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DESIGNING THEORY AND METHOD STUDY FOR CONTINUOUSLY

REINFORCED CONCRETE PAVEMENT STRUCTURES

Dr. Hu Chang-shun Dr. Cao Dong-wei

Professor, Dean Associate Researcher

Highway College, Changan University Beijing Highway Reseach Institute

Xian 710064, P.R.China Beijing , 100088 P.R.China

Tel: +86 (29) 2334451

E-mail: [email protected]

Abstract Continuously reinforced concrete pavement (CRCP) is one of high

performance concrete pavement structures. A systematic analysis on CRCP design principles

is conducted. In the vehicle-load stress analysisthe orthogonal anisotropic membrane model

is established by treating the longitudinal bars as continuumand three dimensional finite

element analysis is carried out with considering transverse crack. Two critical load positionsare found out. In thermal stress analysisthe calculation model and equilibrium differential

equations are established on the basis of researching the bond-slip constitutive relation

between the reinforced bars and concrete. The analytic solution is derived to calculate the

stress and displacement under the temperature drop and concrete shrinkage. The parameters

sensitivity and stress relaxation caused by concrete creep are analyzed. Using numerical

methods and analytic methodsthe anchor force at CRCP ends is calculatedand the

displacement and stress of trech lugs are analyzedthe design parameters are recommended

and the design nomograms are provided. The indoor model test is carried out to verify the

theoretical values. The method for designing CRCP slab thicknessreinforcement and end

structure is provided.

Key wordscontinuously reinforced concrete pavement (CRCP) ; load stressthermal

stressanchor enddesign method

Continuously Reinforced Concrete Pavement (CRCP) is of high performance concrete

pavement structure, which is well provided with continuous longitudinal steel bars and is

without joints during construction. CRCP eliminates transverse joints existing in conventional

concrete pavement, and is characterized by such merits as comfort driving, high load-bearing

capacity, long service life and little need for maintenance and rehabilitation. CRCP is in stepwith the trend of development of highway transportation, thus is widely used abroad. Greater

attention is also paid to it in China. This article analyzes the load stress, temperature stress

and end anchor structure in CRCP, provides design method practical in engineering work.

1. LOAD STRESS ANALYSIS

1.1 Calculation Model

The difference between CRCP and conventional concrete pavement is: continuous

longitudinal steel bars, high stress transmission capacity at cracks and random crack interval

(slab length). Analytic solution will be hard to obtain when considering transverse crack in

CRCP load stress analysis, the key work to finite element method is the modeling of

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Proceedings of the Eastern Asia Society for Transportation Studies, Vol.4, October, 2003


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continuous reinforcement. Steel bars in CRCP are distributed with certain interval, so a simple

model is to treat each bar as a rod unit, but this will make the calculation model too complex,

and the modeling work will be amazing. According to structure features and mechanic

characteristics of CRCP, by treating the steel bars as continuum, make them equivalent of an

isotropic membrane characterized by orthogonal anisotropy. That is, steel bars have

strengthening effect on the concrete only in the longitudinal direction. An orthogonal

anisotropic membrane unit is put forward. Based on the stress-strain relation and geometric

equations of orthogonal anisotropic materials, stiffness matrix of membrane unit can be

obtained and a finite element model for CRCP load stress analysis, considering cracking

conditions, can be established. To testify its correctness and reliability, two comparisons with

identical parameters are made: one is to compare with the analytic solution of load stress in

CRCP infinitely long slab; the other is to compare with the model in which steel bars are

considered rod units. The results indicate little difference between these two methods. The

finite element model put forward by this article is easy for calculation with reliable precision,

thus can be effective in research on stressing state in CRCP under vehicle load.

1.2 Critical Load Position

Wheel load and axle load in twin wheel group are considered for loading conditions, the

median of neighboring cracks and one side of transverse crack on the slab are mainly

considered as load positions, analysis on disadvantageous positions of vehicle load at CRCP

is conducted. Crack interval may differ, so disadvantageous load position in CRCP slab

correlates with it. Two critical load positions in CRCP are obtained by comparing slab bottom

stresses with various possible vehicle load positions (longitudinal crack, transverse crack,

center of slab, slab corner and of different crack intervals): When transverse crack interval is

less than 1.5m, the critical load position is on one side of the median of transverse crack,

which is marked as critical load position 1. When this crack interval is larger than 2.5m, the

critical load position is at the mid-point of longitudinal free edge, which is marked as critical

load position 2. When the transverse crack interval falls between 1.5m and 2.5m, load stresses

at both two load positions should be checked respectively, bigger one of which is used as

control stress.

