日产5000吨熟料水泥生产线工艺设计参数-毕业论文设计

年日产5000吨熟料水泥生产线工艺设计-参数摘要本次设计的是一条日产5000吨水泥熟料的新型干法水泥生产线。该生产线主要生产的水泥品种为P.O42.5和P.F32.5水泥，袋散比为：40%：60%。本次设计的主要内容包括：全厂生产工艺流程设计；熟料矿物组成设计及配料计算；工艺平衡计算〔物料平衡、储库平衡、主机平衡〕；计算和确定新型回转窑、悬浮预热器、分解炉的型号及规格，以及窑尾气体平衡的计算，同时还编写了全厂工艺流程概述、全厂质量控制表等；最后进行了全厂工艺平面布置的设计。在本次设计中，采用了一些新的工艺技术，例如：高效率立式磨和高效选粉机等，特别是采用的TDF型分解炉为喷腾型分解炉，结构简单，外形规整，便于设计布置，为DD型的改良型，是国内制造的新一代分解炉。本次设计还采用了利用窑尾热废气预热生料以及在窑头窑尾设置余热锅炉进行余热发电的有效方法来降低系统热耗。关键词：配料，选型，预热器，分解炉，烧成窑尾TheDesignofaCementClinkerProductionLineWiththeCapacityof5000TonsPerDay-Parameter3ABSTRACTThetitleofthegraduatingdesignistoconstructacementplantwith5000tonsperdayproductionlinethemainproductionis42.5P.Oand32.5P.F,Bagthanscattered:40%：60%。Themaincontentofthisdesignis:Selectionofratiosandthecalculatingandofrawmixes;Manufacturingprocessandselectionofthemainmachines;Thephasesofthisdesignistocalculateanddesignpreheatedandpre-claimerandalsothebalancingofthemainmachinesatthesametime,Icomposethesummarizationoftechnologyflowforwhatfactoryandqualitycontrolofthewholefactoryandprospectsofthedesignprojectforgraduationetc;The1aststepofthedesignisthelayoutofthewholeplant.Inthedesign,somenewtechnologiesandtechniquesareintroducedsuchasverticalspindlemollandhighefficiencyclassifiersandacts.

Inthisdesign,adoptsomenewtechnology,forexample:efficiencyverticalpolishingandefficientclassifier,etc.EspeciallytheTDFtypeofdecomposingfurnacesmokeforspraytypedecompositionfurnace,simpleandneatappearance,easytodesignlayout,DDtypeforimprovedbytianjincementdesigninstitutetransformation,thedomesticmanufacturingofanewgenerationofdecomposingfurnace.Thisdesignhasalsousedtheuseofhotgaspreheatingandendoftherawmaterialinthekilnheadendofthewasteheatboilertowasteheatpowersettheeffectivemethodtoreducetheheatconsumptionsystem.KEYWORDS:ratioofrawmaterials，slection，preheater,calciner，Burnintokilntail目录前言 ×=5.3688(m3/kg熟料)6.2.5C2废气量1．来自C3的废气=1.5721Nm3/kg熟料2．漏入空气量=3．C2废气量=(1+5%)=1.051.5721=1.6507〔Nm3/kg熟料〕化为工作态：V1=V标××=1.6507××=4.9735〔m3/kg熟料〕6.2.6C1废气量1．来自C2的废气=1.6507Nm3/kg熟料2．漏入空气量=3．