资源描述：
《高性能pva纤维增强水泥基材料地制备与性能》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、第29卷第9期中国材料进展Vol29No9MATERIALSCHINA2010年9月Sep2010高性能PVA纤维增强水泥基材料的制备与性能杨英姿,姚燕(中国建筑材料科学研究总院,北京100024)摘要:为了获得高性能PVA纤维增强水泥基复合材料的制备方法,研究了砂的颗粒级配、水胶比和粉煤灰掺量对高延性纤维增强水泥基复合材料(EngineeredCementitiousComposites,ECC)的弯曲性能、抗压、抗折强度及开裂模式的影响。结果表明:随着砂的细度模数降低,ECC的跨中挠度增大,早期强度提高,但后期强度变化不明显
2、。随着水胶比的增大,ECC的初始开裂荷载降低,跨中挠度增大,平均裂缝宽度增加。025水胶比的ECC的抗压强度可以满足高强度等级的要求。035水胶比的抗压强度可以满足对普通强度等级的要求。随着粉煤灰掺量的增加,ECC的初始开裂荷载降低、抗折和抗压强度逐渐降低,ECC的跨中挠度提高,平均裂缝宽度变小。在水胶比一定的条件下,采用细砂,适当增加粉煤灰掺量有助于提高ECC的韧性和延性。关键词:高延性纤维增强水泥基复合材料;荷载-挠度曲线;多缝开裂中图分类号:TU528文献标识码:A文章编号:1674-3962(2010)09-0019-06P
3、reparationandPropertiesofHighPerformancePVAFiberReinforcedCementitiousMaterialsYANGYingz,iYAOYan(ChinaBuildingMaterialsAcademy,Beijing100024,China)Abstrac:tInordertoobtainthepreparationmethodofhighperformancePVAfiberreinforcedcementitiousmaterial(alsocalledEngineeredCementi
4、tiousComposites,ECC),theeffectsofgradationofsand,waterbinderratio(W/B)andcontentofflyashonthebendingproperties,compressivestrength,flexuralstrengthandcrackingpatternofECCwereinvestigatedinthispaper.Theresultsshowedthatwiththefinenessmodulusofsanddecreased,ECCsmidspandefl
5、ectionincreased,theearlystrengthincreasedbutthestrengthinthelongtermdidnotchangesignificantly.AsthewaterbinderratioofECCincreased,theinitialcrackingloadofECClowered,deflectionatmidspanandtheaveragecrackwidthincreased.ThecompressivestrengthofECCwithW/Bof025couldmeetthereq
6、uirementsofhighstrengthconcretegrades.ThecompressivestrengthofECCwithW/Bof035couldmeettherequirementsofordinarystrengthconcretegrades.WiththeflyashcontentofECCincreased,theinitialcrackingloadofECClowered,theflexuralandcompressivestrengthgraduallydecreased,thedeflectionofE
7、CCenhanced,aswellastheaveragecrackwidthbecamesmaller.AstheW/BofECCisfixed,usingfinersandandincreasingflyashcontentappropriatelywillhelptofurtherimprovethetoughnessandductilityofECC.Keywords:engineeredcementitiouscomposites;loaddeflectioncurve;multiplecracking混凝土是应用于土木工程领域
8、最大宗的人造建筑材土木工程材料。其中聚乙烯醇纤维(PVA)体积掺量通常料,然而存在着脆性大、易开裂、抗拉强度低、极限延在2%左右,ECC的拉应变在2%
