheel was a convenient method used in this survey. The survey team consisted of a wheel operator, a data recorder, and vehicle operator who provided protection from traffic. With careful planning, the wheel operator could record data by use of a tape recorder. It is probable that more convenient methods of failure quantification could be devised for future projects. For future projects it is recommended that center line stations be established prior to the location of pavement failures. This will allow direct referencing of failures to center line stations and eliminate the conversion of stationing as shown in Appendix C 6

14 References. B. F. McCullough, A Pavement Overlay Design System Considering Wheel Loads. Temperature Changes. and Performance, University of California, Berkeley, July Alder, Henry L. and Roessler, Edward B., Introduction to Probability and Statistics, W. H. Freeman and Company, Third Edition, 964. Chapter 7,.Pp. 253 to 254 7

15 APPENDIX A Sample Field Data Sheet and Definition of Coding 8

16 direction I Asphalt Patch 2 Repair date PAVEMENT.DETERIORATION STUDY 3 Cracked highway 4 Construction Joint control,., Dynoflect Distance to Wheel Paths T Comments Stat. No. Deterioration Out- In- y side side Begin End Lane Lane P I E al9dll 2dl ld242d2d272829:J I35b6b7:i3I~d4l ~474.J -J~.J ,.

17 Definition of Coding Shown on Field Data Sheet Code Code 2 Code 3 Code represents an asphalt patch covering most of a failed area. (Photograph 0, Appendix B). Code 2 represents a previously failed area repaired with a concrete patch in good condition at present. (Photographs 3,,7, Appendix B). Code 3 represents a failed or distressed area. Examples and Photograph references for Appendix B are listed below. (a) (b) (c) Asphalt patch where concrete around this patch has failed. Photographs 5,8,0,9. Concrete patch where concrete around it has failed. Photograph 9. Concrete patch where patch itself has failed. Photograph 6. (d) Any longitudinal concrete crack. Photographs 6,4,5,9. (e) Spalled transverse crack greater than H;'. Photographs 6,3,8,9. Code 4 Code 4 represents a construction joint. Photographs 0,20. 0

18 APPENDIX B Sample Photographs of Distressed Areas

19 Photograph 4Fl A distressed area prepared for a concrete patch. Wheel Path {fl. Photograph 4n (Same comment as Photograph 4) Photograph 43 Concrete Patch in place approximately two days. Wheel Path 4. 2

20 Photograph #4 (Same eomment as Photograph #) Photograph 45 Asphalt Patch Wheel Path # Photograph 46 Median size longitudinal crack. Wheel Path #. 3

21 Photograph f7 Mixture of Concrete and Asphalt Patches. Wheel Path f. Photograph IF8 Failure where Concrete is breaking out under traffic adjacent to small asphalt patch. Wheel path Ifl. Photograph f9 Old Concrete Patch Wheel Path. 4

22 Photograph f0 Construction Joint with Asphalt Patch. Failure in Wheel Path # & 2. Photograph fill "New" and "Old" Concrete. Patches. Most Failures in Wheel Path #. Photograph f2 Typical Transverse Cracks with minor spaing not called failure in this survey. 5

23 Photograph ih3 Typical Spaing Wheel Path & 2. Photograph /fl4 Typical Longitudinal Failure with spaing. Wheel Path /fl. Photograph ihs Transverse and Longitudinal failures. 6

24 Photograph Ifl6a Concrete patch failures Wheel Path land 2. Photograph 6b View showing general area of 6a. Photograph 47 Largest Concrete patch old, but in good shape. 7

25 Photograph 48 Spalling failures Wheel Path # 3 & 4. Photograph 49 Failures - Wheel Paths & 2 Rocker failure Wheel Path #2. Photograph ino Good Construction Joint 8

26 APPENDIX C Location of Distressed Areas (Indicates wheel path and the failure length in feet is referenced to the preceeding Dynafect s) 9._._.I ~----

27 ; Dynaflect Sta. Center Line Location of Failure South Bound Lane Date: 4/28/69 Begin End Begin End Wheel Failure Failure Centerline Centerline Path atation * Represents a concrete patch. 20

28 Dynafleet ISb Center Line St.at.ion Location of Failure South Bound Lane Begin End Begin Failure Failure Centerline Date: 4/28/69 End Wheel Centerline Path 2

