钢筋绑扎规范要求

钢筋绑扎规范要求

SteelBarBindingStandardsTheprocessofoperation:(1)Cleanthefoundationcushionanduseastonepenandinkbuckettomarkthepositionlineofthesteelbaronit.(2)Laythefoundationsteelbarsaccordingtothepositionlineofthesteelbars.(3)Bindthesteelbars.Theintersectionpointsofthefoursurroundingtworowsofsteelbarsshouldbetightlyboundateachpoint.Theintersectionpointsinthemiddlepartcanbestaggeredandboundtightly,butitmustbeensuredthatthestresssteelbarsdonotshift.Forthesteelbarmeshofdouble-directionalmainbars,alltheintersectionpointsofthesteelbarsneedtobetightlybound.Theadjacentbindingpointsofthesteelwirearebuckledintoafigure-eightshapetopreventthewindfromcausingdeformation.Forone-wayplates,theplatesteelbarscanbetiedwithplumblossoms,butthetwoplatesteelbarsatthebeamedgemustbefullytied;fortwo-wayplates,theymustbefullytied.Theintersectionpointsofbeamsteelbarsandhoopsteelbarsshouldbefullytied;shearwallsshouldalsobefullytied.Thiscanbefoundinthesteelbarconstructionmanual.(4)Whenusingadouble-layersteelbarmeshforthelargebaseplate,steelbarsupportsorconcretesupportsshouldbesetundertheupperlayerofsteelbarmeshtoensurethecorrectpositionofthesteelbars.Thesteelbarsupportsshouldbeplacedonthelowerreinforcementmesh.RefertoFigures10.6.2-1and10.6.2-2fortheformandsizeofthesteelbarsupports.ThetypeofsupportshowninFigure10.6.2-1isplacedevery1m.Thediameterisselectedasfollows:8-10mmwhenthethicknessislessthanorequalto300mm;12-14mmwhenthethicknessoftheplateisbetween300-500mm;and16-18mmwhenthethicknessisgreaterthan500mm,asshowninFigure10.6.2-2.Thesupportsarearrangedalongtheshortdirection,andthespacingisbasedonensuringthepositionofthesteelbars.(5)Thebendinghooksofthesteelbarsshouldfaceupwardsandnotbetiltedtooneside.Thebendinghooksoftheupperlayerofthedoublesteelbarmeshshouldfacedownwards.(6)Forindependentfoundationsthatarebentinbothdirections,theshort-directionsteelbarsonthebottomsurfaceshouldbeplacedontopofthelong-directionsteelbars.(7)Fortheinsertedsteelbarsusedtoconnectthecast-in-placecolumnandthefoundation,thehoopsteelbarsshouldbeonecolumndiametersmallerthanthecolumn'shoopsteelbarsforeasyconnection.Thepositionofthehoopsteelbarsmustbetightlyboundandfixedtopreventthedeviationofthecolumnaxis.(8)Thethicknessoftheconcreteprotectionlayerofthelongitudinalstresssteelbarsinthefoundationshouldnotbelessthan40mm,andwhenthereisnocushionlayer,itshouldnotbelessthan70mm.(9)Steelbarconnection:1)Thejointofthesteelbarconnectionshouldbesetinaplacewithlessstress.Thedistancefromtheendofthejointtothestartingpointofthesteelbarbendingshouldnotbelessthan10timesthediameterofthesteelbar;2)Ifthebindingoverlapjointisused,thebindingjointsofthelongitudinalstresssteelbarsshouldbestaggered.Thelengthofthebindingjointintheconnectionsectionofthesteelbaris1.3timestheoverlaplength(LL).Allmidpointoverlapjointsintheoverlapjointbelongtothesameconnectionsection.Theareapercentageofthetensionsteelbaroverlapjointinthesamesectionis25%;3)Whenthediameterofthesteelbarisgreaterthan16mm,thebindingjointshouldnotbeused;4)Whenthelongitudinalstresssteelbarsareconnectedbymechanicalconnectionjointsorweldingjoints,thelengthoftheconnectionsectionis35d(disthelargervalueofthelongitudinalstresssteelbars)andnotlessthan50mm.Inthesameconnectionsection,theareapercentageofthelongitudinalstresssteelbarsjointshouldmeetthedesignrequirements.Whenthereisnodesignrequirement,itshouldmeetthefollowingrequirements:①Itshouldnotbegreaterthan50%inthetensilezone.在直接承受动力荷载的基础中，不宜采用焊接接头。当采用机械连接接头时，连接接头不应超过基础的50%。关于基础钢筋的规定，当条形基础的宽度B≥2500mm时，横向受力钢筋的长度可以减至20.9B，并采用交错布置。当单独基础的边长B≥2500mm时（除基础支承在桩上外），受力钢筋的长度可以减至0.9B，并采用交错布置。在基础浇筑完毕后，应该把基础上预留的墙柱插筋扶正理顺，保证插筋位置准确。在承台钢筋绑扎前，一定要保证桩基伸出钢筋到承台的铺固长度。关于质量标准，基础钢筋