摘 要：以南京市江北新区防疫测控方舱为工程案例，展示了建筑3D打印技术在应对新冠肺炎疫情及类似紧急公共事件中的应用方式，探讨了3D打印技术的优势和未来的发展趋势。实践表明，建筑3D打印技术在防疫阶段具有较大的优势。利用3D打印技术进行防疫测控方舱的建造，其建造工艺简洁，生产周期短，安装便捷。构件打印过程由计算机自动控制，人工干预少，且构件以单元模块进行打印，安装用工少。目前，该类型的防疫方舱已经在南京、雄安、海门、濮州等地投入使用。Abstract:TakingtheepidemicpreventioncabinsatJiangbeiNewAreaofNanjingasanengineeringcase,theapplicationof3DprintingconstructionduringtheoutbreakofCOVID-19andotherpublichealthemergencyareintroduced.Theadvantagesandfuturedevelopmentof3Dprintingconstructionarediscussedaswell.Thepracticeshowsthat3Dprintingconstructionhassomeobviousadvantagesforpublicapplication.Specifically,3Dprintingtechnologyenablestheconstructionprocessestobesimplified,withshortenedproductionperiodandconvenientinstallation.Theprintingprocessisautomaticallycontrolledbythecomputer,withlessmanualintervention.Thecomponentsareprintedasunitmodulesthatcanbeinstalledbyafewlabors.Sofar,thistypeofcabinshascomeintoserviceinNanjing,Xiongan,Haimen,Puzhouandothercities.

王香港,王申,贾鲁涛,等.3D打印混凝土技术在新冠肺炎防疫方舱中的应用[J].混凝土与水泥制品,2020(4):1-4+13. WANG X G,WANG S,JIA L T,et al.Application of 3D Printing Technology in Epidemic Prevention Cabins during the Outbreak of COVID-19[J].China Concrete and Cement Products,2020(4):1-4+13.

摘 要：将碳纳米管（CNTs）作为导电填料制备了碳纳米管水泥基复合材料（CNT/CC），分别研究了CNT/CC在不同温度、湿度下的电阻率变化规律，探讨其作为本征型温、湿度传感器的可行性。结果表明，试件在25～55℃区间内具有较好的温敏性，CNTs掺量为0.5%的CNT/CC试件单位温度内电阻率变化率在1.5%以上，且在升温和降温条件下，电阻率变化率随温度线性变化的相关系数分别为-0.950和-0.984；试件内部含水率在0.6%～6.0%时的湿敏性能最佳，且CNTs掺量为0.5%的试件电阻率变化率最大，达到91.2%。Abstract:Carbonnanotubes(CNTs)wereusedasconductivefillerstofabricatecarbonnanotube/cementcomposite(CNT/CC).Bystudyingthechangerateofresistivityunderdifferenttemperatureandhumidity,whetherCNT/CCcouldbeabletomakeanintrinsictemperatureandhumiditysensorwasdiscussed.Theresultsshowthatspecimenshavegoodtemperaturesensitivitybetween25℃and55℃,thechangerateofresistivitycomesupto1.5%/℃.WhenCNT/CCcontaining0.5%CNTsisheatedupandcooleddown,thelinearcoefficientis-0.950and-0.984respectively.Specimenshavethebesthumiditysensitivitywhenwatercontentisbetween0.6%and6.0%.Whileadding0.5%CNTs,thechangerateofresistivityis91.2%,whichreachesthemaximumvalue.

袁娇,刘小艳,陈玉泉,等.碳纳米管水泥基复合材料温敏及湿敏性能研究[J].混凝土与水泥制品,2020(4):5-8. YUAN J,LIU X Y,CHEN Y Q,et al.Study on Temperature and Humidity Sensitivity of Carbon Nanotube/Cement Composite(CNT/CC)[J].China Concrete and Cement Products,2020(4):5-8.

