10-1938

CalME A New Mechanistic-Empirical Design Program for Flexible Pavement Rehabilitation P Ullidtz corresponding Dynatest International Naverland 32 DK 2600 Glostrup Denmark Phone +45 7025 3355 email pullidtzdynatestcom J Harvey University of California Pavement Research Center Department of Civil and Environmental Engineering University of California Davis California USA Phone 530 754 6409 email jtharveyucdavisedu I Basheer Division of Pavement Management California Department of Transportation (Caltrans) 5900 Folsom Blvd Sacramento California 95819 USA Phone (916) 227-5840 email imadbasheerdotcagov D Jones University of California Pavement Research Center Department of Civil and Environmental Engineering University of California Davis California USA Phone 530 754 2241 email djjonesucdavisedu R Wu University of California Pavement Research Center Department of Civil and Environmental Engineering University of California Davis California USA Phone 510-665-6721 email rzwuucdavisedu J Lea University of California Pavement Research Center Department of Civil and Environmental Engineering University of California Davis California USA Phone 530 752 1752 email jdleaucdavisedu Q Lu University of California Pavement Research Center 1353 S 46th St Bldg 452-T University of California Berkeley Richmond CA 94804 USA Tel (510) 665-3596 Fax (510) 665-3562 Email qluucdavisedu Word count 4457 words 12 figures 250 words Total 7457 words

TRB 2010 Annual Meeting CD-ROM Paper revised from original submittal

Mechanistic-Empirical Design of Asphalt Overlays using 1

CalME 2

ABSTRACT 3

A computer program known as CalME has been developed for analysis and design of 4 new flexible pavements and rehabilitation of existing pavements The paper describes the 5 overlay design procedure and the calibration of the models for reflection cracking and 6 permanent deformation through Heavy Vehicle Simulator (HVS) tests To simplify the 7 input process the program includes databases for traffic loading climatic conditions and 8 standard materials A companion program was developed for backcalculation of layer 9 moduli and the results may be automatically imported into the CalME database The 10 program incorporates the existing empirical California Department of Transportation 11 (Caltrans) design methods as well as an incremental-recursive analysis procedure based 12 on the mechanistic-empirical method The effects of different pavement preservation and 13 rehabilitation strategies on pavement damage may be studied with several options for 14 triggering timing of placement The influence of within-project variability on the 15 propagation of damage can be evaluated using Monte Carlo simulation The program 16 also permits importation of the results of HVS or track tests into the database and 17 simulation of the experiments on the computer This is very useful for the calibration of 18 the mechanistic-empirical models but may also be used for an in-depth interpretation of 19 accelerated pavement testing results An HVS experiment that was used for calibration of 20 the reflection cracking and the permanent deformation models is described 21

INTRODUCTION 22

23 CalME is a computer program developed by Caltrans for analysis and design of 24 rehabilitation using asphalt overlays and of new flexible pavements It is currently 25 configured for California practice It includes the existing Caltrans empirical design 26 methods a classical mechanistic-empirical (ME) method and an incremental-recursive 27 ME-based procedure using the time-hardening approach for modeling and simulating 28 pavement response and performance The models for new design and their calibration 29 using Heavy Vehicle Simulator (HVS) tests are described in Ullidtz et al 2008 The 30 present paper presents a quick summary of the program and an overview of the models 31 used for rehabilitation design and their calibration using HVS testing 32 33 CalME was developed beginning in the late 1990s using research products from the 34 SHRP program (1989-1993) subsequent Caltrans sponsored research and development 35 and gathering of models and data from research programs around the world CalME was 36 developed to fill the following needs for an ME analysis tool for use in California 37

Emphasis on rehabilitation and pavement preservation (a term invented later) 38 which account for more than 90 percent of Caltrans pavement program rather 39 than new pavements 40

Emphasis on use of in-situ pavement testing data for existing pavements (namely 41 Falling Weight Deflectometer [FWD] data) as opposed to sampling and 42 laboratory testing 43


3

Able to consider reflection cracking rutting in overlays and modified asphalt 1 mixtures particularly rubber- and polymer-modified mixes 2

Capable of simulating damage and predicting pavement response (deflections 3 strains stresses) throughout the pavement life as opposed to only the initial and 4 final conditions 5

Compatible with calibration using accelerated pavement testing data (made 6 possible by the previous item) 7

Able to consider variability through Monte Carlo simulation with reasonable run 8 times 9

Source code available to Caltrans and partner agencies for understanding and 10 modification 11

Development was continued by Caltrans early in this decade when it was determined 12 from available information that the National Cooperative Highway Research Program 13 (NCHRP) Mechanistic Empirical Pavement design Guide (MEPDG) flexible pavement 14 models did not fully meet these criteria Caltrans ultimate goal is that CalME or its 15 models and ideas become part of multi-state or national long-term research and 16 development programs 17

