混凝土的收缩（中英文对照）

科技资料原文SHRINKAGEOFCONCRETEWHENCONCRETELOSESMOISTUREBYEVAPORATIONITSHRINKSSHRINKAGESTRAINSAREMDEPENDENTOFTHESTRESSCONDITIONSINTHECONCRETEIFRESTRAINED,SHRINKAGESTRAINSCANCAUSECRACKINGOFCONCRETEANDWILLGENERALLYCAUSETHEDEFLECTIONOFSTRUCTURALMEMBERSTOINCREASEWITHTIMETHECALCULATIONOFSTRESSANDDEFORMATIONSDUETOSHRINKAGEISDEFERREDUNTILCHAPTER10ACURVESHOWINGTHEINCREASEINSHRINKAGESTRAINWITHTIMEAPPEARSINFIG221THESHRINKAGEOCCURSATADECREASINGRATEWITHTIMEAPPEARDINSHRINKAGESTRAINSVARYGREATLY,BEINGGENERALLYINTHERANGE00002TO00006BUTSOMETIMEASMUCHAS00010TOTIMESHRNKAGSTOTIMEAWHCNRSUBJDYGVSHRINKAGESFIG221TYPICALSHRINKAGECURVEFORCONCRETESHRINKAGEISTOALARGEEXTENTAREVERSIBLEPHENOMENONIFTHECONCRETEISSATURATEDWITHWATERAFTERITHASSHRUNK,ITWILLEXPANDTOALMOSTITSORIGINALVOLUMETHUSALTERNATINGDRYANDWETCONDITIONSWILLCAUSEALTERNATINGVOLUMECHANGESOFCONCRETETHISPHENOMENONISPARTLYRESPONSIBLEFORTHEFLUCTUATINGDEFLECTIONSOFSTRUCTURESEGCONCRETEBRIDGESEXPOSEDTOSEASONALCHANGESEACHYEARASARULE,CONCRETETHATEXHIBITSAHIGHCREEPALSODISPLAYSHIGHSHRINKAGETHUSTHEMAGNITUDEOFTHESHRINKAGESTRAINDEPENDSONTHECOMPOSITIONOFTHECONCRETEANDONTHEENVIRONMENTINMUCHTHESAMEWAYASDISCUSSEDPREVIOUSLYFORCREEPBOTHTHEACICOMMITTEE209226ANDTHECEBFIP227HAVEPROPOSEDEMPIRICALMETHODSFORTHEESTIMATIONOFSHRINKAGESTRAINSTHEFORMERAPPROACHISDESCRIBEDBLOWACCORDINGTOACICOMMITTEE209226FORNORMALWEIGHT,SANDLIGHTWEIGHTCONCRETEUSINGBOTHMOISTANDSTEAMOURINGANDTYPESIANDIIICEMENT,THEUNRESTRAINEDSHRINKAGESTRAINATANYTIMETISGIVENBYSHSHUTTHSFECWHERETHECOEFFICIENTSAREGIVENBELOWULTIMATESHRINKAGESTRAIN,SHUTHEVALUEOFCANVARYWIDELYINACICOMMITTEE209REVIEW,SHUWASFOUNDTOBEINTHERANGE0000415TO000107,WITHMEANSHUVALUESOF000080FORMOISTCUREDCONCRETEOR000073FORSTEAMCUREDCONCRETETHESEAVERAGEVALUESSHOULDBEASSUMEDONLYINTHEABSENCEOFMOREEXACTDATEFORTHECONCRETETOBEUSEDTIMEOFSHRINKAGECOEFFICIENT,STATANYTIMEAFTERAGE7DAYS,FORMOISTCUREDCONCRETE,217A35TSTWHERETTIMEINDAYSFROMAGE7DAYSST046,072,084,091,AND098FORT1MONTH,3MONTHS,6MONTHS,1YEAR,AND5YEARS,RESPECTIVELYOR,ATANYTIMEAFTERAGE1TO3DAYSFORSTEAMCUREDCONCRETE,217B5TSTWHERETTIMEINDAYSFROMAGE3DAYSST035,062,077,087,AND097FORT1MONTH,3MONTHS,6MONTHS,1YEAR,AND5YEARS,RESPECTIVELYFORSHRINKAGECONSIDEREDFROMGREATERAGESTHANGIVENABOVE,THEDIFFERENCEMAYBEDETERMINEDUSEEQ217