field validation of intelligent compaction monitoring...
TRANSCRIPT
tech transfer summary
Field Validation of Intelligent Compaction Monitoring Technology for Unbound Materials
ObjectivesThe objective of this research project was to evaluate intelligent compac-tion (IC) monitoring technology for use in earthwork construction for purposes of quality control and assurance. The following research tasks were established for the study:
• Develop relationships between roller-integrated and in situ compaction measurements, including dry unit weight, dynamic cone penetration (DCP) index, Clegg impact value (CIV), and light weight defl ectometer (LWD) modulus.
• Characterize measurement variation observed for the various measure-ment systems.
• Identify the infl uences of compaction energy and method on laboratory moisture-density relationships.
• Characterize laboratory resilient modulus in terms of soil type, stress state conditions, moisture content, and density.
• Develop QC/QA guidelines for incorporating roller-integrated compac-tion monitoring technology into soil compaction specifi cations.
Problem StatementThe successful implementation of IC technology into earthwork con-struction practice requires knowledge of the roller-integrated compaction measurements and their relationships with the engineering and index properties of soil that may be used for pavement design (e.g., California bearing ratio, elastic modulus, resilient modulus). These relationships, which are infl uenced by the factors affecting roller response, were studied at three earthwork construction projects in Minnesota.
Technology DescriptionTo improve upon the traditional approaches of process control and spot tests, intelligent compaction may provide real-time compaction results with 100 percent test coverage. This study investigated compaction meter value (CMV), also known as Caterpillar compaction value (CCV), and machine drive power (MDP) from Caterpillar rollers, and kB stiffness from an Ammann roller.
RESEARCH PROJECT TITLEField Validation of Intelligent Compaction Monitoring Technology for Unbound Materials
FINAL REPORT DATEApril 2007
SPONSORSMinnesota Department of TransportationFederal Highway Administration
PRINCIPAL INVESTIGATORDavid J. White, Ph.D.Assistant Professor, Civil, Construction, & Environmental EngineeringIowa State [email protected]
CO-AUTHORSPavana K R. VennapusaMark J. Thompson
KEYWORDSEarthwork Quality, Intelligent Compaction, Geostatistics, In situ Testing, Laboratory Compaction Testing, Resilient Modulus
MORE INFORMATIONwww.ctre.iastate.edu/pga
PGAIowa State University2711 S. Loop Drive, Suite 4700Ames, IA 50010-8664515-294-8103
The Partnership for Geotechnical Advancement (PGA) is part of the Center for Transportation Research and Education (CTRE) at Iowa State University. The mission of the PGA is to increase highway performance in a cost-effective manner by developing and implementing methods, materials, and technologies to solve highway construction problems in a continuing and sustainable manner.
The sponsors of this research are not responsible for the accuracy of the information presented herein. The conclusions expressed in this publication are not necessarily those of the sponsors.
Field Evaluation of IC TechnologyThree fi eld studies were conducted to investigate relation-ships between roller compaction values (CMV, MDP, kB) and in situ test measurements including dry unit weight, DCP index, CIV, and LWD modulus. Key fi ndings from each fi eld study are as follows:
• Field Study 1: IC mapping trials were performed in con-junction with in situ testing at select locations. Results showed that IC technology has the potential to effectively identify the areas of weak or poorly-compacted soil with real-time readings and 100 percent coverage.
• Field Study 2: Test strips were established for collecting compaction data and performing regression analysis to better describe the relationships between in situ and IC measurement values. Statistically-signifi cant correlations were observed between different measurement values for data collected over a relatively wide range of soil char-acteristics. Ammann kB was also related to rut depth measured after test rolling procedures.
• Field Study 3: This study was conducted on a grading project, in which IC technology was used as the principal method for quality control. The testing and analysis of this study, therefore, focused on evaluating the experience in terms of how the technology was used and how the technology performed. The calibration procedure and fi eld results were documented, and the relationships between in situ and IC measurement values were investigated at the proof scale and at the project scale. The study fi ndings show that IC technology is a feasible alternative for qual-ity control and acceptance, but that some challenges in interpreting the measurement values still remain.