OVERLAY DESIGN WITH CalME 18

An important input for design of an asphalt overlay is the structural condition of the 19 existing pavement The material types the layer thicknesses and resilient moduli must be 20 determined A companion program called CalBack has been developed for 21 backcalculation of layer moduli from FWD data (for details see Lu et al 2009) CalBack 22 stores the material types test temperatures layer thicknesses and backcalculated moduli 23 in a database from which the information is automatically imported into CalME The 24 variability of the layer moduli is calculated by CalME for use with the Monte Carlo 25 simulation option 26 27 For existing asphalt pavements with surface cracking the typical distance between the 28 cracks must be recorded For jointed Portland cement concrete (PCC) pavements the 29 distance between the joints is required for use in the reflection cracking model 30

Traffic Data 31

The required traffic input is the axle load spectrum from a Weigh In Motion (WIM) 32 station CalME has a database with axle load spectra from all WIM stations in California 33 and the appropriate WIM station is selected from a list by the user For Californian 34 conditions a procedure has been developed to obtain axle load spectra for highways 35 without WIM information (Lu and Harvey 2006 Lu 2008) 36

Climate 37

California has been divided into a number of climate zones for the purpose of flexible 38 pavement design (Harvey et al 2000) For each zone the surface temperature each hour 39 during a period of 30 years has been precalculated for a range of pavement structures 40 and included in the CalME database CalME calculates the temperatures at the required 41 depths based on interpolation between EICM simulations for representative structures 42


4

(Ongel et al 2004) using an algorithm that reduces the size of the database and speeds 1 retrieval 2 3

4 Figure 1 Basic input parameters for rehabilitation design 5 6 In the caption of the form shown in Figure 1 the climate zone (Mountain High Desert) 7 and the WIM station (WIM057058) are indicated Both of these are chosen by the user 8 from a list The design life for the initial treatment is selected by the user (default 20 9 years shown) The number of axle loadings in the design lane during the first year of the 10 design period and the annual growth rate in percent are imported from the traffic 11 database The values may be changed by the user 12

Materials Library 13

In Figure 1 the layer names thicknesses and moduli are imported from the CalBack 14 database Each name is associated with a large number of model parameters describing 15 the master curve fatigue properties permanent deformation susceptibility and other 16 model parameters appropriate for the material type The CalME database has a library of 17 standard pavement materials based on their specification class with default data based on 18 laboratory and field testing for representative materials When imported from a CalBack 19 database the names are preceded by ldquoOld-ldquo to indicate that these are existing materials 20 The moduli are the mean values and for asphalt materials the values displayed are for the 21 annual average temperature and to a loading time of 15 msec The remaining information 22 in the table and the information in the Rehabilitation frame is related to the Caltrans 23 empirical design methods 24

Caltrans Empirical Method 25

The present Caltrans rehabilitation design method is based on the 80th percentile 26 deflection value (D80) corresponding to the California deflectograph load This is 27 calculated from the temperature adjusted layer moduli in CalBack The CalME 28 architecture is amenable to inclusion of other empirical methods for initial design and 29 comparison purposes 30


5

1 The Tolerable Deflection at Surface and the required Percent Reduction in Deflection for 2 the design traffic is calculated in accordance with the Caltrans Highway Design Manual 3 (Caltrans 2008) A list of rehabilitation alternatives is then presented (see Figure 2) 4 Clicking on the line of one of the alternatives will add this alternative to the structure 5 shown in Figure 1 The solution with Mill 180 for example would remove all of the 6 existing asphalt layer (150 mm thick) and 30 mm of the aggregate base (AB) and replace 7 it with 180 mm of Dense Graded Asphalt Concrete (DGAC) 8 9

10 Figure 2 List of Rehabilitation alternatives from Caltrans rehabilitation design 11 12 Classical ME Method 13 14 In Figure 1 the Classical Design method uses the Asphalt Institute design criteria 15 (although other criteria may be used) The user may select this method to check the 16 residual life of the existing structure This method may also be used to design an overlay 17 for fatigue cracking and overall pavement rutting (subgrade strain criteria) 18

Incremental-Recursive Analysis 19

In Figure 1 this method is labeled as Recursive The incremental-recursive procedure 20 does not propose a rehabilitation design but may be used to determine how a given 21 design performs with respect to rutting and cracking in each layer For instance selecting 22 the 90 mm DGAC solution from Figure 2 and running the incremental-recursive analysis 23 (with no lateral traffic wander and including reflection cracking) would result in a total 24 permanent deformation (RD) of 55 mm and cracking density (Cr) of 02 mm2 after 20 25 years which would be satisfactory for typical design limits of 10 mm of permanent 26 deformation and 05 mm2 of cracking 27 28


