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ST9302-SY011127WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS SANDY LAKE ROAD PAVEMENT Nondestructive Testing for Mud Balls In Pavement Coppell, Texas Aldo Delahaza Douglas W. Deno, P.E. Project Engineer Senior Consultant and Project Manager ° ° ' ° S t OF w : DOUGLAS • W. + DEN O � 44871�� 1 STE t e. FgS••..• . . • G Final Report 27 November 2001 WJE No. 2000.3576.2 Prepared for: Alpha Testing, Inc. 2209 Wisconsin Street, Suite 200 Dallas Texas 75229 Prepared by: Wiss, Janney, Elstner Associates, Inc. 3050 Regent Boulevard, Suite 100 Irving, Texas 75063 -3107 972.550.7777 tel 1972.373.9403 fax ENGINEERS WJE ARCHITECTS MATERIALS SCIENTISTS TABLE OF CONTENTS In troduction............................................................... ............................... Backgroundand Scope .................................................................................................. ............................... 1 Investigation.................................................................... ............................... 1 ......................... Discussion .............................................. ............................... 3 .................................. ............................... Conclusions ................................................ ............................... Recommendations.... ..................................................................................................... ............................... 4 LIST OF FIGURES Figure 1. Westbound lanes of Sandy Lake Road exhibiting large surface voids ........ ..............................6 Figure 2. Surface voids in Sandy Lake Road pavement .... ............................... Figure 3. Large and smaller surface voids in pavement .............. ............................... ............................... Figure 4. Large surface voids in pavement ................................................................. ..............................7 Figure 5. Test Panel 1; west of Nash Street .................. ........................ 8 ................... ............................... Figure 6. Test Panels 2 and 3; east of Holly Street ..................................................... ..............................9 Figure 7. Test Panel 4; east of Lodge Road ............................................................... .............................10 Figure 8. Test Panel 5; west of Trailwood Lane ........................................................ .............................11 Figure 9. Test Panel 6; west of Dobecka Dri ve .......................................................... .............................12 Figure 10a. Schematic of Impact -Echo technique ......................................................... .............................13 Figure lob. Typical Impact -Echo frequency spectral plot ............................................. .............................13 Figure 11. Impact -Echo test in progress ........... ............................... Figure 12. Impact -Echo impactor / transducer ............................................................... .............................14 Figure 13. Ground - Penetrating Radar (GPR) in progress ............................................ .............................15 Figure 14. Data analyzer and LCD screen used with GPR technique .......................... .............................15 Figure 15. Grid marked on panels at 1 ft x 1 ft spacing ............................................... .............................16 Figure 16. Location of indication of internal flaw marked for subsequent core removal (Panel 4, Core16) ................................................... ............................... Figure 17. Panel 1; Panel located near STA 50 +55 ..................................................... .............................17 Figure 18. Panel 2; Panel next to the east side of Panel 3 ............................................ .............................18 Figure 19. Panel 3; Panel located approximately 51 ft. east of Holly Street ................ .............................19 Figure 20. Panel 4; Panel located between STA 43 +50 and 44+ 00 ............ ............................... .......20 Figure 21. Panel 5; Panel located just west of STA 34 +00 .......... ......... ......21 Figure 22. Panel 6; Panel located approximately 32 ft. west of STA 31 +00 ............. ............................... Figure23. Coring operation ......................................................................................... .............................23 Figure 24. Four cores removed from pavement .......... ............................... ......................23 ......................... Figure 25. Location of internal flaw indication (Panel 2, Core 15) ............................. .............................24 Figure 26. Core 15. Note mud ball at mid -depth of core ............................................. .............................24 Figure 27. Top portion of Core 10 in Panel 3 .............................................................. .............................25 Figure 28. Core hole at location of Core 10 in Panel 3 ......... ............................... ............25 ......................... Figure 29. Location of Core 16 in Panel 4 ................................................................... .............................26 Figure 30. Close -up view of Core 16 in Panel 4. Concrete at surface was only about 1/2 to 1 in. thick. There was only mud throughout remainder of pavement thickness . .............................26 Figure 31. Core hole at Panel 3, Core 1 location. Note that mud ball extends into pavement beyondthe core hole ................................................................................... .............................27 Figure 32. Core hole at Panel 2, Core 5, a random core. No mud ball present at this location .................27 Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page i WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS SANDY LAKE ROAD PAVEMENT Nondestructive Testing for Mud Balls in Pavement Coppell, Texas INTRODUCTION As requested, Wiss, Janney, Elstner Associates, Inc. has completed the authorized initial phase of nondestructive testing at selected locations of the westbound lanes of Sandy Lake Road, Coppell, Texas. The purpose of the initial phase of this proposed nondestructive testing program was to attempt to determine if mud balls, not visible at the surface of the pavement, exist deeper within the pavement, and if nondestructive testing (NDT) techniques are a viable method of detecting them. BACKGROUND AND SCOPE When extensive visible surface voids, Figures 1 through 4, were noted on the recently constructed westbound lanes of Sandy Lake Road between MacArthur Boulevard and Denton Tap Road, a limited coring program was conducted. The cores, taken at the locations of both large and small visible surface voids, verified that the voids were due to large mud balls within the pavement concrete. In fact, at some instances, the size of the mud ball was much larger than anticipated based on the size of the existing visible surface voids. Due to this, there was concern as to whether more large mud balls, not visible at the surface, were present in the pavement. The detection of internal discontinuities in concrete is possible with various NDT techniques. For structural members, the use of Ultrasonic Pulse Velocity is commonplace when the concrete member can be accessed from two sides. Pavements, where only one -sided access is possible, require a different procedure, the Impact -Echo (IE) technique. When relatively small discontinuities are present, their detection is more difficult and requires that the IE readings be made at a close spacing. In fact, it must be noted that neither this method, nor any other that we are aware of, will reliably detect very small subsurface mud balls. We proposed that this work be performed in a phased manner, the initial phase being a trial program to determine the reliability of the method and determine the required spacing of the impact readings. The results would be used to determine the feasibility of a reliable test program. The work was to be limited to a few selected panels in the westbound lanes, and was to be performed following construction of the eastbound lanes. INVESTIGATION The initial test program was performed during the week of August 13 -17, 2001, at six selected pavement panels (between control joints and two lanes wide) in the westbound lanes, Figures 5 through 9. The approximate locations, numbered sequentially from east to west, and the extent of visible surface voiding were: Panel 1 — Sixth panel west of Nash Street. "Good" panel with only a few small surface voids. Panel 2 — Fourth panel east of Holly Street. "Bad" panel with many visible surface voids, some of which are large. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 1 ENGINEERS WJE ARCHITECTS MATERIALS SCIENTISTS Panel 3 — Third panel east of Holly Street. "Bad" panel with many visible surface voids, some of which are large. Panel 4 — Sixth panel east of Lodge Road. "Moderate" panel with a few small surface voids and one large surface void. Panel 5 — Fourth panel west of Trailwood Lane. "Moderate" to "Poor" panel with several small to medium surface voids and one large surface void. Panel 6 — Seventh panel west of Dobecka Drive. "Good" panel with only a few small surface voids. The proposed investigation was based on utilization of the Impact -Echo NDT technique. The impact -echo testing is one nondestructive testing technique used to detect internal flaws within concrete. This testing technique is also used to provide an indication of the in -situ quality of concrete as well as to measure the thickness of concrete members. The impact -echo method involves introducing a mechanical energy, in the form of a short pulse, into the structure. A small diameter steel sphere (impactor) is used to generate the sound wave through the pavement. A transducer mounted on the surface of the concrete receives energy reflections from discontinuities, flaws or the bottom surface of the pavement. In essence, as the transmitted energy travels through the material, changes in acoustic impedance in the material are detected, and the energy is reflected back to the surface. A schematic of the NDT set -up is attached as Figure 10a, and a typical signal pattern as Figure 10b. Figures 11 and 12 show the equipment in use on Sandy Lake Road. A second technique, ground penetrating radar, Figures 13 and 14, was also attempted, but it was determined that the IE technique was more effective in this application. At each test panel, a 1 ft x 1 ft grid was marked on the pavement, Figure 15. However, due to time and weather constraints, different grids were used on the various panels, some at the 1 ft x 1 ft grid, some at a 2 ft x 2 ft alternating grid, etc. Also, in some locations, the entire panel was not tested. As the NDT work progressed, locations of indicated internal flaws were temporarily marked on the pavement, Figure 16. At some locations where an internal flaw was indicated, a closer grid was used to more precisely define the location and extent of the mud ball. Figures 17 through 22 are schematic plan representations for the six panels illustrating the grid system and noting locations where internal flaws were indicated. As shown in the legends on Figures 17 through 22, the letter "G" is noted at the grid locations where no internal flaw was indicated. An "F" was noted at the locations where an internal flaw was indicated, and a "Q" was noted at grid locations where the test signal indicated a possible flaw. Upon completion of the IE tests, full depth cores were removed, Figure 23 and 24, by a coring company retained by Alpha Testing, at several locations where the IE tests indicated an internal discontinuity and from locations where no internal discontinuity was indicated. The core locations are indicated on Figures 17 through 22 by the letter "C ". The purpose of these cores was to calibrate the NDT equipment and to verify the reliability of the test procedure. Additionally, WJE selected one random location in test panels 1, 2, 4, 5, and 6 and removed a core at those locations. The purpose of the random cores was to determine if mud balls could or would be located by random core removal. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 2 WJ E ALNG IN E RCHIT ARCHITECTS MATERIALS SCIENTISTS Figures 25 through 30 are views of various cores and core locations, illustrating some of the conditions found to exist. Figures 28 and 31, at a core hole, illustrate that the mud balls were more extensive than what is indicated by the cores; i.e., the mud balls extend into the pavement beyond the core holes. Figure 32 is the core hole where a random core was removed. DISCUSSION The Impact -Echo technique was successful in locating several mud balls that were not visible at the pavement surface. In particular, the IE technique was useful for locating mud balls