Caterpillar vibratory smooth drum roller with integrated CMV and MDP technology: Field Study 1
Ammann vibratory smooth drum roller with ACE system to output kB stiffness values: Field Study 2
Caterpillar vibratory smooth drum roller with integrated CMV technology: Field Study 3
Rutting of subgrade following test roller operation
ELW
D-K
3(61
) (M
Pa)
0
50
100
150
200
CIV
4.5-
kg
0
10
20
30
40
DC
PIS (m
m/b
low
)
0
50
100
150
kB (MN/m)
0 10 20 30 40 50
ELW
D-K
3 (M
Pa)
0
50
100
150
200
kB (MN/m)
0 10 20 30 40 50
CIV
4.5-
kg
0
10
20
30
40
kB (MN/m)
0 10 20 30 40 50
DC
PIS (m
m/b
low
)
0
50
100
150
R 2 = 0.79
R 2 = 0.49
R2 = 0.48
R 2 = 0.49 R2 = 0.52
R 2 = 0.86DCPI = 939.2 kB -1.19
DCPI = 222.1 kB -0.65
CIV = 0.62 kB + 1.32
CIV = 0.23 kB + 3.97
ELWD = 3.30 kB - 13.84
ELWD = 3.50 kB - 26.25
Strip 1 Strip 1 Strip 1
Strip 4Strip 4Strip 4
Relationships between kB and in situ measurements for subgrade soil from Strips 1 and 4 (Field Study 2)
CC
V
0
50
100
150
ELW
D (M
Pa)
0
50
100
150200 mm300 mm
CC
V
0
50
100
150
! d (k
N/m
3)
20
22
24
CC
V
0
50
100
150
ELW
D(M
Pa)
0
100
200
300
Station (100 ft)
160 170 180 190 200 210 220 230 240 250
CC
V
0
50
100
150
DC
PIS (
mm
/blo
w)0
10
20
Zorn ZFG
300-mm Keros
Comparison of CCV and in situ compaction measurements on a 2-inch granular capping material underlain by native sand subgrade over 1.7 miles (Field Study 3)
GIS DatabaseIC technology provides opportunity to collect and evaluate information for 100 percent of the project area, but it also produces large data fi les that create analysis, visualization, transfer, and archival challenges. An approach for managing the data by creating a “geodatabase” using ArcGIS/ArcInfo modules is presented in the report. The geodatabase consists of TH 64 project IC data from proof and control sections, spot test measurements, and aerial images. Data visualiza-tion and analysis such as creating histogram plots, semivar-iogram models, and geostatistical analysis can be performed using ArcGIS.
Geostatistical AnalysisApplying geostatistical methods in the analysis of IC data has the advantage of quantifying spatial variability, which is not possible with classical statistical analysis. A “semivario-gram” model can be used to characterize uniformity of the IC data. To demonstrate the application, IC data collected for two control and two proof sections of the TH 64 project were analyzed and compared with the Mn/DOT specifi ed quality control criteria. Critical differences in spatial statis-tics relating to uniformity were observed between the two control sections, which were not observed with the univari-ate statistics. The two proof sections which “pass” the Mn/DOT acceptance criteria failed to meet an alternatively pro-posed “sill” criterion that establishes a uniformity criterion at a 30 m spatial scale. The implication of such incremental spatial analysis is that it will aid the contractor in identify-ing localized poorly compacted areas or highly non-uniform conditions, which are often the cause of
Field Study 1: Compaction monitor view at County 55 (viewing area 137 x 110 m) identifi ed by DCP test locations
Kriged surface map of CCV from proof no. 14 with overlaid spot test measurements (in red circles) – created using ArcMap
Location (m)
0 10 20 30 40 50 60
k B (M
N/m
)
5
10
15
20
25
30
Rut
Dep
th (c
m)
0
2
4
6
8
10
kB
Rut
Comparison of Ammann kB and rut depth along a subgrade test section (Field Study 2)
Field Study 1: DCP profi les at test shown in the above fi gure
pavement problems. Using “range” distance determined from a semivariogram model as the minimum window size for an area of evaluation, a 60 m long section was analyzed. The results showed that several isolated locations failed to meet the Mn/DOT acceptance criteria. The scale at which the acceptance criterion is based is still a question that needs further research.