6

1 Figure 3 Performance versus time with 90 mm DGAC overlay ( 5 years between vertical bold lines) 2 3 Simulations are carried out to two times the design life plus one year or 41 years in this 4 example (Figure 3) to limit truncation of data for the Monte Carlo simulations 5

Monte Carlo Simulation 6

The simulation in Figure 3 is based on the mean values of all parameters CalME has a 7 Monte Carlo simulation option where the input includes the distribution of a number of 8 important structural parameters This makes it possible to determine the influence of 9 within-project variability on the propagation of damage The variability of layer moduli is 10 calculated from the backcalculated values imported from the CalBack database For each 11 of the Monte Carlo runs the parameters are selected randomly from the distributions 12

Wes02FLM_MC

0

02

04

06

08

1

12

14

16

18

0 5 10 15 20 25 30 35 40 45

Years

Cra

ckin

g m

msq

13 Figure 4 Cracking severity as a function of time (20 simulations) mean and plusmn one standard deviation 14


7

Wes02FLM_MC

0

10

20

30

40

50

60

70

80

90

0 5 10 15 20 25 30 35 40 45

Years

Per

cen

t gt=

05

mm

sq

1 Figure 5 Crack propagation as a function of time (20 simulations) 2 3 Figure 4 shows the development of cracking severity over time The heavy curve is the 4 mean cracking severity for the 20 Monte Carlo simulations the thin curves indicate the 5 mean value plus and minus one standard deviation and the horizontal line is the limit 6 The mean cracking severity will reach the limit after 32 years Figure 5 shows the 7 propagation of the cracked area within the project through progressive crack development 8 in sub-sections with cracking having a cracking severity of 05 mm2 or more within a 9 sub-section Less than 5 of the area will reach the limit within the design life of 20 10 years 11 12 Twenty simulations of 41 years each for this structure took approximately 20 minutes on 13 a 2007 model X61s Lenovo laptop computer 14

Maintenance and Rehabilitation Scheduling 15

CalME offers the user the ability to schedule one or more maintenance and rehabilitation 16 (MampR) or pavement preservation activities An example is shown in Figure 6 where 30 17 mm has been milled and inlaid with HMA at year 20 and simulation of cracking (red line) 18 and rutting (blue line) is continued for another 20 years 19


8

1 Figure 6 Performance prediction with 30 mm mill and fill with HMA after 20 years 2 3 MampR strategies may also be set up based on the pavement condition in terms of level of 4 permanent deformation andor cracking of the wearing course rather than a fixed year 5 which permits consideration of different pavement preservation actions and trigger 6 criteria 7

CALIBRATION OF MODELS 8

9 One of the facilities of CalME is that the results of HVS or track tests can be imported 10 into the CalME database The test may then be simulated hour by hour for the duration 11 of the test and the predicted responses and performances can be compared to the 12 measured values from pavement instrumentation thus facilitating the calibration of the 13 CalME models 14 15 The HVS project used for calibration of overlay models was divided into two phases In 16 the first phase six test sections of a uniform pavement were trafficked with the HVS to 17 induce fatigue cracking on the asphalt concrete layer The original pavement consisted of 18 approximately 80 mm of DGAC on a design thickness of 410 mm of aggregate base (AB) 19 on a clay subgrade The AB consisted of 100 recycled building waste material with a 20 high percentage of crushed concrete Reactive cement was found in the AB In the second 21 phase selected overlay mixes were placed both on the trafficked and untrafficked 22 sections to evaluate reflection cracking as well as permanent deformation 23 24 The test sections were instrumented with Multi Depth Deflectometers (MDDs) and 25 thermocouples At regular intervals during the HVS tests the resilient deflections were 26 recorded at several depths using the MDDs and at the pavement surface using a Road 27 Surface Deflectometer (RSD similar to a Benkelman beam) The permanent 28 deformations were also recorded by the MDDs and the pavement profile was measured 29 using a laser profilometer Any distress at the surface of the pavement was recorded 30 During HVS testing the temperature was controlled using a climate chamber Falling 31 Weight Deflectometer (FWD) tests were carried out before and after the HVS tests 32 Details on the HVS and the instrumentation can be found in Harvey et al 1996 and on 33 the overall study in Jones et al 2007a and 2007b 34 35


