Braun Intertec Pavement Recommendations 08-30-2012Braun Intertec Corporation }'crone: Q52.gg3. 000
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August 30, 2012
Mr. Todd Simning
Galpin Boulevard Partners, LLC
PO Box 218
Chanhassen, MN 55317
Project BL -12 -05123
CITY OF CHANHASSEN
RECEIVED
SEP 13 2012
Re: Pavement Recommendations
Song Property
7042 Galpin Boulevard
Chanhassen, Minnesota
Dear Mr. Simning:
CHANHASSEN PLANNING i]py
As requested by Otto and Associates, we are providing you with a bituminous pavement section for
the referenced property.
Background
You plan on developing the Song property into a small 4 -lot residential housing development. As part
of this development, a new private street will be constructed. You requested that we provide you and
your design team with a proposed bituminous pavement section for this street.
it is our understanding that the city requires that the street be designed as a 7 -ton street to allow for
emergency vehicle traffic. It will be constructed as a rural section, without curb and gutter. Based on
the size of this street, we have assumed that the road will be subjected to no more than 400 ADT
(Average Daily Traffic).
Recommendations
We have completed numerous projects in this area of Chanhassen, including the development on the
east side of Galpin Boulevard, just north of West 78th Street. The soils in this part of Chanhassen
generally consist of sandy lean clay. Based on experience, these soils generally will test to have
Hveem Stabilometer R- values ranging from 10 to 20. For this project we recommend using an
assumed R -value of 10. This translates into an AASHTO classification of A -7 -6 and a soil factor of 130.
Based upon these assumptions, we recommend a pavement section that includes 3 1/2 inches of
bituminous pavement (a 1 1/2 -inch surface course over a 2 -inch base course) over 10 inches of
aggregate base material. This assumes that the subgrade is prepared so that it will be stable and pass
a proof roll with a loaded tandem axle dump truck.
The above pavement designs are based upon a 20 -year performance life. This is the amount of time
before major reconstruction is anticipated. This performance life assumes maintenance, such as seal
coating and crack sealing, is routinely performed. The actual pavement life will vary depending on
variations in weather, traffic conditions and maintenance.
AA,! 1.01. Pnwidinq E °nr(neering and oil :irr. solatiom sittce' 195.
Galpin Boulevard Partners, LLC
Project BL -12 -05123
August 30, 2012
Page 2
We recommend specifying crushed aggregate base meeting the requirements of Minnesota
Department of Transportation (Mn /DOT) Specification 3138 for Class 5 or similar. We recommend
that the bituminous wear and base courses meet the requirements of Specifications 2360, Type SP.
We recommend the aggregate gradations for the asphalt mixes meet Gradation B for the base course
and Gradation B or A for the surface course. Gradation A contains a smaller aggregate size than
Gradation B and will provide a surface with less visible aggregate which is desirable for some owners.
We recommend the Performance Graded Asphalt cement be a PG 58 -28. (If additional resistance to
rutting, scuffing and dimpling is desired, we recommend utilizing a PG 64 -28. If additional resistance
to cold weather cracking is desirable, we recommend utilizing a PG 58 -34.)
We recommend that the aggregate base be compacted to a minimum of 100 percent of its maximum
standard Proctor dry density. We recommend that the bituminous pavement be compacted to at
least 92 percent of the maximum theoretical Rice density.
We recommend installing perforated drainpipes throughout pavement areas at low points and about
catch basins. The drainpipes should be placed in small trenches extended at least 8 inches below the
granular subbase layer — or aggregate base material where no subbase is present.
Remarks
In performing its services, Braun Intertec used that degree of care and skill ordinarily exercised under
similar circumstances by reputable members of its profession currently practicing in the same locality.
No warranty, express or implied, is made.
If you have any questions about this report, please call Henry Vloo at 952.995.2238 or Gregg Jandro at
952.995.2270.
Sincerely,
BRAUN INTERTEC CORPORATION
Professional Certification:
I hereby certify that this plan, specification or report
was prepared by me or under my direct supervision
and that I am a duly Licensed Professional Engineer
under the laws of the State of Minnesota.
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Henry oo, PE a �yi»•''
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Associate —Senior Engineer
License Number: 21140 IfFlYgyVL
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Vice President — Principal Engineer , 1 1 of
c: Ms. Cara Schwahn Otto; Otto Associates B RA U N
INTERTEC