C1废气量=(1+5%)=1.051.6507=1.7332〔Nm3/kg熟料〕化为工作态：V1=V标××=1.7332××=3.9203〔m3/kg熟料〕窑尾废气温度压力表如下页表6-3：表6-3窑尾废气温度压力表名称标况Nm3/kg熟料工况m3/kg熟料负压温度℃总风量103m单位风量m3/S窑尾0.36031.66913001050380.55105.71分解炉1.12314.932012008801109.95312.40C51.42596.047320008501378.78383.00C41.49725.704026007501300.51361.25C31.57215.368830006201224.09340.03C21.65074.973538005101133.96314.99C11.73323.92034600320893.83248.29第七章烧成窑尾旋风筒的流体阻力主要由两局部组成:一局部是在管道内气流使生料粉上升所需的能量;另一局部为气流在旋风筒及其进出口的能量损失,因而可以通过选取适宜的断面流速,进口风速与进口尺寸,在进口处安装导向板及改良顶盖型式等来降低阻力损失,也可设置偏心内筒及扁内筒或改良旋风筒下料口结构,即在旋风筒底部增设膨胀仓,使下料顺畅,防止二次飞扬,提高旋风筒别离效率.采用普通型旋风筒时,截面风速大多采用3.5～4.0m/s。在新设计的五级新预热器中,一级预热器的断面风速为3.5m/s,2～3级预热器为4.5m/s,4～5级预热器为5m/s,进口气流速度均为20m/s左右为宜[19]。一些风速数值的设定[20]如表7-1：表7-1一些风速数值的设定(参考烟台东源水泥)工程C1C2C3C4C5分解炉风速(m/s)4.05.08.0新型预热器尺寸比例[21]如表7-2：表7-2新型预热器尺寸比例型式级别直径料管直径进口宽进口高柱体高锥体高总高新型D〔m〕d2〔m〕b〔m〕a〔m〕h1〔m〕h2〔m〕H〔m〕110.160.380.602～410.110.360.630.311.132.21510.110.360.630.471.132.357.1窑尾烧成系统的热工设备简介7.1.1预热器预热器是由五级旋风筒〔2-1-1-1-1双系列〕和连接旋风筒的气体管道构成，在其内部窑尾废气和生料粉进行热交换。旋风预热器内分散的生料与气流的接触面积大，传热速度快，升温效率高。生料和热气流的热交换主要是在气体管道中进行，各级旋风筒的主要作用是进行气固别离和收集粉尘的作用。设置四个一级旋风筒的目的是提高系统的别离效率，降低出预热器气体的含尘量，减少飞灰。生料由提升机提入二级旋风筒的出风管道内。生料在快速移动气流的作用下立即分散。悬浮在气流中，随气流进入一级旋风筒。气料别离后，物料借助自身的重力下落到下级气体管道中。如此循环，经过了四个热交换过程，物料的温度升至760℃左右之后，经由四级旋风筒的下料管从分解炉的两侧进入分解炉。在分解炉内受热分解后的物料，与窑尾废气一起进入五级旋风筒。别离收集下来的物料〔850各级下料管道均设置有起锁风作用的翻板阀，以提高旋风筒的别离效率，各级风管上均设有撒料装置，便于生料均匀分散。悬浮于热气流中，从而提高换热效率。7.1.2TDF型分解炉本厂采用的TDF型分解炉为喷腾型分解炉，为DD型的改良型。是引进日本神户制刚所的技术，由天津水泥设计院转化，国内制造的新一代分解炉。它具有如下的特点[16]：1．简单，外形规整，便于设计布置。2．TDF炉与窑尾烟室直接连通，可以防止结皮，保证稳定操作。由窑内排出的气体，温度为950℃～10503．熟料篦冷机来的三次风由径向分成两路进入分解炉，与TDF炉底部向上的喷腾气流集合，形成一个强烈搅动的涡流区，使生料与煤粉混合均匀，煤粉在混合气体中燃烧不会造成炉内局部过热，保证炉内温度分布均匀。中心气流温度约900℃，边缘温度约8804．炉的中部设置了第二个缩口，其目的是再次形成喷腾效应，并使气固流通过缩口冲撞至炉顶返回后进入五级旋风筒，从而加速气流与生料的混合搅动，在较小的过剩空气下就能使煤粉完全燃烧并加速与生料的热交换过程。由于在炉内形成两次喷腾效应，大大延长了物料在炉内的停留时间。5．炉用煤粉由罗茨风机经四路阀门进入分解炉。喷煤管位于三次风管入口上部，煤粉喷入时形成涡流，在富氧条件下立即分解，氧化和燃烧，其热量迅速传递给由上流下来的呈悬浮状态的生料，使之受热分解。煤粉交汇点比下料点略低，三次风紧接在下面，这种设计保证了混合与燃烧及炉内温度的均匀。7.1.3回转窑窑保持4%的斜度，借助与斜度和旋转，使物料慢慢地向窑头方向移动，由窑头煤粉燃烧器燃烧煤粉提供热量进行煅烧。烧成带采用强制通风冷却，以保证烧成带的筒体，延长耐火砖的使用寿命。窑中设置了液压挡轮，限制和调节筒体的上下移动。7.2三次风管直径确实定有效内径:D有=18.815〔V/W〕1/2为简化起见,计算图形截面的统一计算系数风量[立方米/小时]/3600秒=断面面积[平方米]×W[m/s]V〔M3/H〕/3600=Π/4D2/〔106×W〕m/s所以D㎜=[V×106/〔3600×Π/4/W〕]1/2D有=18.815〔V/W〕1/2式中V—风量度W—假定风速一般取20m/sD有=18.815×[460846/20]1/2=2856mmD=D有+2ξ=2856+2×140=3136mm7.3分解炉规格确实定1．解炉有效内径确实定〔直筒局部〕S炉=VG/3600WG?概论?P130著5-71D炉=〔4S炉/Π〕1/2=〔4VG/Π/3600WG〕1/2=18.815〔VG/WG〕1/2=18.815×〔1109950÷7.9〕1/2=7052式中:S炉—分解炉有效截面积mm2D炉—分解炉的有效直径mmWG—分解炉的断面风速〔直筒局部〕m/s取8.0m/sVG—通过分解炉的工况风量m2/hD=D炉+2ξ=7052+2×220=7492mm2．