9

Elastic Parameters and Calculation of Response 1

Elastic parameters of the materials were backcalculated from the last FWD tests before 2 commencement of the HVS loading For asphalt layers the master curve was obtained 3 from frequency sweep tests on beams in the laboratory With the exception of the original 4 DGAC layer the agreement between the backcalculated moduli and the laboratory master 5 curves was good For the subgrade the change in stiffness with changing stiffness of the 6 pavement layers and with changing load level was obtained from FWD backcalculated 7 values These parameters were used with a layered elastic response model to calculate 8 stresses strains and deflections in the pavement structure for each hour of the tests 9 10 Reflection cracking damage was calculated using the method developed by Wu (2005) In 11 this method the tensile strain at the bottom of the overlay over an existing crack is 12 estimated using a regression equation developed using many 2D and 3D finite element 13 calculations This tensile strain is used with the fatigue equation to calculate damage in 14 the asphalt layers The tensile strain at the bottom of the overlay in igravestrain is calculated 15 from the following equation assuming a dual wheel on a single axle 16 17

aHHa

HHaLSLS

EEEEE

EEEEE

EbHbHbLSbaEE

uun

aann

so

ns

uun

sb

bns

aan

nununannbnan

41312expln1121

18

19 Equation 1 20 21 where Ea and Ha are the overlay modulus and thickness respectively Eu and Hu are the 22 underlayer modulus and thickness respectively Eb is the modulus of the basesub-base 23 Es is the modulus of the subgrade LS is the crack spacing oacuteo is the tire pressure and a is 24 the radius of the loaded area for one wheel and constants are as follows aacute = 342650 acirc1 25 = -073722 acirc2 = -02645 acirc3 = -116472 a1 = 088432 b1 = 015272 26 b2 = -021632 b3 = -0061 b4 = 0018752 27 28

Prediction of Damage in Asphalt 29

To predict reflection cracking the resulting principal tensile strain at the tip of the crack 30 from Equation 1 was used with the model for the master curve of the damaged asphalt 31 which has the format 32 33

tr

Elogexp1

1log

34

Equation 2 35 36 where auml aacute acirc and atilde are constants tr is reduced time in sec and ugrave is the damage 37 calculated from 38 39


10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1

Equation 3 2 3 where E is the modulus of damaged material Ei is the modulus of intact material MN is 4 the number of load repetitions in millions (N106) igravearing is the strain at the bottom of the 5 asphalt layer SE is the strain energy and A Arsquo aacute acirc igravearingref Eref and SEref are constants 6 (not related to the constants of Equation 2) 7 8 The initial (intact) modulus Ei corresponds to a damage ugrave of 0 and the minimum 9 modulus Emin=10auml to a damage of 1 The parameters of Equation 3 were determined 10 from four point bending beam fatigue tests in the laboratory 11 12

Prediction of Damage in Aggregate Base (AB) 13

The recycled base showed some cementing characteristics (un-hydrated cement released 14 from the crushed concrete) and CalME can calculate damage in lightly cemented layers 15 Before the HVS tests the material might reach a modulus of more than 1000 MPa which 16 during the HVS loading could drop to about 100 MPa To ensure that the stresses and 17 strains were correctly calculated for the duration of the experiment it was necessary to 18 model this performance A crushing model was developed based on a model used in a 19 Nordic HVS experiment on weak cement treated bases (Thoegersen et al 2004) The 20 model was changed to use the vertical stress at the top of the layer instead of the tensile 21 strain at the bottom resulting in the following damage function for the aggregate base 22 23

iref

z

E

EMN 24

Equation 4 Damage function for recycled aggregate base 25 26 Where ugrave is the damage MN is the number of load applications in millions oacutez is the 27 vertical normal stress at the top of a layer oacuteref is a permissible stress E is the modulus of 28 the material (= (1 - ugrave)timesEi) Ei is the initial modulus of the material and aacute acirc and atilde are 29 calculated in the same way as for the HVS-Nordic model 30 31 The initial modulus (Ei) was backcalculated from the last FWD test before the HVS 32 experiment and the value of the permissible stress (oacuteref) was chosen so that the final 33 modulus of the base would be close to the modulus determined for the layer from the first 34 FWD test after the HVS experiment and that the calculated RSD and MDD deflections 35 would be close to the measured values The base layer was originally constructed in three 36 lifts and for the simulations it was subdivided into three layers The model was used on 37 each of the layers resulting in the lowest modulus being at the top of the base Dynamic 38


11

Cone Penetrometer tests confirmed this to be the case Extension of this type of model to 1 full-depth in-place recycling and no modification or modification with cement andor 2 foamed asphalt is a next step in development 3 4

Simulation of Pavement Response 5

The deflections normally increase considerably during an HVS test as a result of damage 6 to the bound layers (asphalt and re-cementing AB in this case) This means that the 7 stresses and strains in the pavement layers which are used in calculation of the pavement 8 performance also change during the test To ensure that the pavement response 9 calculated by CalME was reasonably correct for the duration of the test the surface 10 deflections and the deflections at the depths of the MDD modules were calculated by 11 CalME and compared to the RSD and MDD measurements 12 13

