Post on 07-Jun-2020
transcript
Roller Compacted Concrete for DOTs
Andy Johnson, Ph.D., P.E.
Pavement Design Engineer
Stan Bland, P.E.
Pavement Applications Director, Carolinas/Virginia
Portland Cement Association – SE Region
Maryland Concrete 2015 Conference
March 17, 2015
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Roller Compacted Concrete
• What is it?
– No-slump concrete that is compacted by vibration
– No forms
– No reinforcing steel
– No finishing
– Traditionally compacted with vibratory rollers
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Concrete pavement placed in a different way!
Why use RCC?
• Most or all of pavement structure can be placed in one lift.
• Does not require the curing time or adjacent lane encroachment of traditional PCC.
• Can handle heavy loads and high traffic volumes.
• Should be able to bridge poor subgrades effectively, if you can get it installed.
• Overall structure cost is very competitive with other pavement types.
Engineering Properties
• Compressive strength (f’c)
- 4,000 to 10,000 psi
• Flexural strength (MR)
- 500 to 1,000 psi
- MR = C(f’c)1/2 where C = 9 (up to 11)
• Modulus of elasticity
- 3,000,000 to 5,500,000 psi
- E = CE(f’c)1/2 where CE = 57,000 (up to 67,000)
Sieve Opening (mm)
Perc
en
t P
assin
g
0
20
40
60
80
100
0.075 0.150 1.180 2.360 4.750 12.5 25
#200 #100 #16 #4 1/2" 1"
RCC in black
RCC vs. HMA Intermediate Course
Sieve Opening (mm)
Perc
en
t P
assin
g
0
20
40
60
80
100
0.075 0.150 1.180 2.360 4.750 12.5 25
#200 #100 #16 #4 1/2" 1"
RCC in black
HMA in red
RCC vs. HMA Intermediate Course
Sieve Opening (mm)
Pe
rce
nt
Pas
sin
g
0
20
40
60
80
100
0.075 0.150 1.180 2.360 4.750 12.5 25
#200 #100 #16 #4 1/2" 1"
SCDOT 2010 RCC in black
SCDOT 2013 RCC in red
Evolving Gradation Specs
Surface Appearance
• Not as smooth as
conventional concrete
• Important to recognize
difference
• Similar appearance to
asphalt only light grey
instead of black
Surface Texture
SCDOT has been using RCC since 2008
• Has let over 20 projects
• Quantity exceeds 700,000 sy
• 130,000 sy used for shoulders on I-385
reconstruction
• Remainder used for urban reconstruction
SCDOT has been using RCC since 2008• Powell Pond Rd, Aiken County (Demo. Project)
• SC 5, York County
• US 78, Charleston County
• New State Road, Lexington County
• Greystone Boulevard, Richland County
• South Beltline Boulevard, Richland County
• Richland Street (US78), Aiken County
• SC 9, Horry County
• S-11-171, Cherokee County
• I-385 Shoulders, Laurens County
• I-385 Shoulders, Greenville County
• J A Cochran BP, Chester County
• SC 9 and SC 151 Intersection, Chester County
• SC 21 , Albright Rd, York County
I-385 RCC Shoulder
Highway Shoulders
I-285 Highway
Atlanta, GA
US Route 78, Charleston County• 5-lane section
• Original pavement built 1920’s, widened in
1980’s.
• ADT is 41,700 with 10% trucks.
• Asphalt pavement condition was very poor.
US Route 78, Charleston County2007
US Route 78, Charleston County
• Alternate pavement design:
– 200 psy HMA Surface
– 10 inches RCC
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US Route 78, Charleston County
March 2015
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Greystone Blvd. Columbia, SC
2009
Greystone Blvd. - 2009
Greystone Blvd. - 2014
Greystone Blvd.
2010 2013
Greystone Blvd.
2014 2013
Greystone Blvd. -2014
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US-78, Aiken, SC
Constructed 2009
March 2015
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SC-72, Chester, SC
2013
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SC-72, Chester, SC
2013
SC Route 72, Phase III, let January 2014
• PG 64-22 – 421 tons @ $617/ton
• HMA Surface Type B – 4864 tons @ $40.30/ton (Typically has 5.3% liquid. Comparable to a 12.5 mm mix.)
• Variable milling – 15,900 sy @ $3.75/sy
• 8” uniform milling – 12,500 sy @ $6.50/sy
• 8” RCC – 12,500 sy @ $32.00/sy
• Special use concrete – 1,000 cy @ $129.00/cy (included for contingency removal and replacement of soft areas after 8” milling)
Future Developments
• Admixtures providing:
– Drastically improved surface texture
– Compaction obtained in high-density paver, no
rolling required
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Thank you!
Stan Bland, PE
Pavement Applications Director – Carolinas/Virginia
sbland@cement.org
704-975-2951
Andy Johnson, PhD, PE
Pavement Engineer
ajohnson@cement.org
803-556-2889
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