本文選題：混凝土耐久性　切入點：氣體滲透性　出處：《安徽建筑大學》2015年碩士論文　論文類型：學位論文

【摘要】：隨著經(jīng)濟的發(fā)展以及科技力量的突飛猛進,各種在特種嚴酷環(huán)境下服役的混凝土結構層出不窮,如海底隧道、跨海大橋、核反應堆等。這些混凝土結構不僅要有滿足按結構荷載設計的強度要求,更重要的是要有滿足在特定環(huán)境下能夠達到預定工作時間的能力,這就是要求混凝土結構有足夠的耐久性。而高性能混凝土正是以耐久性作為其設計的主要指標,不僅對耐久性、工作性有保證,還有必須滿足適用性和經(jīng)濟性,是一種新型的高技術混凝土,是未來混凝土技術發(fā)展的方向。然而尋求一套科學的、可靠的、實用的方法來檢驗和評定混凝土的耐久性能,一直是工程界渴望得到解決的問題。長久以來,國內外許多專家學者都對混凝土的滲透性做了廣泛而深入的研究,并取得了大量的研究成果。本文基于TORRENT方法,研究了氣體在混凝土中的滲透性及其與碳化性之間的關系,結果表明氣體滲透性隨水灰比的降低而減小,粉煤灰的摻入降低了混凝土碳化性能,氣體滲透性與碳化無相關性。同時研究了混凝土的水分滲透與氯離子滲透,結果表明,粉煤灰對混凝土的抗水滲透產(chǎn)生不利影響,使混凝土的滲水系數(shù)大幅度提高,而混凝土氯離子遷移系數(shù)也隨著粉煤灰摻量的增加而增加。通過對比分析水分滲透性及氯離子滲透性與抗凍性的關系,發(fā)現(xiàn)水分滲透與抗凍性相關性較小,而混凝土氯離子遷移系數(shù)與抗凍性相關性較好。最后對不同配合比、摻合料混凝土的微觀結構進行了分析,以探究孔結構對混凝土滲透性的影響,發(fā)現(xiàn)混凝土氣孔含量隨著粉煤灰的增加而增加,粉煤灰可以改善混凝土中的孔結構,使混凝土中的孔隙孔徑越多的向無害孔轉移。而混凝土孔隙率與氯離子遷移系數(shù)DRCM相關性很好,混凝土氯離子遷移系數(shù)DRCM隨著孔隙率的增加而增加。
[Abstract]:With the development of economy and the rapid development of science and technology, various kinds of concrete structures, such as subsea tunnels and bridges across the sea, have emerged in special and harsh environments. Nuclear reactors and so on. These concrete structures must not only meet the strength requirements of the structural load design, but also, more importantly, have the ability to meet the scheduled working hours in a given environment. This is to require concrete structures to have sufficient durability. And high performance concrete is designed with durability as its main index, not only to ensure durability and workability, but also to satisfy applicability and economy. Is a new type of high-tech concrete, is the direction of the future development of concrete technology. However, to seek a scientific, reliable, practical method to test and evaluate the durability of concrete, For a long time, many experts and scholars at home and abroad have done extensive and in-depth research on the permeability of concrete, and obtained a lot of research results. The relationship between the permeability of gas in concrete and its carbonation is studied. The results show that the gas permeability decreases with the decrease of water-cement ratio, and the carbonation property of concrete decreases with the addition of fly ash. There is no correlation between gas permeability and carbonation. At the same time, the moisture permeation and chloride ion permeation of concrete are studied. The results show that fly ash has a negative effect on the water permeability of concrete, and the permeability coefficient of concrete is greatly increased. The chloride ion transport coefficient of concrete also increases with the increase of fly ash content. By comparing and analyzing the relationship between water permeability and chlorine ion permeability and frost resistance, it is found that the correlation between water permeability and frost resistance is relatively small. However, the chlorine ion transfer coefficient of concrete has a good correlation with the frost resistance. Finally, the microstructure of concrete with different mix ratio and admixture is analyzed to explore the influence of pore structure on the permeability of concrete. It is found that the pore content of concrete increases with the increase of fly ash, and the pore structure in concrete can be improved by fly ash. The more pore pore size in concrete is transferred to the harmless pore, the better the correlation between concrete porosity and chloride migration coefficient (DRCM) is. The chloride ion migration coefficient (DRCM) of concrete increases with the increase of porosity.
【學位授予單位】：安徽建筑大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU528

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本文編號：1627538