29 Dynaflect Sta Center Line Stat,; on Location of Failure South Bound Lane Begin End Begin Failure Failure Centerline Date: 4/29/69 End Wheel Centerline Path 22

30 Location of Failure Dynafect Center Line South Bound Lane Begin End Begin Failure Failure Centerline S tio Date: 4/29/69 End Wheel Centerline Path S 2 -~ J.',...,2,2,2.., L... _._.. 2.,2....,2 ~2,3,4 23

31 Dynaflect Sta. Oenter Line St.~Hnn Location of Failure South Bound Lane Begin End Begin Failure Failure Oenterline Date: 4/29/69 End Wheel Oenterline Path 24

32 Location of Failure Dynaflect St.::I Center Line St.at.ian South Bound Lane Begin End Begin Failure Failure Centerline Date: 4/29/69 End Wheel Centerline Path JQI.O '<)

33 Dynaflect St,A Center Line Stat.; on +-_._-.- Location of Failure South Bound Lane Begin End Begin Failure Failure Centerline... Date: 4/29/69 End Wheel Centerline Path.',. 3._ '.;L_.._..._...,2,3,4'=. --.._"' * :.'-..,2,2;3, , ~._,2._... ],,2,3 * * * * l~f- ~f- * ~f- 2?<" " *,2,3.,4 2 26

34 Location of Failure Dynaflect St.:! Center Line St.At.; ('In South Bound Lane Begin End Begin Failure Failure Centerline Date: 4/29/69 End Wheel Centerline Path 72_ 74 ''''.."... * *,2 *,_,~ " *2*,2,2,J,4 L L...,2...,.,2,...,_,2,2 *,2*,2,),4,2,2,2,2,2,2'),.4_ *,2,,2,2,2,2,2,2,2,2,2,Z,2' *,2:*,. 27,_. ~c~"

35 .. Center Line Dynafleet Sta. Location of Failure South Bound Lane Date: 4/29/69 Begin End Begin End Wheel Failure Failure Centerline Centerline Path 28

36 Dynafleet! Sta. Center Line Location of Failure South Bound Lane Begin End Begin Failure Failure Centerline Date: 4/29/69 End Centerline Wheel Path -- * f " --- * * * * 3,4 J.* ~ * ljlj.l,2,2,2,2,

37 Dynaflect ISt.~ Center Line St.a.t,; on Location of Failure South Bound Lane Begin End Begin Failure Failure Centerline Date: 4/29/69 End Wheel Centerline Path St,at"ion _ ~--'-'--'«"" 06 30

38 Dynaflect St.::I Center Line S+.J:l.tion Location of Failure South Bound Lane Begin End Begin Failure Failure Centerline Date: 4/29/69 End Wheel Centerline Path 2... _,--- J) End 3

39 Dynafleet St,,q Center Line St,at,; on Co. Lir e=o+qq 7 0. :rl ; Location of Failure North Bound Lane Begin End Begin Failure Failure Centerline ~Q ~"5i7.() ~ () _.. '.. Date: 4/29/69 End Wheel Centerline Path ,3,2 3,4,2 ---""!-,2,3,4 --,2,2 3,4,2,2,2,2,2 ~2,2.",J.". ;2,2 4 J,.,2,2,3 3,2,2,3,4 3, ,2,3,4 3,4,2,3,4 2 -:;-2~3-;Ii Ii- 2- ~;r,,_. 32

40 Location of Failure North Bound Lane Date: 4/29 & 30./69? Dyna- Center- Begin End Begin End Wheel flect Line Failure Failure Centerline Centerline Path Sta. Stat; on -- fts ,JL ~. -.~----~-~'~,",-~,. =~J~ ---.~ I f--_._ B "._ '-' r...'.,.2.,)., ~---~~ '......,..,... go. f ' ".~.--~ ~--.".. 2 ~ I _... _.0...l... -.=~:--':" ~- I , ~J l." , _ _~3_.. r- ' _-" -.., , , ,2 2J± ,,_...,'--".,," ~9 lll.j± \-----_ ~-.---~ "~'----' I--C : , _29_ f , _3.:....: t3.6 I--~ , ,2-l! _ ,2* ' :..,2,3, ,2'.. _~J9_ ,2,3, :,2 I " f ,2,3, , ,o._. I--.~_JQI~O~.,2 U2~,.. -,~.--.~--.--~ , 33

