Mark B. Snyder, Ph.D., P.E., Engineering Consultant Bridgeville, Pennsylvania

Transcription

1 Mark B. Snyder, Ph.D., P.E., Engineering Consultant Bridgeville, Pennsylvania Prepared for presentation at the 2008 Minnesota Concrete Conference Continuing Education and Conference Center, St. Paul, MN February 14, 2008

2 FHWA-Sponsored Research Physical and Mechanical Properties f Recycled PCC Aggregate Concret University of Minnesota ERES Consultants, Inc.

3 RCA has been used widely with varying results. Most common failures: deteriorated midpanel cracks loss of load transfer

4 Determine causes of pavement distress related to use of RCA in PCC pavements. Develop practical, reliable guidelines for RCA concrete mix designs. Identify pavement designs for which RCA concrete is appropriate.

5 Extensive Literature Review Field Testing and Evaluation Laboratory Testing and Evaluation

6 Distress (cracked, uncracked, other) JRCP, JPCP (CRCP?) Available control section Range of climates, traffic Uniform traffic flow No substructures

7 Original 1993 Study: 9 Projects 5 RCA + Control 4 RCA Only 2 Single Sections 1 Varying LT 1 Varying Performance 16 Sections Total

8 Category Location Climatic Region 1 (Good) 2 (Structural Problems) 3 (Other Distresses) CT 1, I-84 near Hartford MN 1, I-94 near Brandon KS 1, K-7 Johnson County MN 4, US52 near Zumbrota MN 2, I-90 Beaver Creek WI 1, I-94 near Menomonie MN 3, US59 near Worthington WI 2, I-90 near Beloit WY 1, I-80 near Pine Bluffs 1994 Age, Yrs Control Section 2 Way ADT, veh/day Pavement Type (% long. reinf.) W-F 14 yes 56,000 9-in JRCP (0.10 %) W-F Transition 6 yes 8, in JRCP (0.06 %) W-F 9 yes 7,310 9-in JPCP (n/a) W-F 10 yes 7,820 9-in JRCP (0.06 %) W-F Transition 10 no 1,670 9-in JRCP (0.06 %) W-F 10 no 8, in JPCP (n/a) W-F Transition 14 no 2,150 8-in JPCP (n/a) W-F 8 no 22, in CRCP (0.67 %) D-F 9 / 10 yes 4,410 (RCA) 4,280 (Con.) 10-in JPCP (n/a) Joint Spacing, ft Dowel Diam., in (I-beam) None None / None n/a n/a None

9 Condition Survey Drainage Survey FWD Coring Midpanel Joints Cracks Crack, Joint Width Faulting PSR Photolog

10 Compression Split Tension Static E Dynamic E α Surface Texture Sand Patch Profilometer Freeze-Thaw Linear Traverse Petrography

11 FHWA-Sponsored Research Performance of Concrete Pavements Containing Recycled Concrete Aggregate 2006 (Update of previous study) University of New Hampshire Recycled Materials Resource Center

12 Revisit 1994 study sections to obtain longer-term materials and performance data. Include additional test sites to expand inference base of original study. Update conclusions from 1994 study.

13 Category Location Climatic Region 3 (Other Distresses) IA 1, US 75 near Rock Rapids IL 1, I-57 near Effingham 2006 Age, Yrs Control Section 2 Way ADT, veh/day Pavement Type (% long. reinf.) W-F 30 no 2,150 9-in JPCP (n/a) W-F 20 no 4,410 (RCA) 4,280 (Con.) 10-in CRCP (n/a) Joint Spacing, ft Dowel Diam., in None n/a n/a

14 Condition Survey Drainage Survey Coring Midpanel Joints Cracks Crack, Joint Width Faulting PSR Photolog [No FWD]

15 Compression Split Tension Static E Modified ASTM C 1293 (ASR) ASTM C 856 (Uranyl Acetate) Volumeteric Surface Texture Petrography

16 Project Review and Performance Summary (Age 18 yrs)

17 Recycled

18 Recycled

19 Recycled

20 Control

21 Control

22 Control

23 MN 1-1 (Recycled) MN 1-2 (Control) Sturtevant M.S. Thesis

24 Test and Value MN 1-1 (Recycled) MN 1-2 (Control) Transverse Joint Spalling, % Joints Avg. Faulting between Panels, mm Longitudinal Cracking, m/km 0 0 Transverse Cracking, % Slabs 31 0 Deteriorated Transverse Cracks/km 35 0 Total Transverse Cracks/km 38 0 PSR IRI Tensile Strength, MPa Compressive Strength, MPa Uranyal Acetate Reaction None None Young s Modulus, GPa

25 Comparable performances in 1994 Mortar Content 77% RCA 66% Control Similar Thermal Coefficients in /C o RCA 11.9/C o Control ~25% increase in Young s modulus since 1994 Inconsistent strength trends since 1994 RCA strength consistently lower, but adequate

26 Project Review and Performance Summary (Age 22 yrs)

27 I-90 EB

28 I-90 EB

29 I-90 EB

30 I-90 WB

31 I-90 WB

32 I-90 WB

33 MN 2-1 (Recycled) MN 2-2 (Recycled) Sturtevant M.S. Thesis

34 Test and Value MN 2-1 (RCA 1) MN 2-2 (RCA 2) Transverse Joint Spalling, % Joints Avg. Faulting between Panels, mm Avg. Joint Width, mm Longitudinal Cracking, m/km 26 0 Transverse Cracking, % Slabs Deteriorated Transverse Cracks/km Total Transverse Cracks/km PSR IRI Tensile Strength, MPa Compressive Strength, MPa Uranyal Acetate Reaction Low None Modified ASTM 1293, % Expansion at 108 Days n/a Young s Modulus, GPa n/a 31.1

