混凝土裂缝修补用长效抗冻融环氧树脂开发研究

发布时间：2018-04-25 02:14

本文选题：环氧树脂 + 抗冻融性能　；参考：《兰州交通大学》2013年硕士论文

【摘要】：在高寒高原地区，尤其是受自然因素(低温、昼夜温差大、干湿循环、冻融循环、盐碱腐蚀和风蚀等)变化影响较大的中国东北、西北和华北地区，基本上100%的混凝土结构工程，局部或大面积的都遭受了不同程度的冻融破坏，甚至有些工程在施工过程中或者施工后不久就遭受了严重的冻融破坏，这严重影响了混凝土结构的耐久性。因此，采用适当的材料和技术对混凝土结构裂缝进行修补来保证其耐久性是非常重要的。近年来，环氧树脂修补材料已成为混凝土裂缝修补的一种不可或缺的材料。但是，环氧树脂低的抗冲击性能、韧性和抗开裂性能限制了其实际应用。本文通过在环氧树脂引入一些增强和增韧成分对环氧树脂进行改性，以期研制高性能的环氧树脂修补材料来应对高寒高原地区由于风蚀和冻融等因素引起混凝土开裂问题。本文分别以丁腈橡胶、沥青、糠醛/丙酮和聚氨酯接枝改性的NH2-nano-SiO_2粒子来增韧环氧树脂以研制高性能改性环氧树脂修补材料。通过配方设计和实验研究，，对各种修补材料试样的基本力学性能、抗冻融性能、耐水性和耐化学品特性进行了考察和评价，最终筛选出性能较优的修补材料配方及工艺。 (1)丁腈改性环氧树脂/LB-B1体系：当LB-B1固化剂、丁腈橡胶、活性稀释剂和硅灰石填料分别为20phr、10phr、5phr和100phr时，修补材料的综合性能最好，而且随着冻融循环次数的增加，其性能随之增加。 (2)丁腈改性环氧树脂/F固化剂体系：当E-44环氧树脂、F固化剂、丁腈橡胶和KH-550分别为100phr、11phr、5phr、10phr时，修补材料的综合性能最优。在对该体系性能最优配比修补材料的抗冻融性能、耐水性和耐化学品性能测试过程中发现，材料的综合性能随着冻融循环次数的增加都会慢慢变好。 (3)沥青改性环氧树脂体系。综合对该修补材料的拉伸剪切、抗压、抗冻融、耐水性和耐化学品特性的分析，找到了该修补材料体系性能较优异的配方。当环氧树脂、改性脂肪胺LB-B1和沥青分别为100phr、15phr和10phr时，修补材料的综合性能较好，并且该体系修补材料的抗冻融性能很好。 (4)糠醛/丙酮改性环氧树脂体系。当环氧树脂、聚酰胺/LB-B1、糠醛/丙酮和KH-550的用量分别为100phr、25/25phr、10/10phr和5phr时，环氧树脂修补材料的综合性能最好。并且它是一种韧性很好的修补材料，虽然耐酸性略差，不能经受长期的冻融循环条件，但是仍可用于不太苛刻的使用环境。 (5)聚氨酯/nano-SiO_2改性环氧树脂体系。通过正交试验、实验验证以及对最优性能配比修补材料的增韧分析，得到了改性环氧树脂修补材料的最优性能配比。当环氧树脂、F固化剂、PU预聚体、NH2-nano-SiO_2和KH-550的用量分别为100phr、11phr、10phr、4phr和3phr，修补材料的综合性能较好。并且最优性能配比修补材料的抗压强度，拉伸剪切强度、拉伸强度、抗弯强度和断裂伸长率分别可以达到148.68MPa、23.57MPa、56.08MPa、86.76MPa和36.33%。此外，该修补材料的抗冻融、耐水和耐化学品性能优异。另外，本文通过室内冻融循环实验、FT-IR和SEM方法对增韧和增强剂用量对经受冻融循环和化学品侵蚀的环氧树脂修补材料结构和性能的影响规律进行了研究，并将各修补材料体系的性能与设计要求(拉伸剪切强度、抗压强度、拉伸强度、拉伸模量、抗弯强度和断裂伸长率分别超过14MPa、70MPa、40MPa、2500MPa、50MPa和1.5%)进行对比，发现丁腈改性环氧树脂/LB-B1体系和沥青改性环氧树脂体系修补材料的基本力学性能虽然在早期未能满足设计要求，但其固化时间较短，冻融循环之后力学性能增长显著，最终能达到设计要求；丁腈改性环氧树脂/F固化剂体系、糠醛/丙酮改性环氧树脂体系和聚氨酯/纳米二氧化硅改性环氧树脂体系的各项性能指标都能满足设计要求。在抗冻融性能、耐水和耐化学品特性方面，除了糠醛/丙酮改性环氧树脂体系的抗冻融和耐酸性能略差以外，各体系的抗冻融性能、耐水性和耐化学品特性都很好，这些研究结论为修补材料进一步的优化和高寒高原环境条件下混凝土裂缝的修补提供了理论基础和实践指导。
[Abstract]:In the high and cold plateau area, especially in the northeast of China, northwest and North China, 100% of the concrete structural engineering, local or large area have been damaged by different degrees of freezing and thawing, and even some projects are in the area of natural factors (low temperature, day and night temperature difference, dry and wet cycle, freezing and thawing cycle, salt alkali corrosion and wind erosion). In the course of construction or shortly after construction, serious freezing and thawing damage has been suffered, which seriously affects the durability of concrete structures. Therefore, it is very important to use appropriate materials and techniques to repair the cracks of concrete structures to ensure their durability.
In recent years, epoxy resin mending materials have become an indispensable material for the repair of concrete cracks. However, the low impact resistance, toughness and cracking resistance of epoxy resin have limited its practical application. In this paper, epoxy resin was modified by introducing some reinforcing and toughening components in epoxy resin, in order to develop high performance. The epoxy resin repair material is used to deal with the cracking of concrete due to wind erosion and freeze-thaw.
High performance epoxy resin mending materials were toughened with nitrile rubber, asphalt, furfural / acetone and polyurethane graft modified NH2-nano-SiO_2 particles. The basic mechanical properties, freezing thawing resistance, water resistance and chemical resistance of all kinds of repair materials were made by formula design and experimental study. After investigation and evaluation, the formula and process of better repair materials were selected.
(1) nitrile modified epoxy resin /LB-B1 system: when LB-B1 curing agent, NBR, active diluent and wollastonite filler are 20phr, 10phr, 5phr and 100phr, the comprehensive performance of the mending material is best, and its performance increases with the increase of the number of freezing and thawing cycles.
