John R. Anderson, Ph.D., P.E.

John R. Anderson, Ph.D., P.E.
4 Lawn Street
Oviedo, FL 32765
407-365-7229
jranderson@tigerbrain.com
Wednesday, 27 October 2010
Concrete Airport Pavement Workshop
Renaissance Concourse Hotel – Atlanta, Georgia

• Design – 3 agency “policies”
• Army
• Air Force/Air National Guard
• Navy/Marine/Coast Guard
• Construction –2 agency “policies”
• Army/Air Force/Air National Guard
• Navy/Marine/Coast Guard

• Basic data need to know:
• Agency (just discussed)
• Aircraft/Airfield Type
• Subgrade Strength

• Rotary Wing functions
• Transport
• Tactical
Most Rotary Wing Airfields 6 –12 inches PCC
• Airlift
• Equipment
• Personnel
• 12 –20 inches PCC

• USAF/ANG use same standards
• Base normally has one primary
mission aircraft:
• Fighters
• Airlift/Tankers
• Bombers

• Fighter
• “Light Load Airfield”
▪ 400,000 passes F‐15 C/D ( 68,000 lb)
▪ 400 passes C‐17 (590,000 lb)
• Airlift
• “Medium Load Airfield”
▪ 100,000 passes F‐15 E ( 81,000 lb)
▪ 400,000 passes C‐17 (590,000 lb)
▪ 400 passes B‐52 (400,000000 lb)

• Bomber “ Heavy Load Airfield”
• 100,000 passes F‐15 E (81,000 lb)
• 200,000 passes C‐17 (590,000 lb)
• 120,000 passes B‐52 (480,000 lb)*
*Combat Load

• Carriers/Destroyers/Subs Primary Missions
• Shore‐based airfields are support/training
• (a.k.a. less funding)
• Navy Standard Traffic (Peace‐Time Weight)
• 300,000 passes F‐14 (72,000 lb)
• 150,000 passes P‐3 (135,000 lb)
• 15,000 passes C‐17 (585,000 lb)
• 10,000 passes KC‐10 (590,000 lb)

1. Pentagon develops War Plan
2. Estimate Number of Targets
3. Targets require rotary wing, fighters,
bombers, UAVs
4. Support / Logistics ‐ airlift/tanker missions

5. War Planners determine number of Light,
Medium and Heavy Load airfields to win
6. No time to rebuild airfield during war
7. Therefore, life of each airfield is…
“One standard war”

• Modulus of Subgrade Reaction, k, psi/in (pci)
• Typically 100‐200 psi/in; outside that range is
unusual
• Essentially a “spring constant”
• Concrete slab thickness equations based upon
subgrade behaving as a “dense liquid” id” when
loaded:

• HWD Best
• 55,000 lb load
• 200 points / day
• DoD tests on
5 year cycle

• CBR/k Correlations using
Field or Lab CBRs
• Field CBRs
• Existing Pavement Only
• 18 inch test pits
• Several hours plus
patching/cure time
Field CBR in Afghanistan

• Bulk samples from multiple borings or test
pits
• 4‐day soak CBR
• 4‐6 weeks for sampling and testing

• Agency Policies Differ
• Aircraft Type
• Subgrade k

• Army/Navy /Air Force use same spec
• UFGS 32 13 11 www.wbdg.org
• DISCONTINUED SMALL PROJECT,
“LESS THAN 10,000 CY” SPEC

• ASR / Deicer / Accelerated ASR
• De‐Icer / Accelerated ASR (expected to be removed from
requirements pending research)
• Combined / Optimized Gradation
• Beam/Cylinder & w/c Correlations
• Paver
• Test Section

• Cement/admixture alkali+aggregate silica +
water = expansive reaction
Cracking after 10 years,
Channel Islands, California
Apron Expansion Shoves Asphalt
Shoulder-damage shown required
replacement every 6 months

• 0.08% maximum expansion at 28 days
• FAA is 0.10% at 28 days;
• ASTM C ‐1260 is 0.10% at 14 days
• Considering easing based upon observed
performance (Tigerbrain involved with revision)
• Deicer‐ considering removing requirement
based upon pending research

• Use Combined Materials
• Workability and Coarseness Factors
• WF: Percent Pass No. 8 Sieve
• CF: 3/8 Retained % / No. 8 Retained %
• Percent Aggregate Retained
• 0.45 Power Curve
(See also ACPA 2009 Annual Meeting Presentation )

