Thermally and Mechanically Balanced Structural Design of Insulated Pavements for Cold Region Applications
Zhuang Zhuo1, Ayman Ali1, Cheng Zhu1, Yusuf Mehta1, Wade Lein2, Christopher DeCarlo2, Zhaoxing Xie1
1Rowan University; 2US Army Corps of Engineers
Experimental Setup
Results and Discussion
44’’
Surface
HMA 4’’
5’’
RCA
0
Thermocouples
44’’
#6
5’’
5’’
#4
RCA 5’’
Insulation 2’’
Layer
5’’
#2
5’’
#1
2’’
5’’
4’’
5’’
5’’
Subgrade 20’’
5’’
8
Base
10
12
14
Insulation
16
22’’
11’’
11’’
18
11’’
11’’
22’’
Schematic view of insulated pavement boxes
20
-15
Jan
May
Sep
-10
Mar
Jul
Dec
-5
0
4
6
8
Base
10
12
Jan
Mar
May
Jul
Sep
Dec
14
16
Subgrade
18
20
5
Temperature (C)
10
15
0.0
Insulation
Subgrade
2.0x10-4 4.0x10-4 6.0x10-4 8.0x10-4 1.0x10-3
Vertical Strain
Predicted thermal and mechanical responses
datalogger
Start
Chiller
Select Failure Limits or
Design Criteria and
Reliability Level
6
HMA
2
HMA
4
5’’
HMA
5’’
#3
Subgrade 20’’
4’’
4’’
#5
0
2
Thermocouples
44’’
Depth (in.)
Add an insulation layer above the frostsusceptible layer have been proved to be an
efficient strategy to mitigate frost effect on
pavements in cold regions.
Limited research was conducted on the thermal
and mechanical design of insulated pavement
Objective: Propose a thermally and mechanically
design approach based on a novel finite element
model
Methodology and Finite Element Model
44’’
Depth (in.)
Background and Objective
Loading area
Photos of insulated pavement boxes
Maximum Load Repetitions of Insulated Pavement
(millions)
tHMA (in.)
4
EHMA (ksi)
500
1100
tBase (in.)
5
9
13
5
9
13
1
6
8
8
21
43
50
tInsulation
2
5
7
8
20
32
35
(in.)
3
5
6
7
20
30
30
Select Trial Design Structure
Validating the FE model with Test Results
Predict Performance and Maximum
Allowable Traffic ESALs
0.3L
Meet the Criteria?
Yes
Output Results
L
End
Flow chart of the design process
Loading area
20
DVertical, KENPAVE
DVertical, Elastic
Vertical, KENPAVE
0.025
15
Vertical, Elastic
Horizontal, KENPAVE
Horizontal, Elastic
0.020
10
120
100
80
60
0.015
40
0
0.010
20
0.005
0
5
10
15
Measured Temperature (C)
Thermal Field
20
0.0004
0.0003
0.0002
0.0001
0.0000
-0.0002
-0.0003
-0.0004
-5
-5
0.0005
-0.0001
5
Subgrade R2=0.9627
Base
R2=0.9806
Surface R2=0.9931
Horizontal Strain
Control Box
Vertical Stress (psi)
0.030
Vertical Displacement (in.)
No
25
Symmetric
Simulated Temperature (C)
Estimate Thermal and Mechanical
Responses based on the FE Model
FE model
25
0
3
6
9
12
15
18
21
24
Depth (in.)
Mechanical Field
0
27
-0.0005
30
Conclusions
The design of insulated pavements need
to consider the differential icing effect and
mechanical performance.
Design tables were formulated based on
the FE model and selected criteria.
Acknowledgement
Funding under PE 0602784A, Project T53 "Military Engineering
Applied Research,” Task 08 under Contract W913E518C0008
made it possible to complete this work. Special thanks to the US
Army Engineer Research and Development Center (ERDC) for
managing and supervising this effort.