Comparison of a proof section with a control strip using CCV surface maps and variograms
Hypothetical illustration of semivariograms characterizing uniformity
Laboratory Compaction Study
Laboratory compaction of soils should simulate the mechan-ics and energy delivery system that occurs in the fi eld. This is particularly important as it relates to soil fabric/structure and measuring engineering properties (e.g., strength and stiffness) of materials compacted in the lab. Laboratory com-paction tests performed using impact, static, gyratory, and vibratory compaction methods for one cohesive soil and one granular soil resulted in distinctly different moisture-den-sity relationships. On an energy per unit volume basis, the static compaction method can be more effi cient than impact compaction for the cohesive soil, but is found inadequate for the granular soil as it requires high contact stresses. The vibratory compaction method is inadequate to characterize moisture-density relationships for the cohesive soil, while it works effectively for the granular soil.
From limited laboratory resilient modulus (Mr) and un-consolidated-undrained (UU) strength tests on samples prepared using different compaction methods, it is found that the vibratory and impact compaction samples produce higher Mr and shear strength ( max) than static compac-tion samples for both soils. The vibratory method generally resulted in lower max than the impact method, while it produced similar or slightly higher max than the impact method for granular soil. A profound infl uence of moisture content is realized for the cohesive soil with Mr and max values decreasing with increasing moisture content. Mois-ture content did not have signifi cant infl uence on the Mr and max values for the granular soil.
Comparison of relationship between dry unit weight and impact, static, and vibratory compaction energy, and number of gyrations for mixed glacial till at (a) dry of optimum, (b) optimum, and (c) wet of optimum moisture content from standard Proctor test.
Field Comparison Study of LWD DevicesTo successfully implement the use of different LWD devices in QC/QA, it is important to understand the conditions for which they provide reliable measurements and also if differ-ences exist between the calculated elastic modulus values between the various devices. Some key factors that infl u-ence the estimation of ELWD include plate size, plate contact stress, type and location of defl ection transducer, usage of load transducer, loading rate, and buffer stiffness.
Two LWD devices (ZFG 2000 manufactured by Zorn Stendal from Germany, and the Keros manufactured by Dynatest in Denmark) with different plate diameters were evaluated to observe the differences in ELWD between the devices and the infl uence of plate diameter on the ELWD values. It is found that the Keros ELWD is on average 1.8 to 2.2 times greater than Zorn ELWD. The primary contributor for differences in ELWD between these devices is the difference in measured defl ections. The Zorn device measures about 1.5 times greater defl ection than Keros for the same plate diameter, drop height, and drop weight. A Zorn device with 200 mm plate results in ELWD about 1.4 times greater than with 300 mm plate.
An effort was made in this research to build a database of ELWD to Mr relationship by obtaining shelby tube samples from a compacted subgrade, at the locations of LWD tests. Based on limited data, a linear relationship between ELWD and Mr is observed at a selected stress condition, with R2 values ranging from 0.85 to 0.97.
200 mm Zorn ZFG 2000 LWD (left), 200 mm Keros LWD (Right)
Comparison of 200 mm Zorn and Keros ELWD
Comparison of 200 mm Zorn, Keros ELWD, and Resilient Modulus (Mr)
Key Attributes for Quality Management using IC: Equipment Requirements• Real-time corrections in the compaction process by the
roller operator and inspection personnel.
• On-demand visual review of in-cab monitor by inspector.
• Data provided to inspector in a timely manner in the form of printed, plan-view color maps, and electronically in the form of delimited ASCII data fi les.
• Summary of quality control parameters that include roller compaction value (e.g., IC-CTV), resonance meter value (RMV), operation parameters (amplitude, frequency, speed), and roller pass number.
• Roller position for each data record accurate to the fre-quency of the drum (x, y, z) coordinates for each end of the drum in UTM NAD 1983.
• Timestamp for each data record to the frequency of the drum.
