本文選題：聚羧酸減水劑 + 流動度��； 參考：《沈陽建筑大學》2014年碩士論文

【摘要】：隨著建筑行業(yè)的迅猛發(fā)展,在工程應用中對于混凝土外加劑的要求逐步提高,為了滿足不同施工要求,不同種類的混凝土外加劑相繼研發(fā)。作為混凝土外加劑,聚羧酸系減水劑具有減水率高、分散性、坍落度保持性好、提高混凝土強度、降低水泥使用量、功能可控等優(yōu)點,因此了解不同官能團對聚羧酸減水劑的影響具有重要的意義。本論文合成了APEG-AA、APEG-MMA-AA、APEG-SMAS-AA、APEG-MA-AA、APEG-AM-AA五種不同體系的聚羧酸減水劑,并對它們的技術性能、水泥水化速率等進行了研究。對于APEG-AA體系聚羧酸減水劑,以APEG為反應單體的減水劑的減水效果優(yōu)于以TPEG為反應單體;流動度隨APEG與AA摩爾比的增大先增大后減小,n(APEG)∶n(AA)=1.00∶3.27為最佳摩爾比;流動度隨活性調節(jié)劑摻量的增加而增加,活性調節(jié)劑的摻量為大單體質量的0.15%時最好,隨后流動度隨著摻量的增加而降低;通過正交試驗發(fā)現(xiàn),當反應溫度為60℃,反應時間為4.5h,引劑用量為大單體質量的2.0%時,得到的APEGAA體系聚羧酸減水劑的減水效果和保塑性最好。對于APEG-MMA-AA體系、APEGSMAS-AA體系、APEG-MA AA體系和APEG-AM AA體系聚羧酸減水劑,流動度隨不同反應原材料取代AA摩爾的增加、反應溫度的升高和反應時間的增加而先增加后減小,最終確定:取代AA摩爾的20%、溫度70℃、時間4.5h為最佳合成條件。對五種不同體系的聚羧酸減水劑進行技術性能的測試,五種不同體系聚羧酸減水劑的固含量分別為42.7%、39.9%、41.5%、44.3%、41.4%,膠砂減水率分別為37.6%、38.2%、38.5%、39.4%、37.5%,飽和點均為0.20%,且與不同品種的水泥適應性較強,表現(xiàn)出較好的減水和分散效果。通過紅外光譜測試,確認了不同體系聚羧酸減水劑分子結構中應存在羧基(-COOH)、醚基(-O-)、羥基(-OH)、C-H鍵等官能團。對合成的不同體系聚羧酸減水劑的水泥凈漿凝結時間、膠砂強度和水泥水化速率進行了測試。甲基具有較好的緩凝性能;酰胺基具有一定的早強效果;磺酸基、酰胺基具有良好的保塑性。通過測試不同體系聚羧酸減水劑的水泥水化速率曲線可知,出現(xiàn)水化速率峰的順序依次是APEG-AM-AA體系、APEG-AA體系、APEG-SMAS-AA體系、APEG-MMA-AA體系和APEG-MA-AA體系,結果與水泥凈漿凝結時間和膠砂強度的測試結果基本相符。
[Abstract]:With the rapid development of the construction industry, the requirements for concrete admixtures have been gradually raised in engineering applications. In order to meet different construction requirements, different kinds of concrete admixtures have been developed one after another. As a concrete additive, polycarboxylic acid superplasticizer has the advantages of high water reducing rate, high dispersion, good slump retention, increasing concrete strength, reducing cement usage, controllable function, etc. Therefore, it is of great significance to understand the effect of different functional groups on polycarboxylic acid superplasticizer. In this paper, five kinds of polycarboxylic acid water reducers of APEG-AAA, APEG-MMA-AA, APEG-SMAS-AAN, APEG-MA-AM-AA have been synthesized, and their technical properties and hydration rate of cement have been studied. For APEG-AA polycarboxylic acid superplasticizer, the water reducing effect of water reducing agent with APEG as reactive monomer is better than that with TPEG.The mobility increases first with the increase of the molar ratio of APEG to AA and then decreases with the increase of the molar ratio of APEG to AA, and then decreases to 1.00: 3.27 as the optimum molar ratio. The fluidity increased with the increase of the amount of active modifier, and the content of active modifier was the best when the mass of macromonomer was 0.15, then the fluidity decreased with the increase of the amount of active modifier, and it was found by orthogonal experiment that the reaction temperature was 60 鈩，

本文編號：2055787