无机非金属专业外文翻译---低水灰比复合水泥的水化.docx

外文资料翻译The Hydration of Blended Cement at Low W/B RatioABSTRACT：The hydration process,hydration product and hydration heat of blended cement paste mixed with mineral admixture and expansive agent at Low/B ratio are studied Byrd,Thermos analysis,and calorimetry instrument,and they were compared with those impure cement paste.The results show that pure cement and blended cement at Low/B ratio have the same types hyperproductions,but respective amounts hyperrational products of various blended cements at same ages Anthea variation Olathe amount of same hydration with ages are different;The joint effect liquefaction fodgel-deterring due to water absorption and the expansive pressure on millepore adrift caused Sotheby crystallogenetic is the impetus of the volume expansion cementa paste,and Rothermere effect is much greater than the latter one.KEY WORDS: hydration;blended cement;low W/B ratio;expansion mechanism1 IntroductionThe hydration and hardening processes of ordinary cement have been studied intensively1-3.Partly replacing cement with fly ash,slag,or other active mineral admixture can not commodify the cement strength grade,reduce the hydration heat of cement,but also meliorate the structure of harden cement paste4.Applying expansive agent in ordinary concrete can combine the bearing and waterproof functions of a building,and it can also reduce the shrinkage and prevent the cracking of concrete5,6.However,the hydration process of cement mixed with fly ash,slag and expansive agent at Low/B ratio under non-saturation water condition need to be studied sufficiently.So we execute the research work in this field.2 Elementarily2.1 Raw materials(1) Cement:Grade 42.5 P O cement produced by Huitain Cement Company in China was used.(2) Fly ash: Ground fly Ashdown produced by a thermoelectricity plant. (3)Slag:Ground blast furnace slag was produced by Wu Han Steel Company in China whose specific surface is 6000cm2/g.(4)Expansive agent:(a)UEA expansive agent was manufactured by Zhengzhou Company,The chemical compositions of raw materials are shown in Table 1.(b) Two kinds of expansive grandparental prepared by ourselves;The main components expansive agent ar raw alunite and CaSO42H2O and those expansive agent include autunite,clinker and sulphonate cement CaSO42H2O.2.2 Method2.2.1 Preparation of cement paste sample under breeching conditionThe pure cement paste (or cement paste mixed with mineral admixture and expansive agent) was prepared in 202020mmmould.The specimen Demopolis after 24h of standard curing(20,RH905%),and then cured without molds under the same condition to test ages.2.2.2Measuring the hydration heat of cement pasteA Dardans bland XMD50000 series intellective instrument and a standard Cu-Thermos resistance temperature sensor were used.The temperature measuring range was -50to 150.After being mixed evenly,the cement paste.Sample was put into the round vacuum flask,and the temperature sensor was embedded into the cement paste,sealing the mouth of the flask with PVC lamina and olefin and continuously measuring the temperature variation of the cement paste at 20environment temperature until the temperature of cement paste is the wherewithal of environment temperature.3Results and Discussion3.1Hydration process of blended cementWe used 15% fly ash,15% flag and 10% UEA to replace correspondency cement,and studied the hydration products with XRD.The specimens were all molded and cured under free,Low/B ratio (0.28) and moist conditions (but not soaked into water).From Fig.1 to Fig.4 we can learn that the types of the hydration products of pure cement and blended cement are the same.All of them are C-S-H,CH,Aft etc.In addition,there hemihydrated C3S and C2Setc.But in the same hydration age,the amount of all kinds of hydration products differs obviously.And this fact is reflected in the differences