deep within the pavement; i.e., three to four in. below the pavement surface. Eight cores were removed at locations where flaws were indicated, and large mud balls were found at each of the eight locations. At three "questionable" locations, no mud balls were noted on the core surface. Two of these (Cores 19 and 20 from Panel 5) were selected for vertical sectioning, and were cut into three vertical segments. One of these had a small (1/2 to 3/8 in.) mud ball approximately 1/2 in. below the surface. Thus, it is possible that questionable indications occur at small mud balls. A questionable indication might also occur if the core location was slightly offset from a larger mud ball in the pavement. Two adjacent questionable indications might occur if an internal flaw exists between the two grid locations. At the seven coring locations selected where there was no indication of a below- surface anomaly, no mud balls were noted on the core surfaces. Two of these were vertically sectioned, and no mud balls were detected in the sections. Core 2 from Panel 3 was taken where there was a small visible surface void, but surrounding tests indicated otherwise "good" concrete. Except for the surface void, the core surface did not reveal any additional mud balls. At the five randomly selected coring locations, no visible mud balls were noted on the core surfaces. Two of these were selected for vertical sectioning, and no mud balls were noted in the sections. Following is a table listing the panels, the number of test readings in each panel, and the number of internal flaws detected: Test Panel Condition, Based on Visible Surface Voids Number of Primary Test Locations Number of Internal Flaws Detected Number of Questionable Flaw Indications Frequency: Internal flaws per X Test Locations Panell "Good" 228 0 2 - Pane12 "Bad" 247 4 1 1:62 Pane13 "Bad" 469 7 12 1:70 Panel4 "Moderate" 125 1 2 1:125 Panel5 "Moderate" 63 0 5 - Panel6 "Good" 126 1 0 1 1 - Although the frequency varies, the number of mud balls detected is quite large, especially in the panels rated "bad" based on visible surface spalls /voids. The test results indicate that a significant number of mud balls, not visible at the surface, exist within the pavement. Had a closer spacing been used for the test readings, it is probable that more mud balls would have been detected. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 3 WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS Where detected, most of the mud balls were quite large. At one location (Core 16 in Panel 4), the mud ball started about 1/2 to 3/4 in. below the pavement surface and extended full depth for the entire diameter of the core, Figures 29 and 30. There was no visible evidence of the existence of that mud ball at the surface of the pavement. CONCLUSIONS From a technical point of view, the results of the NDT program were judged to be successful in that mud balls, not visible at the surface, could be detected. The tests, and confirmation cores, show that many mud balls exist within the pavement cross - section, some of which are very large. However, it is our opinion that the use of this technique on a closely spaced testing interval, and other nondestructive techniques, may not be cost - effective. Five cores at randomly selected locations did not reveal the presence of mud balls, thus indicating that the use of random coring locations is not a reliable method of detecting the presence of mud balls. RECOMMENDATIONS It is our opinion that performing Impact -Echo tests at the close interval necessary to detect all (or most) of the significant subsurface mud balls in this length of pavement would be cost - prohibitive. A second nondestructive technique, ground- penetrating radar, was also judged to not be an effective technique. Thus, an alternative approach to this problem is suggested. A full length visual survey could be performed and the results used to designate panels as "good ", "moderate ", or "bad ". On the moderate and bad panels, IE tests at a larger test grid spacing would be performed and the results used to develop a standard on which a panel repair /replacement criterion could be based. It is possible that significant mud balls near the surface could be detected by some form of infrared equipment during certain times of the day, or during certain weather conditions. This procedure may also be cost - prohibitive. It is also our opinion that significant near - surface mud balls will eventually result in surface failure of the pavement at those locations. A periodic visual survey would allow detection and documentation of such occurrences. The scope of our work did not include observations or testing of the eastbound lanes or various turning lanes. However, during initial main -line paving of the eastbound lanes a few months after completion of the westbound lanes, we were requested to visit the project. At that time, we observed mud ball contamination in the coarse aggregate stockpile at the concrete batch plant. Consequently, we suspect that mud balls may also exist in some portions of the eastbound pavement lanes. Thus, at the least, it would be prudent to conduct a detailed visual survey of the eastbound lanes to determine if any surface voids, possibly attributable to mud ball contamination, are present. GA2000PR0J\3576.2\FINAL RPT 27 Nov 01 Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 4 WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS FIGURES WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 6 r agure L. westbound lanes of Sandy Lake Road exhibiting large surface voids. N'igure 2. Surface voids in Sandy Lake Road pavement. WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS \ +� r A l r zi �t t� Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 7 Figure 3. Large and smaller surface voids in pavement. Figure 4. Large surface voids in pavement. WJE ENGINEERS ARCH ITECTS MATERIALS SCIENTISTS - - - - - - - - - - - - - - - 5147511 37LT - I --- ft/. IN :! RETT - RANDOM POINT \ SEE LAT. 41 \ . 1 1 RCP A 71+67.6/ SIX - V - j - '1TA ASH l L Z RADIUS PT.. (CRUNE ft)- - 7 -- se - V III 31. X" __R ADIUS W 1 ITT Z 4410�10SF BACK OF CURBqt STA. 31+ C STA. 5 - CONSTRUCT fYli 8 GWH - - - - - - - - -3 ,33' RCP 60, 361 RCP 4r !C 4 MATCH DUSTING CUTTER I Figure S. Test Panel 1; west of Nash Street. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 8 3 02-00 37*RT-J INLET STA. SEE LAT. 40 PROPOSED R.O.W. RADIUS PT. 25' R 10 SLOPE EASMT, STA. 51+27.30. OW RT. I P.C. STA. 51#80.32. SO.: P.T. STA. 51+52.50. 60.49' Rl. T/C ELEV.. 494.18 I T/C ELEV. . ." .43 C +32.30. 705 T STA 51 STA 51*5051!80.30. 70.5'RT (10' DUAL t 0. _ OPENIN WH 4IO' DUAL-OPENING 104 SEE LAT ERAL 42 SEE LATERAL 43 STA. 51+52.00, 8600 T. (7' a 7 : /EOM 9' TRANSITION CURB GUrrEA ELEV. - 494.84 STA. 31 MATCH DUSTING CUTTER I Figure S. Test Panel 1; west of Nash Street. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 8 ENGINEERS ARCHITECTS WJ E MATERIALS SCIENTISTS TC390:6. Ef 02w, U 935.5037U �� n PROPOSED BACK OF CURB . 'RAW U P wT'1 T l/ r ., +4 STA 48+07.7 SLR WS PT ]' R T y _ SA t +00.00 Y S. STA 4B +41.73 S — _ _ _ _ .. 1 _ •_1._._ CCCt 3r- WL RAOM PT.. 3' STA 48+30.72 27'RT PROPOSED BACK OF CURB W 5 LTA 47 +71.9 CONSTRUCT TYPE B SDOH i5' 33 RCP -5. Av - RADK)S PT.. 25' R STA. 48+45.37, 80.0' RT. P.C. STA. 48+2(157, 59.51' RT. PPCW-) 1 - - - - -- o i T/C ELEV. - 300.48 STA 48+20.32, 72.5RT (14' DUAL- OPENING DAET SEE LATERAL 39 Figure 6 Test Panels 2 and 3; east of Holly Street. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 9 E J ENGINEERS ARCHITECTS MATERIALS SCIENTISTS BACK OF DJO I V STA42*64.1015MT J S IR RM CA". - RANDw P,,N� STA. 1. G&zr Itt —C4 W,,. T35. ELEV. . 509.34 42+40.16 103.57' NT :!1RW- r �Sn GUTTER Figure 7. Test Panel 4; east of Lodge Road. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 10 WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS =- -- z- a• SE -- -- 5' SLOPE EASEMENT GRADE SWALE TO �— OPENING IN DROP INLET i PROPOSED R.O.W. — /- / - - -� / W. 7148' LT. — 4' DROP IN IE •/ Ev. - 004.87 CONCRETE APRpN ON SOUTH SIDE 014 ¢ 18TM60 OUTTFR - � J I I d ` , I I I L ,. R 1 I o � ' � 1 r- EXISTING R.O.W. — - -- PROPOSED BACK OF CUM'.. ' > MMaIR ^ 1 C I I— 1 drG (F wr (nrc.�cf 1 ss�... -- _- - --- ------- ------- - - -Q - -- -- 36.00 PROP BACK OF CURB n c STA. 35+38.63 D_LL_._ / 45 24' RCP =- -- z- a• SE -- -- 5' SLOPE EASEMENT GRADE SWALE TO �— OPENING IN DROP INLET i Figure 8. Test Panel 5; west of Trailwood Lane. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 11 PROPOSED R.O.W. — /- / - - -� / 5' SLOPE EASEMENT SL TA 35 +71.7 49 RT 4' DROP IN IE •/ CONCRETE APRpN ON SOUTH SIDE 014 ¢ d o � ' � � z Figure 8. Test Panel 5; west of Trailwood Lane. