2018 Pavement Workshop May 23 24 2018 Laboratory

2018 Pavement Workshop May 23 -24, 2018 Laboratory and Field Performance of Recycled Aggregate Base in a Seasonally Cold Region Bora Cetin Assistant Professor Iowa State University + 46 Associate Members Tuncer Edil & Ali Soleimanbeigi Professor Emeritus / Research Associates University of Wisconsin-Madison 1

OUTLINE ØProblem Statement/Introduction ØObjectives ØMaterials & Methodology ØResults Ø Freezing Point Depression & Freezing Temperatures Ø Resilient Modulus Ø Frost Depth & Freeze-Thaw Cycle Prediction Ø Elastic Modulus ØConclusions ØAcknowledgements Iowa State University of Wisconsin-Madison

PROBLEM STATEMENT Heaving Iowa State University Potholes University of Wisconsin-Madison 3

PROBLEM STATEMENT Frost Action – Alligator Cracking Iowa State University of Wisconsin-Madison 4

CLIMATIC ZONES • Six climatic regions in the United States for pavement design Iowa State University of Wisconsin-Madison 5

OBJECTIVES Base Layer Primary Goals: • • • Stiffness of recycled and natural aggregates Freeze point depression Freezing temperature Prediction of freeze-thaw cycles Prediction of frost depth Iowa State University of Wisconsin-Madison 6

MATERIALS Recycled Concrete Aggregate (RCA) Iowa State University Natural Aggregate (Class 5) University of Wisconsin-Madison Recycled Asphalt Pavement (RAP) 7

MATERIALS Iowa State University of Wisconsin-Madison 8

MATERIALS Iowa State University of Wisconsin-Madison 9

MATERIALS MATERIAL Natural Aggregates RCA Blend RAP Wopt (%) 8. 9 11. 2 8 6. 7 γdmax (k. N/m 3) 20. 1 19. 3 21. 4 20. 7 Absorption (%) - 15 - 1. 8 Asphalt/Mortar Content (%) - 55 - 7. 1 Impurities (%) 0. 25 0. 87 0. 36 0. 06 USCS GW-GM SW SP SP AASHTO A-1 -b A-1 -a Iowa State University of Wisconsin-Madison 10

METHODS Ø Materials were compacted at optimum moisture content Thermocouples Iowa State University of Wisconsin-Madison 11

FREEZE-THAW PROCEDURE ØFreeze-thaw cycles numbers: 0, 5, 10, 20 ØFreeze-Point Depression Tests: Ø Determine the freezing temperature Freeze-Thaw Procedure 1 -D Iowa State University of Wisconsin-Madison 12

RESILIENT MODULUS-AASHTO T-307 Ø Resilient Modulus (MR) Ø Stiffness Ø Durability Ø Test & Compaction Procedure Vertical Stress Vertical Deformation Confining Pressure Iowa State University of Wisconsin-Madison 13

FALLING WEIGHT DEFLECTOMETER Parameters Number of receivers Receiver spacing (m) Total length (m) Distance from the source to the first receiver (m) Iowa State University FWD 9 0. 15 to 0. 31 1. 38 0 University of Wisconsin-Madison 14

FIELD SENSORS Thermocouples Moisture Sensors Iowa State University of Wisconsin-Madison 15

RESULTS Freezing Point Depression Tests Iowa State University of Wisconsin-Madison 16

RESULTS Summary of Freezing Temperatures MATERIALS Freezing Point Depressions (˚C) Freezing Temperature (˚C) Natural Aggregate -5. 2 -12 RCA -10 -12 RAP -10 -12 Ø Based on the results of freeze-point depression tests, all samples were frozen at -15˚C. Iowa State University of Wisconsin-Madison 17

RESULTS Laboratory Resilient Modulus Tests (No Freeze-Thaw) Iowa State University of Wisconsin-Madison 18

RESULTS Laboratory Resilient Modulus Tests (After Freeze-Thaw) Iowa State University of Wisconsin-Madison 19

RESULTS Temperature RCA Iowa State University of Wisconsin-Madison 20

RESULTS Freeze-Thaw Cycles/Year Iowa State University of Wisconsin-Madison 21

RESULTS Cumulative Freeze-Thaw Cycles Iowa State University of Wisconsin-Madison 22

RESULTS Modulus After Freeze-Thaw Cycles Iowa State University of Wisconsin-Madison 23

RESULTS Modulus vs Moisture Content Iowa State University of Wisconsin-Madison 24

RESULTS Laboratory and Field Modulus After Freeze-Thaw Cycles Iowa State University of Wisconsin-Madison 25

CONCLUSIONS Laboratory Tests Ø Stiffness changes slightly after 5 freeze-thaw cycles based on the laboratory tests Ø RCA Modulus Freeze-Thaw Cycles Ø Total modulus reduction: ØRAP ~ 20% ØNatural Aggregate ~ 60% over 20 F-T cycles Iowa State University of Wisconsin-Madison 26

CONCLUSIONS Field Tests Ø Elastic Modulus Freeze-Thaw Cycles Ø RCA & RAP > RCA Blend & Natural Aggregate Ø Elastic Modulus Moisture Content Ø Laboratory Modulus = Field Modulus except RCA Iowa State University of Wisconsin-Madison 27

Acknowledgments • Minnesota Department of Transportation • Mn. ROAD (Benjamin Worel) • Recycled Materials Resource Center (RMRC) at the University of Wisconsin Iowa State University of Wisconsin-Madison 28

Thank You

RESULTS Iowa State University of Wisconsin-Madison 30