1.3 Parameter Analysis

Main factors affecting load stresses in CRCP include: plane size of the slab, concrete modulus,

subgrade modulus, slab thickness, reinforcement ratio and steel position, etc. Graph 1 andGraph 2 indicate how slab bottom stresses with different critical load positions in CRCP

change with slab thickness. Calculation shows that, wherever critical load positions are,

stresses always decrease when slab thickness and subgrade modulus increase, while stresses

increase when concrete modulus increases. These principles are of same as those of

conventional concrete slab. Reinforcement ratio may change the load transmission capacity of

steel bars. As to critical load position 2, increase of longitudinal reinforcement ratio may

decrease the maximum principal stress in slab; As to critical load position 1, increase of

longitudinal reinforcement ratio will slightly increase the maximum principal stress in slab. In

both instances, longitudinal reinforcement ratio has a greater influence on pavement bottom

stress when transverse crack interval is small, while a less influence on stress when crack

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interval is larger. Calculation indicates that load stress reaches minimum when steel bars are

positioned at the median plane of the slab.

Graph1: bottom stress changes with Graph2: bottom stress changes with

slab thickness at critical load position 1 slab thickness at critical load position 2

1.4 Comparison of Slab Bottom Stress in CRCP and JCCPGraph 3 and Graph 4 show the comparison of maximum stress and displacement in

Conventional Concrete Pavement (JCCP) and in CRCP of different slab length, when vehicle

load imposed at critical load position 1. JCCP 1 is concrete slab of the same plane size as

CRCP. JCCP 2 is concrete slab of normal size (4.5m5.0m). According to these graphs, load

transmission of continuous reinforcement in CRCP enhances the overall work capacity and

load dispersion capacity of the slab. Deflection in CRCP is less than that in JCCP of the same

size, while slab bottom stress in CRCP is slightly larger. Compared with now frequently used

concrete slab of normal size, slab bottom stress in CRCP will obviously decrease, for its crack

interval is less than its slab length.

Graph3: stress comparison of CRCP Graph4: deflection comparison of CRCPwith JCCP of different slab length with JCCP of different slab length

When vehicle load imposes at critical load position 2, slab bottom stress in CRCP will be less

than that in JCCP, and there will be a greater loss in bottom stress if the crack interval is

smaller. These indicate that through load transmission of its steel bars, CRCP decrease its

maximum bottom stress, placing the slab under favorable working conditions.

2. CRCP TEMPERATURE STRESS ANALYSIS

The purpose of continuous reinforcement is to restrain crack opening by using steel bars,

prevent rain from corroding steel bars and thus insure pavement durability.

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2.1 Calculation Model

Main load considered in reinforcement design is induced by temperature reduction and dry

shrinkage. Temperature stress includes temperature contraction stress and warping stress,

caused by average temperature reduction in slab and temperature gradient, respectively. To

establish relation between crack interval, crack opening and load in CRCP, the effect of

bonding and slipping between steel bars and concrete must be considered in temperature

stress analysis. This article uses in analysis linear bond-slip constitutive relation between steel

bars and concrete, that is, the bonding stress between bars and concrete is in direct proportion

to their relative slipping. The constraining effect of soil on CRCP slab can be considered as

the relation between the shear stress on contact surface of two mediums and their relative

displacement. Three calculation models are applied when considering soil friction: linear

model. Soil friction is in direct proportion to displacement of structure, the coefficient of

proportionality is called coefficient of soil friction. sectional linear model. Coefficient of

soil friction can be different constants within different ranges. hyperbola model.

Coefficient of soil friction changes with structure displacement.

