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《低鈣粉煤灰粒度對水泥-粉煤灰復(fù)合膠凝材料力學(xué)性能與水化性能的影響》由會員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、2017年第1期混凝土與水泥制品2017No.11月CHINACONCRETEANDCEMENTPRODUCTSJanuary低鈣粉煤灰粒度對水泥-粉煤灰復(fù)合膠凝材料力學(xué)性能與水化性能的影響周祥,李玉香,鄭召,馬雪,倪倩(四川省非金屬復(fù)合與功能材料重點(diǎn)試驗(yàn)室-省部共建國家重點(diǎn)試驗(yàn)室培育基地,西南科技大學(xué),綿陽621010)摘要:為了實(shí)現(xiàn)粉煤灰的高效利用,通過旋風(fēng)分級機(jī)將原狀粉煤灰分成D50=5.06μm、15.63μm、35.01μm三個(gè)不同的粒度區(qū)間。不同粒度粉煤灰按照0、10%、20%和30%替代硅酸
2、鹽水泥。研究了粉煤灰粒度對水泥膠砂強(qiáng)度和水化性能的影響。結(jié)果表明,隨著粉煤灰粒徑的減小,粉煤灰水泥的各齡期強(qiáng)度都逐漸增加,摻入適量細(xì)粒度粉煤灰,水泥各齡期膠砂強(qiáng)度超過了硅酸鹽水泥;粉煤灰水泥的水化放熱速率和累積放熱量都低于硅酸鹽水泥,隨著粉煤灰粒徑的減小,粉煤灰水泥的水化放熱速率和累積放熱量增加。3d齡期時(shí),粉煤灰水泥漿體Ca(OH)2峰強(qiáng)度與硅酸鹽水泥幾乎相同;60d齡期時(shí),隨著粉煤灰顆粒粒徑的減小,粉煤灰水泥漿體Ca(OH)2峰的強(qiáng)度明顯減小;SEM-EDS分析表明,細(xì)粒度區(qū)間的粉煤灰水泥漿體比粗粒度
3、區(qū)間的粉煤灰水泥漿體具有更致密的漿體結(jié)構(gòu)且粉煤灰顆粒水化生成的是一種低Ca/Si的C-S-H凝膠。關(guān)鍵詞:低鈣粉煤灰;粒度;粉煤灰水泥;水化性能Abstract:Toachievethehighefficientutilizationofflyash,alowcalciumoriginalflyashwasclassifiedinto3frac-tionsbyanairclassfier,withmedianparticlesizeof5.06μm,15.63μm,35.01μm,respectively
4、.ThreesizesofflyashwereusedtopartiallyreplacePortalandcementat0,10%,20%and30%byweight.Theeffectofsizefractiononstrengthandhydrationpropertyofflyash-cementcomplexcementitiousmaterialsincorporatingflyashwasstudied.Testresultsindicat-edthatwiththedeclineinth
5、esizeofflyash,thestrengthofflyash-cementmortarsincreased.Andcementwithappropri-atecontentoffineflyashshowedhigherstrengththanPortlandcementateveryage.TheheatevolutionresultsshowedthattherateofheatevolutionandcumulativeheatoftheflyashcementwerelowerthanPor
6、tlandcement.Withthede-clineinthesizeofflyash,therateofheatevolutionandcumulativeheatoftheflyashcementincreased.TheX-raydiffraction(XRD)resultsshowedthattheintensitypeaksofCa(OH)2offlyashcementwerealmostsimilartoPortlandce-mentat3days.However,withthedeclin
7、einthesizeofflyash,theintensitypeaksofCa(OH)2offlyashcementde-creasedobviouslyat60days.Thescanningelectronmicroscope(SEM-EDS)resultsrevealedthatthehardenedblendedcementpastecontainingfinerflyashproducedadenserstructureandthesurfaceofflyashproducedC-S-Hgel
8、withlowCa/Simolarduringpozzolanicreaction.Keywords:Lowcalciumflyash;Sizefraction;Flyashcement;Hydrationproperties中圖分類號:TU528.041文獻(xiàn)標(biāo)識碼:A文章編號:1000-4637(2017)01-01-07[1-6]0前言長等缺陷,限制了粉煤灰的應(yīng)用。許多研究報(bào)道,粉煤灰作為一種固體廢棄物,因其具有潛在的粉煤