dan king, e.i.t. iowa concrete paving association · dan king, e.i.t. iowa concrete paving ... tie...
TRANSCRIPT
Dan King, E.I.T.
Iowa Concrete Paving Association
OUTLINE
Street and Highway Design with WinPAS
AASHTO 93 design method
SUDAS pavement design
ACI Concrete Parking Lot Design Guide
ACI Industrial & Trucking Facility Design
Guide
Previous Image: GCC Ready Mix
WinPAS DESIGN
If Eric hasn’t already convinced you to use
PavementDesigner...
Free-to-use
Easily accessible in your web browser
Modern, streamlined interface
Links to a library of supplemental resources
...PavementDesigner is a fantastic new tool!
WinPAS (AASHTO design) can be a useful
pavement design tool as well
WinPAS DESIGN
WinPAS = Windows Pavement Analyst
Software
Electronic version of AASHTO 1993
Pavement Design Guide
For both concrete and asphalt pavements
Although it is not included in
PavementDesigner.org, AASHTO design is
still used by many agencies across the
country
Basis for SUDAS pavement design
WinPAS DESIGN
AASHTO 93 Design
A mostly empirical design procedure based on
performance of the AASHO road test sections
Has been modified over the years to account for
more variables and concepts
AASHO Road Test, 1950s
Q: Where at?
WinPAS DESIGN
AASHTO 93 Design
Uses many of the same design inputs as
PavementDesigner (PCA Method/StreetPave)
Some different, unique concepts between the two
The equations/models may handle same inputs
differently
AASHO Road Test, 1950s
Ottawa, IL (I-80)
WinPAS DESIGN
Some differences with WinPAS/AASHTO
design:
Traffic level characterized by ESALs
Equivalent single axle loads
Based on load equivalency factors for different types
of trucks
Only considers a particular number of load
repetitions to failure, calibrated based on AASHO
road test results
No modeling of fatigue or erosion like in
PavementDesigner
WinPAS DESIGN
Some differences with WinPAS/AASHTO
design:
End of pavement life: terminal serviceability
index
Instead of defining % slabs cracked
Joint spacing does not play any role in thickness
design
Some different terms for reliability, standard
deviation
WinPAS DESIGN
When might you want to use
WinPAS/AASHTO pavement design?
It does have well-known limitations
But it’s also been used successfully for many
years and is well-understood by many of its
practitioners
Both for concrete and asphalt
The closer you get to the conditions of the
AASHO road test, the more accurate the
procedure will be
WinPAS DESIGN
When might you want to use
WinPAS/AASHTO pavement design?
Climate, materials and soils in Iowa are similar to
those at the road test site in northern Illinois
Designing for low-to-medium traffic volumes may
be closer to road test conditions than higher
volume traffic
Good understanding of the design procedure
and customized local design inputs &
commentary
SUDAS Pavement Thickness Design
WinPAS DESIGN
SUDAS Pavement Thickness Design
Section 5F-1 in design manual
Based on AASHTO 93 design methods for both
concrete and asphalt pavements
Provides full commentary and explanation of
AASHTO 93 input values, including
recommendations for representative Iowa values
WinPAS DESIGN
SUDAS Pavement Thickness Design
Contains basic design tables & sample
calculations for simple designs
Can also plug recommended inputs directly into
WinPAS to perform a custom pavement design
Allows for easy comparison of equivalent
AASHTO 93 concrete & asphalt designs for local
conditions
WinPAS DESIGN
Walk-through design example
WinPAS DESIGN
Other capabilities in WinPAS
Concrete overlays
AASHTO 93 concrete overlay design can be a bit out
of date
PavementDesigner + BCOA-ME are likely better tools
Life cycle cost analysis
Full control of input costs, discount rates, etc.