摘 要：采用界面破坏模型分析法和斜剪黏结强度法对比研究了碱式硫酸镁水泥基与硅酸盐水泥的树脂透光混凝土的强度损失率。研究结果表明，碱式硫酸镁水泥基树脂透光混凝土的28d抗压强度损失率为19.9%，水泥砂浆与树脂界面7d斜剪试验强度为6.8MPa；硅酸盐水泥基透光混凝土的28d抗压强度损失率为41.3%，水泥砂浆与树脂界面7d斜剪试验强度为6.1MPa。碱式硫酸镁水泥在界面结合方面表现更优。Abstract:Theinterfacefailuremodelanalysisandobliqueshearbondstrengthmethodwereusedtocomparethecompressivestrengthlossrateofresintransparentconcretewithbasicmagnesiumsulfatecementandportlandcement.Theresultsshowthatthe28dcompressivestrengthlossrateofbasicmagnesiumsulfatecement-basedresintransparentconcreteis19.9%,the7dobliqueshearstrengthoftheinterfaceofcementmatrixandresinis6.8MPa,andthe28dcompressivestrengthlossrateofportlandcement-basedtransparentconcreteis41.3%,the7dobliqueshearstrengthoftheinterfaceofcementmatrixandresinis6.1MPa.Thus,basicmagnesiumsulfatecementhasbetterperformanceininterfacebonding.

陈思佳,徐迅,王宗浩,等.碱式硫酸镁水泥基树脂透光混凝土界面特性的研究[J].混凝土与水泥制品,2020(4):9-13. CHEN S J,XU X,WANG Z H,et al.Study on Interface Characteristics of Basic Magnesium Sulfate Cement-based Resin Transparent Concrete[J].China Concrete and Cement Products,2020(4):9-13.

摘 要：通过强度试验，运用灰关联熵分析方法，以水压力、荷载、硫酸盐、氯盐与侵蚀时间作为影响因素，研究地下粉煤灰混凝土抗压强度变化情况及其关联程度，结合SEM、XRD分析了不同工况下混凝土内部结构的微观变化。结果表明：灰关联熵分析方法可以有效区分多种因素的主次关系，在选取的五种因素中，硫酸盐与混凝土强度退化灰关联熵值最大；无水压力时，Cl-会先进入混凝土内部与水泥水化产物生成Friedel’s盐。有水压力时，水压力加速硫酸根离子侵蚀混凝土试块，Cl-结合能力减弱并且多以自由离子形式存在于粉煤灰混凝土中；随着侵蚀时间增加，多因素作用下粉煤灰混凝土生成产物石膏越来越多，内部结构越来越稀疏，使得抗压强度下降速率大于单因素与双因素作用下粉煤灰混凝土抗压强度下降速率。Abstract:Throughstrengthtestandgreyrelationentropyanalysismethod,takingwaterpressure,load,sulfate,chlorideanderosiontimeasinfluencingfactors,thevariationofcompressivestrengthofundergroundflyashconcreteanditscorrelationdegreewerestudied.MicroscopicchangesofsoilinternalstructureunderdifferentconditionswasanalyzedbySEMandXRD.Theresultsshowthatthegreyrelationalentropyanalysismethodcaneffectivelydistinguishtheprimaryandsecondaryrelationshipsofvariousfactors.Amongthefiveselectedfactors,thegreyrelationalentropyofstrengthdegradationofsulfateandundergroundflyashconcreteisthelargest.Underanhydrouspressure,chlorideionsfirstentertheconcreteandcementhydrationproductstoformFriedel′ssalt.Whenthereiswaterpressure,thewaterpressureacceleratessulfateiontoerodeconcreteblocks,andchlorideionbindingabilitydecreases,andmostofthemexistinflyashconcreteintheformoffreeions.Withtheincreaseoferosiontime,moreandmoregypsumisproducedinconcreteofflyashconcreteundertheactionofmultiplefactors.Asthestructurebecomesmoreandmoresparse,thedeclinerateofcompressivestrengthofflyashconcreteisgreaterthanthatofflyashconcreteundertheactionoftwofactors.

杜辉,纪荣健,胡杰.多因素作用下地下粉煤灰混凝土抗压强度灰熵分析及微观结构[J].混凝土与水泥制品,2020(4):14-18,23. DU H,JI R J,HU J.Grey Entropy Analysis and Microstructure of Compressive Strength of Underground Fly Ash Concrete under Multi-factor Action[J].China Concrete and Cement Products,2020(4):14-18,23.

