日產(chǎn)5000噸熟料水泥生產(chǎn)線工藝設(shè)計參數(shù)-畢業(yè)論文設(shè)計

年日產(chǎn)5000噸熟料水泥生產(chǎn)線工藝設(shè)計-參數(shù)摘要本次設(shè)計的是一條日產(chǎn)5000噸水泥熟料的新型干法水泥生產(chǎn)線。該生產(chǎn)線主要生產(chǎn)的水泥品種為P.O42.5和P.F32.5水泥，袋散比為：40%：60%。本次設(shè)計的主要內(nèi)容包括：全廠生產(chǎn)工藝流程設(shè)計；熟料礦物組成設(shè)計及配料計算；工藝平衡計算〔物料平衡、儲庫平衡、主機平衡〕；計算和確定新型回轉(zhuǎn)窯、懸浮預(yù)熱器、分解爐的型號及規(guī)格，以及窯尾氣體平衡的計算，同時還編寫了全廠工藝流程概述、全廠質(zhì)量控制表等；最后進行了全廠工藝平面布置的設(shè)計。在本次設(shè)計中，采用了一些新的工藝技術(shù)，例如：高效率立式磨和高效選粉機等，特別是采用的TDF型分解爐為噴騰型分解爐，結(jié)構(gòu)簡單，外形規(guī)整，便于設(shè)計布置，為DD型的改良型，是國內(nèi)制造的新一代分解爐。本次設(shè)計還采用了利用窯尾熱廢氣預(yù)熱生料以及在窯頭窯尾設(shè)置余熱鍋爐進行余熱發(fā)電的有效方法來降低系統(tǒng)熱耗。關(guān)鍵詞：配料，選型，預(yù)熱器，分解爐，燒成窯尾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目錄前言 ×=5.3688(m3/kg熟料)6.2.5C2廢氣量1．來自C3的廢氣=1.5721Nm3/kg熟料2．漏入空氣量=3．C2廢氣量=(1+5%)=1.051.5721=1.6507〔Nm3/kg熟料〕化為工作態(tài)：V1=V標××=1.6507××=4.9735〔m3/kg熟料〕6.2.6C1廢氣量1．來自C2的廢氣=1.6507Nm3/kg熟料2．漏入空氣量=3．C1廢氣量=(1+5%)=1.051.6507=1.7332〔Nm3/kg熟料〕化為工作態(tài)：V1=V標××=1.7332××=3.9203〔m3/kg熟料〕窯尾廢氣溫度壓力表如下頁表6-3：表6-3窯尾廢氣溫度壓力表名稱標況Nm3/kg熟料工況m3/kg熟料負壓溫度℃總風量103m單位風量m3/S窯尾0.36031.66913001050380.55105.71分解爐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第七章燒成窯尾旋風筒的流體阻力主要由兩局部組成:一局部是在管道內(nèi)氣流使生料粉上升所需的能量;另一局部為氣流在旋風筒及其進出口的能量損失,因而可以通過選取適宜的斷面流速,進口風速與進口尺寸,在進口處安裝導向板及改良頂蓋型式等來降低阻力損失,也可設(shè)置偏心內(nèi)筒及扁內(nèi)筒或改良旋風筒下料口結(jié)構(gòu),即在旋風筒底部增設(shè)膨脹倉,使下料順暢,防止二次飛揚,提高旋風筒別離效率.采用普通型旋風筒時,截面風速大多采用3.5～4.0m/s。在新設(shè)計的五級新預(yù)熱器中,一級預(yù)熱器的斷面風速為3.5m/s,2～3級預(yù)熱器為4.5m/s,4～5級預(yù)熱器為5m/s,進口氣流速度均為20m/s左右為宜[19]。一些風速數(shù)值的設(shè)定[20]如表7-1：表7-1一些風速數(shù)值的設(shè)定(參考煙臺東源水泥)工程C1C2C3C4C5分解爐風速(m/s)4.05.08.0新型預(yù)熱器尺寸比例[21]如表7-2：表7-2新型預(yù)熱器尺寸比例型式級別直徑料管直徑進口寬進口高柱體高錐體高總高新型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窯尾燒成系統(tǒng)的熱工設(shè)備簡介7.1.1預(yù)熱器預(yù)熱器是由五級旋風筒〔2-1-1-1-1雙系列〕和連接旋風筒的氣體管道構(gòu)成，在其內(nèi)部窯尾廢氣和生料粉進行熱交換。