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1、摘要聚羧酸系高效減水劑由于其優(yōu)異的應(yīng)用性能和具有環(huán)保生產(chǎn)等特點(diǎn)已成為混凝土夕卜加劑行業(yè)未來發(fā)展的方向。然而由于其在應(yīng)用方面存在的問題及對(duì)其應(yīng)用經(jīng)驗(yàn)的不足,制約了聚羧酸系高效減水劑在我國的快速推廣應(yīng)用。本文通過測(cè)試水泥凈漿流動(dòng)度、凝結(jié)時(shí)間、砂漿減水率、膠砂強(qiáng)度和水化過程的電阻率、水化放熱速率,對(duì)聚羧酸系高效減水劑(PC)與緩凝劑、早強(qiáng)劑、其他減水劑及礦物摻合料之間相容性進(jìn)行了系統(tǒng)地研究。1.結(jié)合凈漿流動(dòng)度和凝結(jié)時(shí)間試驗(yàn)得出,檸檬酸、蔗糖的緩凝性強(qiáng),但輔助塑化效應(yīng)并不好,而緩凝性小的葡萄糖酸鈉卻有較好的輔助塑化效應(yīng),說明緩凝劑并不只是通過延緩水化來影響漿體
2、流動(dòng)性能的。2.凈漿流動(dòng)度實(shí)驗(yàn)結(jié)果表明不同無機(jī)鹽早強(qiáng)劑對(duì)PC的塑化效果產(chǎn)生不同的影響,并從早強(qiáng)劑對(duì)PC吸附量、立體結(jié)構(gòu)及‘-電位影響方面給予解釋;凝結(jié)時(shí)間和膠砂強(qiáng)度試驗(yàn)表明,無機(jī)鹽早強(qiáng)劑有不同程度的促凝效果,早強(qiáng)劑的增強(qiáng)效果存在一個(gè)臨界摻量;水化過程電一熱行為表明,PC與無機(jī)鹽早強(qiáng)劑復(fù)合使用,誘導(dǎo)期的結(jié)束時(shí)間提前,漿體結(jié)構(gòu)的形成加快,放熱峰提前出現(xiàn),且峰值升高,與宏觀試驗(yàn)獲德的結(jié)論一致。3.通過凈漿流動(dòng)度和砂漿減水率試驗(yàn),考查了PC與普通減水劑木鈉或其它高效減水劑的復(fù)合效應(yīng)。結(jié)果表明:少量PC與木鈉復(fù)合產(chǎn)生正效應(yīng),PC與FDN、AS復(fù)合產(chǎn)生負(fù)效應(yīng),PC
3、與FAS復(fù)合產(chǎn)生正效應(yīng),PC與MS復(fù)合產(chǎn)生零效應(yīng)。4.通過凈將流動(dòng)度試驗(yàn)研究礦物摻合料對(duì)PC的輔助減水作用,并從礦物摻合料的延緩作用、吸附作用和顆粒級(jí)配作用方面給予解釋;通過膠砂強(qiáng)度試驗(yàn)研究了PC與礦物摻合料雙摻對(duì)膠砂早期及后期強(qiáng)度的影響,結(jié)果表明石粉部分取代水泥時(shí)的后期強(qiáng)度可超越純水泥。關(guān)鍵詞聚羧酸系高效減水劑;緩凝劑;早強(qiáng)劑;礦物摻合料;相容性摘要ABSTRACTPolycarboxylate-typesuperplasticizer(PC)isoneoftheindispensablematerialsforhigh-fluidityandhig
4、h-strengthconcretebecauseofitssuperiordispersingforceforcement,especiallyatlowwater/cementratios,anditsretentioneffects.Howeverthelarge-scaleapplicationofPCwasbadlyaffectedbytheshortoftheapplicationexperienceandproblems.Bytestingthefluidityandthesettingtimeofcementpaste,thestren
5、gthandwater-reducingratioofthemortal-,andtheelectricalresistivityandtheheatevolutionofhydration,thispapersystematicallystudiedthecompatibilitybetweentheretarder,theearlystrengthagent,thewaterreducer,mineraladmixturesandPC.1.Combinedwiththefluidityandtheinitialsettingtimeofcement
6、paste,theresultsindicatedthat.citrateacidandSucTosehadmoresignificantretardationthanglucose—acidNa,whileglucose-acidNahadbetterauxiliaryplasticizing,SOthattheauxiliaryplasticizingoftheretarderWasnotonlycarriedoutbydelayingthehydrationofcement.2.Theeffectofinorganicsaltearly-stre
7、ngthagentontheauxiliaryplasticizingWasdifferent,andthisresultwasexplained,bytwoaspectsbelow:thesulfateionandPCworecompetitivelyadsorbedoncementparticleandtheionstrengthcausedtheshrinkinginthestericsizeofPC.Ondifferentdegree,theinorganicsaltearly-strengthagentshortedthesettingtim
8、e.Theeffectoftheearly-strengthagentsonadvancing