Options and Approach to Quality Ac-ceptance (and Database Population) Using IC
Method Overview
The results from fi eld studies in this project and data analy-ses provided the basis for a conceptual process of quality acceptance and database development using IC technol-ogy (see fi gure below). As with any instrumented system, some level of calibration is required and is comprised of fi ve primary steps that include (1) roller data collection on a calibration area, (2) semivariogram modeling to determine sampling requirements, (3) in situ testing using other ap-proved testing devices on calibration area parallel with com-paction process, (4) regression analysis to determine target values, and (5) evaluation of production soil compaction using target machine values and semivariogram parameters as indicators of quality.
Level 1: Statistically-Rigorous Roller Calibration
A statistically-rigorous roller calibration can be achieved with suffi cient IC of roller and in situ measurement values. The need for many measurement values results from several sources of variability and measurement error that infl uence the precision and bias and also several factors affecting IC measurement values. These issues complicate generating relationships between IC data and in situ test measurements. Large datasets allow for statistical averaging that increases the reliability of a measurement at a particular location and also for improved correlation between measurement systems. Guidelines for establishing calibration data require-ments apply principally to in situ testing, as IC measure-ment values are monitored and stored nearly continuously. For statistically rigorous correlation studies, in situ testing using approved devices should occur at three locations across the drum width to (1) account for soil variability, (2) account for the infl uence of rear tire compaction, and (3) increase the measurement reliability. These data may be collected at three to fi ve test locations within the calculated (geostatistical) range interval (9 to 15 tests performed per range interval). Then, in building a regression from data collected throughout the entire compaction process (e.g., 1, 2, 4, 8 passes), the data within each range interval (three to fi ve points) may be averaged—in which case IC measure-ment values are also averaged over the range interval—or treated as individual test points.
Level 2: Reduced Roller Calibration Requirements
Level 1 roller calibration admittedly requires signifi cant initial investment in collecting in situ compaction measure-ments. Provided the contractor and/or owner are willing to accept some risk, the sampling requirements may be reduced. Level 2 roller calibration may also be used at later stages of earthwork projects after the initial calibration re-lationships have been developed. An inspector may overlay the regressions from calibration with reduced sampling over those generated from more frequent sampling to evaluate whether signifi cant changes (if any) are attributed to chang-es in material type, construction operations, etc. Calibra-tion that does not appear to refl ect the new conditions may indicate the need to re-calibrate the intelligent compaction measurements (Level 1) for the new conditions. The in situ testing requirements may be reduced to only one test at each location (i.e., not three across the drum width) and only one test location per range interval. These data may still allow for regression model development or verifi cation, but may disallow geostatistical analysis.
Level 3: Options for Eliminating Roller Calibration
The current Mn/DOT IC specifi cation requires the construc-tion of control strips in order to determine target values. The following options may serve as potential alternatives to constructing control/calibration strips:
• Mn/DOT may initially incorporate calibration on projects, but with time and experience, the agency may populate a large database that includes different IC technology compaction measurements and roller confi gurations, soil types, and representative lift sections. Field inspectors may use target values from the database that correspond to conditions of a specifi c project. Some supplemental in situ verifi cation testing for quality assurance may be required during production soil compaction to verify that the target value is providing reasonable estimates of in situ performance parameters.
• Develop new laboratory testing protocols for estimating target values for the roller and other in situ devices that allow for some empirical relationships to in situ compac-tion/stiffness measurements (by roller and in situ devices).
• Use existing relationships between machine parameters and material properties that have been documented in this report and in other literature (White et al. 2006, 2007). These relationships might be extrapolated for use on earthwork construction projects, but must consider the infl uence of moisture content, lift thickness, variable stiffness of underlying layers, and roller operational con-ditions (e.g., amplitude, frequency, speed) on soil compac-tion and machine response.
Recommendations for Implementation
The following recommendations are based on the present research study fi ndings and communication with representa-tives from Mn/DOT personnel, industry, and contractors.
Education
• Prepare a condensed fi eld inspector’s guide to intelligent compaction technologies, testing, documentation, and operations.
• Develop training curriculum for using intelligent compac-tion rollers, as well as other in situ testing methods used for calibration and verifi cation testing.
• Begin implementing IC specifi cations on a limited basis with on-site training/seminars for inspectors and contrac-tors. A research team may further facilitate technology transfer and training and speed up the implementation process. Such demand will additionally increase the avail-ability of IC rollers in Minnesota.