旋風預(yù)熱器內(nèi)分散的生料與氣流的接觸面積大，傳熱速度快，升溫效率高。生料和熱氣流的熱交換主要是在氣體管道中進行，各級旋風筒的主要作用是進行氣固別離和收集粉塵的作用。設(shè)置四個一級旋風筒的目的是提高系統(tǒng)的別離效率，降低出預(yù)熱器氣體的含塵量，減少飛灰。生料由提升機提入二級旋風筒的出風管道內(nèi)。生料在快速移動氣流的作用下立即分散。懸浮在氣流中，隨氣流進入一級旋風筒。氣料別離后，物料借助自身的重力下落到下級氣體管道中。如此循環(huán)，經(jīng)過了四個熱交換過程，物料的溫度升至760℃左右之后，經(jīng)由四級旋風筒的下料管從分解爐的兩側(cè)進入分解爐。在分解爐內(nèi)受熱分解后的物料，與窯尾廢氣一起進入五級旋風筒。別離收集下來的物料〔850各級下料管道均設(shè)置有起鎖風作用的翻板閥，以提高旋風筒的別離效率，各級風管上均設(shè)有撒料裝置，便于生料均勻分散。懸浮于熱氣流中，從而提高換熱效率。7.1.2TDF型分解爐本廠采用的TDF型分解爐為噴騰型分解爐，為DD型的改良型。是引進日本神戶制剛所的技術(shù)，由天津水泥設(shè)計院轉(zhuǎn)化，國內(nèi)制造的新一代分解爐。它具有如下的特點[16]：1．簡單，外形規(guī)整，便于設(shè)計布置。2．TDF爐與窯尾煙室直接連通，可以防止結(jié)皮，保證穩(wěn)定操作。由窯內(nèi)排出的氣體，溫度為950℃～10503．熟料篦冷機來的三次風由徑向分成兩路進入分解爐，與TDF爐底部向上的噴騰氣流集合，形成一個強烈攪動的渦流區(qū)，使生料與煤粉混合均勻，煤粉在混合氣體中燃燒不會造成爐內(nèi)局部過熱，保證爐內(nèi)溫度分布均勻。中心氣流溫度約900℃，邊緣溫度約8804．爐的中部設(shè)置了第二個縮口，其目的是再次形成噴騰效應(yīng)，并使氣固流通過縮口沖撞至爐頂返回后進入五級旋風筒，從而加速氣流與生料的混合攪動，在較小的過?？諝庀戮湍苁姑悍弁耆紵⒓铀倥c生料的熱交換過程。由于在爐內(nèi)形成兩次噴騰效應(yīng)，大大延長了物料在爐內(nèi)的停留時間。5．爐用煤粉由羅茨風機經(jīng)四路閥門進入分解爐。噴煤管位于三次風管入口上部，煤粉噴入時形成渦流，在富氧條件下立即分解，氧化和燃燒，其熱量迅速傳遞給由上流下來的呈懸浮狀態(tài)的生料，使之受熱分解。煤粉交匯點比下料點略低，三次風緊接在下面，這種設(shè)計保證了混合與燃燒及爐內(nèi)溫度的均勻。7.1.3回轉(zhuǎn)窯窯保持4%的斜度，借助與斜度和旋轉(zhuǎn)，使物料慢慢地向窯頭方向移動，由窯頭煤粉燃燒器燃燒煤粉提供熱量進行煅燒。燒成帶采用強制通風冷卻，以保證燒成帶的筒體，延長耐火磚的使用壽命。窯中設(shè)置了液壓擋輪，限制和調(diào)節(jié)筒體的上下移動。7.2三次風管直徑確實定有效內(nèi)徑:D有=18.815〔V/W〕1/2為簡化起見,計算圖形截面的統(tǒng)一計算系數(shù)風量[立方米/小時]/3600秒=斷面面積[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—風量度W—假定風速一般取20m/sD有=18.815×[460846/20]1/2=2856mmD=D有+2ξ=2856+2×140=3136mm7.3分解爐規(guī)格確實定1．解爐有效內(nèi)徑確實定〔直筒局部〕S爐=VG/3600WG?