本文選題：堿 + 液體速凝劑　； 參考：《鄭州大學(xué)》2014年碩士論文

【摘要】：液體無堿（或低堿）速凝劑(Liquid Alkalifree Accelerator,LAA)是一種噴射混凝土所使用的外加劑，能顯著縮短混凝土的凝結(jié)硬化時(shí)間。跟傳統(tǒng)堿性粉狀速凝劑相比，它具有堿含量低、在拌合料中分散充分以及施工時(shí)空氣中粉塵濃度低等優(yōu)點(diǎn)，能有效減小在施工過程中對(duì)施工人員的腐蝕傷害，并且能提高噴射混凝土的強(qiáng)度和避免噴射混凝土的質(zhì)量大幅度波動(dòng)。因此，開發(fā)液體無堿（或低堿）速凝劑以替代傳統(tǒng)速凝劑已成為當(dāng)前有關(guān)混凝土及施工技術(shù)方面研究的熱點(diǎn)之一。 本文較為系統(tǒng)地闡述了速凝劑的發(fā)展歷史和國(guó)內(nèi)外的研究應(yīng)用現(xiàn)狀，通過分析現(xiàn)有速凝劑的不足，進(jìn)而指出研究開發(fā)液體無堿（或低堿）速凝劑的必要性和可行性，并進(jìn)行了大量的理論分析和試驗(yàn)探索，得出主要研究成果如下: （1）提出了制備高效液體無堿速凝劑的關(guān)鍵是獲得高鋁離子含量的穩(wěn)定溶液。研究了鋁離子在溶液中穩(wěn)定存在的條件，提出了高濃度鋁離子合成思路。 （2）進(jìn)行了無堿液體速凝劑配制研究，得出無堿液體速凝劑優(yōu)化配比為：AlF3理論含量7％～8％，硫酸鋁含量43％±2％，，配位劑摻量為1.5%。以此制備的速凝劑穩(wěn)定性好，對(duì)于大部分普通水泥來說，速凝劑用量在5％時(shí)初凝時(shí)間小于3min，終凝時(shí)間小于5min，1d抗壓強(qiáng)度可達(dá)到10MPa左右，28d抗壓強(qiáng)度比大于100％。 （3）研制了無堿速凝劑SNJ-2（基礎(chǔ)配方），其生產(chǎn)原料易得、工藝簡(jiǎn)單、成本低廉，用量少（摻量3%～5%）。通過SNJ-2對(duì)商品水泥的適應(yīng)性研究，提出了具有良好適應(yīng)性水泥的建議：對(duì)于P.O42.5水泥，指標(biāo)參考值：28d抗壓強(qiáng)度≥48MPa，比表面積：320～350m2/kg，同時(shí)應(yīng)重視水泥助磨劑與速凝劑的相容性問題。 （4）探討了速凝組分的速凝機(jī)理，結(jié)果表明：以Al2（SO4）3溶液、含Al絡(luò)合物等復(fù)合而成的無堿速凝劑主要是通過形成鈣礬石（AFt）和C3AH6而導(dǎo)致水泥漿體的快速凝結(jié)；溶液中Al3+或Al的絡(luò)合物起到的是速凝作用，而F-在速凝劑溶液中起增溶作用，在水泥水化體系中起緩凝作用。 （5）針對(duì)特殊水泥（基礎(chǔ)配方不適用的水泥）進(jìn)行了速凝劑配方的調(diào)整，建立了特殊水泥速凝劑調(diào)配方法，制備了各項(xiàng)性能優(yōu)良的液體低堿速凝劑SNJ-3和SNJ-4。經(jīng)工程應(yīng)用證明，該速凝劑具有早強(qiáng)、小時(shí)強(qiáng)度增進(jìn)率高、回彈低且無后期強(qiáng)度損失等優(yōu)點(diǎn)。
[Abstract]:Liquid Alkalifree accelerator LAA (liquid Alkalifree accelerator LAA) is a kind of admixture used in shotcrete, which can shorten the setting and hardening time of concrete. Compared with the traditional alkaline powder accelerator, it has the advantages of low alkali content, full dispersion in the mixing material and low dust concentration in the air during construction, which can effectively reduce the corrosion damage to the construction personnel during the construction process. And it can improve the strength of shotcrete and avoid the large fluctuation of shotcrete quality. Therefore, the development of liquid alkaline-free (or low-alkali) accelerators to replace traditional accelerators has become one of the hotspots in the research of concrete and construction technology. In this paper, the history of the development of the accelerator and the present research and application situation of the accelerator at home and abroad are described systematically. By analyzing the deficiency of the existing accelerator, the necessity and feasibility of the research and development of the liquid accelerator without alkali (or low alkali) are pointed out. A large number of theoretical analysis and experimental exploration have been carried out, and the main research results are as follows: 1) the key of preparing high efficiency liquid alkali-free accelerator is to obtain stable solution with high aluminum ion content. The conditions for the stable existence of aluminum ions in solution were studied, and the synthesis of high concentration aluminum ions was put forward. 2) study on the preparation of alkali-free liquid accelerator. The optimum ratio of alkali-free liquid accelerator is 7% AlF3, 43% 鹵2% aluminum sulfate and 1.5% coordination agent. For most common cement, the initial setting time is less than 3 mins and the final setting time is less than 5 mins. The compressive strength of the accelerator can reach about 28d of 10MPa or more than 100d. The basic formula of SNJ-2 (basic formula) is easy to obtain raw material, simple process, low cost and low dosage. Based on the research on the adaptability of SNJ-2 to commercial cement, some suggestions are put forward: for P.O42.5 cement, the compressive strength of P.O42.5 cement is 鈮

本文編號(hào)：1940109