14 Figure 7 Measured (RSD) and calculated (Calc) surface deflection versus load applications 15 16 Figure 7 shows a comparison of surface deflection under a 60 kN wheel load for the test 17 section with a 45 mm MB15 (modified binder containing up to 15 recycled tire rubber) 18 overlay Even though the monitored test section is only 6 m long the measured surface 19 deflections vary considerably over the area of the test section sometimes by as much as a 20 factor of 2 The coefficient of variation on the RSD measurements varies from less than 21 10 to more than 20 It may be noticed that the deflection increases by more than 50 22 within the first one million load applications The drop in deflection after one million 23 load applications is due to the pavement temperature being reduced from 20 ordmC to 15 ordmC 24 The deflections calculated by CalME are seen to be in reasonably good agreement with 25 the average of the RSD deflections 26 27


12

1 Figure 8 Monte Carlo simulation of the MB15 section 2

In Figure 8 the Monte Carlo option in CalME was used for the MB15 section It shows 3 that the predicted scatter in surface deflection using the Monte Carlo approach is similar 4 to the scatter of the measured values 5

Permanent Deformation 6

Once the pavement response had been successfully simulated it was possible to calibrate 7 the permanent deformation models Permanent deformations were measured both during 8 the rutting experiment and during the reflection cracking experiment The permanent 9 deformation (down rut) in the asphalt layers was calculated from 10 11

iiihKdp 12

Equation 5 13 14 where K is a calibration factor determined from HVS testing hi is the thickness of layer 15 i and atildeii is the inelastic (permanent) shear strain in layer i determined from 16 17

e

ref

i NNA

expln1lnexp1exp 18

Equation 6 19 20 where atildee is the elastic (resilient) shear strain ocirc is the shear stress N is the number of load 21 repetitions ocircref is a reference shear stress (01 MPa) and A aacute acirc and atilde are constants 22 determined from the Repeated Simple Shear Tests at Constant Height 23 24 The summation in Equation 5 is done for the top 100 mm of the asphalt Permanent 25 deformation due to post compaction was not calculated Permanent deformations of the 26

Measured and calculated surface deflections MB15

-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000

Number of load applications

Def

lect

ion

mm

RSDMonte Carlo


13

unbound layers were calculated using the model given in Ullidtz et al (2008) and were 1 found to be relatively small for all tests 2 3 The same calibration factor (K = 14) was used for all of the tests even though the rutting 4 experiment was done using uni-directional loading at a temperature of 45-50 ˚C at a 5 depth of 55 mm and the reflection cracking experiment was with bi-directional loading 6 at temperatures of 15-20 ˚C 7 8

Rutting study uni-directional 45-50 C at 50 mm

0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18

Measured down rut mm

Cal

cula

ted

do

wn

ru

t m

m

MB15 45 mmRAC-G 45 mmDGAC 90 mmMB4 45 mmMB4 90 mmMAC15 45 mm =

9 Figure 9 Measured and calculated down rut during rutting study 10

Reflection cracking study bi-directional 20 C

0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m

MB15 45 mmRAC-G 45 mmDGACa 90 mmDGACb 90 mmMB4 45 mmMB4 90 mmMAC15 45 mm =

11 Figure 10 Measured and calculated down rut during reflection cracking study 12


14

1 The measured and the simulated down rut during the rutting study are shown in Figure 9 2 For all of the tests the calculated down rut is 6 lower than the measured values with an 3 R2 of 086 and a standard error of estimate of 13 mm For the reflection cracking study 4 (Figure 10) the calculated down rut is 19 below the measured values the R2 is 083 and 5 the standard error of estimate is 09 mm 6

Cracking 7

A reasonably good fit could be obtained for the reflection cracking density using the 8 following equations 9

53

2

1

10

o

mmCr

10

Equation 7 11 12 where Cr is the cracking in mm2 ugraveo is a constant determined from the crack density (05 13 mm2) at crack initiation ugravei is the amount of damage at crack initiation and is calculated 14 from 15 16

1

3901

1

mm

hAC

i 17

Equation 8 18 19 where hAC is the combined thickness of the asphalt layers 20 21 Figure 11 compares the observed reflection cracking on the overlay sections to the 22 reflection damage predicted using Equation 7 as a function of the reflection damage 23 calculated from Equation 1 and Equation 3 Note that some of the sections did not crack 24 which was predicted by CalME 25 26


15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2

MB15 45 mmRAC-G 45 mmDGAC 90 mm aDGAC 90 mm bMB4 45 mmMB4 90 mmMAC15 45 mmCalc 125 mmCalc 170 mm

1 Figure 11 Surface cracking as a function of reflection damage 2 3 Figure 12 shows the predicted reflection cracking severity as a function of the observed 4 severity The predicted cracking levels were in good agreement with observed values 5 6