2.2 Temperature Contraction Stress, Dry Shrinkage Stress and Warping Stress

According to the above calculation models, set of differential equations for calculating

temperature stress can be established through stress equilibrium condition, geometric relation

and constitutive equation. With general solution of differential equations, a specific solution

can be obtained by applying it to boundary condition. Analyzing the temperature contraction

stress induced by annual temperature change indicates that concrete stressc is largest at the

center of slab, while concrete displacementc, steel bar stresss, bonding stresss between

bars and concrete and crack openingc reach their maximum at the crack. The calculation

equations are as follows:

33

33

)tanh(

]1)(sech[

LrLr

LrLrTE ccc

+

=

+

= 1

)coth(1

)](coth1[

33

33

LrLr

LrLrTE scsss

)(coth1)1(

33 LrLr

TLu cc

+

+=

1)(coth

)1(

33 +

+=

LrLr

TLk css

1)(coth

)1(2

33 +

+=

LrLr

TLw cc

2/SL= n= )1

1(3

+=

cc

ss

EA

kDr

In it: S is crack interval in CRCP; is contribution ratio of reinforcement stiffness; P is

reinforcement ratio in CRCP; n is modulus ratio of reinforcement to concrete; Ds is diameter

of steel bar; Ks is stiffness factor of bonding between steel bars and concrete; T is design

temperature difference for CRCP; Ec, c, Ac is concrete modulus, coefficient of linear

expansion and area of section, respectively; Es, s is reinforcement modulus and coefficient

of linear expansion, respectively.

Hydration and volatilization of moisture during hardening process of concrete shrink and

deform the concrete, shrinkage stress will emerge if this deformation is restrained by

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continuous reinforcement. Equations for calculating pavement stress and displacement can be

obtained through reasoning. By superimposing the stress and displacement of concrete and

reinforcement induced by temperature reduction on those induced by shrinkage deformation,

the stress and displacement induced by both will be obtained.

Continuous reinforcement in CRCP is usually positioned at the median plane of slab, which

makes it contribute little to bending rigidity of the slab. So warping stress induced by

temperature gradient is of same as that in conventional concrete pavement. The difference is

that warping deformation will lead to longitudinal extension of median plane of the slab,

restraint from continuous reinforcement will result in additional stress in pavement. First, use

integration to calculate horizontal extension of median plane of the slab caused by warping

deformation, then on the basis of general solution to fundamental equations of temperature

stress, apply it to boundary condition and obtain the stress and displacement. Calculation

shows that the stress and deformation of this part are too small to be counted in CRCP

reinforcement design.

2.3 Sensitivity Analysis

Through calculation and analysis, interrelation between main design parameters in CRCP as

temperature stress, displacement and reinforcement ratio, can be obtained. (see table 1)

Results indicate that under the effect of temperature load and shrinkage deformation, the

concrete stressing state in CRCP will determine indexes of external service behavior as crack

interval and crack opening, while change in crack interval will affect such internal working

state as concrete and reinforcement stress. The crack interval in CRCP is an important factor

which affects both external service behavior and internal stressing, deforming state. Graph 5

and Graph 6 show the influence of reinforcement ratio and reinforcement method on concrete

stress and displacement in CRCP. One curve shows how reinforcement ratio vary with

different transverse intervals b, with a diameter of steel bar Ds=1.4cm. The other one shows

how reinforcement ratio vary with different diameters of steel bar, with b=12m. These graphs

indicate that, whatever the reinforcement method is, concrete displacement always decreases

when reinforcement ratio increases, while concrete stress increases when reinforcement ratio

increases. This is the case because when reinforcement ratio increases, bonding area of steel

bars increases accordingly, restraint on concrete is strengthened, and deformation of concrete

is reduced. With same reinforcement ratio, however, the small interval, small diameter

reinforcement method can reduce, more effectively than the large diameter, large intervalmethod, the crack opening, reinforcement stress and bonding stress between steel bars and

concrete, because the bonding area of reinforcement is larger in the former method.

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Graph5: influence of reinforcement ratio Graph6: influence of reinforcement ratio

and method on concrete displacement and method on concrete stress

Table1 sensitivity analysis for temperature contraction stress

parameterViscosity

factor

Reinforceme

nt ratio

Crack

interval

Coefficient ofconcrete linear

expansion

Slabthicknes

s

Concrete

modulus

Concrete

displacementdecreased decreased increased increased

increase

dincreased

Crack interval decreased decreased increased increasedincrease

dincreased

Concrete stress increased increased increased increaseddecrease

dincreased

Reinforcement

stressincreased decreased increased increased

increase

dincreased

Bonding stress increased decreased increased increasedincrease

dincreased

2.4 Stress Relaxation Analysis

Under the influence of natural and environmental factors, the temperature in CRCP changes

slowly by yearly period, creeping and relaxation may occur in concrete materials under