Factor
Workability
45
40
35
30
25
Well Graded,
Minus 3/4"
,
Not For
Paving
Paving Box
SIDE
Rocky,
DO NOT PLOT
BELOW LOWER
LIMIT
Sandy
HAND
SLIP
Coarse,
Gap Graded
20
20 30 40 50 60 70 80 90
Coarseness Factor

45
Paving Box
Sandy
Wo orkability Fac ctor
40
35
30
25
Well Graded,
Minus 3/4",
Not For
Paving
SIDE
Rocky,
DO NOT PLOT
BELOW LOWER
LIMIT
HAND
SLIP
Coarse,
Gap Graded
20
20 30 40 50 60 70 80 90
Coarseness Factor

No. 100
35
30
25
20
15
10
5
0
Percent Retained
Combined Aggregates
Percent Retained
2"
1 1/2"
1"
3/4"
1/2"
3/8"
No. 4
No. 8
No. 16
No. 30
No. 50
US Standard Sieve

100
90
80
70
60
50
40
30
0.45 Power Curve
Combined Aggregates
Combined Percent Passing
No. 2000
No. 1000
No. 50
No. 30
No. 16
No. 8
No. 4
2"
1.5"
3/8"
1/2"
3/4"
1"
20
10
0
Sieve to 0.45 power

• Thickness based upon 90 day beam strength
• Purpose: Avoid waiting 90 days for
results/payment
• Requires Laboratory Study Prior to Paving
• Army & Air Force (Navy uses 28 day beams w/o correlations)

• 14 day : 90 day beam (or cylinder)
correlations
• Project specific
• 6 beams @ 3, 7 , 14, 28, 90 days
• 3 different w/c ratio’s (to consider climate change
during production
• Therefore, 90 Beams
• For 14 day cylinder : 90 day beam ratio,
ADDITIONAL 90 cylinders

• 7 day : 90 day used for QC
• add more cement if low strength th predicted
d
• Still require 2 beams per lot
• Correlations are extensive

• What the Owner ideally wants from the Paver:
• Consolidation
• Flat surface
• No excess slurry/paste
• Square, solid corners
• Flat edges
All preferably without people touching the
concrete

• Central Mix on site/ample delivery fleet
• Ensure paver/vibrators work
• Flat pan; flat, solid slipforms
• No thin, ragged, bent, torn steel
• Optimize Mix to Paver
• Paper / software analysis
• Several 5 cy + batches in yard
• Trial paving/pours before test section
• Core/full depth sawcut for visual inspection

• Equipment Tigerbrain has worked with
and easily meet the Paver Wants:
• Gomaco
• Guntert & Zimmerman
• Wirtgen
• Allen Form‐rider Pavers (heavy model)

• Following equipment may be possible to meet
the Paver Wants, but must demonstrate
process is under control to consistently meet
Paver Wants:
• Trusses (acceptable standard d for odd‐shaped d areas; welded d steel
performs better than aluminum)
• Roller Screed*
• Bridge Deck*
• Laser Screed* (Navy allowed on 2 projects)
Laser Screed (Navy allowed on 2 projects)
*Expect strong negative reaction/rejection from DoD

• Additional test batches to match mix to paver
and labor
• Use 3+ spud vibrators
• Trial pours prior to test section
• Sawcut full depth to demonstrate
consolidation, ld no segregation or excess paste

After Taliban Attack, June 2010, Afghanistan
(one member of escort detail survived to report; USAF flew in contractor’s
backup paver)

Nighttime paving due to wind and heat; moon and artificial
lights enabled mortar attacks (bad aim-no injuries)

Afternoon sandstorm moving in
at MiG junkyard
Haul road through
thousands of Soviet-era
mines on Base (marked
with white painted rocks)

Gun tower
Gomaco pan
thin and
ragged
Used vibrating truss for
entire 35,000 square meter
apron

PCC w/ 10% silica
PCC w/ 10% silica
fume and
superplasticizer
4 meter
Concrete
T-Walls;
deflects
gunfire
from bad
guys

Dover AFB,
Atlantic Contracting

West Virginia

West Virginia

APAC-Tennessee

AJAX-Detroit

Not Quite…

Got it!

John R. Anderson, Ph.D., P.E. 407-365-7229 jranderson@tigerbrain.com