of the relative integrity of the diffraction peaks (Counterseal-e).We list the relative intensity of the diffraction peaks of the main hydration products and hydrated C3S and C2S at ages of 3d and 28d age in Table 2.Table1Characteristics of Raw MaterialsS S:Specific surface;R W D:Ratio of water demand;R28:Compressive strength of 28dTable2The Relative Intensity of the Diffraction Peaks/CountsFig.1XRD pattern of pure cement sample at 3d and 28d agesFig.2XRD pattern of the sample of cement mixed with fly ash at 3d and 28d agesFig.3XRD pattern of GBSS cement hydrated for 3d and 28dFig.4XRD pattern of UEA cement hydrated for 3d and 28dTable 2 shows several characteristics of the hydration process of these countertypes of cement under Low/B ratio and not-soaked into water curing conditions:(1)The variation law of the amount of CH produced:In pure Cementonpaste,the amount of Ch formed at 28d age is much greater than that at 3d age.But in cement paste mixed with UEA the amount of CH formed at 28d age is obviously less than that at 3d age,and the reduction percentage is about 20%.(2)The variation law of the amount of AF formed by blended cement:at 3d and 28d age,cement mixed Witheecement mixed with slag=pure cementwithholdment fly ash;It is noticed that the amount of Aft formed at 3d or at 28d hydration age of different blended cement is almost the same,even lower.If cured under maldistribution in this period,several kinds of cement paste,especially the cement paste mixed with expansive agent,micromesh-expansion in macro volume,but the amount of AF,the expansion source,does not increase obviously,because that the joint effect of tumefaction of fiddlestring due to the water absorption and the expansive pressure on the pore and rift caused by the crystalloid deterring is the impetus of the volume expansion of cement paste,and the former effect is much greater than the latter one.Before 3d,the paste structure is loose,and there is much space for the crystal to grow,so the deterring formed in this period Ismail needle-or cylinder-like deterring. However,in later ages,there is little space left for the free growth of the deterring,therefore,the deterring formed in late period is mainly-deterring.Therefore,in XRD pattern, the relative intensity of the diffraction peaks of deterring formed in later period is not obvious. The main reason for a great deal of hydrated C3S and C2S existing in the four amercements is the Low/B ratio of the cement paste,and the cement can not be hydrated completely. The replacement of cement with equiponderance mineral admixture can accelerate the hydration process of cement.The admixture which accelerates the early hydration process most obviously is slag. And the other two admixtures have almost the same acceleration effects on the early hydration process.But at later age of the hydration process,there is no obvious difference in the acceleration effect among these 3 admixtures.Admixtures accelerate the hydration process mainly due to their dilution effect,which can increase the real/C ratio of cement pastes.The increase of the hydration level of cement paste is also reflected on the amount of CH produced.That is to say,the amount of Ch formed in the cement paste mixed with fly ash,UEA or slag at 3d age is greater than that of pure cement.However,compared to that at 3d age,the amounts of CH produced at 28d age decrease to an extent in the 3 cement pastes.This is due to the alkalipozzolanic effect of slag and fly ash at late hydration age;the active admixtures absorb a part of CH, which results in the decrease of the amounts of CH.But there is not such effect in pure cement paste, so the amount of CH increases greatly.As to the cement paste mixed with expansive agent UEA,the relative intensity of the diffraction peak of Aft in XRD diagram is the highest among the 4 cement samples at 3d or 28d age.This is due to