Understanding F&A Costs Date Presenter Name Presenter Phone Number Presenter E-mail.
With Application to Rural Roads in Presenter: Michael...
Transcript of With Application to Rural Roads in Presenter: Michael...
With Application to Rural Roads in
Michigan
Presenter: Michael Duell P.E.
With Permission from: M.I. Pinard,
AFCAP
Background
DCP Design Method
Material Selection and Specification
Compaction Quality Control Using the DCP
Strengths and Limitations of DCP Design Method
Additional Sources of Information:
ASTM D 6951, User Guide to the Dynamic Cone
Penetrometer (MnDOT), Saskatchewan Highways and
Transportation-STP 240-20, AASHTO Interim Structural
Pavement Design Procedure, Chapter 5-Geotechnical Inputs
for Pavement & Design-FHWA, NHI-05-037.
Details Worth Sweating
• Soil investigationo Appropriate number and type of borings
o Verify limits of existing poor soil
o Include appropriate pay items for soil removal
o (i.e. subgrade undercutting, earth excavation, etc.)
o Include boring logs on either the plans or in the GI submittal documents
o DO NOT include the geotechnical report
•Pavement cores?o Good idea!o Should extend at least 1-inch beyond the proposed removal/
replacement thicknesso Example-project proposing milling 4” of existing 5” HMA depth, actual
depth was less than 4”
Backgroundo Increasingly difficult to maintain:
Constraints: Financial, logistical, and technical burden coupled with depletion of non-renewable resource (gravel)
Consequences: Lack reliable access to many rural communities
1 Mile= 1.61 Kilometers
o Solution: Upgrade unpaved roads to a paved standardo Problem: Cost of upgrading following traditional approaches is prohibitively
expensiveo Way forward: Research has led to development of new approach for
upgrading gravel roads to a paved standard based on the use of the Dynamic Cone Penetrometer (DCP)
1 Inch= 25.4 mm
1 Pound= 0.454 kg
1 INCH= 25.4 mm
E 80 x 106 kN= 18,000 x LBS (Single) AXLE LOAD)103
)
1 Mile = 1.61 Kilometers
(Low Volume Sealed Roads) pavement.
*= AASTO T180 (Modified Proctor)
*
Conclusions
The DCP-DN Design Method:Makes use of a relatively inexpensive, multi-purpose device for characterizing
existing gravel road, testing pavement materials and undertaking compaction quality control.
Is based on a relatively simple design procedure that produces cost-effective environmentally optimized designs
Allows more extensive use to be made of local materials
Offers potential for economically upgrading a significantly greater length of gravel roads to a paved standard with similar risk as conventional pavement design techniques
Need for full appreciation of the strengths and weaknesses of the DCP device
Conclusions
Chip Seal Road10 Years After Construction
Gravel Road 4 Years After Construction
1 Mile = 1.61 Kilometers
Correlation of Data
log CBR = 2.46-1.12 log DPI
Where DPI = mm/Blow
MnDot 2502 Acceptance Specification of Pavement Edge
Drain Backfill Material
Locating Layers in Pavement Structures and Pavement
Rehabilitation Strategy Determination
Supplementing Foundation Testing for Design
Identifying Weak Spots in Constructed Embankments
Locating Boundaries of Required Subcuts
Determining Thaw/Freeze Depth During Spring
MnDOT
Pavement Design AASHTO ‘93 MOD. Crush & Shape Given: Reg. Factor = 4.5 Terminal Serv. =4.5 SSV=3.0SN =4.63 ESAL=1,000,000 ADT =320 DES. Life =20yrs Comm. ADT =2% MR (psi) =30,000 (ai /0.14)3
MR (psi) =2555 (CBR)0.64 CBR =292/( DCP1.12 ) mm/Blow
Auger Sample
Pvmnt Des.ai
MR PSi CBR %
IN/Blow
1.5 HMA1.5 HMA2.5 Recycle
0.420.420.20
9” AGG Base
8” AGG Base 0.14 30,000 46.9 0.20
24”Sand
12” SandSubbase
0.10 10,900 9.7 0.83
13”Sand SubgradeSSV = 3 CBR 3.5
0.08 5,700 3.5 2.86
SN = 5.12 › 4.63
0
9
33
0” 1” 2” 3”
Required LSP
Questions?