35 Project Summary and Performance Review (Age 26 yrs)

36 MN

37 MN

38 MN

39 MN

40 MN 3-1 (Recycled) Sturtevant M.S. Thesis

41 Test and Value MN 3 (1994) MN 3 (2006) Transverse Joint Spalling, % Joints Transverse Joint Seal Damage, % Joints D-cracking, % Slabs 0 0 Avg. Faulting between Panels, mm Avg. Joint Width, mm Longitudinal Cracking, m/km 19 0 Transverse Cracking, % Slabs 2 12 Deteriorated Transverse Cracks/km 3 26 Total Transverse Cracks/km 3 26 PSR IRI Tensile Strength, MPa Compressive Strength, MPa

42 Recycled section only Constructed in 1980 Rehabilitated after 1994 Diamond grinding Retrofitting of transverse dowel bars PSR = 4.3 (3.0 in 1994) Avg. faulting between panels = 0.3 mm (6.1 mm in 1994) No recurring D-cracking ASR found during uranyl acetate testing Moderate expansion in Modified ASTM 1293 testing No ASR related distress found in field 42

43 Project Summary and Performance Review (Age 22 yrs)

44 MN 4-1 (Recycled) MN 4-2 (Control) Sturtevant M.S. Thesis

45 Test and Value MN 4-1 (Recycled) MN 4-2 (Control) Transverse Joint Spalling, % Joints D-cracking, % Slabs 0 0 Pumping, % Slabs 0 0 Slab/Patch Deterioration, 3 0 % Slabs Avg. Faulting between Panels, mm Avg. Joint Width, mm Longitudinal Cracking, m/km 17 0 Transverse Cracking, % Slabs Deteriorated Transverse Cracks/km Total Transverse Cracks/km PSR IRI Tensile Strength, MPa Compressive Strength, MPa Uranyal Acetate Reaction None None Young s Modulus, GPa Average VSTR (cm 3 /cm 2 )

46 In 1994, performances were comparable, but RCA section was showing signs of imminent deterioration Foundation Stiffness (backcalculated) 30% lower for RCA section Aggregate Top Size 1.0-in RCA 1.5-in Control Mortar Content 84% RCA (higher shrinkage?) 52% Control Similar Thermal Coefficients in /C o RCA 11.9/C o Control ~10% increase in compressive strength since 1994

47 Recycled and control sections rehabilitated after 1994 Diamond grinding Retrofitting of transverse dowel bars Field survey showed recycled did not perform as well as control Recycled had higher mortar content (74% vs. 52%) Formation of shrinkage cracks early on 47

48 100% 80% 60% 40% 20% 0% -20% -40% Figure 58: Recycled Pavement Distresses (Avg. % Change from 1994 to 2006) All Rehabilited Not Rehabilitated % Change (94 to 06) T. J. Spalling T. J.Seal Damage L. J. Seal Damage D-cracking Pumping Slab/Patch Deterioration L. to S. Drop off L. to S. Separation Faulting Joint Width L. Cracking T. Cracking Deteriorated T. Cracks Total T. Cracks PSR IRI Sturtevant M.S. Thesis

49 100% 80% 60% 40% 20% 0% -20% -40% Figure 59: Control Pavement Distresses (Avg. % Change from 1994 to 2006) All Rehabilited Not Rehabilitated % Change (94 to 06) T. J. Spalling T. J.Seal Damage L. J. Seal Damage D-cracking Pumping Slab/Patch Deterioration L. to S. Drop off L. to S. Separation Faulting Joint Width L. Cracking T. Cracking Deteriorated T. Cracks Total T. Cracks PSR IRI Sturtevant M.S. Thesis

50 Need to treat RCA as engineered material and modify mix and structural designs accordingly Reduce w/c ASR mitigation Reduced panel lengths Etc. Mortar contents generally higher for RCA Reclaimed mortar content varied with virgin aggregate type, crushing process RCA, conventional aggregate PCC performance comparable when natural CA types and quantities are similar Higher mortar contents had more distress need to control reclaimed mortar content

51 Granular Base Sections CT1-1, 16.6, 66% CT1-2, 15.2, 93% MN1-1, 7.3, 1% MN1-2, 7.3, 0% MN2-1, 8.2, 84% MN4-1, 7.8, 88% MN4-2, 8.2, 22% WI1-1, 4.4, 8% WI1-2, 4.6, 2% WY1-1, 4.3, 0% WY1-2, 4.3, 0% Stabilized Base Sections KS1-1, 5.5, 0% KS1-2, 5.5, 0% MN3-1, 5.0, 2%

52 Use of RCA has no apparent direct influence on joint faulting (dowels, aggregate size, structural design parameters are more important) Recycled ASR concrete used successfully in Wyoming with mitigation measures Isolated recurrent ASR RCA performed better than control Recycled D-cracked concrete used successfully with mitigation measures Reduced aggregate size Reduced moisture exposure?

53 Federal Highway Administration Minnesota Department of Transportation Jeff Sturtevant, Prof. David Gress and the University of New Hampshire Recycled Materials Resource Center (RMRC) Greg Cuttell, Julie Vandenbossche and many other former U-M Grad and Undergrad Research Assistants Applied Research Associates, Inc. (formerly ERES Consultants)

54 Thank You! Any Questions?