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 11 E ENGINEERS ARCHITECTS MATERIALS SCIENTISTS VICK hl., it L- r* - CIR19 !t E - IT STA 32+10.: At -- PROPOS=ACK W CUM C -6 1.4 R.A.". 45- t CENT NE %) ' 24* RCP STA RO±4335 A qD RFC wuT SEE U1E11AE 21 RA-DS PT_ A PROPOSED 3 _ I RADIUS 31+68,51k W At 5LVE EASIAT P.T. STA 31+23.48. G&W 4 LLJ T/C .305.0) 07 70 INLE Figure 9. Test Panel 6,- west ofDobecka Drive. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 12 WJE ENGINEERS ARCH ITECTS MATERIALS SCIENTISTS FFT ANALYZER SIGNAL TRANDUCER d Q ,7 10 20 30 40 Frequency, KHz IMPACT SOURCE SHEAR WAVE ^ ^ REFLECTED ^ WAVE LONGITUDINAL WAVE SURFACE WAVE DISCONTINUITY Figure l0a. Schematic of Impact -Echo technique. CONCRETE MEDIUM 8.7 KHz Figure lob. Typical Impact -Echo frequency spectral plot. 50 Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 13 WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS Figure 11. Impact -Echo test in progress. Sandy Lake Road Pavement Nondestructive Testing for Mud Balls in Pavement Final Report: 27 November 2001 Page 14 Figure 12. Impact -Echo impactor /transducer. A C E G I K M 0 Q S Figure 17. Panel 1; Panel located near STA 50 +55 D n D X z n n m = D m m r � F V: n m z Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 17 A C E G I K M 0 Q S Cores Legend No. 6 C -D / 8 -9 G = Good reading North No. 11 W19 C = Core location Q = Questionable reading rri D Z —1 n LI z z r, D m m n M Z Sandy Lake Road Pavement Figure 18. Panel 2; Panel next to the east side of Panel 3 Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 18 Cores Legend No. 5 N -0/1 8-19 G = Good reading North No. 14 F/9 C = Core location No. 15 M Q = Questionable reading F = Flaw D m 7� n m D m m r � � m Z Figure 19. Panel 3; Panel located approximately Sl ft. east of Holly Street Sandy Lake Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 19 Cores Cores Legend No. 1 A- B/19 -20 No. 10 Next to W18 G = Good reading No 2 J -K/15 No. 12 1/21 C = Core location North No. 3 C/23 -24 No 13 K/g Q = Questionable reading No. 4 D/24 F = Flaw l"r1 3 D r„ n n m = D m m n x v� �n n m Z -I --I Figure 20. Panel 4; Panel located between STA 43 +50 and 44 +00 Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 20 Cores Legend No. 7 R- 5117 -18 G - Good reading North No. 16 13 C = Core location No.17 K13 Q = Questionable reading F - Flaw C'r1 3 D � n D m m r � � n m Z Figure 21. Panel S; Panel located just west of STA 34 +00 Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 21 Cores Legend No. 8 N/A G = Good reading North No 18 A9 C = Core location No 19 All Q = Questionable reading No 20 C18 F = Flaw No 21 E17 rri y Z .inn m = Z —I m D m m � n A v; ;n m z - 'I cn Figure 22. Panel 6; Panel located approximately 32 ft. west of STA 31 +00 Sandy Lake Road Pavemnent Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 22 Cores Legend No. 9 near K/12 G - Good reading North No. 22 E4 C = Core location No. 23 E5 Q - Questionable reading F - Flaw ENGINEERS WJE ARCHITECTS MATERIALS SCIENTISTS gin i N % .. Figure 23. Coring operation. Sandy Lake Road Pavement Nondestructive Testing for Mud Balls in Pavement Final Report: 27 November 2001 Page 23 Figure 24. Four cores removed from pavement. 09 ENGINEERS ARCH ITECTS MATERIALS SCIENTISTS Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 24 Figure 25. Location of internal flaw indication (Panel 2, Core 15). Figure 26 Core 15. Note mud ball at mid -depth of core. WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS __ ---- - - - - -- -----.._..----- - -- Figure 28. Core hole at location of Core 10 in Panel 3. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 25 Figure 27. Top portion of Core 10 in Panel 3. WJE ENGINEERS ARCH ITECTS MATERIALS SCIENTISTS 4 '5r, h' 1 A A r y i 3 » Figure 29. Location of Core 16 in Panel 4. • ,r r 1 ° 1 s- J . s- jam.. J , ✓ Figure 30. Close -up view of Core 16 in Panel 4. Concrete at surface was only about 112 to 1 in. thick. There was only mud throughout remainder of pavement thickness, Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 26 WJE ENGINEERS ARCHITECTS MATERIALS SCIENTISTS a r Figure 31. Core hole at Panel 3, Core 1 location. Note that mud ball extends into pavement beyond the core hole. Sandy Lake Road Pavement Final Report: 27 November 2001 Nondestructive Testing for Mud Balls in Pavement Page 27 Figure 32. Core hole at Panel 2, Core S, a random core. No mud ball present at this location.