(2) the /F curing agent system of NBR modified epoxy resin: when E-44 epoxy resin, F curing agent, NBR and KH-550 are 100phr, 11phr, 5phr, 10phr, the comprehensive properties of the mending materials are best. With the increase of freeze-thaw cycles, the performance will gradually improve.
(3) asphalt modified epoxy resin system. Comprehensive analysis of the tensile shear, compression, freezing and thawing, water resistance and chemical resistance of the mending material found the better formula for the repair material system. When epoxy resin, modified aliphatic amine LB-B1 and asphalt are 100phr, 15phr and 10phr, the comprehensive properties of the repair materials are better. Moreover, the system has good freeze-thaw resistance.
(4) the furfural / acetone modified epoxy resin system. When epoxy resin, polyamide /LB-B1, furfural / acetone and KH-550 are used for 100phr, 25/25phr, 10/10phr and 5phr, the epoxy resin mending material has the best comprehensive performance. And it is a kind of good toughness repair material, although the acid resistance is poor, it can not withstand the long-term freeze-thaw cycle strip. But it can still be used in a less harsh environment.
(5) the polyurethane /nano-SiO_2 modified epoxy resin system. The optimum performance ratio of the modified epoxy resin mending material was obtained by orthogonal test, experimental verification and the toughening analysis of the optimal performance mending material. The dosage of epoxy resin, F curing agent, PU prepolymer, NH2-nano-SiO_2 and KH-550 were 100phr, 11phr, 10phr, 4phr, respectively. And 3phr, the comprehensive properties of the mending materials are better. And the optimum properties can be matched to the compressive strength, tensile shear strength, tensile strength, bending strength and elongation at break, respectively, can reach 148.68MPa, 23.57MPa, 56.08MPa, 86.76MPa and 36.33%., and the resistance to freezing and thawing, water resistance and chemical resistance of the mending material are excellent.
In addition, the effects of toughening and reinforcing agent dosage on the structure and properties of epoxy resin mending materials subjected to freeze-thaw cycle and chemical erosion were studied by FT-IR and SEM methods, and the performance and design of the mending materials system (tensile shear strength, compressive strength, tensile strength, tensile strength, and tensile strength) were also studied. The tensile modulus, flexural strength and elongation at break are more than 14MPa, 70MPa, 40MPa, 2500MPa, 50MPa and 1.5%. The basic mechanical properties of the modified epoxy resin /LB-B1 system and the asphalt modified epoxy resin system repair material are not required at the early stage of full foot design, but the curing time is shorter and the freeze-thaw cycle is after the freezing and thawing cycle. The mechanical properties have increased significantly, and the design requirements can be achieved. The properties of the /F curing agent system of nitrile modified epoxy resin, the furfural / acetone epoxy resin system and the polyurethane / nano silica modified epoxy resin system can meet the design requirements. The frost resistance and acid resistance of the aldehyde / acetone modified epoxy resin system are slightly poor, and the freezing thawing properties, water resistance and chemical resistance of each system are very good. These conclusions provide theoretical basis and practical guidance for the further optimization of repair materials and the repair of concrete cracks in the high cold plateau environment.

【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU532;TU581

【参考文献】