• Educate designers on how to use intelligent compac-tion technology to refi ne/validate pavement design and, ultimately, participate in establishing quality criteria for IC rollers.
• Facilitate discussion between roller manufacturers for the purpose of establishing some level of consistency between roller usage—a measure that will help eliminate bias towards a specifi c technology and enabling the users to select from a wide range of manufacturers.
Future Research
• Continue research in identifying and quantifying all the factors affecting IC measurements. Continue evaluating the relationships between in situ test results and IC data for different pavement foundation conditions.
• Continue development of database of relationships between design parameters (e.g., Mr) to in situ LWD mea-surements.
• Develop new or refi ne existing roller calibration proce-dures.
• Continue research on the appropriate scale at which the acceptance criteria are based.
• Continue research in the areas of modulus-based QC/QA protocols implicit to performance-based specifi cations.
• Monitor construction expediency and cost of projects using IC technology. Favorable comparison with conven-tional construction methods would warrant more rapid implementation. In the long term, pavement performance may further support the effectiveness of IC technology.
• Document/verify that use of IC technology produces a higher quality product than does the conventional ap-proach. This task may involve comparing IC output with test rolling results or may involve, in the longer term, comparison of performance of road sections constructed using different technologies/methods.
• Investigate how intelligent compaction technologies and specifi cations can be used to improve conventional earth-work operations (e.g., improved compaction effi ciency, improved material uniformity).
• Develop standard methods for managing, analyzing, and archiving the large quantities of IC data produced throughout a project.
Con
cept
ual p
roce
ss fo
r qu
alit
y as
sura
nce
usin
g IC
tech
nolo
gy
Values for CMV, dry unit weight, ELWD, and DCP index for different soils (mean, coeffi cient of variation)
Soil Type
GM a
SM b
GP c
SM d
GC e
SW-SM
SP f
Roller Confi guration
Vibratory Smooth
Vibratory Smooth
Vibratory Smooth
Vibratory Smooth
Vibratory Smooth
Vibratory Smooth
Vibratory Smooth
CMV
10.3
17.3
21.5
15.1
14.9
0-50
40-65
w (%)
8, 10
4, 15
3, 15
6, 14
8, 11
5-15
7-12
Dry Unit Weight (kN/m3)
17.2, 4
19.4, 3
15.0, 6
18.7, 3
18.5, 2
16-19
17-21
ELWD (MPa)
38, 38
34, 18
!
23, 25
40, 49
!
35-90 h
DCP Index (mm/blow)
17, 21
17, 10
!
45, 20
19, 31
!
10-25 i
Dataset Reference
White et al. (2007)
Field Study 1
Field Study 3
a wopt = 8%, d,max = 19.5 kN/m3; b d,max = 20.1 kN/m3; c Standard Proctor not applicable; d wopt = 8%, d,max =
19.8 kN/m3; e wopt = 10%, d,max = 20.0 kN/m3; f wopt = 10%, d,max = 20.0 kN/m3; g ELWD-K3(61); h ELWD-Z2(63);
i Mn/DOT DPI calculation
Values for kB, dry unit weight, ELWD, and DCP index for different soils (range)
Soil Type
CL a, b
SP-SM c
CL a, b
SP-SM c
CL a
Roller Confi guration
Vibratory Smooth
Vibratory Smooth
Vibratory Smooth
Vibratory Smooth
Vibratory Smooth
kB (MN/m)
30-40
20-35
20-45
25-40
10-35
w (%)
!
10-14
15-20
7-10
15-20
Dry Unit Weight (kN/m3)
!
