本文關(guān)鍵詞： 聚羧酸減水劑 熱帶海洋性氣候 抗氯離子滲透性 抗硫酸鹽侵蝕性　出處：《海南大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：如何建造更加耐久的混凝土建筑,成為當(dāng)今混凝土行業(yè)面臨的主要問題。由于地處熱帶海洋氣候地區(qū),海南省同時處于熱帶和海洋兩種惡劣的自然環(huán)境中：高溫高濕高輻射；海水蒸發(fā)量大；空氣中氯離子相對含量高；氧氣、水汽、紫外線照射等腐蝕性介質(zhì)活躍。因此,海南省的混凝土建筑的抗氯離子滲透性及抗硫酸鹽侵蝕性更需要受到重視。 聚羧酸(PCE)是目前研究和應(yīng)用最廣泛的混凝土減水劑,其分子結(jié)構(gòu)對混凝土耐久性的影響機理研究鮮有報道。本文通過合成不同羧酸根系列、磺酸根系列及支鏈系列的PCE,從分子結(jié)構(gòu)層面研究PCE對水泥凈漿性能、熱帶海洋性氣候下混凝土抗氯離子滲透性和抗硫酸鹽侵蝕性能的影響,進一步初探其作用機理。 對于不同羧酸根系列PCE,研究了酯型短側(cè)鏈、醚型短側(cè)鏈以及醚型長側(cè)鏈三個不同側(cè)鏈類型的PCE,結(jié)果表明：摻酯型和醚型短側(cè)鏈PCE凈漿均在酸酯比為2.5：1時得到最優(yōu)凈漿流動度和最小損失率,而摻醚型長側(cè)鏈PCE凈漿在3.5：1時達到最優(yōu)凈漿流動度,在2.5：1時得到最小損失率；20℃凈漿表觀粘度測試結(jié)果與流動度結(jié)果一致,但隨著溫度升高到40℃,摻高酸醚(酯)比PCE凈漿表現(xiàn)出表觀粘度出先升高后降低的現(xiàn)象；就抗硫酸鹽侵蝕性而言,摻短側(cè)鏈PCE混凝土在酸酯(醚)比較小的情況下抗硫酸鹽侵蝕性能更差,摻醚型長側(cè)鏈PCE混凝土抗硫酸鹽侵蝕性則隨著羧酸根密度增加而減�。粚τ诳孤入x子滲透性來說,酯型短側(cè)鏈PCE酸酯比的變化對混凝土抗氯離子滲透性能沒有明顯的影響,而醚型PCE無論側(cè)鏈長短,都在較高酸醚比下獲得較好的混凝土抗氯離子滲透性能；從混凝土內(nèi)部孔結(jié)構(gòu)的結(jié)果可知,酸酯比對摻酯型短側(cè)鏈PCE的混凝土孔結(jié)構(gòu)參數(shù)的變化沒有明顯的規(guī)律,摻長側(cè)鏈醚型PCE混凝土隨著PCE酸醚比增加,孔隙率減小,毛細孔含量沒有明顯變化,摻短側(cè)鏈醚型PCE混凝土隨酸醚比增加,孔隙率增大,毛細孔含量減小。 對于不同磺酸根根系列PCE研究了甲基丙烯磺酸鈉(MAS)用量對醚型長側(cè)鏈PCE性能的影響,結(jié)果表明：隨著甲基丙烯磺酸鈉(MAS)加入量的增多,其凈漿流動度、流動度損失以及表觀粘度均是先增加后減小,均在MAS含量為0.32時達到最優(yōu)值；隨著溫度升高,摻高MAS含量的PCE凈漿表觀粘度增加值是小于摻低MAS含量PCE的；MAS加入量的增加對混凝土抗硫酸鹽侵蝕性能沒有太大的影響,但會降低混凝土抗氯離子滲透性能。 對于不同側(cè)鏈系列PCE,研究了不同酯基取代,不同長短側(cè)鏈,不同側(cè)鏈長度及PO嵌段長側(cè)鏈PCE性能的差異,結(jié)果表明：摻不同酯基取代的PCE凈漿在10%酯基取代的羧酸根的情況下可提高凈漿流動度并減少損失率；摻長短側(cè)鏈的PCE凈漿無論是流動度還是表觀粘度變化均介于摻單長側(cè)鏈PCE凈漿和單短側(cè)鏈PCE凈漿之間；側(cè)鏈長度增長,凈漿流動度增大、損失率和表觀粘度減小,特別是摻PO嵌段的長側(cè)鏈PCE凈漿,變化效果最明顯；凈漿表觀粘度會隨著溫度升高而升高,但當(dāng)所摻PCE存在高含量的酯鍵時,無論是酯基取代還是醚酯型長短側(cè)鏈PCE,其凈漿粘度均會在高溫下有一定程度的降低；抗蝕性結(jié)果表明,摻醚型PCE混凝土,隨著PCE側(cè)鏈長度變短,混凝土孔隙率減小,混凝土抗蝕性能變好；部分酯基取代和引入側(cè)鏈分子上含有PO嵌段的結(jié)構(gòu)PCE,有利于混凝土抗氯離子滲透性能的提高,但酯類基團的引入會因和易性不好而降低混凝土抗硫酸鹽侵蝕性能；對于長短側(cè)鏈,無論是醚酯型還是醚醚型,其混凝土孔隙率都比摻單側(cè)鏈種類PCE的混凝土要大一些,因此長短側(cè)鏈對于抗蝕性能的提高是沒有幫助的。聯(lián)系凈漿結(jié)果與混凝土抗蝕性結(jié)果發(fā)現(xiàn),凈漿表觀粘度與混凝土抗硫酸鹽侵蝕性存在著一定的內(nèi)在聯(lián)系,隨著對應(yīng)PCE凈漿表觀粘度增加,混凝土抗硫酸鹽侵蝕性也會變好。
[Abstract]:How to build a more durable concrete building, become the main problem facing concrete industry. Due to the tropical marine climate area is located in Hainan Province, at the same time in the tropical and marine two kinds of harsh natural environment, high radiation, high temperature and high humidity; evaporation; high relative content of chloride ions in the air; oxygen, water vapor, ultraviolet exposure to corrosive medium active. Therefore, concrete construction in Hainan Province, the anti chloride ion permeability and sulfate resistance need more attention.