Predicted reflection cracking versus observed cracking

y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8

Observed cracking mm2

Cal

cula

ted

cra

ckin

g m

m2

7 Figure 12 Predicted reflection cracking severity as a function of observed severity 8 9


16

CONCLUSIONS 1

CalME has been found to be a useful tool for progressing from the presently used 2 empirical models to mechanistic-empirical models for design of rehabilitation 3 maintenance and pavement preservation overlays and new asphalt pavements The use of 4 pre-established databases for traffic loading climatic conditions and standard materials 5 simplify the input process For overlay design the results of backcalculated FWD data 6 may be automatically imported and different maintenance and rehabilitation strategies 7 may be quickly analyzed Laboratory data can also be used for input Reliability-based 8 designs can also be performed by utilizing the Monte Carlo option in CalME which 9 allows studying the influence of within-project variability on the progression of pavement 10 damage The Monte Carlo simulations have run times on typical personal computers that 11 are feasible for engineering practice 12 13 The facility for importing accelerated pavement testing results (eg HVS or track tests) 14 into the CalME database and simulating the experiment on the computer has been found 15 useful for calibrating the models used in CalME These calibrations increase the 16 confidence in the models but the facility may also be used to enhance the interpretation 17 of HVS experiments Even though great efforts are taken to ensure uniform conditions for 18 all experiments it is impossible to avoid variations in materials subgrade support or in 19 climatic conditions during testing Once the experiments have been imported into CalME 20 virtual experiments may be carried out with exactly identical conditions for all of the 21 tests 22 23 Future enhancement of CalME includes calibrating the developed pavement roughness 24 model (based on variability) investigating the influence of temperature on fatigue 25 damage and the importance of rest periods and the correct modeling of the effects of 26 time and temperature on hardening of materials Several models for including these 27 effects have been developed but not yet evaluated Additional calibration using track tests 28 and in-situ pavement sections (for example SPS5 sections in California) is also required 29 Particularly valuable will be the information gathered into the new California Pavement 30 Management System Inclusion of additional materials parameters for full-depth 31 recycling with and without modification with cement andor foamed asphalt and asphalt 32 emulsion and other recycled materials will be performed as funding becomes available 33

ACKNOWLEDGEMENT 34

35 This paper describes research activities that were requested and sponsored by the 36 California Department of Transportation (Caltrans) Division of Research and Innovation 37 Caltrans sponsorship is gratefully acknowledged The contents of this paper reflect the 38 views of the authors and do not reflect the official views or policies of the State of 39 California or the Federal Highway Administration 40

REFERENCES 41

Caltrans Highway Design Manual Chapter 630 Flexible Pavements Edition Jul1 1 42 2008 httpwwwdotcagovhqoppdhdmhdmtochtm pp1-21 43


17

1 Harvey J T du Plessis L Long F Shatnawi S Scheffy C Tsai B-W Guada I 2 Hung D Coetzee N Reimer M and Monismith C L ldquoInitial CALAPT Program 3 Site Information Test Pavement Construction Pavement Materials Characterizations 4 Initial CALAPT Test Results and Performance Estimatesrdquo Report for the California 5 Department of Transportation Report No RTA-65W485-3 Pavement Research Center 6 CALAPT Program Institute of Transportation Studies University of California 7 Berkeley June 1996 8 9 Harvey JT A Chong J Roesler ldquoClimate Regions for Mechanistic-Empirical 10 Pavement Design in California and Expected Effects on Performancerdquo Pavement 11 Research Center CALAPT Program Institute of Transportation Studies University of 12 California Berkeley June 2000 13

Jones D Harvey J and Monismith C ldquoReflective cracking study Summary reportrdquo 14 Davis amp Berkeley CA University of California Pavement Research Center (UCPRC-15 SR-2007-01) 2007a 16 17 Jones D Tsai B Ullidtz P Wu R Harvey J and Monismith C ldquoReflective 18 Cracking Study Second-Level Analysis Reportrdquo Davis amp Berkeley CA University of 19 California Pavement Research Center (UCPRC-SR-2007-09) 2007b 20 21 Lu Q ldquoEstimation of Truck Traffic Inputs Based on Weigh-in-Motion Data in 22 Californiardquo Davis amp Berkeley CA University of California Pavement Research Center 23 (UCPRC-TM-2008-08) January 2008 24 25 Lu Q Ullidtz P Basheer I Ghuzlan K amp Signore JM rdquoCalBack Enhancing 26 Caltrans Mechanistic-Empirical Pavement Design Process with New Back-Calculation 27 Softwarerdquo Journal of Transportation Engineering ASCE Vol 135 No 7 pp 479-488 28 July 2009 29 30 Lu Q and J Harvey Characterization of Truck Traffic in California for Mechanistic 31 Empirical Design Transportation Research Record Journal of the Transportation 32 Research Board National Research Council No 1945 2006 pp 61ndash72 33 34 Ongel A and Harvey JT 2004 ldquoAnalysis of 30 Years of Pavement Temperatures using 35 the Enhanced Integrated Climate Model (EICM)rdquo Draft report prepared for the 36 California Department of Transportation Pavement Research Center Institute of 37 Transportation Studies University of California Berkeley University of California Davis 38 UCPRC-RR-200405 39 40 Thoegersen F Busch C and Henrichsen A ldquoMechanistic design of semi-rigid 41 pavements - An incremental approachrdquo Floslashng Denmark Danish Road Institute 42 (Report 138) 2004 43 44 Ullidtz P Harvey J Tsai B-W and Monismith C ldquoCalibration of Mechanistic-45 Empirical Models for Flexible Pavements Using the California Heavy Vehicle 46


