The Use of Shrinkage Compensating Concrete in an Underground Water Tank. In-situ testing of Shrinkage Compensating Concrete

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1 1/14/213 -Compensating Concrete Past, Present, and Future, Part 2 Kyle R. Renevier, Sstudent, University of Oklahoma, Norman, OK ACI WEB SESSIONS ACI Fall 212 Convention October 21 24, Toronto, ON ACI WEB SESSIONS The Use of Compensating Concrete in an Underground Water Tank In-situ testing of Compensating Concrete Kyle Renevier Chris Ramseyer Ph.D., P.E Kyle Renevier Chris Ramseyer Ph.D., P.E ACI Oct 212 Investigation of Compensating Concrete Research Locations Restrained Tank (Springfield, IL) Unrestrained slab on ground (Los Angeles, CA) Restrained slab on ground (Fears Lab, Norman, Oklahoma) Testing Results Conclusion Purpose of Research Investigate behavior of concrete tank walls & slabs Review ACI 223 notes on shrinkage compensating concrete SCC cast wall sequence 1

2 1/14/213 Purpose of Research Strain evaluations of walls during construction Review base boundary condition of tank walls Should the wall be designed to slide or Is typical tank detailing ok i.e. high fixity Long term shrinkage Previous Research JingJing (211) Temperature impact on SCC At 1 F increases in SCC Faster strength gain At 16 F SCC becomes unstable Ettringite degrades Strength and expansion does not occur Previous Research Eskildsen et al. (24) Vibrating wire strain gages (VWSG) Post-tensioned SCC Previous Research Xia et al. (29) VWSG to monitor construction of skyscraper Installation of VWSG Noise in the first 5 days Performance Max 14με Max 12με Out performed Portland Cement Equipment Geokon Vibrating Wire Strain Gages Model 42 (with 1 of cable) Measures microstrains Measures temperature Equipment Geokon Data Acquisition System Model (16 Channels) 2

3 1/14/213 Underground Clear Water Well, Springfield, IL Constructed at Springfield, IL Power Plant 6 million gallon water tank 9 yd of SCC 18 at the top 18 tall 42 at the bottom Restrained Testing locations 3 vibrating wire strain gages located at top of tank wall One Vertical One Horizontal One Lateral Restrained Testing locations 5 vibrating wire strain gages located at bottom of tank wall Two Vertical Two Horizontal One Lateral strain gages isolated from rebar method 1 Testing Set Up strain gages isolated from rebar method 2 3

4 1/14/213 Testing Set Up Wires fed through form work System ran for 17 days Testing Set-Up Cables run to Data Acquisition System Testing Testing A cap was poured around day 35 Interval of 15 minutes between each reading After initial set up Adjoining tank walls were poured 23 days later CSA cement Portland type I Type C Fly Ash w/cm MRWR Air entraining #67 Aggregate Sand ASTM C 878 =.7% expansion = 9 lbs/yd = 418 lbs/yd = 57 lbs/yd =.46 to.48 = 4% - 4.5% Elastic Modulus Testing 7 day 6 Compressive Strength (psi) Springfield Mix Ec = 3,873 ksi

5 1/14/213 Testing - Horizontal 5 Horizontal Outside 4 Horizontal Inside 18 inches Horizontal Top 36 inches 18 inches 8 inches Wet Cure Adjoining Wall Cap Horizontal Outside Horizontal Inside Horizontal Top s Horizontal Outside Horizontal Inside Horizontal Top Portland Cement Testing - Vertical 18 inches Wet Cure 36 inches Bottom Verrtical Outside Bottom Vertical Inside Vertical Top 18 inches 8 inches

6 1/14/213 Testing - Transverse -1 Cap Wall Cast 18 inches -2-3 Bottom Verrtical Outside -4 Adjoining Wall Bottom Vertical Inside Vertical Top inches 18 inches 8 inches s Wet Cure Transverse Bottom s 1 Adjoining Wall Transverse Bottom -4 Top Transverse -5 Temperature ( F) Max. Temperature = 132 F Horizontal Outside Horizontal Inside Middle Bottom Horizontal Top Testing Set-Up Four Additional VWSGs Placed Two in the thin slab (8 inches)

7 1/14/213 Testing Set-Up Four Additional VWSGs Placed Two in the thick slab (18 inches) 8 ft x 184 ft slab 7

8 1/14/213 Testing - Perpendicular 3 18 inches 25 2 Perpendicular Thick Slab Wet Cure MicroStrain inches 18 inches 8 inches Testing - Parallel 3 MicroStrain Perpendicular Thick Slab 18 inches inches 18 inches 8 inches Wet Cure Thick Slab Parallel Thin Slab Parallel Thick Slab Parallel Thin Slab Parallel