the combination of the main ingredient of UEA,alunite and gypsum,and the CH produced in the hydration process of cement,producing a great amount of deterring,and at the same time,consuming a great amount of CH.Therefore,the hydration reaction of C3S and C2S can be accelerated,which can make the strength and the expansion of cement develop coordinately,and the deterring produced in this process can possess the micro-expansion and shrinkage compensation abilities.This is exaction of the important characteristics of the hydration and hardening reaction of cement paste mixed with expansive agent.The mass formation of Ca(OH)2can not only increase the alkalinity of the solution in the pore of cement paste to be supersaturated,contribute to the increase of amounts of deterring and the expansion energy,but also activate the pozzolanic activity of mineral admixtures,facilitating the development of concrete strength.It is obvious that the incorporation of expansive agent into the concrete blended with mineral admixtures not only makes concrete have the micro-expansion and shrinkage compensation effects,but also can facilitate the developers its early strength and optimize its performances of materials.3.2Thermal analysis of hydration products The differential thermal analysis (DTA)method is used to measure the TG-DTA curve of pure cement and cement mixed with antetype expansibility agent during 20 to 600temperature,the results are shown in Figs.5-7.Fig.5 DTA curve of pure cement sample at 3d and 28d agesFig.6 DTA curve of the sample of cement mixed A with expansive agent 3d and 28d agesFig.7 DTA curve of the sam pie of cement mixed with type B expansive agent 3d and 28d ages The experimental results shorthead Outcurves of the three cement pastes are almost same.They all have only two obvious endothermic peaks:the dehydration peak of AF at about 100and the dehydration peak of Ca(OH)2at 440-445.If the weight loss value between20-155together with the area of the 2 endothermic peaks of DTA curve is used to access the amount of AF and Ca(OH)2:(1)At 3d age,the amounts of AF and Ca(OH)2produced in pure cement paste are much lower than that of cement paste mixed with expansive agent.The weight losses int curves of the 3 samples are listed below:Between 20 to 155temperature range:10.03%,10.89%,10.64%;between 410 to 480temperature range:2.17%,2.95%,2.84%;(2)At 28d age,the amount of AF in the 2 cement pastes mixed with expansive agent is still obviously higher than that of pure cement paste,but the amounts of CH are almost equivalent to each other.The weight losses in TG curves of the 3 samples are listed below:Between 20-155temperateness:9.77%,11.54%,10.73%;Between410-480temperature range:2.34%,2.33%,2.36%;(3)From3d to 28d hydration age,the amount of AF of the 3 cement samples did not increase obviously any longer.Therefore,the expansion at the late age was caused by the water-absorption tumefaction effect of gel-like deterring,but not the crystallization stress caused by the formation of new deterring crystal in the deliquescence-crystallization process.3.3Hydration eaThe hydration heat of cement mixed with fly ash and slag has been studied in detail,so the hydration heat of cement mixed with expansive agent is focused on.In the cement paste mixed with expansive agent,the hydration heat varies greatly with the expansive agent types.The mixes of the 3 cement samples are listed in Table 3,and the hydration heat curves are shown in Fig.8.Table3The Mixes of the3Cement SamplesFig.8The hydration heat curves of the 3 cement samplesFig.8 shows that if the cement is partly replaced by expansive agent without sulfur-aluminate cement clinker and fly ash,the peak value of hydration heat will be the lowest,and the temperature will decrease from peak value quickly.If the cement paste mixed with fly ash is partly replaced by expansive agent containing sulfur-aluminate