long-time load effect. By using in analysis linear creep theory and creek degree in exponent

form, coefficient of concrete relaxation and shrinkage stress considering relaxation effect, are

obtained. Suppose linear change and sine curve change of temperature between summer and

autumn, relaxation stress of concrete by yearly period, can be obtained. Numerical analysisindicates that, when the influence of relaxation is considered, concrete stress will decrease

somewhat, and when pavement temperature experiences linear change, relaxation stress will

be less than that when the change of pavement temperature is considered a sine curve. In

order to facilitate design and use, modified coefficient of temperature contraction stress

relaxation in concrete is provided with different forms of yearly temperature change, which

can be used directly to revise the calculation results of elastic stress.

3. CRCP END ANCHOR STRUCTURE ANALYSIS

CRCP has no expansion joints, severe deformation may occur in pavement under the

influence of temperature change, especially at pavement ends. Unrestrained displacement of

ends under influence of yearly temperature change may exceeds 10cm, thus produce shoving

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force on pavement or other structures near the CRCP ends. So at bridgeheads or joints of

CRCP with other type of pavement, structural means should be taken to limit its deformation.

Presently, the most frequently used CRCP end structure is the convex anchor ground beam.

3.1 Calculation and Analysis of End Anchoring Strength

Basic equations for calculating end anchoring strength can be obtained on the basis of stress

equilibrium relation. Analytic equation for calculating end anchoring strength can be obtained,

when considering soil friction with linear or sectional linear model. Method for calculating

CRCP end anchoring strength is:

determine such parameters as reinforcement ratio, coefficient of soil friction.

calculate free extension of the ends when of no anchoring structure.

decide whether the extension should be restrained and if yes, determine the maximum

displacement allowed at ends (UR).

calculate the concrete and reinforcement stress at anchored ends.

calculate the resultant force of anchorage stress (FX).

If URis large, ])(coth[)1( 11 TLauaAEF Rccx +=

If URis small, )()1( 31 TacLbAEF ccx ++=

In it;cc

x

EA

bC

pna

+=

1

11 ; b is slab width; CX is coefficient of soil friction; L is effective

length for calculation of end anchoring; other parameters are of same as above.

3.2 Structure Analysis for Convex Anchor Ground Beam

Provided with anchor load at the ends, establish and analyze the finite element model for

convex anchor ground beam. Three indexes should be mainly considered: end displacement,

maximum tensile stress in pavement and maximum tensile stress in end wall. At the same

time, matrix displacement method is used to analyze. Main questions concerned with

calculation model are how to treat the restraint force of soil on end structures, such as the

vertical soil pressure and horizontal friction at the contact surface between end wall,

pavement slab and the soil. Strength of these forces correlates with structure deformation, two

methods are given to treat. One is to regard them as equivalent external load at nodes; the

other is additional stiffness matrix. Calculation indicates that result obtained by finite elementmethod and result obtained by matrix displacement method coincide with each other not only

in law, but also in numerical value.

3.3 Result Analysis

According to above computation principle, the influence of main design parameters as end

wall height, end wall interval on stress and displacement of CRCP end wall is investigated.

(see table 2). Based on the results, value of main design parameter of end wall is suggested as:

end wall interval 4~6m, end wall height 1.0~2.0m, base width of end wall 0.4~0.6m.

Materials of high rigidity and full compaction are recommended in construction of soil in the

CRCP end structure zone. When dealing with more than two end walls, the principle of

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equivalent force on each end wall can be used to convert it to a question of two end walls to

calculate.

Table2 influence of design parameter on stress and displacement of CRCP end wall

parameterEnd wallinterval

wL

End wall

heightw

H

End wallbase

widthw

b

Concretemodulus

cE

Slabthickness

ch

Subgra

de

modulu

ss

E

Quantity of end

wall

End

displacem

ent

decreasedIncreased

slightly

Basically

unchanged

Decreased

slightlydecreased

decreas

ed

decrease

d

Maximum

stress in

pavement

decreasedRelated

withw

L decreased

Increased

slightlydecreased

decreas

ed

decrease

d

Maximum

stress inend wall

decreasedRelated

withw

L Basically

unchanged

Increased

slightly increaseddecreas

ed

decrease

d

To facilitate design and use, calculation nomograph is provided with results of finite element

analysis as end maximum displacement, design bending moment of pavement slab and design

bending moment of end wall. In graph 7, calculation nomograph is provided for design

bending moment of end anchor walls, when pavement depth is 22cm and 26cm.