9 1/14/ Temperature Variations Parallel Thin Slab Parallel Thick Slab Restrained Testing Tank Wall Results Temperature ( F) Highest Microstain Value for Each Direction Location / Vertical Interior Bottom 41 Vertical Outer Bottom 29 Vertical Top 32 Horizontal Interior Bottom 13 Horizontal Outer Bottom 2 Horizontal Top 38 Restrained Testing Slab on Ground Results Highest Microstain Value for Each Direction Location Thick Slab Perpendicular Thick Slab Parallel Thin Slab Parallel Transverse Bottom Transverse Top / Why do we not see.7% expansion? And why does it expand beyond 7 days? Slab to grade restraint Wall to slab restraint Difference in surface area to volume ratio Exposed Surface Area Total Volume Surface Area (ft 2 ) (ft 3 ) Volume ASTM C Wall Segment Unrestrained Testing Los Angeles, California No rebar placed in the slab Testing for 7 days LA Mix CSA cement = 9 lbs/yd Portland type I = 48 lbs/yd w/cm =.46 to.48 #3 & 4 Aggregate = 1782 lbs/yd Sand = 1458lbs/yd MRWR = 59.6 oz/yd 9

10 1/14/213 Measuring 2 directions Parallel to slab edge Perpendicular to slab edge Unrestrained Testing Set Up Three depths Top (4.5 inches from the ground) Middle (3 inches from the ground) Bottom (1.5 inches from the ground) Two locations measured of slab Middle of slab Mature Concrete, Carport slab 25 1 Unrestrained Results Middle of Slab-Parallel to Slab Rebar 12 o.c. 3 Middle of Slab, Parallel with Top Middle 3 Bottom

11 1/14/ Unrestrained Results Middle of Slab-Parallel to Slab Top Middle 3 Bottom Mature Concrete, Carport slab Rebar 12 o.c. 3 Middle of Slab, Perpendicular with Unrestrained Results Middle of Slab- Perpendicular to Slab Top 5 Middle Bottom Unrestrained Results 1 Middle of Slab- Perpendicular to Slab Top -5 5 Middle 6 Bottom Mature Concrete, Carport slab Unrestrained Results of Slab, Parallel with of Slab- Parallel to Slab Rebar 12 o.c. 3 7 Top Middle 9 Bottom

12 1/14/213 Unrestrained Results Mature Concrete, Carport slab of Slab- Parallel to Slab Top 8 Middle 9 Bottom 25 of Slab, Perpendicular with Rebar 12 o.c Unrestrained Results of Slab- Perpendicular to Slab Top Middle 12 Bottom Unrestrained Results of Slab- Perpendicular to Slab 1 Top 11 Middle 12 Bottom Unrestrained 6x12 Cylinder GeoKon VWSG imbedded in center: 12

13 1/14/213 Unrestrained Test Results Max. Location (microstrains) Bottom Middle Top Middle Parallel Perpendicular Parallel Perpendicular Increasing Unrestrained Test Results Mature Concrete, Carport slab 25 Max. Location (microstrains) Bottom Middle Top Middle Parallel Perpendicular Parallel Perpendicular Increasing Increasing Least Most Restrained Orientation Rebar 12 o.c Middle of Slab, Parallel with Max Bottom 343 µε Middle 322 µε Top 318 µε Mature Concrete, Carport slab Mature Concrete, Carport slab Middle of Slab, Perpendicular with of Slab, Parallel with Rebar 12 o.c. 3 Max Bottom 496 µε Middle 472 µε Top 423 µε Rebar 12 o.c. 3 Max Bottom 548 µε Middle 534 µε Top 463 µε 13

14 1/14/213 Mature Concrete, Carport slab Restrained Testing Most Least Restrained Orientation of Slab, Perpendicular with Fears Lab, Norman, Oklahoma (4) x 5 x 6 slabs (2) #4 14 o.c. (2) w/ (2) #5 rebar at perimeter Rebar 12 o.c. 3 Max Bottom 612 µε Middle 587 µε Top 57 µε #4 14 o.c. 14

15 1/14/213 (2) #5 perimeter Conclusion Restraining Type K, Compensated Concrete in one direction does Not restrain the expansion in other directions. Restraining σ 1 does not restrain σ 2 or σ 3 15

16 1/14/213 Conclusion Type K, Compensated Concrete will not self destruct at the expansions acceptable to ACI 223 if there is no rebar Highly restrained placement of Type K, Compensated Concrete will have minimum expansion and shrinkage Conclusion VWSG are a suitable measuring tool for SCC Durable, Accurate and not prone to bias Scale of the project affects SCC Greater surface area verse volume of the prism or wall may cause discrepancies between lab and in-situ testing Acknowledgement Thank You! City of Springfield CTS University of Oklahoma Geokon ACI 223 Questions? 16