分解炉的高度:一般可以根据气流在分解炉内需要停留的时间来计算:H1=WT=4×7=28.0m式中H1—分解炉高度mW—气体在分解炉内的平均风速成取7.0T—气体在分解炉内停留的时间取4s有效截面积：S炉=40.16m2;有效内经;D有=7.14m;分解炉高：3．分解炉的直径:D向=(VG/VW)1/2×18.815=18.815×〔1109950÷15〕1/2=5118.1D=D有+2ξ=5118.1+2×220≈5500VW—分解炉的断面风速〔缩口局部〕m/s取15.0m4．进口尺寸与五级预热器的进口尺寸相同.5．排风管尺寸计算：有效内径:D有=18.815〔W/V〕1/2V—排风管的断面风速m/s取15.0m/s五级—四级排风管d=18.815×〔1378780÷15.0÷2〕1/2=4033.5α=200mmd5=d+α×2=4433.5四级—三级排风管d=18.815×(1300510÷15.0÷2)1/2=3917.4α=200mmd4=d+α×2=4317.4三级—二级排风管d=18.815×(1224090÷15.0÷2)1/2=3800α=200mmd3=d+α×2=4200二级—一级排风管d=18.815×(1133960÷15.0÷2)1/2=3658α=200mmd2=d+α×2=排风管：d1=18.815×(893830÷4÷18)1/2=2096≈2100主排风管：d=18.815×(893830÷18)1/2=4192≈42007.4预热器规格确实定7.4.1五级预热器规格确实定柱体有效直径:D5=18.815×〔VG/VW〕1/2=18.815×〔1378780÷2÷5.5〕1/2=666D=D5+2ξ=6661+2×200=7061mm料管直径:d2=D5×0.11+2ξ=932.71≈950mm〔取ξ=进口宽:b=D5×0.36+2ξ=2597.96≈2600进口高:a=D5×0.63+2ξ=4396.43≈4400柱体高:h1=0.47×D5+ξ=3230.67≈3400锥体高:h2=1.13×D5=7496.42≈7500总高:H=a+h1+h2=4400+3400+7500=153007.4.2四级预热器规格确实定柱体有效直径:D4=18.815×〔VG/VW〕1/2=18.815×〔1300510÷2÷5.3〕1/2=6469D=D4+2ξ=6469+2×200=6869mm料管直径:d2=D4×0.11+2ξ=911.59≈950mm〔取ξ=进口宽:b=D4×0.36+2ξ=2528.84≈2600进口高:a=D4×0.63+2ξ=4275.477≈4柱体高:h1=0.31×D4+ξ=2105.39≈2200锥体高:h4=1.13×D4=7309.97≈7总高:H=a+h1+h2=4400+2200+7500=141007.4.3三级预热器规格确实定D3=18.815×(VG/VW〕1/2=18.815×(1224090÷2÷5.3)1/2=6393D=D3+2ξ=6393+2×200=6793mm料管直径:d2=D3×0.11+2ξ=903.23≈900mm〔取ξ=进口宽:b=D3×0.36+2ξ=2501.48≈2510进口高:a=D3×0.63+2ξ=4227.59≈4柱体高:h1=0.31×D3+ξ=2081≈2锥体高:h4=1.13×D3=7224≈7200总高:H=a+h1+h2=4300+2200+7200=137007.4.4二级预热器规格确实定D2=18.815×(VG/VW〕1/2=18.815×(1133960÷2÷5.0)1/2=6153D=D2+2ξ=6153+2×200=6553mm料管直径:d2=D2×0.11+2ξ=876.83≈900mm〔取ξ=进口宽:b=D2×0.36+2ξ=2415.08≈2600进口高:a=D2×0.63+2ξ=4076.39≈4200柱体高:h1=0.31×D2+ξ=207.43≈2100锥体高:h4=1.13×D2=6952.89≈7总高:H=a+h1+h2=4200+2100+7200=134007.4.5一级预热器规格确实定D1=18.815×〔VG/VW〕1/2=18.815×〔893830÷4÷4〕1/2=4447一级预热器内的温度较低不设衬料,其有效直径就为其外径,故D1=4500料管直径:d2=0.16×D1=711≈720进口宽:b=D1×0.38=1689.86≈1700进口高:a=D1×0.65=2890.55≈2900柱体高:h1=D1×1.3=5781.1≈5800锥体高:h4=D1×1.15=5114.05≈5总高:H=a+h1+h2=2900+5800+5150=13850新型预热器尺寸参数如表7-3：表7-3新型预热器尺寸参数级别直径mm料管直径mm进口宽mm进口高mm柱体高mm锥体高mm总高mmDd2bah1h2HC14500720170029005800515013850C26700900260042002100720013400C36800900251043002200720013700C47100950260044002200750014100C57100950260044003400750015300结论本次设计是在综合应用四年来的理论知识根底上，吸收国内已设计的几条同类型窑型生产线的优点，在指导老师的精心指导下，并参考了大量的设计资料的前提下进行的，通过本次设计使我学到了许多新的设计思想和设计新理念:1．