【摘要】：隨著我國(guó)基礎(chǔ)設(shè)施工程建設(shè)的大規(guī)模發(fā)展，我國(guó)對(duì)商品混凝土的質(zhì)量要求越來(lái)越嚴(yán)格。目前在高性能混凝土中，聚羧酸系高性能減水劑的使用非常廣泛。聚羧酸系減水劑因其無(wú)毒、環(huán)保、減水率高等特點(diǎn)受到廣泛關(guān)注，今后的應(yīng)用前景將更加廣泛。在聚羧酸減水劑的應(yīng)用過(guò)程中遇到了許多工程難題，最為突出的就是因水泥、混合材、砂石含泥等質(zhì)量問(wèn)題相應(yīng)帶來(lái)了摻聚羧酸高效減水劑的混凝土坍落度損失加快，影響到了聚羧酸高效減水劑的應(yīng)用和發(fā)展。 本文在聚羧酸減水劑合成技術(shù)的基礎(chǔ)上，通過(guò)合理的分子結(jié)構(gòu)設(shè)計(jì)，采用甲基烯丙基聚氧乙烯醚（TPEG）與丙烯酸（AA），在加入復(fù)合分子量調(diào)節(jié)劑、改性引發(fā)劑的條件下共聚，，開(kāi)發(fā)出性能優(yōu)異的聚羧酸系高性能保坍劑。 通過(guò)單因素分析探討反應(yīng)時(shí)間、反應(yīng)溫度、改性引發(fā)劑用量、丙烯酸與甲基烯丙基聚氧乙烯醚的摩爾比（酸醚比）以及復(fù)合分子量調(diào)節(jié)劑對(duì)保坍劑性能的影響。運(yùn)用正交試驗(yàn)設(shè)計(jì)，發(fā)現(xiàn)各個(gè)因素協(xié)同作用對(duì)保坍劑性能的影響較大，得出各個(gè)因素對(duì)合成聚羧酸保坍劑性能的影響由大到小依次為：酸醚比＞復(fù)合分子量調(diào)節(jié)劑＞改性引發(fā)劑＞反應(yīng)溫度＞反應(yīng)時(shí)間。并得到優(yōu)化后的最佳反應(yīng)條件為：反應(yīng)溫度為60℃、反應(yīng)時(shí)間為2h、n(AA):n(TPEG)為1.5:1、改性引發(fā)劑用量為0.84%和復(fù)合分子量調(diào)節(jié)劑用量為0.28%。并通過(guò)改變單體種類，發(fā)現(xiàn)不同單體對(duì)保坍劑性能的影響較大。 通過(guò)混凝土坍落度及其經(jīng)時(shí)損失試驗(yàn)、抗壓強(qiáng)度試驗(yàn)、水泥適應(yīng)性試驗(yàn)和貯存穩(wěn)定性試驗(yàn)得出：摻加研究的聚羧酸保坍劑90min后坍落度和擴(kuò)展度基本無(wú)損失，且自制聚羧酸保坍劑對(duì)混凝土的早期強(qiáng)度沒(méi)有影響，能夠提高混凝土的后期強(qiáng)度，并與武漢市市售的大部分水泥的適應(yīng)性良好，該聚羧酸保坍劑不緩凝且有較好的貯存穩(wěn)定性，給混凝土工程帶來(lái)了良好的施工條件。 運(yùn)用紅外光譜等手段對(duì)所研究的聚羧酸保坍劑的分子結(jié)構(gòu)進(jìn)行表征，結(jié)合合成試驗(yàn)所用的原料得到聚羧酸保坍劑的理想分子結(jié)構(gòu)，并從微觀結(jié)構(gòu)上探討了聚羧酸保坍劑的空間位阻效應(yīng)的主要作用機(jī)理。
[Abstract]:With the large-scale development of infrastructure construction in China, the quality requirements of commercial concrete are becoming more and more strict. At present, polycarboxylic acid series high performance water reducer is widely used in high performance concrete. Polycarboxylic acid superplasticizer is widely concerned because of its nontoxic, environmental protection and high water reducing rate, and its application prospect will be more extensive in the future. In the application of polycarboxylic acid superplasticizer, many engineering problems have been encountered. The most outstanding problem is that the slump loss of concrete mixed with polycarboxylic acid superplasticizer is accelerated due to the quality problems such as cement, mixing material, sand and stone, etc. The application and development of polycarboxylic acid superplasticizer are affected. On the basis of the synthesis technology of polycarboxylic acid water reducer and reasonable molecular structure design, the copolymerization of methyl allyl polyoxyethylene ether (TPEG) and acrylic acid (AA),) was carried out under the condition of adding compound molecular weight regulator and modifying initiator. A high performance polycarboxylic acid slump retention agent was developed. The effects of reaction time, reaction temperature, amount of modified initiator, molar ratio of acrylic acid to methallyl polyoxyethylene ether (acid ether ratio) and complex molecular weight modulator on the properties of slump retention agent were studied by single factor analysis. By using orthogonal test design, it is found that the synergistic effect of various factors has a great effect on the performance of the anti-collapse agent. The effects of various factors on the properties of the synthetic polycarboxylic acid slump retention agent were obtained as follows: acid / ether ratio > complex molecular weight regulator > modified initiator > reaction temperature > reaction time. The optimum reaction conditions were obtained as follows: the reaction temperature was 60 鈩

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