摘 要：对利用未经淡化处理海砂配制的超高性能混凝土（UHPC）的抗压强度、抗折强度、劈裂抗拉强度、弹性模量、抗冻性能、抗氯离子渗透性能和护筋性能进行了系统的试验研究。结果表明：抗压强度、抗折强度和劈裂抗拉强度分别大于120MPa、20MPa和12MPa，弹性模量大于40GPa，其抗冻等级超过F500，电通量值不超过50C，力学性能和耐久性指标均满足GB/T31387—2015《活性粉末混凝土》的要求。此外，本试验显示，经过40次的盐水浸烘循环试验后，未淡化海砂UHPC中的钢筋锈蚀风险较低。Abstract:Thecompressivestrength,flexuralstrength,splittingtensilestrength,elasticmodulus,frostresistance,chloride-permeationresistanceandprotectionforsteelofultra-highperformanceconcrete(UHPC)madewithuntreatedseasandwerestudied.Theresultsofresearchshowthat:compressivestrength,flexuralstrength,splittingtensilestrengthandelasticmodulusarehigherthan120MPa、20MPa、12MPaand40GParespectively,andthefrostresistancedegreefarexceedesF500andelectricfluxislessthan50C.Accordingtotheaboveresults,themechanicalpropertyanddurabilitycanmeettherequirementsofcurrentnationalstandardGB/T31387—2015ReactivePowderConcrete.Inaddition，through40timesofsaltwaterimmersiondryingcycletest,thesteelinUHPCmadewithuntreatedseasandshowslowriskofcorrosion.

王晶,王祖琦,倪博文,等.未淡化海砂超高性能混凝土的性能研究[J].混凝土与水泥制品,2020(4):19-23. WANG J,WANG Z Q,NI B W,et al.Study on the Properties of Ultra-high Performance Concrete with Untreated Sea Sand[J].China Concrete and Cement Products,2020(4):19-23.

摘 要：对欧美及我国规范中保护层厚度相关要求作了对比，并分别按照碳化寿命准则、锈胀开裂寿命准则对保护层厚度合理值进行了计算。结果表明，我国规范中保护层厚度取值与锈胀开裂准则计算值接近，与欧美规范值相比偏小，在恶劣环境下尤其明显，最大差值达到30%以上，并且规范中未考虑施工允许偏差的影响；按碳化准则计算时，现行规范要求的保护层厚度值远达不到相应耐久年限的可靠指标要求。在设计和施工阶段，关于保护层厚度的要求应进一步加强。这将使结构更安全耐久，并减少使用期内的维护及大修次数，降低能耗。Abstract:ThecomparisonofconcretecoverthicknessrequirementsinEuropeanandAmericanandChinesecodeswascarriedout,andthethicknessoftheconcretecoverwascalculatedaccordingtothecarbonizationlifecriterionandthecorrosioncrackinglifecriterion,respectively.TheresultsshowthatthethicknessoftheconcretecoverinChinesespecificationsisclosetothecalculatedvalueoftherustexpansioncriterion,andit’ssmallcomparedwiththeEuropeanandAmericannormativevalues,especiallyinharshenvironments,themaximumdifferenceismorethan30%,andtheinfluenceofconstructiontoleranceisnotconsideredinthespecification.Whencalculatedaccordingtothecarbonizationcriteria,thethicknessoftheconcretecoverrequiredbythecurrentspecificationisfarfromthereliableindexrequirementforthecorrespondingenduranceperiod.Therequirementsforthethicknessoftheconcretecovershouldbefurtherstrengthenedduringthedesignandconstructionphases.Thiswillmakethestructuresaferandmoredurable,andreducethenumberofmaintenanceandoverhaulsduringtheuseperiod,reducingenergyconsumption.

王鹏刚,焦茂鹏,范宏,等.关于混凝土保护层厚度合理性的相关研究[J].混凝土与水泥制品,2020(4):24-28. WANG P G,JIAO M P,FAN H,et al.Sesearch on the Rationality of Concrete Cover Values[J].China Concrete and Cement Products,2020(4):24-28.