进行总平面布置设计时考虑到所给风向，把员工生活区和办公区设在了上风口，尽量防止或减轻对附近城镇居民点及本厂区的污染。2．进行工艺流程设计时，为了降低能耗，将窑尾废气引入生料磨作烘干介质，出磨气体经电收尘净化后再排入大气中，将窑系统与生料磨或煤磨系统组合成一个联合流程，彼此联接紧密，此种生产系统的工艺流程比拟简单。3．在生料粉磨工序中普遍采用烘干兼粉磨系统。4．本次设计为一台窑外分解窑，在生产工艺上要求煅烧高饱和比高硅率的生料，这样能提高熟料的质量并能减少预热器分解炉系统的堵塞和回转窑烧成带的结圈。5．在水泥粉磨系统采用辊压机、球磨、高效选粉机〔如O—SEPA选粉机等〕的联合粉磨系统。在本次毕业设计中,由于受本人知识结构及能力所限和参考文献的制约，设计时间比拟短，在设计中难免有错误和欠缺之处，恳请各位老师批评指正。谢辞光阴似箭、日月如梭，转瞬即到了要毕业的时间，即将离去，流连忘返也许是此时心情最贴切的诠释。回溯过去，老师们的谆谆教诲，同学的热情帮助，仍然历历在目久久不能忘怀，失败时的悲伤，成功时的喜悦，明亮的教室，翻得有点卷页的课本，还有大家一起嬉闹呐喊的一幕幕，一切的一切都成为我脑海中永远的回忆。忙碌了，努力了，最终带来了收获，我相信有付出就会有回报。我深深的意识到老师教给我们的不仅是书本上的理论知识，还有他们丰富的人生阅历，工作经验，生活品味等等。此外，在我们的屡次课程设计以及这次的毕业设计中，老师们不厌其烦的教我们怎么看，怎么想，怎么做，如何发现并解决问题，如何将我们学到的理论知识与实际工程相结合，这对我们来说是全新的体验和无比珍贵的经验。也必将在我未来的工作学习中获得表达。因为有老师们四年来无私的奉献，使我由一个稚气未脱的高中生成长为有着扎实理论根底的毕业生。我对未来充满了信心和憧憬。在这里深深的对指导老师张新爱老师表示衷心的感谢，是她的孜孜不倦的指导，我才顺利完成了毕业设计，对我帮助很大，令我收获颇丰，因此我想说一句，谢谢对于这次毕业设计，三个多月的时间里，进行实际工程的设计，对于实际工程中的假设干问题也有了深刻的体会。这次的毕业设计使我对这门专业有了更为完整的体验，这也将成为我们将来工作中的伟大财富。感谢老师的用心良苦，同时感谢在本次设计中给予我帮助的李冲和李辉等同学，这次设计的完成与他们的帮助是分不开的。在这里也向他们道谢，并祝他们今后的生活工作能够一帆风顺，万事如意。参考文献[1]曾学敏.水泥工业现状及开展趋势.中国水泥.2005.4.[2]金容容.水泥厂工艺设计概论【M】.武汉:武汉理工大学出版社，1993,21~214.[3]孙晋涛.硅酸盐工业热工根底【M】，武汉，武汉工业大学出版社，1992.5.[4]李涛平.再论新型干法水泥厂设计新概念..[5]简淼夫.用办公软件EXCEL作配料计算.水泥，2001.10.[6]沈威.水泥工艺学，武汉，武汉理工大学出版社，1991.7.[7]驻马店豫龙同力水泥有限责任公司5000T/D烧成系统调试操作说明书.天津水泥工业设计研究院.2003.12.[8].[9]龚文虎.水泥厂工艺设计中物料平衡的计算方法..[10]GB175-2007通用硅酸盐水泥.2007.11.[11]何俊元.水泥厂工艺设计概论(1982年版).中国建工出版社.1982.3.[12]李海涛，郭献军，吴武伟..新型干法水泥生产技术与设备.北京，化学工业出版社，2006.1.[13]两渣一灰综合利用日产4000吨特种水泥熟料生产线可行性研究报告中材国际工程股份官网.2006.3.[14]曹文聪、杨树森.普通硅酸盐工艺学【M】，武汉，武汉工业大学出版社，1996.10~26.[15]高长明.预分解窑水泥生产技术及进展，北京，化学工业出版社，2006.1[16]严生，常捷，程麟.新型干法水泥厂工艺设计手册.中国建材工业出版社，2007.1.[17]第三代5500t/d预分解系统的研究开发及应用.天津水泥工业设计研究院.2021.1.[18]陈守强；胡庆银；高冬美.年产100t吨水泥粉磨站生产线实践.山东东华水泥水泥，cement.2007．No.1[19]熊会思，熊然.新型干法水泥厂设备选型使用手册-5000t/d熟料生产线工艺系统设计.中国建材工业出版社，2007.1[20]刘志江.新型干法水泥技术.中国建材工业出版社，2005.1[21]潘轶、蒋超鹏.华润水泥〔贵港〕2×5000t/d熟料生产线工艺设计简介.