16-17
16-18
18-19
16-17
ELWD-K3(61) (MPa)
10-50
20-40
60-110
10-70
10-80
DCPIS (mm/blow)
5-10
40-110
10-40
25-50
10-60
Dataset Reference
Field Study 2
a wopt = 18%, d,max = 16.2 kN/m3; b Excludes median testing; c wopt = 8%, d,max = 19.6 kN/m3
Values for EVIB, dry unit weigh, and DCP index for different soils (mean and coeffi cient of variation)
Soil Type
SM b
GW-GM c
Roller Confi guration
Vibratory Smooth
Vibratory Smooth
EVIB (MPa) a
46.6, 91
46.6, 91
w (%)
10, 28
4, 25
Dry Unit Weight (kN/m3)
19.6, 4
20.6, 4
DCPIS (mm/blow)
40, 77
23, 18
Dataset Reference
Petersen (2005)
a Values for combined soils; b wopt = 10%, d,max = 19.3 kN/m3; c wopt = 11%, d,max = 20.7 kN/m3
Sum
mar
y of
inte
llige
nt c
ompa
ctio
n sp
ecifi
cati
ons
Equi
pmen
tFi
eld
Siz
eLo
cati
on S
pecs
Doc
umen
tati
onC
ompa
ctio
n S
pecs
Spe
edFr
eq.
Mn/
DO
T (2
006
TH
64)*
Smoo
th d
rum
or
padf
oot v
ibra
tory
ro
ller (
25,0
00 lb
s.)
300
ft x
32 ft
(m
ini-m
um
at b
ase)
. M
ax 4
ft
thic
k.
One
calib
ratio
n/
cont
rol s
trip
per
type
or s
ourc
e of
gr
adin
g m
ater
ial
Com
pact
ion,
stif
fnes
s, m
oist
ure,
QC
activ
ities
, and
cor
rect
ive
actio
ns
(wee
kly
repo
rt)
90%
of t
he s
tiffn
ess
mea
sure
men
ts m
ust b
e at
90%
of t
he c
ompa
ctio
n ta
rget
val
ue.
Sam
e du
ring
calib
ratio
n an
d pr
oduc
tion
com
pact
ion
ISS
MG
ERo
ller c
hose
n by
ex
perie
nce
100
ft by
the
wid
th o
f the
si
te
Hom
ogen
ous,
eve
n su
rface
. Tra
ck
over
lap
10%
dr
um w
idth
.
Rolli
ng p
atte
rn, s
eque
nce
of
com
pact
ion
and
mea
surin
g pa
sses
; am
plitu
de, s
peed
, dyn
amic
mea
surin
g va
lues
, fre
quen
cy, j
ump
oper
atio
n, a
nd
corr
espo
ndin
g lo
catio
ns
Corr
elat
ion
coef
fi cie
nt
0.7
. Min
imum
val
ue
95%
of E
v 1, and
mea
n sh
ould
be
105%
(o
r 10
0% d
urin
g ju
mp
mod
e). D
ynam
ic
mea
surin
g va
lues
sho
uld
be lo
wer
than
the
spec
ifi ed
min
imum
for
10%
of t
he tr
ack.
M
easu
red
min
imum
sho
uld
be
80%
of t
he
spec
ifi ed
min
imum
. Sta
ndar
d de
viat
ion
(of
the
mea
n) m
ust b
e 20
% in
one
pas
s.
Cons
tant
2–6
km
/h(±
0.2
km
/h)
Cons
tant
(±
2 H
z)
Eart
hwor
ks(A
ustr
ia)
Vibr
atin
g ro
ller
com
pact
ors
with
ru
bber
whe
els
and
smoo
th
drum
s su
gges
ted
100
m lo
ng
by th
e w
idth
of
the
site
No
inho
mog
enei
ties
clos
e to
sur
face
(m
ater
ials
or w
ater
co
nten
t). Tr
ack
over
lap
10%
dr
um w
idth
.
Com
pact
ion
run
plan
, seq
uenc
e of
com
pact
ion
and
mea
sure
men
t ru
ns, v
eloc
ity, a
mpl
itude
, fre
quen
cy,
spee
d, d
ynam
ic m
easu
ring
valu
es,
jum
p op
erat
ion,
and
cor
resp
ondi
ng
loca
tions
Corr
elat
ion
coef
fi cie
nt
0.7.
Min
imum
val
ue
95%
of E
v1, a
nd m
edia
n sh
ould
be
105%
(o
r 10
0% d
urin
g ju
mp
mod
e). D
ynam
ic
mea
surin
g va
lues
sho
uld
be lo
wer
than
the
spec
ifi ed
min
imum
for
10%
of t
he tr
ack.
