轻骨料对中等强度混凝土耐久性能影响的研究

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1、2012年第12期(总第278期)混凝土原材料及辅助物料Number12in2012(TotalNo．278)ConcreteMATERIALANDADMINICLEdoi：10．39698．issn．1002-3550．2012．12．016轻骨料对中等强度混凝土耐久性能影响的研究孔丽娟(石家庄铁道大学材料科学与工程学院，河北石家庄050043)摘要：研究了不同掺量及种类的轻骨料配制的中等强度混凝土抗渗及抗冻性能，并通过对轻骨料及界面结构的观察研究，分析了轻骨料对中等强度混凝土耐久性能的影响机理。结果表明：对于水灰比较高的中等强度混凝土，轻骨料的掺人可提高混凝土耐久性，这是由

2、于其可细化骨料附近水泥石的孑L结构，使得界面区更为致密，而且可使新拌混凝土的含气量有所增加，说明其在混凝土内部具有“引气”作用。但是所选轻骨料吸水率不宜过高，因为其过多的开放连通孔又会对混凝土耐久性不利。本研究条件下，掺量50％的高吸水率粉煤灰陶粒配制的混合骨料混凝土抗渗性已于同水灰比的普通混凝土相当，其抗冻性甚至低于普通混凝土。关键词：中等强度混凝土；耐久性；孔结构；界面区；轻骨料中图分类号：TU528．04文献标志码：A文章编号：1002—3550(2012)12—0046—04Eefectoflightweightaggregateondurabilityofmodera

3、testrengthconcreteKONGLi-juan(SchoolofMaterialsScienceandEngineering，Sh~iazhuangTiedaoUniversity，Sh~iazhuang050043，China)Abstract：Theimpermeabilityandfrost-resistanceofmoderatestrengthconcretepreparedwithdiferentvolumecontentsandvarietiesoflightweightaggregate(LWA)weretested，andthroughtheexa

4、minationofthemicrostructureoflightweightaggregateandinterracialzone，thein·fluenceoflightweightaggregateondurabilityofmoderatestrengthconcretewasstudied．Theresultsshowedthat，asforthemoderatestrengthcon—cretepreparedwithahigherwater-cementratio，themixingoflightweightaggregateintoconcreteCalimp

5、rovetheconcretedurability，thatwasbe—causeitcanrefinetheporestructureofthecementpastearoundaggregate，andmadethemicrostructureoftheinterracialzonebecamedenser，fur-thermoreincreasedtheaircontentoffreshconcrete，whichtestifiedthattheporouslightweightaggregatehad“air—entraining”efectHoweverthewate

6、rabsorptionoflightweightaggregateshouldnotbetOOhigh．becausethelightweightaggregatewithexcessiveopenandinterconnectedporewasdisadvantageoustoconcretedurability．Underthisstudycondition，theimpermeabilityofcombinedaggregateconcretecontaining50％volumecontentflyashceramsitewithhighwaterabsorptionw

7、asalmostthesalnewiththatofordinaryconcretepreparedwiththesamewater-cementra—tio，andthefrost-resistanceofthecombinedaggregateconcretewasevenworsethanthatofordinaryconcrete．Keywords：moderatestrengthconcrete；durability；porestructure；interracialzone；li