【摘要】：隨著水資源的持續(xù)開發(fā),近年來納入規(guī)劃的172項重大水利工程主要集中于中西部地區(qū),并逐漸往水資源豐富的西部高海拔、寒冷地區(qū)轉(zhuǎn)移。該地區(qū)水工建筑物通常面臨更為復(fù)雜和苛刻的服役環(huán)境(如海拔高、溫差大、紫外線輻照強、凍融循環(huán)頻繁等),其中凍融和紫外輻照是造成水工混凝土結(jié)構(gòu)損傷劣化的最具代表性的影響因素。因此,開發(fā)出防水、耐候性佳且高效持久的水工混凝土表面防護涂層,使混凝土結(jié)構(gòu)免受或減緩環(huán)境因子侵蝕作用,將有助于提高西部高海拔地區(qū)水工建筑物耐久性和安全性,提升我國水利工程建設(shè)質(zhì)量和運行維護水平。氟碳涂層由于具有優(yōu)異的低表面能特性、耐介質(zhì)腐蝕性能和耐候性等優(yōu)點,已成為表面防護的有效手段之一。然而,此類涂層用于水工混凝土表面防護時,尚面臨粘結(jié)性能不足、表界面耐久性有限等技術(shù)難題,限制了其大規(guī)模使用。本文通過在低表面能氟碳涂層中引入納米材料,制備兼具優(yōu)異表面疏水性能和粘接性能的氟碳納米復(fù)合涂層。通過分析涂層組成和涂覆工藝對表界面性能的影響,研制了由“氟碳/納米SiO2底涂+氟硅烷面涂”組成的氟碳納米復(fù)合涂層雙涂層體系,即首先將自制的室溫固化型氟碳/納米二氧化硅復(fù)合涂層涂覆于水泥砂漿表面,待其表干后涂覆全氟辛基三乙氧基硅烷。通過紫外老化試驗、凍融循環(huán)試驗、凍融-紫外交替循環(huán)試驗以及耐水性試驗,并采用傅里葉變換紅外光譜、掃描電鏡、接觸角測試、拉拔試驗等測試手段研究了涂層材料本身和涂層/砂漿體系的耐久性。結(jié)果顯示,納米SiO2的引入能夠改善涂層/砂漿試件的耐紫外老化性能、抗凍融循環(huán)性能和抗凍融-紫外交替循環(huán)性能;當(dāng)納米SiO2粒子含量為10%時,涂層/砂漿表面耐久性最佳,界面粘接耐久性能保持良好。結(jié)合傅里葉變換紅外光譜、掃描電鏡等微觀表征結(jié)果以及耐久性研究結(jié)果,初步分析了涂層本體和涂層/砂漿體系的老化規(guī)律和機理。涂層本體老化的主因是光老化過程中,氟碳中的酯鍵易發(fā)生斷裂,導(dǎo)致耐紫外老化性能下降;涂層/砂漿界面老化過程中,長時間的紫外輻照使得涂層容易發(fā)生交聯(lián)反應(yīng),致使涂層分子與砂漿基體之間的結(jié)合更加緊密,但紫外老化達到一定時間后,持續(xù)的紫外高溫照射使得涂層與砂漿界面的相容性變差,導(dǎo)致涂層與砂漿之間的結(jié)合強度有所下降。
[Abstract]:With the sustainable development of water resources, 172 major water conservancy projects which have been included in the planning in recent years are mainly concentrated in the central and western regions, and gradually transferred to the high altitude and cold regions of the western regions with abundant water resources. Hydraulic structures in the area generally face more complex and demanding service environments (such as high altitude, large temperature differences, strong ultraviolet radiation, Among them, freeze-thaw and ultraviolet irradiation are the most representative factors that cause damage and deterioration of hydraulic concrete structure. Therefore, the development of waterproof, weatherproof and efficient and durable surface protection coating of hydraulic concrete, which can protect concrete structure from or slow down the erosion of environmental factors, will help to improve the durability and safety of hydraulic structures at high altitude in western China. We will improve the quality of water conservancy construction and the level of operation and maintenance in China. Fluorocarbon coating has become one of the effective methods of surface protection because of its excellent low surface energy properties, corrosion resistance and weathering resistance. However, when this kind of coating is used for surface protection of hydraulic concrete, it still faces some technical problems, such as insufficient bond property and limited durability of surface interface, which limits its large-scale application. In this paper, fluorocarbon nanocomposite coatings with excellent surface hydrophobic and adhesive properties were prepared by introducing nano-materials into low surface energy fluorocarbon coatings. By analyzing the influence of coating composition and coating process on the surface interface properties, a fluorocarbon nanocomposite coating double coating system composed of fluorocarbon / nano Sio 2 coated fluorosilane surface was developed. The self-made room temperature curing fluorocarbon / nano-silica composite coating was first coated on the surface of cement mortar, and then perfluorooctyl triethoxy silane was coated on the surface of cement mortar. Through ultraviolet aging test, freeze-thaw cycle test, freeze-thawing-ultraviolet alternate cycle test and water resistance test, Fourier transform infrared spectroscopy, scanning electron microscope, contact angle test, The durability of coating material and coating / mortar system was studied by drawing test. The results show that the introduction of nano-SiO _ 2 can improve the UV aging resistance, freeze-thaw resistance and anti-freeze-thaw alternate cycle performance of the coating / mortar, and the surface durability of the coating / mortar is the best when the content of nano-SiO _ 2 particles is 10. Interfacial adhesion durability is maintained. The aging law and mechanism of coating body and coating / mortar system were preliminarily analyzed by means of Fourier transform infrared spectroscopy, scanning electron microscope and other microscopic characterization results as well as the results of durability study. The main reason of coating body aging is that the ester bond in fluorocarbon is easy to break, which leads to the deterioration of UV aging resistance, and during the aging of coating / mortar interface, the coating is easily crosslinked by ultraviolet irradiation for a long time. The bonding between coating molecules and mortar matrix is closer, but after UV aging reaches a certain time, the compatibility between coating and mortar interface becomes worse by continuous ultraviolet high temperature irradiation. The bonding strength between the coating and mortar decreases.
【學(xué)位授予單位】：長江科學(xué)院
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TV431

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