Poly carboxylic acid (PCE) is currently the most widely research and application of concrete superplasticizer, the effect of molecular structure on the durability of concrete mechanism has not been studied. Through the synthesis of different carboxylic acid series, sulfonic acid series and branched PCE series, from the molecular structure of the level of PCE on the properties of cement paste, resistance to chloride ion penetration effect of sulfate resistance of concrete tropical marine climate, further research on its mechanism.
For different series of carboxylic acid ester type PCE, the short side chain is studied, and the short side chain polyether ether type long side chain side chain of three different types of PCE, the results show that the mixed ester and ether type short side chain of PCE paste in ester ratio to obtain the optimal paste fluidity and minimum loss the rate of 2.5:1, and with long side chain ether type PCE paste in 3.5:1 to achieve optimal fluidity, get the minimum loss rate in 2.5:1 is 20 DEG C; paste apparent viscosity test results and fluidity results, but with the increase of temperature to 40 degrees Celsius, with high acid (ester ether) than PCE the paste showed apparent viscosity increased first and then decreased; on the sulfate resistance, with short side chain PCE (ester ether) in concrete under the condition of small resistance to sulfate attack is even worse, with long side chain ether type PCE sulphate resistance of concrete decreases with increasing density of carboxylic acid but for; The resistance to chloride ion permeability, change of ester type short side chain PCE esters than the chloride penetration resistance of concrete has not obvious effect on the length of the side chain of both ether type PCE, are higher than under the acid ether to obtain better resistance of concrete to chloride ion penetration; it can be seen from the internal pore structure of concrete results. The change of pore structure parameters on the mixed ester ester short side chain PCE has no obvious regularity, with long side chain ether type PCE concrete with PCE acid ether ratio increases, the porosity decreases, the pores content did not change significantly, with short side chain ether type PCE concrete with acid ether ratio increases, the porosity increases the pores, reduce the content.
For different PCE series of methyl sulfonic acid by sodium allyl sulfonate (MAS), the amount of ether type long side chain PCE performance results show that with sodium methylacrylsulfonate (MAS) content increased, the fluidity, fluidity loss and apparent viscosity were increased first and then decreased. In the content of MAS is to achieve the optimal value of 0.32; with the increase of temperature, with high content of MAS PCE paste increased the apparent viscosity value is less than PCE with low MAS content; the increase of the amount of MAS had no impact on the sulfate resistance of concrete, but will reduce the chloride permeability of concrete.
For the different side chain of PCE, study the different ester substituted, different length of side chain, difference, different side chain length and PO block long side chain PCE performance. The results showed that the carboxylic acid ester substituted with different PCE paste in 10% case of ester substituted can improve the fluidity of cement paste and to reduce the loss rate; the length of the side chain of PCE doped paste both between fluidity or apparent viscosity change between doped single long side chain of PCE paste and PCE paste single short side chain; side chain length increases, the fluidity loss rate increases, and the apparent viscosity decreased, especially with PO block the long side chain of PCE paste, the most obvious change effect; paste viscosity increases with the increase of temperature, but when the ester bond of PCE doped high contents, either ester substituted or ether ester side chain length PCE, the paste viscosity will be decreased to a certain degree the resistance at high temperature; The results show that the corrosion resistance of concrete, mixed with ether type PCE, with the PCE side chain length, concrete porosity, corrosion resistance of concrete is better; the structure of PCE part and the introduction of ester substituted side chain molecules containing PO block, is conducive to the chloride permeability of concrete increases, but the introduction of ester groups because of bad workability and reduce concrete sulfate resistance; for the length of the side chain, either ether ester or ether ether type, the porosity of concrete than with unilateral PCE chain concrete ones, thus improving the length of side chain for corrosion resistance is not helpful. Contact paste the results of corrosion and concrete results showed that the apparent viscosity of paste and concrete sulfate resistance there exists a certain relationship, with the increase of the apparent viscosity of corresponding PCE paste, concrete sulfate resistance will become better.

【學(xué)位授予單位】：海南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU528.042.2

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本文編號：1448364