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1、多孔混凝土材料的粘结强度采用无砂大孔混凝土作小区道路与人行道结构层的施工方法及质量要求,基本上与室内地坪施工相同,不同之处只是面层的材料及施工方法,即面层采用透水砖,用砂干铺。在浇灌无砂大孔混凝土前,地基应平整、密实、均匀。无砂大孔混凝土最好采用机械搅拌,浇灌时不需振动,找平即可。抹面砂浆或细石混凝土应在无砂大孔混凝土胶凝后施工,力求干硬,以免形成浆液滚人无砂大孔的空隙中,宜采用1:(1.5一3.0)的水泥砂浆。Usingmacroporousconcretewithoutsandvillageroadandthepavementstructurelayerconstru
2、ctionmethodandqualityrequirements,basicallythesameastheinteriorfloorconstruction,thedifferenceisonlythesurfaceofthematerialsandconstructionmethods,namelythesurfaceUSESthepermeablebrick,drysand.Beforethewatersandfreemacroporousconcrete,foundationshouldbeflat,denseanduniform.Macroporousconc
3、retewithoutsandisbestbymechanicalagitation,pourout,withoutvibrationwhenleveling.Plastermortarorconcretewithfinestonesshouldbeintheabsenceofsandmacroporousconcreteconstructionaftergelling,makeseveryefforttohard,soasnottoformslurryrolledthegapnosandhole,appropriateUSES1:(1.5a3.0)cementmorta
4、r.混凝土结构的破坏特征表明,水泥石与粗骨料界面的粘结强度,往往是混凝土中的最薄弱环节。尽管无砂大孔混凝土中的孔洞多、空隙大,但仍具有较高的强度。这是因为单一级配的骨料颗粒在混凝土结构中排列紧密,相互接触的几率增大,形成无数个大大小小的“拱结构”,使得骨料界面间的接触点能在外力作用下受力均匀、共同工作,保证了无砂大孔混凝土具有较高的强度。Damagecharacteristicsofconcretestructureshowsthatthecementandaggregatebondstrengthofinterface,areoftentheweakestlinkint
5、heconcrete.Althoughmacroporousconcretewithoutsandholesandgapsinthebig,butitstillhashighstrength.Thisisbecausethesingleparticlegradationofaggregateinconcretestructureisarrangedclosely,increasechancestocontacteachother,formnumerouslargeandsmall"arch"structure,makestheaggregatecontactpointto
6、inundertheactionofexternalforceontheinterfacebetweenuniformstress,worktogetherandensurethatnosandmacroporousconcretehashigherstrength.由于骨料自身的强度高,胶凝材料的活性、品种、数量就是决定混凝土强度的关键因素,无砂大孔混凝土没有细骨料,空隙率大,与一般混凝土比较,水泥石与骨料之间的粘结强度对其整体的强度,就显得极为重要。试验结果及现场抽检表明,无砂大孔混凝土强度等级一般大于c10。Duetothehighstrengthaggregate
7、itself,theactivityofgelledmaterial,type,quantity,isthekeyfactorofconcretestrength,bigholesdonotfineaggregateconcretewithoutsand,voidfractionislarge,comparedwithnormalconcrete,thebondingstrengthbetweencementandaggregateofitsoverallstrength,itisextremelyimportant.Expe