1 PRESENTATION FLOWABLE FILL Presented By: Mac McArthur, P.E. Construction Engineering Services Bureau Mike Lynch Materials Bureau Highways and Engineering Conference – February/March 2006

2 AGENDA  WHAT IS FLOWABLE FILL?  WHY USE FLOWABLE FILL?  WHEN SHOULD FLOWABLE FILL BE USED?  HOW IS FLOWABLE FILL USED?  QUESTIONS/ANSWERS

3 WHAT IS FLOWABLE FILL?  OTHER NAMES  Controlled Low-Strength Material (CLSM)  Controlled Density Fill  Flowable Mortar  Low Strength Slurry Cement Backfill  Lean Mix Backfill  Lean Fill  Un-shrinkable Fill  Flowable Fly Ash  Flowable Backfill  Flowable Grout  WHAT IT IS NOT!  Non-Shrink Concrete (Old MDT Concrete Type – “NS”)

4 NOT FLOWABLE FILL! Just Very Wet Concrete!

5 SLUMP TEST? THE WAY IT IS SUPPOSE TO LOOK

6 WHY USE FLOWABLE FILL? FLOWS LIKE A LIQUID SETS LIKE A SOLID SELF-LEVELING REQUIRES NO COMPACTION REQUIRES NO VIBRATION TAKES THE PLACE OF CONCRETE TAKES THE PLACE OF COMPACTED SOILS TAKES THE PLACE OF COMPACTED SAND FILLS VOIDS IS REMOVABLE  Excavatable – Easily Removed with a Shovel  Non-Excavatable – Easily Removed with Light Equipment (Backhoe or Bob Cat) COST EFFECTIVE

7 14 REASONS TO USE FLOWABLE FILL 1) Readily Available 2) Easy to Deliver 3) Easy to Place 4) Versatile 5) Strong and Durable 6) Can be Excavated to Remove 7) Requires Less Inspection 8) Allows Fast Return to Traffic 9) Will Not Settle 10) Reduces Excavating 11) Improves Worker Safety 12) Allow All-Weather Work 13) Reduces Equipment Needs 14) Requires No Storage

8 STANDARD SPECIFICATIONS

9

10

11 WHEN SHOULD IT BE USED? PIPES/UTILITY CONDUITS Haunch/Sides For Large Pipe Backfill Small Culverts Backfill Conduits/Pull Boxes – Urban Traffic Projects FILL ABANDONED FACILITIES Wells Sewer Lines and Manholes Small Culverts Underground Storage Tanks RETAINING WALL BACKFILL BRIDGE END BACKFILL Bridge Bureau Design and Approval

12 CULVERT BACKFILL PTW TRENCH BACKFILL

13 RETAINING WALL BACKFILL UTILITY CONDUIT BACKFILL

14 HOW IS IT USED? CONSTRUCTION METHODS Use Chute or Pump Do Not vibrate or Compact Cannot Freeze Provide Restraints to Prevent Flotation Confine Flow and Prevent Intrusion * Do Not Use as Driving Surface TESTING Mix Design Required No compressive Strength Test Required Set Time (Weight of a Person or Penetrometer)

15 TEST TRENCH LESS THAN 24 HOURS

16 HOW IS IT USED? (Continued) FLOWABLE FILL HELP GUIDE Link = OTHER USES FOR FLOWABLE FILL Short Span Bridge Rehabilitation * Large Culvert Rehabilitation * PHOTOGRAPHS FOLLOW

17 LOTS OF FLOWABLE FILL – NOTE CONFINEMENT

18

19

20

21

22 QUESTIONS/ANSWERS