水泥工程,2007.01外文资料翻译TheHydrationofBlendedCementatLowW/BRatioABSTRACT：Thehydrationprocess,hydrationproductandhydrationheatofblendedcementpastemixedwithmineraladmixtureandexpansiveagentatLow/BratioarestudiedByrd,Thermosanalysis,andcalorimetryinstrument,andtheywerecomparedwiththoseimpurecementpaste.TheresultsshowthatpurecementandblendedcementatLow/Bratiohavethesametypeshyperproductions,butrespectiveamountshyperrationalproductsofvariousblendedcementsatsameagesAntheavariationOlatheamountofsamehydrationwithagesaredifferent;Thejointeffectliquefactionfodgel-deterringduetowaterabsorptionandtheexpansivepressureonmilleporeadriftcausedSothebycrystallogeneticistheimpetusofthevolumeexpansioncementapaste,andRothermereeffectismuchgreaterthanthelatterone.KEYWORDS:hydration;blendedcement;lowW/Bratio;expansionmechanism1IntroductionThehydrationandhardeningprocessesofordinarycementhavebeenstudiedintensively[1-3].Partlyreplacingcementwithflyash,slag,orotheractivemineraladmixturecannotcommodifythecementstrengthgrade,reducethehydrationheatofcement,butalsomelioratethestructureofhardencementpaste[4].Applyingexpansiveagentinordinaryconcretecancombinethebearingandwaterprooffunctionsofabuilding,anditcanalsoreducetheshrinkageandpreventthecrackingofconcrete[5,6].However,thehydrationprocessofcementmixedwithflyash,slagandexpansiveagentatLow/Bratioundernon-saturationwaterconditionneedtobestudiedsufficiently.Soweexecutetheresearchworkinthisfield.2Elementarily2.1RawmaterialsCement:Grade42.5POcementproducedbyHuitainCementCompanyinChinawasused.Flyash:GroundflyAshdownproducedbyathermoelectricityplant.(3)Slag:GroundblastfurnaceslagwasproducedbyWuHanSteelCompanyinChinawhosespecificsurfaceis6000cm2/g.(4)Expansiveagent:(a)UEAexpansiveagentwasmanufacturedbyZhengzhouCompany,ThechemicalcompositionsofrawmaterialsareshowninTable1.(b)Twokindsofexpansivegrandparentalpreparedbyourselves;ThemaincomponentsexpansiveagentarrawaluniteandCaSO4·2H2Oandthoseexpansiveagentincludeautunite,clinkerandsulphonatecementCaSO4·2H2O.2.2Method2.2.1Thepurecementpaste(orcementpastemixedwithmineraladmixtureandexpansiveagent)waspreparedin20×20×20mmmould.ThespecimenDemopolisafter24hofstandardcuring(20℃,RH90±5%),andthencuredwithoutmoldsunderthesameconditiontotestages.2.2.2MeasuringthehydrationheatofcementpasteADardansblandXMD50000seriesintellectiveinstrumentandastandardCu-Thermosresistancetemperaturesensorwereused.Thetemperaturemeasuringrangewas-50℃to150℃.Afterbeingmixedevenly,thecementpaste.