概論?P130著5-71D爐=〔4S爐/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爐—分解爐有效截面積mm2D爐—分解爐的有效直徑mmWG—分解爐的斷面風速〔直筒局部〕m/s取8.0m/sVG—通過分解爐的工況風量m2/hD=D爐+2ξ=7052+2×220=7492mm2．分解爐的高度:一般可以根據(jù)氣流在分解爐內(nèi)需要停留的時間來計算:H1=WT=4×7=28.0m式中H1—分解爐高度mW—氣體在分解爐內(nèi)的平均風速成取7.0T—氣體在分解爐內(nèi)停留的時間取4s有效截面積：S爐=40.16m2;有效內(nèi)經(jīng);D有=7.14m;分解爐高：3．分解爐的直徑:D向=(VG/VW)1/2×18.815=18.815×〔1109950÷15〕1/2=5118.1D=D有+2ξ=5118.1+2×220≈5500VW—分解爐的斷面風速〔縮口局部〕m/s取15.0m4．進口尺寸與五級預(yù)熱器的進口尺寸相同.5．排風管尺寸計算：有效內(nèi)徑:D有=18.815〔W/V〕1/2V—排風管的斷面風速m/s取15.0m/s五級—四級排風管d=18.815×〔1378780÷15.0÷2〕1/2=4033.5α=200mmd5=d+α×2=4433.5四級—三級排風管d=18.815×(1300510÷15.0÷2)1/2=3917.4α=200mmd4=d+α×2=4317.4三級—二級排風管d=18.815×(1224090÷15.0÷2)1/2=3800α=200mmd3=d+α×2=4200二級—一級排風管d=18.815×(1133960÷15.0÷2)1/2=3658α=200mmd2=d+α×2=排風管：d1=18.815×(893830÷4÷18)1/2=2096≈2100主排風管：d=18.815×(893830÷18)1/2=4192≈42007.4預(yù)熱器規(guī)格確實定7.4.1五級預(yù)熱器規(guī)格確實定柱體有效直徑:D5=18.815×〔VG/VW〕1/2=18.815×〔1378780÷2÷5.5〕1/2=666D=D5+2ξ=6661+2×200=7061mm料管直徑:d2=D5×0.11+2ξ=932.71≈950mm〔取ξ=進口寬:b=D5×0.36+2ξ=2597.96≈2600進口高:a=D5×0.63+2ξ=4396.43≈4400柱體高:h1=0.47×D5+ξ=3230.67≈3400錐體高:h2=1.13×D5=7496.42≈7500總高:H=a+h1+h2=4400+3400+7500=153007.4.2四級預(yù)熱器規(guī)格確實定柱體有效直徑:D4=18.815×〔VG/VW〕1/2=18.815×〔1300510÷2÷5.3〕1/2=6469D=D4+2ξ=6469+2×200=6869mm料管直徑:d2=D4×0.11+2ξ=911.59≈950mm〔取ξ=進口寬:b=D4×0.36+2ξ=2528.84≈2600進口高:a=D4×0.63+2ξ=4275.477≈4柱體高:h1=0.31×D4+ξ=2105.39≈2200錐體高:h4=1.13×D4=7309.97≈7總高:H=a+h1+h2=4400+2200+7500=141007.4.3三級預(yù)熱器規(guī)格確實定D3=18.815×(VG/VW〕1/2=18.815×(1224090÷2÷5.3)1/2=6393D=D3+2ξ=6393+2×200=6793mm料管直徑:d2=D3×0.11+2ξ=903.23≈900mm〔取ξ=進口寬:b=D3×0.36+2ξ=2501.48≈2510進口高:a=D3×0.63+2ξ=4227.59≈4柱體高:h1=0.31×D3+ξ=2081≈2錐體高:h4=1.13×D3=7224≈7200總高:H=a+h1+h2=4300+2200+7200=137007.4.4二級預(yù)熱器規(guī)格確實定D2=18