Graph7: calculation nomograph for design bending moment of CRCP anchored end

wall

3.4 Model Test of Convex Anchor Ground Beam

To testify the correctness of theory analysis, indoor model test is conducted. Test is conducted

in big experimental tank, using organic glass to simulate pavement and end wall. Test process

is as follows: paving soil, bearing plate test, sticking strain gauge and embedding soil pressure

cell, structure positioning, test. Main test index includes: end displacement, maximum

compressive stress in pavement, maximum compressive stress in end wall. Comparing test

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results with theory analysis indicates that they share the same laws, with great difference in

numerical value on rare data. But as for the most concerned indexes--maximum end

displacement, maximum tensile stress in pavement slab, maximum tensile stress in end wall,

the error is trivial, which testify the reliability of theory analysis. Distribution type of soil

pressure behind end walls is also obtained.

4. CRCP STRUCTURE DESIGN METHOD

Main questions in CRCP design are slab thickness design, reinforcement design and end

structure design.

4.1 Slab Thickness Design

When determining slab thickness of conventional concrete pavement, transverse fatigue crack

of the slab is considered control target in current specification. Flexural tensile stress at slab

bottom is considered control index, load stress at the mid-point of longitudinal crack and

temperature warping stress should not exceed the flexural tensile strength of concrete.Transverse crack is allowed to exist in CRCP, so it cannot be regarded as main damage.

Instead, the main damage in CRCP is slab edge breaking. So slab thickness design should be

based on two factors: First, to prevent small crack interval. At critical load position 1, there

should not be longitudinal crack induced by excessive load stress; second, with present crack

interval, transverse crack will not occur at critical load position 2. Two steps are suggested to

determine slab thickness in CRCP: determine initial design slab thickness by critical load

position 2; then, conduct checking computation at critical load position 1.

Critical load position 2 in CRCP is of the same as critical load position in JCCP, so with

considering the change of load transmission capacity, initial design slab thickness in CRCP

can directly be calculated following current specification. According to above comparison of

load stress between CRCP and JCCP, coefficient of stress reduction (Kcn) can be introduced

into load stress calculation. When crack interval s>2.5m, Kcn=1.00; when 1ms2.5m,

Kcn=0.90~1.00. Take the minimum value when S is small, while take its maximum value

when S is large.

1pscrcfrpKKKK =

In it, P is load fatigue stress; Kr is coefficient of stress reduction considering load

transmission capacity at longitudinal crack: Kf is coefficient of fatigue stress consideringcumulative load effect; Kc is comprehensive modification factor considering factors as

overload and dynamic load; Kcr is stress influence factor considering load transmission

capacity of longitudinal continuous reinforcement in CRCP; ps1 is slab bottom stress when

standard axle load imposed at the median of neighboring cracks.

Warping fatigue stress can be calculated following current specification, taking crack interval

in CRCP as slab length. Calculation shows that warping stress in CRCP is far less than that in

conventional concrete pavement. Based on the load fatigue stress and warping fatigue stress

obtained by calculation, if the sum is no larger than 103% of concrete flexural tensile strength,

and no less than 95% of this strength, the slab thickness can be used as design value.

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Otherwise, calculation should be retaken with different slab thickness, until the above

requirements are met.

Obtaining initial design thickness of slab is followed by reinforcement design. Design crack

interval in CRCP can be obtained by reinforcement design, then checking computation is

carried our for slab bottom stress at critical load position 1, to prevent slab edge breaking

induced by small crack interval.

2pscfpKK =

In it, ps2 is slab bottom stress when standard axle load imposed at critical load position 1,

having relation with design crack interval. Load transmission capacity of longitudinal

reinforcement should be considered under the most disadvantageous condition at the end of

service life, half of reinforcement can be supposed to have been damaged. Graph 8 is the

nomograph for calculation of slab bottom stress with a crack interval of 1.5m, mid-point of

slab width should be the point for calculating temperature fatigue stress.

Graph8: calculation graph for ps2 with a crack interval of 1.5m

4.2 Reinforcement DesignThe purpose of reinforcement is to restrain cracks in CRCP, mainly including crack interval

and crack opening. Crack interval, crack opening, reinforcement stress and bonding stress

between reinforcement and concrete can be considered as control indexes for design. For

crack interval is the primary parameter when deciding internal stressing state and external

service behavior of CRCP, it can be considered as design index, other three items can be

considered as check index. On the basis of above equations for calculating temperature

contraction stress and dry shrinkage stress:

(1) Design requirement: LS DS HS

(2) Check requirement: LDTw wshc )(2 += ][w

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])[( TDTE ssshcss ++= ][ s

LDTk wshcss )( += ][ s

Crack interval can be determined as follows: )()( DcshccT SDTE +=

33

33

)tanh(

)](ch1[

LrLr

LrseLrDc

+

=

1)coth(

1)(coth

33

33

+

=

LrLr

LrLrDs

)coth(1

1

33 LrLrDw

+

+=

In it, SD is design crack interval in CRCP; SL and SH is the lower limit and upper limit of

crack interval, respectively; [s] is yield strength of steel bars; [S] is bonding strength

between reinforcement and concrete; T is tensile strength of concrete; sh is long-term

shrinkage strain of concrete in CRCP, other parameters are of same as above.

Referring to other countrys research and results of investigation in Xu Chang, Tong Chuan

test roads, it is suggested that the optimum crack interval in CRCP is 1.0-2.5m, and the

maximum crack opening allowed is 1.0mm. Yield strength of steel bars and bonding strength

between reinforcement and concrete can be determined according to related information. To

gain ideal service behavior of CRCP, besides structure design, concrete with low coefficient

of linear expansion and with small shrinkage deformation, such as aggregate and cement with

desirable properties, should be used in concrete ratio design. In reinforcement design in CRCP,

spiral reinforcement or crescent reinforcement, instead of plain bar, should be used in CRCP

reinforcement design. Steel bars with small diameter should be used, but transverse interval

should be no less than 10cm.

Some design parameters can be assigned value following current specification. Test can be

taken to determine concrete tensile strength, bonding strength between reinforcement and

concrete or stiffness factor, values recommended in document [1] can also be assigned to

them.

4.3 End Anchor Structure Design

End displacement serves as ultimate control index for CRCP end structure design. Maximum

bending moment of pavement end and end wall is considered in reinforcement design.Method for end anchor structure design is:

(1) Based on design information (test when necessary), calculate end deformation,determine the maximum allowable end displacement, calculate anchoring

strength following above equations, and obtain design load on end wall.

(2) Analyze the stress and displacement of end wall. Based on the calculation of endanchoring strength, determine initially quantity of wall, wall height, wall interval

and wall width. If the end wall number is not 2, first convert them to two walls

under the principle of equivalent anchoring strength on each wall, then obtain

through design nomograph the maximum displacement, design bending moment

of pavement and design bending moment of end wall (can also be obtained

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through matrix displacement method) under anchoring strength.

(3) Compare end displacement obtained through calculation with allowabledisplacement. If the former is larger than the latter, increase the number of end

walls; otherwise, the bearing capacity of anchor end wall may be excessive, thus

can reduce the number of end walls, change their geometric size, or can redesign

the end wall and recalculate the anchoring strength by taking the displacement

obtained through calculation as the allowable displacement.

5. CONCLUSION

CRCP is a concrete pavement structure of high performance. It is not only related somewhat

to JCCP, but also different from it. Based on characteristics of CRCP, this paper conducts load

stress analysis, temperature stress analysis and end anchor structure analysis on design theory,

and provides design method and scientific foundation for CRCP design. CRCP is still a new

pavement structure in China, the design method of it will be perfected through its ever

increasing use in practice.

References

(1) Hu Changshun Cao Dongwei Design Theory and Method for CRCP [R]

Research Project Sponsored by the State Natural Science Fund Changan University,

Xian, 2000

(2) Wang Hu Hu Chnagshun Wang Binggang An Analytic Solution of CRCP

under Vertical Load Action [J] Journal of Xian Highway University, Vol. 19(4), 1999

(3) Tian Yanchun Hu Changshun Load Stress Analysis for CRCP [J] Journal of

Xian Highway University, Vol. 20(3), 2000

(4) Cao Dongwei Hu Changshun Temperature Stress Analysis for CRCP [J]

Journal of Xian Highway University, Vol. 21(2), 2000

(5) Zhang Hongliang A Study of End Bolt-locking Structure in CRCP [D] Changan

University, Xian, 2000

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0389.Pdfconcrete Pavements