18

Simulatorsrdquo Transportation Research Record Journal of the Transportation Research 1 Board No 2087 2008 pp 20-28 2 3 Wu R-Z ldquoFinite Element Analyses of Refective Cracking in Asphalt Concrete Overlaysrdquo 4 Doctoral dissertation Department of Civil and Environmental Engineering University of 5 California Berkeley 2005 6


ABSTRACT

INTRODUCTION

OVERLAY DESIGN WITH CalME

Traffic Data

Climate

Materials Library

Caltrans Empirical Method

Incremental-Recursive Analysis

Monte Carlo Simulation

Maintenance and Rehabilitation Scheduling

CALIBRATION OF MODELS

Elastic Parameters and Calculation of Response

Prediction of Damage in Asphalt

Prediction of Damage in Aggregate Base (AB)

Simulation of Pavement Response

Permanent Deformation

Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

Mechanistic-Empirical Design of Asphalt Overlays using 1

CalME 2

ABSTRACT 3

A computer program known as CalME has been developed for analysis and design of 4 new flexible pavements and rehabilitation of existing pavements The paper describes the 5 overlay design procedure and the calibration of the models for reflection cracking and 6 permanent deformation through Heavy Vehicle Simulator (HVS) tests To simplify the 7 input process the program includes databases for traffic loading climatic conditions and 8 standard materials A companion program was developed for backcalculation of layer 9 moduli and the results may be automatically imported into the CalME database The 10 program incorporates the existing empirical California Department of Transportation 11 (Caltrans) design methods as well as an incremental-recursive analysis procedure based 12 on the mechanistic-empirical method The effects of different pavement preservation and 13 rehabilitation strategies on pavement damage may be studied with several options for 14 triggering timing of placement The influence of within-project variability on the 15 propagation of damage can be evaluated using Monte Carlo simulation The program 16 also permits importation of the results of HVS or track tests into the database and 17 simulation of the experiments on the computer This is very useful for the calibration of 18 the mechanistic-empirical models but may also be used for an in-depth interpretation of 19 accelerated pavement testing results An HVS experiment that was used for calibration of 20 the reflection cracking and the permanent deformation models is described 21

INTRODUCTION 22

23 CalME is a computer program developed by Caltrans for analysis and design of 24 rehabilitation using asphalt overlays and of new flexible pavements It is currently 25 configured for California practice It includes the existing Caltrans empirical design 26 methods a classical mechanistic-empirical (ME) method and an incremental-recursive 27 ME-based procedure using the time-hardening approach for modeling and simulating 28 pavement response and performance The models for new design and their calibration 29 using Heavy Vehicle Simulator (HVS) tests are described in Ullidtz et al 2008 The 30 present paper presents a quick summary of the program and an overview of the models 31 used for rehabilitation design and their calibration using HVS testing 32 33 CalME was developed beginning in the late 1990s using research products from the 34 SHRP program (1989-1993) subsequent Caltrans sponsored research and development 35 and gathering of models and data from research programs around the world CalME was 36 developed to fill the following needs for an ME analysis tool for use in California 37

Emphasis on rehabilitation and pavement preservation (a term invented later) 38 which account for more than 90 percent of Caltrans pavement program rather 39 than new pavements 40

Emphasis on use of in-situ pavement testing data for existing pavements (namely 41 Falling Weight Deflectometer [FWD] data) as opposed to sampling and 42 laboratory testing 43