.815×(VG/VW〕1/2=18.815×(1133960÷2÷5.0)1/2=6153D=D2+2ξ=6153+2×200=6553mm料管直徑:d2=D2×0.11+2ξ=876.83≈900mm〔取ξ=進口寬:b=D2×0.36+2ξ=2415.08≈2600進口高:a=D2×0.63+2ξ=4076.39≈4200柱體高:h1=0.31×D2+ξ=207.43≈2100錐體高:h4=1.13×D2=6952.89≈7總高:H=a+h1+h2=4200+2100+7200=134007.4.5一級預(yù)熱器規(guī)格確實定D1=18.815×〔VG/VW〕1/2=18.815×〔893830÷4÷4〕1/2=4447一級預(yù)熱器內(nèi)的溫度較低不設(shè)襯料,其有效直徑就為其外徑,故D1=4500料管直徑:d2=0.16×D1=711≈720進口寬:b=D1×0.38=1689.86≈1700進口高:a=D1×0.65=2890.55≈2900柱體高:h1=D1×1.3=5781.1≈5800錐體高:h4=D1×1.15=5114.05≈5總高:H=a+h1+h2=2900+5800+5150=13850新型預(yù)熱器尺寸參數(shù)如表7-3：表7-3新型預(yù)熱器尺寸參數(shù)級別直徑mm料管直徑mm進口寬mm進口高mm柱體高mm錐體高mm總高mmDd2bah1h2HC14500720170029005800515013850C26700900260042002100720013400C36800900251043002200720013700C47100950260044002200750014100C57100950260044003400750015300結(jié)論本次設(shè)計是在綜合應(yīng)用四年來的理論知識根底上，吸收國內(nèi)已設(shè)計的幾條同類型窯型生產(chǎn)線的優(yōu)點，在指導老師的精心指導下，并參考了大量的設(shè)計資料的前提下進行的，通過本次設(shè)計使我學到了許多新的設(shè)計思想和設(shè)計新理念:1．進行總平面布置設(shè)計時考慮到所給風向，把員工生活區(qū)和辦公區(qū)設(shè)在了上風口，盡量防止或減輕對附近城鎮(zhèn)居民點及本廠區(qū)的污染。2．進行工藝流程設(shè)計時，為了降低能耗，將窯尾廢氣引入生料磨作烘干介質(zhì)，出磨氣體經(jīng)電收塵凈化后再排入大氣中，將窯系統(tǒng)與生料磨或煤磨系統(tǒng)組合成一個聯(lián)合流程，彼此聯(lián)接緊密，此種生產(chǎn)系統(tǒng)的工藝流程比擬簡單。3．在生料粉磨工序中普遍采用烘干兼粉磨系統(tǒng)。4．本次設(shè)計為一臺窯外分解窯，在生產(chǎn)工藝上要求煅燒高飽和比高硅率的生料，這樣能提高熟料的質(zhì)量并能減少預(yù)熱器分解爐系統(tǒng)的堵塞和回轉(zhuǎn)窯燒成帶的結(jié)圈。5．在水泥粉磨系統(tǒng)采用輥壓機、球磨、高效選粉機〔如O—SEPA選粉機等〕的聯(lián)合粉磨系統(tǒng)。在本次畢業(yè)設(shè)計中,由于受本人知識結(jié)構(gòu)及能力所限和參考文獻的制約，設(shè)計時間比擬短，在設(shè)計中難免有錯誤和欠缺之處，懇請各位老師批評指正。謝辭光陰似箭、日月如梭，轉(zhuǎn)瞬即到了要畢業(yè)的時間，即將離去，流連忘返也許是此時心情最貼切的詮釋。回溯過去，老師們的諄諄教誨，同學的熱情幫助，仍然歷歷在目久久不能忘懷，失敗時的悲傷，成功時的喜悅，明亮的教室，翻得有點卷頁的課本，還有大家一起嬉鬧吶喊的一幕幕，一切的一切都成為我腦海中永遠的回憶。忙碌了，努力了，最終帶來了收獲，我相信有付出就會有回報。我深深的意識到老師教給我們的不僅是書本上的理論知識，還有他們豐富的人生閱歷，工作經(jīng)驗，生活品味等等。