摘 要：测试了多组配合比砂浆不同龄期的强度及孔隙结构，引入基于热力学关系的分形模型计算得到了砂浆的孔表面积分形维数。利用统计学方法，探讨了孔隙量参数和孔径分布参数与砂浆抗压强度的定量关系，建立了同时考虑孔隙量和孔径分布的强度预测模型，采用该模型对多组配合比混凝土的抗压强度进行预测。结果表明，预测强度接近室内试验实测强度。Abstract:Thestrengthandporestructureofcementmortarwithdifferentproportionsatdifferentagesweremeasured.Thefractalmodelbasedonthethermodynamicrelationshipwasintroducedtocalculatetheporesurfacefractaldimensionofthecementmortar,whichcouldbeusedasoneofthecharacteristicparametersoftheporesizedistribution.Thequantitativerelationshipsbetweenthecompressivestrengthandtheporevolumeparametersandtheporesizedistributionparameterswerediscussedbystatisticalmethod.Thestrengthpredictionmodelwithconsiderationofbothporevolumeandporesizedistributionwaspresented.Thestrengthofconcretewithdifferentproportionswascalculatedbythestrengthpredictionmodel.Theresultsshowthecalculationstrengthapproachestothetestedstrength.Thestrengthpredictionmodelproposedinthisresearchcanbeappliedintheassessmentofthematerialstrengthofexistingconcretestructure.

金珊珊,杨金龙,索智,等.基于分形理论的水泥砂浆强度预测模型[J].混凝土与水泥制品,2020(6):1-5,12. JIN S S,YANG J L,SUO Z,et al.The Strength Prediction Model of Cement Mortar Based on Fractal Theory[J].China Concrete and Cement Products,2020(6):1-5,12.

摘 要：通过控制调孔剂、粉煤灰掺量来调整相关轻质多孔混凝土的气孔孔径大小和孔径分布，使其具有仿火山渣的装饰效果。基于抗压强度和装饰效果的要求，提出了A08级仿火山渣轻质多孔装饰混凝土的适宜配合比。试验结果表明，按此配合比制备的轻质多孔装饰混凝土不但具有良好的仿火山渣装饰效果，同时具有良好的物理力学性能，多孔混凝土的密度等级为A08级，强度等级达到A5.0级。Abstract:Theporesizeandporedistributionoflightweightporousconcretecanbechangedbyadjustingagentandflyashcontent.Basedonthecompressivestrengthanddecorationeffectrequirements,thesuitablemixingratioofA08gradelightweightporousconcretewithimitationvolcanicslagdecorationwasproposed.Theresultsshowthelightweightporousdecorativeconcrete,accordingtothemixingratio,notonlyhasthegoodimitationvolcanicslagdecoration,butalsohasgoodphysicalandmechanicalproperties.Thedensitygrade,compressivestrengthgradecanreachA08,A5.0respectively.

张磊蕾,刘洪彬,王武祥,等.仿火山渣装饰效果的轻质多孔混凝土制备与性能研究[J]混凝土与水泥制品,2020(6):6-8. ZHANG L L,LIU H B,WANG W X,et al.Research on the Preparation and Properties of Lightweight Porous Concrete with Volcanic Slag Imitation[J].China Concrete and Cement Products,2020(6):6-8.

摘 要：试验研究了不同掺量纳米CaCO3对混凝土力学性能和抗冲磨性能的影响，并通过水化热测试方法研究了纳米CaCO3对混凝土性能影响的机理。试验结果表明，适量的纳米CaCO3可以提升混凝土的力学性能，提高混凝土的抗压强度、劈裂抗拉强度和抗冲磨性能。当纳米CaCO3的掺量为1.5%时，混凝土抗冲磨强度提高约6倍；纳米CaCO3促进了水泥的水化反应，改善了水泥浆体微观结构，提升了整体的密实性。Abstract:TheeffectsofNano-CaCO3withdifferentcontentonthemechanicalpropertiesandabrasionresistanceofconcretewereinvestigatedexperimentally.TheinfluencemechanismofNano-CaCO3onconcretewasstudiedbyhydrationheattest.TheexperimentalresultsshowthatappropriateamountofNano-CaCO3(notexceed1.5%)canimprovethemechanicalpropertiesofconcrete,suchasthecompressivestrength,splittingtensilestrengthandabrasionresistanceofconcrete.Thecompressivestrengthofconcretewith1.5%Nano-CaCO3isabout6timesthantheonewithoutNano-CaCO3.TheresultsrevealthatNano-CaCO3promotehydrationreaction,acceleratehydrationheatreleaserate,refinethemicrostructureofcementpaste,andenhancetheoverallcompactness.

田竞,苏骏,吴鹏,等.纳米CaCO3对混凝土抗冲磨性能影响试验研究[J]混凝土与水泥制品,2020(6):9-12. TIAN J,SU J,WU P,et al.Experimental Research on Abrasion Resistance of Concrete Mixed with Nano-CaCO3[J].China Concrete and Cement Products,2020(6):9-12.