3









Traffic Data 31


Climate 37



4








5






6




Wes02FLM_MC

0

02

04

06

08

1

12

14

16

18

0 5 10 15 20 25 30 35 40 45

Years

Cra

ckin

g m

msq



7

Wes02FLM_MC

0

10

20

30

40

50

60

70

80

90

0 5 10 15 20 25 30 35 40 45

Years

Per

cen

t gt=

05

mm

sq





8





9



aHHa

HHaLSLS

EEEEE

EEEEE

EbHbHbLSbaEE

uun

aann

so

ns

uun

sb

bns

aan

nununannbnan

41312expln1121

18




tr

Elogexp1

1log

34



10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1




iref

z

E

EMN 24



11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

3









Traffic Data 31


Climate 37



4








5






6




Wes02FLM_MC

0

02

04

06

08

1

12

14

16

18

0 5 10 15 20 25 30 35 40 45

Years

Cra

ckin

g m

msq



7

Wes02FLM_MC

0

10

20

30

40

50

60

70

80

90

0 5 10 15 20 25 30 35 40 45

Years

Per

cen

t gt=

05

mm

sq





8





9



aHHa

HHaLSLS

EEEEE

EEEEE

EbHbHbLSbaEE

uun

aann

so

ns

uun

sb

bns

aan

nununannbnan

41312expln1121

18




tr

Elogexp1

1log

34



10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1




iref

z

E

EMN 24



11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

4








5






6




Wes02FLM_MC

0

02

04

06

08

1

12

14

16

18

0 5 10 15 20 25 30 35 40 45

Years

Cra

ckin

g m

msq



7

Wes02FLM_MC

0

10

20

30

40

50

60

70

80

90

0 5 10 15 20 25 30 35 40 45

Years

Per

cen

t gt=

05

mm

sq





8





9



aHHa

HHaLSLS

EEEEE

EEEEE

EbHbHbLSbaEE

uun

aann

so

ns

uun

sb

bns

aan

nununannbnan

41312expln1121

18




tr

Elogexp1

1log

34



10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1




iref

z

E

EMN 24



11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

5






6




Wes02FLM_MC

0

02

04

06

08

1

12

14

16

18

0 5 10 15 20 25 30 35 40 45

Years

Cra

ckin

g m

msq



7

Wes02FLM_MC

0

10

20

30

40

50

60

70

80

90

0 5 10 15 20 25 30 35 40 45

Years

Per

cen

t gt=

05

mm

sq





8





9



aHHa

HHaLSLS

EEEEE

EEEEE

EbHbHbLSbaEE

uun

aann

so

ns

uun

sb

bns

aan

nununannbnan

41312expln1121

18




tr

Elogexp1

1log

34



10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1




iref

z

E

EMN 24



11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

6




Wes02FLM_MC

0

02

04

06

08

1

12

14

16

18

0 5 10 15 20 25 30 35 40 45

Years

Cra

ckin

g m

msq



7

Wes02FLM_MC

0

10

20

30

40

50

60

70

80

90

0 5 10 15 20 25 30 35 40 45

Years

Per

cen

t gt=

05

mm

sq





8





9



aHHa

HHaLSLS

EEEEE

EEEEE

EbHbHbLSbaEE

uun

aann

so

ns

uun

sb

bns

aan

nununannbnan

41312expln1121

18




tr

Elogexp1

1log

34



10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1




iref

z

E

EMN 24



11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

7

Wes02FLM_MC

0

10

20

30

40

50

60

70

80

90

0 5 10 15 20 25 30 35 40 45

Years

Per

cen

t gt=

05

mm

sq





8





9



aHHa

HHaLSLS

EEEEE

EEEEE

EbHbHbLSbaEE

uun

aann

so

ns

uun

sb

bns

aan

nununannbnan

41312expln1121

18




tr

Elogexp1

1log

34



10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1




iref

z

E

EMN 24



11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

8





9



aHHa

HHaLSLS

EEEEE

EEEEE

EbHbHbLSbaEE

uun

aann

so

ns

uun

sb

bns

aan

nununannbnan

41312expln1121

18




tr

Elogexp1

1log

34



10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1




iref

z

E

EMN 24



11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

9



aHHa

HHaLSLS

EEEEE

EEEEE

EbHbHbLSbaEE

uun

aann

so

ns

uun

sb

bns

aan

nununannbnan

41312expln1121

18




tr

Elogexp1

1log

34



10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1




iref

z

E

EMN 24



11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

10

22

refrefref SE

SEA

E

EAMNp

MNp

MN

1




iref

z

E

EMN 24



11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

11






12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

12





iiihKdp 12


e

ref

i NNA

expln1lnexp1exp 18



-05

-04

-03

-02

-01

0

0 500000 1000000 1500000 2000000 2500000


Def

lect

ion

mm

RSDMonte Carlo


13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

13



0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14 16 18


Cal

cula

ted

do

wn

ru

t m

m




14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

14


Cracking 7


53

2

1

10

o

mmCr

10


1

3901

1

mm

hAC

i 17



15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

15

0

1

2

3

4

5

6

7

8

9

10

0 01 02 03 04 05 06 07 08 09 1

Reflection damage

Cra

ckin

g m

m2




y = 10173xR2 = 09486

0

2

4

6

8

0 1 2 3 4 5 6 7 8


Cal

cula

ted

cra

ckin

g m

m2



16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

16

CONCLUSIONS 1


ACKNOWLEDGEMENT 34


REFERENCES 41



17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

17




18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

18



ABSTRACT

INTRODUCTION


Traffic Data

Climate

Materials Library











Cracking

CONCLUSIONS

ACKNOWLEDGEMENT

REFERENCES

10-1938

Documents

Transcript of 10-1938