DeformationAnalysisofPrestresdContinuous
Steel-ConcreteCompositeBeams
JianguoNie1;MuxuanTao2;C.S.Cai3;andShaojingLi4
Abstract:Deformationcalculationofprestresdcontinuoussteel-concretecompositebeamsaccountingfortheslipeffectbetweenthe
steelandconcreteinterfaceunderrviceloadsisanalyzed.Asimplifiedanalyticalmodelisprented.Badonthismodel,formulasfor
predictingthecrackingregionofconcreteslabneartheinteriorsupportsandtheincreaoftheprestressingtendonforcearederived.A
table for calculating the midspan deflection of two-span prestresd continuous composite beams is also propod. It is found that the
internalforceoftheprestressingtendonunderrviceloadscanbeaccuratelycalculatedusingthepropodformulas.Byignoringthe
increaofthetendonforce,thecalculateddeflectionareoverestimated,andconsideringtheincreaofthetendonforcecansignificantly
黄体酮副作用
improvetheaccuracyofanalyticalpredictions.Asthecalculatedvaluesshowgoodagreementwiththetestresults,thepropodformulas玩法
can be reliably applied to the deformation analysis of prestresd continuous composite beams. Finally, bad on the formulas for
calculating the deformation of two-span prestresd continuous composite beams, a general method for deformation analysis of pre-
stresdcontinuouscompositebeamsispropod.
DOI:10.1061/͑ASCE͒treatST.1943-541X.0000067
自相矛盾什么意思CEDatabasubjectheadings:Prestresdconcrete;Compositebeams;Deformation;Deflection;Cracking;Concreteslabs;Con-
tinuousbeams.
Introduction
͑2͒ increasing the ultimate loading capacity; ͑3͒ decreasing the
巴尔扎克简介
deformation under rvice loads; ͑4͒ being favorable in crack-
widthcontrol;͑5͒fullyusingthematerialsandthusreducingthe
structural height and overall dead load; and ͑6͒ improving the
fatigueandfracturebehavior.
Continuous steel-concrete composite beams are widely ud in
buildingsandbridgesforhigherspan/depthratiosandlessdeflec-
tionetc.,whichresultsinsuperioreconomicalperformancecom-
pared with simply supported composite beams. For continuous
composite beams, negative bending near interior supports will
resultinearlycrackingofconcreteslabandreductionofstiffness.
Whenbeamsaredesignedforspanlengthsandloadsgreaterthan
usual, the requirement of rviceability limit state due to unac-
ceptabledeflectionandcrackwidthwouldrequireusingprestress-
ingtechnique.
Since Szilard ͑1959͒ suggested a method for the design and
analysisofprestresdsteel-concretecompositebeamsconsider-
ingtheeffectsofconcreteshrinkageandcreep,manyrearchers
have developed methods for analyzing the behavior of simply
牵着猫的童话supportedprestresdcompositebeams͑Hoadley1963;Klaiberet
al.1982;Dunkeretal.1986;Saadatmanesh1986;Saadatmanesh
etal.1989a,b,c;Albrechtetal.1995,Nieetal.2007͒ .However,
continuous prestresd composite beams have not been re-
arched until the late 1980s ͑Troitsky and Rabbani 1987;
Troitsky 1990; Dall’Asta and Dezi 1998, Ayyub et al. 1990,
1992a,b;Dall’AstaandZona2005͒.Asaresult,prestresdcon-
tinuouscompositebeamshavenotwidelybeenudpartlydueto
thelackofdesigntheory.
In fact, the behavior of prestresd continuous composite
beamsdependsontheinteractionbetweenfourmaincomponents:
thereinforcedconcreteslab,thesteelprofileofbeams,theshear
connections, and the prestressing tendons, which makes pre-
stresdcontinuouscompositebeamsmorecomplexthanconven-
tional ones. Dall’Asta and Zona ͑2005͒ propod a nonlinear
finiteelementmodelsimulatingthebehaviorofprestresdcon-
tinuouscompositebeamsaccurately.Thisnumericalapproachisa
very powerful rearch tool for analyzing the externally pre-
stresdstructures,butitperhapsistoocomplicatedforaroutine
designpractice.
Comparedwithconventionalsteel-concretecompositebeams,
prestresdsteel-concretecompositebeamshaveafewmajorad-
vantages: ͑1͒ extending the elastic range of structural behavior;
1Professor,Dept.ofCivilEngineering,KeyLaboratoryofStructural
EngineeringandVibrationofChinaEducationMinistry,TsinghuaUniv.,
Beijing100084,China.
2Ph.D. Candidate, Dept. of Civil Engineering, Key Laboratory of
拓跋鲜卑
Structural Engineering and Vibration of China Education Ministry,
Tsinghua Univ., Beijing 100084, China ͑corresponding author͒ . E-mail:
dmh03@mails.tsinghua.edu
3AssociateProfessor,Dept.ofCivilandEnvironmentalEngineering,
LouisianaStateUniv.,BatonRouge,LA,70803;prently,AdjunctPro-
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