此外，在我們的屢次課程設(shè)計以及這次的畢業(yè)設(shè)計中，老師們不厭其煩的教我們怎么看，怎么想，怎么做，如何發(fā)現(xiàn)并解決問題，如何將我們學到的理論知識與實際工程相結(jié)合，這對我們來說是全新的體驗和無比珍貴的經(jīng)驗。也必將在我未來的工作學習中獲得表達。因為有老師們四年來無私的奉獻，使我由一個稚氣未脫的高中生成長為有著扎實理論根底的畢業(yè)生。我對未來充滿了信心和憧憬。在這里深深的對指導老師張新愛老師表示衷心的感謝，是她的孜孜不倦的指導，我才順利完成了畢業(yè)設(shè)計，對我?guī)椭艽?，令我收獲頗豐，因此我想說一句，謝謝對于這次畢業(yè)設(shè)計，三個多月的時間里，進行實際工程的設(shè)計，對于實際工程中的假設(shè)干問題也有了深刻的體會。這次的畢業(yè)設(shè)計使我對這門專業(yè)有了更為完整的體驗，這也將成為我們將來工作中的偉大財富。感謝老師的用心良苦，同時感謝在本次設(shè)計中給予我?guī)椭睦顩_和李輝等同學，這次設(shè)計的完成與他們的幫助是分不開的。在這里也向他們道謝，并祝他們今后的生活工作能夠一帆風順，萬事如意。參考文獻[1]曾學敏.水泥工業(yè)現(xiàn)狀及開展趨勢.中國水泥.2005.4.[2]金容容.水泥廠工藝設(shè)計概論【M】.武漢:武漢理工大學出版社，1993,21~214.[3]孫晉濤.硅酸鹽工業(yè)熱工根底【M】，武漢，武漢工業(yè)大學出版社，1992.5.[4]李濤平.再論新型干法水泥廠設(shè)計新概念..[5]簡淼夫.用辦公軟件EXCEL作配料計算.水泥，2001.10.[6]沈威.水泥工藝學，武漢，武漢理工大學出版社，1991.7.[7]駐馬店豫龍同力水泥有限責任公司5000T/D燒成系統(tǒng)調(diào)試操作說明書.天津水泥工業(yè)設(shè)計研究院.2003.12.[8].[9]龔文虎.水泥廠工藝設(shè)計中物料平衡的計算方法..[10]GB175-2007通用硅酸鹽水泥.2007.11.[11]何俊元.水泥廠工藝設(shè)計概論(1982年版).中國建工出版社.1982.3.[12]李海濤，郭獻軍，吳武偉..新型干法水泥生產(chǎn)技術(shù)與設(shè)備.北京，化學工業(yè)出版社，2006.1.[13]兩渣一灰綜合利用日產(chǎn)4000噸特種水泥熟料生產(chǎn)線可行性研究報告中材國際工程股份官網(wǎng).2006.3.[14]曹文聰、楊樹森.普通硅酸鹽工藝學【M】，武漢，武漢工業(yè)大學出版社，1996.10~26.[15]高長明.預(yù)分解窯水泥生產(chǎn)技術(shù)及進展，北京，化學工業(yè)出版社，2006.1[16]嚴生，常捷，程麟.新型干法水泥廠工藝設(shè)計手冊.中國建材工業(yè)出版社，2007.1.[17]第三代5500t/d預(yù)分解系統(tǒng)的研究開發(fā)及應(yīng)用.天津水泥工業(yè)設(shè)計研究院.2021.1.[18]陳守強；胡慶銀；高冬美.年產(chǎn)100t噸水泥粉磨站生產(chǎn)線實踐.山東東華水泥水泥，cement.2007．No.1[19]熊會思，熊然.新型干法水泥廠設(shè)備選型使用手冊-5000t/d熟料生產(chǎn)線工藝系統(tǒng)設(shè)計.中國建材工業(yè)出版社，2007.1[20]劉志江.新型干法水泥技術(shù).中國建材工業(yè)出版社，2005.1[21]潘軼、蔣超鵬.華潤水泥〔貴港〕2×5000t/d熟料生產(chǎn)線工藝設(shè)計簡介.水泥工程,2007.01外文資料翻譯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/