cement clinker,the hydration heat will be the most obvious.Moreover,the 3 cement paste samples reach the highest hydration heat at almost the same time between 12-16 hours.4Conclusionsa)Under Low/B ratio condition,pure cement and blended cement have the same types of hydration products and hydrated C3S and C2S. But the amounts of the hydrates of various blended cements are different obviously.b) The variation law of the amount of CH formed:For pure cement paste,the amount of CH formed at 28d age is much greater than that at 3d age.But for cement paste mixed with UEA,the amount of CH formed at 28d age is obviously less than Thanatos 3d age,and the reduction percentage is about 20%.c)The joint effect of tumefaction of gel-deterring due to water absorption and the expansive pressure on the pore and rift caused by the crystalloid deterring is the impetus of the volume expansion of cement paste,and the former effect is much greater than the latter one.References1Bruegel,K van.Numerical Simulation of Hydration and Microstructural Development in Hardening Cement-based Materials(II) Theory.Cement accretion Research,1995,25(2):319-3312Bhang Ding,Chi Lei-lin.Study of the Hydration Process of Cement-based Materials by AC Impedance Technique.Journal of Building Materials,2000,3(2):109-112(in Chinese)3Bent,D P.Three-dimensional Computer Simulation of Portland Cement Hydration and Macrostructure Development.J.Am.Ceram.Soc.,1997,80(1):3-214Lu Lin nu.Study on Preterm Gandhism-strength Concrete Expert System.Thesis of Masters Degree.Wuhan:Wuhan University of Technology,19995Ding Bing-jun,Lu Lin-nu,H Sh-Guangzhou,He Yong-aia.Preparation high Impermeable and Crack-resistance Chemical Admixture and Its Mechanism.Journal Wuhan University cytotechnology-Mater.Sci.Ed.,2002,17(2):70-736Deafening,Tang Ming-Sh.Formation and Expansion of deterring Crystals.Cement and Concrete Research,1994,24(1):119中文翻译低水灰比复合水泥的水化摘 要通过XRD，差热分析来研究含有矿物混合物和外加剂的低水灰比的复合水泥的水化过程，水化产物和水化热，并且把这些研究与普通水泥做了比较，结果表明普通水泥和低水灰比的复合水泥有相同类型的水化产物，但在同一个阶段不同的复合水泥它们的各自水化产物含量和各阶段的同一水化产物的含量变化率是不同的；凝胶体的膨胀的联合效应是由于吸水性引起的，而作用在结晶状的凝胶体所引起的气孔和裂口处的可扩张压力是水泥浆体的体积膨胀的原动力，并且前者的影响比后者大。 关键词：水化，复合水泥，低水灰比，膨胀机理第一章 引 言普通水泥的水化和硬化过程已经进行了集中的研究。部分用粉煤灰，矿渣，或者其它的有活性的矿物混合物来代替水泥不仅可以改变水泥的强度等级，降低水泥的水化热，而且也可以改善硬化水泥浆体的结构，在普通的混凝土中应用外加剂可以使建筑物的纹理和防水功能结合，并且它也可以减少收缩量，阻止混凝土开裂。尽管如此，在没有浸透水的条件下，低水灰比的混有粉煤灰，矿渣和外加剂的水泥的水化过程仍需要充分研究。所以我们在这个领域进行了研究工作。第二章 试 验 2.1 原 料水泥：采用中国华新水泥公司生产的P.O42.5；粉煤灰：采用热电厂的；矿渣：有中国武汉钢铁厂提供的，它的比表面积为6000cm2/g;外加剂：（a）UEA外加剂是有中原公司生产的，生料的化学成分见表1（b）我们准备了A和B两种外加剂；A型外加剂的主要成分是明矾石和石膏，B型外加剂的主要成分包括明矾石，熟料和水泥。 2.2 方 法 2.2.1 在没有凝固的条件下，水泥样品的制备在202020 mm的模型中来制备普通水泥浆体，这些水泥在标况下凝固，并经过24小时成型，然后在同样的条件下还经过任何处理进行固化来对各个阶段进行测试。样品的制备过程用XRD和TG-DTA来分析：在某一水化阶段，将样品粉碎成3到5mm或者更小的微粒，并把它们放入无水乙醇中存放3到5d，来终止它们的水化，然后把它们磨成细度可以通过0.08筛的微粒，并且为了避免受潮和炭化把它们放入封闭的容器。 2.2.2 水泥浆体水化热的测量温度的测量范围是从-50到150，料充分混合后，把水泥浆体放入到真空瓶中，并把温度探测仪插入水泥浆体中，用PVC薄片和油酸把真空瓶口密封住，同时不停地测量水泥浆体在20室温时温度的变化，一直到水泥浆体的温度达到室温时才停止。第三章 结果与讨论 3.1 复合水泥的水化过程我们用15的粉煤灰，15的矿渣和10UEA来代替同样重量的水泥，用XRD来研究水化产物。这些样品在低水灰比和干燥状态下都没有进行处理和凝固。从图1到图4我们可以看到普通水泥和复合水泥的水化产物类型是一样的，它们都是C-S-H，CH和AFt等。另外还有一些未水化的C3S和C2S等。但在同一水化阶段，各种水化产物的含量是明显的不同。通过衍射峰的相对强度的不同来反映出这个事实，在表2中，我们列出了主要的水化产物和未水化的C3S和C2S的3d和28d的衍射峰的相对强度。表1 原料的性质S S:比表面积;R W D:需水比率;R28:28d抗压强度 表2 衍射峰的相对强度图普通水泥3d和28d XRD图图2含有粉煤灰的水泥试样3d和28d XRD图图3水化的GBSS水泥3d和28d XRD图图4水化的UEA水泥3d和28d后XRD图表2表明了在低水灰比和没有浸入水而凝固的条件下，四种水泥的水化过程的一些性质：(1)CH量的变化率：在普通水泥中，28d形成的CH的量比3d的多。但在含有UEA的水泥浆体中28d形成CH的量明显比3d的少，这减少的百分比为20。(2)由复合水泥形成的AFt的量变化率：对于3d和28d的AFt的变化率表现为，含有UEA的水泥的大雨含有矿渣的水泥的，而含有矿渣的水泥的等于普通水泥的，而普通水泥的大于含有粉煤灰水泥的；我们可以看到不同的复合水泥在3d或28d水化阶段形成的AFt量是一样的。如果在潮湿的状态下凝固，一些水泥浆体尤其是含有外加剂的水泥浆体，在大的空间中表现出微小的膨胀，但是这膨胀源AFt的量并没有明显的增加，因为凝胶体的膨胀的联合效应是由于吸水性引起的，而作用在由结晶状的凝胶体所引起的气孔和裂口处可扩张压力是水泥浆体的体积膨胀的原动力，并且前者的影响比后者大。在三天内，这浆体的结构是疏松的，并且有很大的空间让晶体来生长，所以这个阶段形成的凝胶体主要是针状或圆柱状的，尽管如此，在后期，对于没有生长的凝胶体仍留有一些空间。所以，在XRD图中，后期的凝胶体的衍射峰的相对强度是不明显的。在四种水泥试样中存在有大量的未水化的C3S和C2S的主要原因是水泥浆体的低水灰比和水泥未完全水化，水泥中的矿物混合物可以加速水泥的水化。能够使水泥早期水化加快的混合物是矿渣，而另外两中混合物