【摘要】：對于未采取任何防滲措施的早期建成的填埋場,或者防滲處理不完善的老填埋場常常有必要使用垂直防滲墻來補救。自凝灰漿防滲墻是一種垂直防滲墻,具有較低的彈性模量、適應(yīng)地基變形能力強、施工工藝簡單、成本廉價等優(yōu)點,經(jīng)常被應(yīng)用在環(huán)境保護類工程。但在自凝灰漿的一些現(xiàn)實應(yīng)用中,常呈現(xiàn)出墻體的滲透系數(shù)不滿足設(shè)計要求的情形,因此,提高自凝灰漿固結(jié)體的防滲性能,研究其力學(xué)性能和微觀機理,對了解和應(yīng)用這類墻體材料具有指導(dǎo)性意義。本文從宏觀和微觀兩個層面進行研究,對自凝灰漿進行了室內(nèi)配合比的防滲性能、力學(xué)性能和孔隙結(jié)構(gòu)的試驗研究,試圖提高自凝灰漿固結(jié)體的防滲性能,得到優(yōu)化配合比,通過室內(nèi)試驗,得到了一些有價值的結(jié)論和結(jié)果:(1)針對自凝灰漿原材料的不同種類和數(shù)量設(shè)計了三組不同的配合比,利用ST55-2改進型滲透儀測定了它們的7d和28d的滲透系數(shù),討論并闡明了膨潤土、粉煤灰及堿激發(fā)劑等材料對滲透系數(shù)的影響,研究了齡期對防滲性能的作用,得到了優(yōu)化后的配合比配方,粉煤灰在無堿激發(fā)時,最佳摻量為230~250g/1000g水,滲透系數(shù)最低可達1.99×10-7cm/s;粉煤灰在有堿激發(fā)劑的環(huán)境中,滲透系數(shù)會降低;1000g水中,NaOH和Na2SiO3加量各50g,膨潤土加量180~200g,粉煤灰加量350g,水泥200g時可獲得滲透系數(shù)在1×10-7cm/s以下的自凝灰漿固結(jié)體;28d的養(yǎng)護齡期比7d的養(yǎng)護齡期的固結(jié)體防滲性能要好很多。(2)按照優(yōu)化配合比配制試塊,利用電子萬能試驗機對固結(jié)體進行力學(xué)試驗,得到了固結(jié)體的應(yīng)力-應(yīng)變關(guān)系曲線和抗壓強度及變形模量,其強度最高可達2.42MPa,變形模量最高可達60.15MPa。(3)通過電子顯微鏡對固結(jié)體進行圖像觀察,并使用ToupView軟件對固結(jié)體的孔隙結(jié)構(gòu)特征進行分析,得到自凝灰漿固結(jié)體的臨界孔徑大致在23~80μm之間,并從微觀層面簡要分析了水泥-膨潤土的反應(yīng)機理和粉煤灰受堿激發(fā)的模型,對固結(jié)體的孔隙與防滲性的關(guān)系進行了分析和探討。
[Abstract]:It is often necessary to use vertical cutoff walls for early constructed landfills without any seepage control measures or for old landfills that are not well disposed of seepage. Self-mortar impervious wall is a kind of vertical impervious wall, which has the advantages of low elastic modulus, strong ability to adapt to the deformation of foundation, simple construction technology, low cost and so on. It is often used in environmental protection projects. However, in some practical applications of the self-coagulating mortar, the permeability coefficient of the wall often does not meet the design requirements. Therefore, the anti-seepage performance of the self-coagulating mortar consolidation body is improved, and its mechanical properties and microscopic mechanism are studied. It is instructive to understand and apply this kind of wall material. In this paper, the anti-seepage performance, mechanical properties and pore structure of self-coagulating mortar were studied from macroscopic and microscopic aspects, and the optimum mix ratio was obtained by improving the anti-seepage performance of self-coagulating mortar consolidation body. Through the laboratory test, some valuable conclusions and results are obtained: (1) three groups of different mix ratios are designed for different kinds and quantity of raw materials of self-coagulating mortar. The permeability coefficients of 7 d and 28 d were measured by ST55-2 modified osmometer. The effects of bentonite, fly ash and alkali activator on the permeability coefficient were discussed, and the effect of age on impermeability was studied. The optimized formula is obtained. When the fly ash is excited without alkali, the best dosage is 230~250g/1000g water, and the lowest permeability coefficient can be up to 1.99 脳 10 ~ (-7) cm ~ (-1) 路s ~ (-1) 路L ~ (-1) 路L ~ (-1); In the environment with alkali activator, the permeability coefficient of fly ash will be decreased, the addition of NaOH and Na2SiO3 in 1000g water, the addition of bentonite at 180g, the addition of fly ash by 350g, and the cement by 200g, the self-coagulating mortar consolidation body with permeability coefficient below 1 脳 10-7cm/s can be obtained. The curing age of 28 days is much better than that of the curing age of 7 days. (2) according to the optimized mix ratio, the mechanical tests of the consolidation body are carried out by using the electronic universal testing machine. The stress-strain relationship curve, compressive strength and deformation modulus of the consolidated body are obtained. The maximum strength and deformation modulus of the consolidated body are 2.42 MPA and 60.15 MPA respectively. (3) the image of the consolidated body is observed by electron microscope. The pore structure characteristics of consolidation body were analyzed by ToupView software, and the critical pore size of the consolidation body was about 2380 渭 m. The reaction mechanism of cement-bentonite and the model of fly ash excited by alkali were briefly analyzed from the microcosmic level. The relationship between porosity and impermeability of consolidation body is analyzed and discussed.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TU57

【相似文獻】

相關(guān)期刊論文 前5條

1 李雪梅;涂興懷;;材料與配合比對自凝灰漿性能的影響[J];科協(xié)論壇(下半月);2013年01期

2 阮文軍,黃曉平,牛麗滿;特大深基坑自凝灰漿擋水帷幕技術(shù)[J];長春工程學(xué)院學(xué)報(自然科學(xué)版);2004年02期

3 劉清文;;自凝灰漿墻施工技術(shù)應(yīng)用性分析[J];土工基礎(chǔ);2013年04期

4 王勇;;GCL防滲性能及其在填埋場中的應(yīng)用[J];環(huán)境工程;2009年06期

5 陳若志;;對RCCD滲流控制分析[J];建材與裝飾(中旬刊);2007年07期

相關(guān)重要報紙文章 前2條

1 ;自凝灰漿的研究及應(yīng)用[N];科技日報;2006年

2 ;自凝灰漿防滲墻技術(shù)[N];科技日報;2005年

，

本文編號：2357773