Not included in PavementDesigner
WinPAS DESIGN
Final thoughts on thickness design for PCC
streets and highways
Different design procedures can be effective and
useful tools, provided:
Good understanding by practitioner
Applicable to situation you are designing for
Quality of data and inputs
Ability to customize input values
WinPAS DESIGN
In the future, street/highway design will
continue to transition to more mechanistic
procedures like Pavement ME
State agency-level: gradually phasing in now
across US
Local level: implementation is a bit farther out,
could be quite different
ACI PARKING LOT DESIGN
ACI 330R-08: Guide for the
Design and Construction of
Concrete Parking Lots
Available through
ICPA/IRMCA
Thickness design
components are fully
incorporated into
PavementDesigner.org
Same StreetPave/PCA
design methodology
ACI PARKING LOT DESIGN
PavementDesigner.org:
ACI PARKING LOT DESIGN
Some things to consider for design of
concrete parking lots:
Traffic
Subbase & Subgrade
Jointing
Reinforcement
ACI PARKING LOT DESIGN
Traffic Inputs
Choose a category based on chart below
Each category is available in PavementDesigner
Traffic category dictates assumed axle load
distribution for thickness design
ACI PARKING LOT DESIGN
Subbase & Subgrade
Just like with concrete streets and roads,
uniformity of support is more important than
strength
Subbase more useful to promote good drainage
& ensure stable working platform on weak soils
Water Table – 100%
Saturation
Cracking
from non-
uniform
support from
differential
soil
movement.
Capillary
Fringe
Adsorption
Water
Surface Water
ACI PARKING LOT DESIGN
Jointing
Contraction joints
Timely sawing necessary to prevent random cracking
Recommended minimum T/4 saw depth with
conventional saws
Recommended 1” to 1 1
4” saw cut depth with early-
entry saws
Filling/sealing joints
May not be necessary if you have a drainable
subbase
Recommended 1/8” saw cut width if leaving unsealed
Recommended 1/4” to 3/8” saw cut width if
filling/sealing
ACI PARKING LOT DESIGN
Jointing
Recommended joint spacing
Smaller slabs help control cracking, mitigate curling
stresses
Panel length should not exceed width by more than
25% (square slabs)
Guidelines in ACI guide currently a bit longer than
what PavementDesigner may show as an output
ACI PARKING LOT DESIGN
Reinforcement
“Distributed steel reinforcement is not
necessary.”
Stay within recommended joint spacings from table
Steel can help prevent cracks from opening
Construction difficulties...
Proper joint spacing and incorporating subbase may be
more proactive way to prevent cracking
Consider fiber-reinforced concrete as an alternative to
steel
Dowel bars generally only needed for load
transfer in case of heavy, one-way truck traffic
(driving lane)
ACI PARKING LOT DESIGN
Tie bars recommended
for outermost row of
panels around the
perimeter:
Tension Ring
Exception for integral
curb
Also recommended for
centerline joint on drive
lanes, etc.
ACI PARKING LOT DESIGN
In summary:
PavementDesigner makes concrete parking lot
thickness design simple and easy
The ACI guide is still a valuable resource to help
with some of the other unique aspects of
concrete parking lot design
INDUSTRIAL & TRUCKING FACILITY
DESIGN
ACI 330.2R-17: Guide for the Design and Construction of Concrete Site Paving for Industrial and Trucking Facilities
Brand new in 2017!
Available through ICPA/IRMCA
Thickness design components use
combination of StreetPave/PCA Methodology + ACPA AirPave
Included in PavementDesigner.org
INDUSTRIAL & TRUCKING FACILITY
DESIGN
Many of the general principles in this guide
follow those of “regular” parking lots
Industrial-type facilities can have unique
traffic loadings:
Not only heavy trucks, but
forklifts, telehandlers, lulls...
INDUSTRIAL & TRUCKING FACILITY
DESIGN Thickness design tables are available for
over-the-road trucks and various types of lift
trucks:
INDUSTRIAL & TRUCKING FACILITY
DESIGN Because of nature of loading at these
facilities, dowel bars may be needed for load
transfer
Two-directional doweling for all-way movements
Guidance provided on use of alternative dowel
bar types, such as square or plate dowels
May better handle stresses, shrinkage, and lateral
movement than round dowels when two-directional
doweling is needed
Images: PNA Construction
THANK YOU!
ICPA Workshop, 1980