摘 要：为了研究混凝土在压剪复合状态下的动态力学性能，采用大型多功能动静力三轴仪进行了5种不同应变速率和5种不同法向应力下的压剪复合受力状态的剪切试验。分析其剪切强度变化规律，构建了基于八面体应力空间二次形式破环准则，转换为正应力与剪应力表示的压剪破环准则形式。结果表明，随着应变速率增加，混凝土的抗剪强度呈增大趋势，而随法向应力的增加，混凝土抗剪强度则呈现出先增大后减小的趋势；基于八面体应力空间二次形式破环准则，建立了考虑速率效应的混凝土压剪破环准则，通过试验数据对比得出该破环准则与试验数据吻合较好。Abstract:Inordertostudythedynamicmechanicalpropertiesofconcreteundercompression-shearcombinedstate,fivesheartestsunderfivedifferentstrainratesandfivedifferentnormalstresseswerecarriedoutusingalargemulti-functionaldynamic-statictriaxialapparatus.Thechangeruleofshearstrengthwasanalyzed,andaquadraticcriterionofringbreakingbasedonoctahedralstressspacewasconstructed.Thecriterionwastransformedintoacompression-shearringbreakingcriterionexpressedbynormalstressandshearstress.Theresultsshowthatwiththeincreaseofstrain,theshearstrengthofconcretetendstoincrease,whilewiththeincreaseofnormalpressure,theshearstrengthofconcretetendstoincreasefirstandthendecrease.Basedontheoctahedralstressspacequadraticformcriterion,thecompression-shearcriterionofconcreteconsideringtherateeffectisestablished.Bycomparingthetestdata,thecriterionisingoodagreementwiththetestdata.

孙尚鹏,彭刚,程卓群,等.压剪共同作用下混凝土的动态力学性能研究[J]混凝土与水泥制品,2020(6):13-16,21. SUN S P,PENG G,CHENG Z Q,et al.Dynamic Mechanical Properties of Concrete under the Combined Action of Compression and Shear[J].China Concrete and Cement Products,2020(6):13-16,21.

摘 要：为研究风积沙混凝土与钢筋之间的黏结性能，制作了28个试块进行中心拉拔试验，研究了风积沙掺量、钢筋形状、钢筋直径和龄期对黏结性能的影响规律，并基于试验结果拟合出风积沙混凝土与带肋钢筋之间的黏结强度-滑移本构关系曲线。研究结果表明，风积沙掺量小于30%时，极限黏结强度随着风积沙掺量、钢筋直径、龄期的提高而提高；风积沙掺量分别为10%、20%和30%时，带肋钢筋对应的极限黏结强度分别比光圆钢筋提高了61.2%、58.5%、56.1%。Abstract:Inordertostudythebondbehaviorbetweenaeoliansandconcreteandsteelbars,28aeoliansandconcretespecimensweremadeforcentralpull-outtests.Theeffectsofaeoliansandcontent,shapeofsteelbars,diameterofsteelbarsandcuringageonthebondbehaviorbetweenaeoliansandconcreteandsteelbarswerestudied.Besides,thebondstrength-slipconstitutiverelationshipcurvebetweenaeoliansandconcreteandribbedbarswasfittedbasedonthetestresults.Theresultsshowthattheultimatebondstrengthincreaseswiththeincreaseoftheaeoliansandcontent,diameterofsteelbarsandcuringagewhentheaeoliansandcontentislessthan30%.Whentheaeoliansandcontentis10%,20%and30%,theultimatebondstrengthofribbedbarsis61.2%,58.5%and56.1%higherthanthoseofplainroundbarsrespectively.

张泽平,王尧鸿,楚奇,等.风积沙混凝土与钢筋的黏结性能试验研究[J]混凝土与水泥制品,2020(6):17-21. ZHANG Z P,WANG Y H,CHU Q,et al.Experimental Study on Bond Behavior Between Aeolian Sand Concrete and Reinforcing Bars[J].China Concrete and Cement Products,2020(6):17-21.

摘 要：利用Torrent法研究了矿物掺合料、强度等级、含水率等因素对混凝土空气渗透系数的影响，并结合混凝土氯离子扩散系数和电通量的试验结果，分析了利用空气渗透系数来表征混凝土渗透性的可行性。试验结果表明，混凝土强度等级越高，密实度越好，空气渗透系数越小；空气渗透系数随混凝土含水率的降低而增大，变化呈现指数递增的关系；空气渗透系数与氯离子扩散系数和电通量有良好的相关性。Abstract:Theinfluenceofmineraladmixture,strengthgrade,moisturecontentonconcreteairpermeabilitycoefficientwasstudiedbyTorrentmethod.Combinedwiththeexperimentalresultsofconcretechlorideiondiffusioncoefficientandelectricfluxofconcrete,thefeasibilityofusingTorrentmethodcoefficienttocharacterizeconcretepermeabilitywasanalyzed.Theresultsshowthatthehighertheconcretestrengthgrade,thebetterthecompactness,andtheairpermeabilitycoefficientissmaller.Theairpermeabilitycoefficientincreaseswiththedecreaseofwatercontentofconcrete,andthechangeshowsapowerexponentialrelationship.Theairpermeabilitycoefficienthasagoodcorrelationwithchloridediffusioncoefficientandelectricflux.

余韬,李天艳,窦妍,等.基于Torrent法的混凝土渗透性研究[J]混凝土与水泥制品,2020(6):22-25. YU T,LI T Y,DOU Y,et al.Study on Permeability of Concrete Based on Torrent Method[J].China Concrete and Cement Products,2020(6):22-25.