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1、學(xué)兔兔www.xuetutu.com第18卷第3期建筑材料學(xué)報(bào)Vo1.18。No.32015年6月JOURNALOFBUILDINGMATERIALSJun.,2015文章編號(hào):1007—9629(2015)03—0471-06車(chē)橋耦合振動(dòng)對(duì)混凝土早期性能的影響及其損傷機(jī)理蔣正武,任強(qiáng),袁政成(同濟(jì)大學(xué)先進(jìn)土木工程材料教育部重點(diǎn)實(shí)驗(yàn)室,上海201804)摘要:在分析車(chē)橋耦合振動(dòng)參數(shù)變化規(guī)律的基礎(chǔ)上,提出了合理的振動(dòng)模擬試驗(yàn)方法與評(píng)價(jià)指標(biāo),研究了車(chē)橋耦合振動(dòng)參數(shù)對(duì)不同水膠比混凝土性能的影響,并結(jié)合微觀結(jié)構(gòu)試驗(yàn)
2、結(jié)果,探討了混凝土損傷機(jī)理.研究發(fā)現(xiàn):車(chē)橋耦合振動(dòng)會(huì)加速混凝土的泌水,降低實(shí)際水膠比,一定程度上有利于其抗壓強(qiáng)度測(cè)試值的提高,但會(huì)提高混凝土內(nèi)部大于200nm的多害孔比例,同時(shí)加劇石子下沉和漿體上浮,使得混凝土早期離析程度增大,均勻性降低,密實(shí)度降低,從而降低混凝土長(zhǎng)期性能.在混凝土凝結(jié)硬化初期(貫入阻力≤0.5MPa)和后期(貫入阻力≥28.0MPa),車(chē)橋耦合振動(dòng)產(chǎn)生的破壞作用較??;在凝結(jié)硬化中期(貫入阻力為0.5--~28.0MPa),車(chē)橋耦合振動(dòng)會(huì)導(dǎo)致混凝土內(nèi)部產(chǎn)生永久微裂紋等缺陷,對(duì)混凝土性能影響
3、較大.關(guān)鍵詞:耦合振動(dòng);頻率;損傷;機(jī)理中圖分類(lèi)號(hào):TU528.01文獻(xiàn)標(biāo)志碼:Adoi:10.3969/j.issn.1007—9629.2015.03.019EffectsofVehicle-BridgeCoupledVibrationonEarly-AgePropertiesofConcreteandItsDamageMechanismJIANGZhengwu,RENQiang,YUANZhengcheng(KeyLaboratoryofAdvancedCivilEngineeringMaterial
4、sofMinistryofEducation,TongjiUniversity,Shanghai201804,China)Abstract:Thevariationlawofvehicle-bridgecoupledvibrationwasanalyzedandareasonablemethodtosimulatecoupledvibrationin1abaswel1astheevaluationindexeswasproposed.Thentheeffectsofvehi—cle—bridgecouple
5、dvibrationparametersonthepropertiesofconcretewithdifferentwater-cementratiowerestudied.Thedamagemechanismofvehicle—bridgecoupledvibrationonconcretewasinvestigatedac—cordingtothemicrostructureresults.Theresultsindicatethatundervehicle-bridgecoupledvibration
6、,thebleedingofconcreteaccelerates,theactualwater—cementratioreduces,andthecompressivestrengthin—creasestoacertainextent.However,theearlysegregationofconcreteisaggravatedbythevibration,whichleadstoworseuniformityandcompactness.Thelong—termperformanceofconcr
7、eteisdeterioratedasseenfromahigherproportionofdeleteriouspores(~200nm)ofconcrete.Attheearlyage(i.e.pene—trationresistanceS0.5MPa)ofsettingandlaterage(i.e.penetrationresistance≥28.0MPa)ofharden—ing,thenegativeinterferenceofvehicle-bridgecoupledvibrationisin
8、significant,however,vehicle—bridgecoupledvibrationcan1eadtoalotofirreversiblemicro—cracksinconcreteatthemiddleage(i.e.penetra-收稿日期:2013—03—05;修訂日期:2013—04—04基金項(xiàng)目:國(guó)家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(973計(jì)劃)項(xiàng)目(2011CB013805);國(guó)家自然科學(xué)基金資助