M
easu
red
min
imum
sho
uld
be
80%
of t
he
set m
inim
um. M
easu
red
max
imum
in a
run
cann
ot e
xcee
d th
e se
t max
imum
(150
% o
f the
de
term
ined
min
imum
).Sta
ndar
d de
viat
ion
(of
the
med
ian)
mus
t be
20%
in o
ne p
ass.
Cons
tant
2–6
km
/h(±
0.2
km
/h)
Cons
tant
(±
2 H
z)
Res
earc
h S
ocie
ty
for
Roa
d an
d Tr
affi c
G
erm
any)
Self-
prop
elle
d ro
llers
with
ru
bber
tire
driv
e ar
e pr
efer
red;
to
wed
vib
rato
ry
rolle
rs w
ith
tow
ing
vehi
cle
are
suita
ble.
Each
ca
libra
tion
area
mus
t co
ver a
t le
ast 3
pa
rtial
fi e
lds
~20
m
long
Leve
l and
free
of
pudd
les.
Sim
ilar
soil
type
, wat
er
cont
ent,
laye
r th
ickn
ess,
and
be
arin
g ca
paci
ty
of s
uppo
rt la
yers
. Tr
ack
over
lap
10%
mac
hine
w
idth
.
Dyna
mic
mea
surin
g va
lue;
freq
uenc
y;
spee
d; ju
mp
oper
atio
n; a
mpl
itude
; di
stan
ce; t
ime
of m
easu
rem
ent;
rolle
r typ
e; s
oil t
ype;
wat
er c
onte
nt;
laye
r thi
ckne
ss; d
ate,
tim
e, fi
le n
ame,
or
regi
stra
tion
num
ber;
wea
ther
co
nditi
ons;
pos
ition
of t
est t
rack
s an
d ro
lling
dire
ctio
n; a
bsol
ute
heig
ht o
r ap
plic
atio
n po
sitio
n; lo
cal c
ondi
tions
an
d em
bank
men
ts in
mar
gina
l are
as;
mac
hine
par
amet
ers;
and
per
ceiv
ed
devi
atio
ns
The
corr
elat
ion
coef
fi cie
nt re
sulti
ng fr
om a
re
gres
sion
ana
lysi
s m
ust b
e 0.
7. In
divi
dual
ar
ea u
nits
(the
wid
th o
f the
rolle
r dru
m) m
ust
have
a d
ynam
ic m
easu
ring
valu
e w
ithin
10
% o
f adj
acen
t are
a to
be
suita
ble
for
calib
ratio
n.
Cons
tant
Väg
verk
et
(Sw
eden
)Vi
brat
ory
or
osci
llatin
g si
ngle
-dru
m
rolle
r. M
in. l
inea
r lo
ad 1
5–30
kN
. Ro
ller-m
ount
ed
com
pact
ion
met
er o
ptio
nal.
Thic
knes
s of
larg
est
laye
r 0.
2–0.
6 m
Laye
r sha
ll be
ho
mog
enou
s an
d no
n-fro
zen.
Pr
otec
tive
laye
rs
< 0.
5 m
may
be
com
pact
ed w
ith
sub-
base
.
—
Bear
ing
capa
city
or d
egre
e of
com
pact
ion
requ
irem
ents
may
be
met
. Mea
n of
co
mpa
ctio
n va
lues
for t
wo
insp
ectio
n po
ints
89
% fo
r sub
-bas
e un
der r
oadb
ase
and
for p
rote
ctiv
e la
yers
ove
r 0.5
m th
ick;
mea
n sh
ould
be
90%
for r
oadb
ases
. Req
uire
d m
ean
for t
wo
bear
ing
capa
city
ratio
s va
ries
depe
ndin
g on
laye
r typ
e.
Cons
tant
2.
5–4.
0 km
/h
—
* N
ote:
The
200
7 M
n/DO
T in
telli
gent
com
pact
ion
proj
ects
will
impl
emen
t new
/revi
sed
spec
ifi ca
tions
for g
ranu
lar a
nd c
ohes
ive
mat
eria
ls in
clud
ing
a lig
ht w
eigh
t defl
ect
omet
er
(LW
D) q
ualit
y co
mpa
ctio
n pi
lot s
peci
fi cat
ion.