Samplewasputintotheroundvacuumflask,andthetemperaturesensorwasembeddedintothecementpaste,sealingthemouthoftheflaskwithPVClaminaandolefinandcontinuouslymeasuringthetemperaturevariationofthecementpasteat20℃environmenttemperatureuntilthetemperatureofcementpasteisthewherewithalofenvironmenttemperature.3ResultsandDiscussion3.1HydrationprocessofblendedcementWeused15%flyash,15%flagand10%UEAtoreplacecorrespondencycement,andstudiedthehydrationproductswithXRD.Thespecimenswereallmoldedandcuredunderfree,Low/Bratio(0.28)andmoistconditions(butnotsoakedintowater).FromFig.1toFig.4wecanlearnthatthetypesofthehydrationproductsofpurecementandblendedcementarethesame.AllofthemareC-S-H,CH,Aftetc.Inaddition,therehemihydratedC3SandC2Setc.Butinthesamehydrationage,theamountofallkindsofhydrationproductsdiffersobviously.Andthisfactisreflectedinthedifferencesoftherelativeintegrityofthediffractionpeaks(Counterseal-e).WelisttherelativeintensityofthediffractionpeaksofthemainhydrationproductsandhydratedC3SandC2Satagesof3dand28dageinTable2.Table1CharacteristicsofRawMaterialsSS:Specificsurface;RWD:Ratioofwaterdemand;R28:Compressivestrengthof28dTable2TheRelativeIntensityoftheDiffractionPeaks/CountsFig.1XRDpatternofpurecementsampleat3dand28dagesFig.2XRDpatternofthesampleofcementmixedwithflyashat3dand28dagesFig.3XRDpatternofGBSScementhydratedfor3dand28dFig.4XRDpatternofUEAcementhydratedfor3dand28dTable2showsseveralcharacteristicsofthehydrationprocessofthesecountertypesofcementunderLow/Bratioandnot-soakedintowatercuringconditions:(1)ThevariationlawoftheamountofCHproduced:InpureCementonpaste,theamountofChformedat28dageismuchgreaterthanthatat3dage.ButincementpastemixedwithUEAtheamountofCHformedat28dageisobviouslylessthanthatat3dage,andthereductionpercentageisabout20%.(2)ThevariationlawoftheamountofAFformedbyblendedcement:at3dand28dage,cementmixedWithee>cementmixedwithslag=purecement>withholdmentflyash;ItisnoticedthattheamountofAftformedat3dorat28dhydrationageofdifferentblendedcementisalmostthesame,evenlower.Ifcuredundermaldistributioninthisperiod,severalkindsofcementpaste,especiallythecementpastemixedwithexpansiveagent,micromesh-expansioninmacrovolume,buttheamountofAF,theexpansionsource,doesnotincreaseobviously,becausethatthejointeffectoftumefactionoffiddlestringduetothewaterabsorptionandtheexpansivepressureontheporeandriftcausedbythecrystalloiddeterringistheimpetusofthevolumeexpansionofcementpaste,andtheformereffectismuchgreaterthanthelatterone.Before3d,thepastestructureisloose,andthereismuchspaceforthecrystaltogrow,sothedeterringformedinthisperiodIsmailneedle-orcylinder-likedeterring.However,inlaterages,thereislittlespaceleftforthefreegrowthofthedeterring,therefore,thedeterringformedinlateperiodismainly-deterring.Therefore,inXRDpattern,therelativeintensityofthediffractionpeaksofdeterringformedinlaterperiodisnotobvious.ThemainreasonforagreatdealofhydratedC3SandC2SexistinginthefouramercementsistheLow/Bratioofthecementpaste,andthecementcannotbehydratedcompletely.Thereplacementofcementwithequiponderancemineraladmixturecanacceleratethehydrationprocessofcement.Theadmixturewhichacceleratestheearlyhydrationprocessmostobviouslyisslag.Andtheothertwoadmixtureshavealmostthesameaccelerationeffectsontheearlyhydrationprocess.Butatlaterageofthehydrationprocess,thereisnoobviousdifferenceintheaccelerationeffectamongthese3admixtures.Admixturesacceleratethehydrationprocessmainlyduetotheirdilutioneffect,whichcanincreasethereal/Cratioofcementpastes.TheincreaseofthehydrationlevelofcementpasteisalsoreflectedontheamountofCHproduced.Thatistosay,theamountofChformedinthecementpastemixedwithflyash,UEAorslagat3dageisgreaterthanthatofpurecement.However,comparedtothatat3dage,theamountsofCHproducedat28dagedecreasetoanextentinthe3cementpastes.Thisisduetothealkali—pozzolaniceffectofslagandflyashatlatehydrationage;theactiveadmixturesabsorbapartofCH,whichresultsinthedecreaseoftheamountsofCH.Butthereisnotsucheffectinpurecementpaste,sotheamountofCHincreasesgreatly.AstothecementpastemixedwithexpansiveagentUEA,therelativeintensityofthediffractionpeakofAftinXRDdiagramisthehighestamongthe4cementsamplesat3dor28dage.ThisisduetothecombinationofthemainingredientofUEA,aluniteandgypsum,andtheCHproducedinthehydrationprocessofcement,producingagreatamountofdeterring,andatthesametime,consumingagreatamountofCH.Therefore,thehydrationreactionofC3SandC2Scanbeaccelerated,whichcanmakethestrengthandtheexpansionofcementdevelopcoordinately,andthedeterringproducedinthisprocesscanpossessthemicro-expansionandshrinkagecompensationabilities.Thisisexactionoftheimportantcharacteristicsofthehydrationandhardeningreactionofcementpastemixedwithexpansiveagent.ThemassformationofCa(OH)2cannotonlyincreasethealkalinityofthesolutionintheporeofcementpastetobesupersaturated,contributetotheincreaseofamountsofdeterringandtheexpansionenergy,butalsoactivatethepozzolanicactivityofmineraladmixtures,facilitatingthedevelopmentofconcretestrength.Itisobviousthattheincorporationofexpansiveagentintotheconcreteblendedwithmineraladmixturesnotonlymakesconcretehavethemicro-expansionandshrinkagecompensationeffects,butalsocanfacilitatethedeveloper'sitsearlystrengthandoptimizeitsperformancesofmaterials.3.2ThermalanalysisofhydrationproductsThedifferentialthermalanalysis(DTA)methodisusedtomeasuretheTG-DTAcurveofpurecementandcementmixedwithantetypeexpansibilityagentduring20to600℃temperature,theresultsareshowninFigs.5-7.Fig.5DTAcurveofpurecementsampleat3dand28dagesFig.6DTAcurveofthesampleofcementmixedAwithexpansiveagent3dand28dagesFig.7DTAcurveofthesampieofcementmixedwithtypeBexpansiveagent3dand28dagesTheexperimentalresultsshortheadOutcurvesofthethreecementpastesarealmostsame.Theyallhaveonlytwoobviousendothermicpeaks:thedehydrationpeakofAFatabout100℃andthedehydrationpeakofCa(OH)2at440-445℃.Iftheweightlossvaluebetween20-155℃togetherwiththeareaofthe2endothermicpeaksofDTAcurveisusedtoaccesstheamountofAFandCa(OH)2:(1)At3dage,theamountsofAFandCa(OH)2producedinpurecementpastearemuchlowerthanthatofcementpastemixedwithexpansiveagent.Theweightlossesintcurvesofthe3samplesarelistedbelow:Between20to155℃temperaturerange:10.03%,10.89%,10.64%;between410to480℃temperaturerange:2.17%,2.95%,2.84%;(2)At28dage,theamountofAFinthe2cementpastesmixedwithexpansiveagentisstillobviouslyhigherthanthatofpurecementpaste,buttheamountsofCHarealmostequivalenttoeachother.TheweightlossesinTGcurvesofthe3samplesarelistedbelow:Between20-155℃temperateness:9.77%,11.54%,10.73%;Between410-480℃temperaturerange:2.34%,2.33%,2.36%;(3)From3dto28dhydrationage,theamountofAFofthe3cementsamplesdidnotincreaseobviouslyanylonger.Therefore,theexpansionatthelateagewascausedbythewater-absorptiontumefactioneffectofgel-likedeterring,butnot/