41 Dynaflect Center- Location of Failure North Bound Lane I tl Begin End Failure Failure Begin Centerline Date: 4/30/69 End Wheel Centerline Path 54,4,2,2 b2~. 2..,.2,2,3,4,2,3 3 ~,2,J ".. 2,2... ~...,2.,3,4,2,3 ----" , ".",,2 3,4. 3,4. 3,4 34

42 Dynaflect S Center Line S Location of Failure North Bound Lane Begin End Begin Failure Failure Centerline Date: 4/30/69 End Wheel Centerline Path Stat" on g5.g_ 32' _. 484.~L ~ '242.4' !~ ' Q_ 3,4 ::l".2. k~... }.,-_... L.hL_-,2,3,4. 3.,2,.3,2,2* 3,4,2,3,4 3,4,2,3,4 l,l.,2.,3,.....,2 J,,,2*,2..,2.,,3.,,4,2 L,2. 3~,.4_.. _,2".3,4,2,3,k.,2.,2.,2,,2,.3,._.,2..,2*,2 2*...,.2,.. :,2. l..t..,2,2.. 2 J..._ ,4. * 35

43 Dynafleet Sta. Center Line Location of Failure North Bound Lane Date: 4/30/69 Begin End Begin End Wheel Failure Failure Centerline Centerline Path I 36

44 Dynafect St..<'l. Center Line St,ati rm Location of Failure North Bound Lane ','j- Begin f End Begin Failure " Failure Centerline,, Date: 4/30/69 End Wheel Centerline Path St.R.tion , '-= =2~56~.~ =2::..::::6;-LO.!...:.5~-l--~ I f-----",,=-30-=-:8:.c::.., I *!---'--r- 37=-=6~.-=;i_+----",;j.=-86:::.c.:2=~:~~-----=--~~~~~-,~-~---~_-~--_-~.;.--~:,'- '::2_'--_,- -_--' ---I ,2 r----"'-<'-'-"-l-..--i---~~' ,---_+t~= l~ 95.5'20~O ':'f-7~~i--~=-=-=-- +_----+_~-'--- H~ ' '4.5' !---,-~~=--+_~~~~ '.5 ~~ ~~ ~:::-::-::-~-I I I+-~j:~- 5' ~~~ ~~ ~~~~-+--=~= ~-_--_~3~~ ,,_42--_ , , ' ' , ).6 c----!7~--!---,----""-'~= +_ ~, '".--~-I----, '-, I--~~=----_l_-~;.:.=--l---- I H- --,--, '8.0 65'..2 ~ * t-- 88:6 ::::..:::..::..;:---+-~~= ' =,.=---2_ , J------=,~-=--- +_-=:;.=-t t i-~.-~2=------i * ,2, , , )02. 5],

45 Dynafleet Sta 03 0L 0) 06 Center Line ' Location of Failure North Bound Lane Begin End Begin Failure Failure Centerline l: "2--" ~ Q.. f-._ ~~}L e_--lqls... ~..,_... "- I :: ,... _ _..M..<3)2.!'~_. _... -,~0:.,L ~_._ f-._...-'so. 2_ _ ~8.".. ::.Q9_ r End Date: 4/30/69 End Wheel Centerline Path,2,2 l,~_,2,2,2,2,2,2~._---_ _....,2, 'i~2'~j~ _-:... ~_8 ~~.Q~ t I

46 APPENDIX D Tabulation of Percent Failures 39

47 TABULATION OF PERCENT FAILURES SBL NBL DYNAFLECT % DYNAFLECT % STATION FAILURE STATION FAILURE L l Overlay Overlay " " ti " ti ti " ti II " " " " ,

48 SBL TABULATION OF PERCENT FAILURES NBL DYNAFLECT % DYNAFLECT % STATION FAILURE STATION FAILURE

49 SBL TABULATION OF PERCENT FAILURES NBL DYNAFLECT % DYNAFLECT % STATION FAILURE STATION FAILURE