AOR217BFORANYPERIODAFTERTHANTIMETHATISSHRINKAGEFORMOISTCUREDCONCRETEBETWEEN,SAY,1MONTHAND1YEARWOULDBEEQUALTOTHE7DAYTO1YEARPROCEDUREASSUMESTHATTHEMOISTCUREDCONCERTEHSBEENCUREDTHESHRINKAGENEEDSTOBEMULTIPLIEDBY12ALINEARINTERPOLATIONBETWEEN12AT1DAYAND10ABD10AT7DAYSMAYBEUSEDRELATIVEHUMIDITYCOEFFICIENT,SHSH14001HFOR40H80218AOR,SH30003HFOR80H100218BWHEREHRELATIVEHUMIDITYINPERCENTSH100,080,060,0,FOR40,60,80,AND100RELATIVEHUMIDITYMINIMUMTHICKNESSOFMEMBERCOEFFICIENT,STHSTH100FOR6INORLESSAND084FOR9IN1IN254MMSLUMPOFCONCRETECOEFFICIENT,SSSS097FOR2IN,100FOR27IN,101FOR3IN,105FOR4IN,AND109FOR5IN1IN254MMFINESCOEFFICIENT,SFSF086FOR40,100FOR50,AND104FOR70FINESBYWEIGHTAIRCONTENTCOEFFICIENT,SESE098FOR4,100FOR6,AND103FOR10AIRCEMENTCONTENTFACTOR,SCSC087FOR3761B/YD3,095FOR5641B/YD3,100FOR7051B/YD3AND109FOR9401B/YD311B/YD30593KG/M3EXAMPLE22ESTIMATETHEFREESHRINKAGESTRAINTHATCANBEEXPECTEDTOOCCURINA9IN230MMTHICKCONCRETEWALLFROMTHEAGEOF7DAYSDURINGA5YEARPERIODATARELATIVEHUMIDITYOF60THECONCRETEHASASLUMPOF3IN76MM,AFINESCONTENTOF34BYWEIGHT,ACEMENTCONTENTOF6001B/YD3356KG/M3,ANAIRCONTENTOF5,ANDISMOISTCUREDFOR5DAYSAFTERBEINGPLACEDSOLUTIONFROMEQ016WEHAVESH08908408107890634原文翻译混凝土的收缩当混凝土由蒸发丢失水分时便产生了收缩现象。混凝土的收缩是一种自发的变形，并不依靠作用在混凝土上的外力。因此当收缩变形不能自由进行时，有可能导致混凝土产生裂缝，并且裂缝的数量随着时间的增加而增多。在后面的第10章具体介绍收缩产生的变形和裂缝的计算。图221反应了混凝土的收缩随时间发展的规律，早期混凝土的收缩变形速率随时间的增加变化较快，但是到了后期混凝土的收缩变形和初期相比有很大的不同，收缩的总量一般为（25）104，有时达到1103。图221混凝土收缩随时间发展的规律混凝土的体积变形，包括收缩和膨胀两个方面。如果混凝土在水中硬结时，体积就会增大，因此分别在干、湿环境中会引起体积的收缩和膨胀。这种现象与结构的环境变化有很大的关系，（如混凝土桥梁）很容易受到每年季节变化。通常混凝土呈现收缩和徐变两种情形。因此混凝土的收缩大小与混凝土的构成及前面介绍的徐变的环境有关。ACI209226和CEBFIP227早就提出了混凝土的收缩变形的经验公式。公式如下所述。根据ACI209226给出的重量、集料级配及所有的混凝土强度等级（使用I到III级水泥）在假设没有外力条件的混凝土收缩变形的时间已给出。SHSHUTTHSFEC系数由下面给出最终的收缩变形SHU值的变化范围很大。在ACI209226提到过，变化范围为SHUSHU0000415000107，采用湿养护方法取000080，采用蒸气养护方SHU法取000073。平均值常用在缺乏精确的数据时被使用。SHUSHU干燥前的养护时间，ST采用湿养护7天后217A35TSTT养护7天后的时间，ST046,072,084,091,和098从T1个月,3个月,6个月,1年,和5年,各自取值或者,采用蒸汽养护3天后,217B5TSTT养护3天后的时间，ST035,062,077,087,和097从T1个月,3个月,6个月,1年，和5年各自取值湿度条件，SHSH14001HFOR40H80218A或者，SH30003HFOR80H100218BH湿度的百分比SH100,080,060,0,从40,60,80,和100各自取值试件的平均厚度，STHSTH小于6英尺时取084，9英尺时取1001英尺254MM塌落度,SSSS2英尺时取097,27英尺时取100,101，3英尺时取101,4英尺时取105,5英尺时取1091IN254MM砂率，SFSF含砂率40取086,含砂率50取100，含砂率70取104。含气量影响系数,SESE含气量4时取098,含气量6时取100，R含