【作者】 何波玲；

【导师】 郑秀华；

【作者基本信息】 哈尔滨工业大学 ， 材料学， 2010， 硕士

【摘要】 我国的土木工程建设发展迅猛,在新建工程项目不断增加的同时,对现有结构的修复加固已引起工程界的广泛重视。由于各种原因所引起的建筑结构失效和功能失效,不仅影响了人们的正常生活,而且造成了巨大的经济损失。为此,研制适合混凝土表面修补加固的新型材料,延长建筑物的使用寿命,减少维修成本具有重要的意义。本文将研究的聚丙烯腈纤维聚合物水泥砂浆是一种具有抗折强度高、粘结强度高和收缩小的高性能复合砂浆,是一种新型高性能修补加固材料。本文研究聚合物胶粉和聚丙烯腈纤维对砂浆和易性及物理力学性能的影响,选择了合适的胶粉品种,确定胶粉及纤维的适宜掺量。在此基础上,进一步研究了纤维聚合物水泥砂浆的粘结性能、干缩性能和抗冻性能,并对其机理进行了分析。研究表明,聚合物胶粉提高了砂浆抗折强度,砂浆的柔韧性变好,但抗压强度降低。其中胶粉P1改善的作用效果更好,其合适掺量在1.0%-1.5%。在聚合物砂浆中加入聚丙烯腈纤维,可进一步改善新拌砂浆的施工和易性,随纤维掺量的增加保水性更好,无泌水现象。在适宜掺量范围内,聚丙烯腈纤维可以提高聚合物砂浆的抗折强度及柔韧性,但对抗压强度影响不大。当胶粉掺量为1.0%、1.5%,聚丙烯腈纤维掺量为0.8%、1.0%时,纤维聚合物水泥砂浆的综合物理性能最佳。聚合物胶粉能提高砂浆的拉伸粘结强度,胶粉掺量在1.0%-2.0%比较合适,可以明显提高其粘结强度；复掺聚合物胶粉和聚丙烯腈纤维,砂浆的粘结性能更好,随着纤维掺量增加,粘结强度增大。聚合物胶粉和聚丙烯腈纤维可减小砂浆的干缩率和提高砂浆的抗冻性能,相对于普通砂浆,聚合物砂浆和纤维聚合物砂浆的干缩率分别降低了16.7%,25.1%。经过30次冻融循环后,普通砂浆的抗折强度损失了28.9%,单掺聚合物胶粉1.5%,抗折强度损失了12.8%；双掺聚合物胶粉和聚丙烯腈纤维时,抗折强度只损失了7.8%-10.1%。更多还原

【Abstract】 As the construction of civil engineering is developing rapidly in China, new construction projects increase. At the same time, repairing and reinforcing the structure existed has aroused great attention from the engineering sector. The structural failure and function loss caused by various reasons not only affect people’s normal life, but also bring enormous economic losses. Therefore, developing new materials suitable for surface repairing and strengthening of concrete, extending the service life of buildings and reducing the maintenance cost are significant. The cement-mortar of polyacrylonitrile (PAN) fiber polymer studied in this paper is a high-performance composite mortar with high flexural strength, high adhesive strength and small contraction. It is also a new repairing and strengthening material with high performance.The influences, from polymer gelatine powder and PAN fiber, on workability and physical mechanical properties of mortar were studied in this paper. Appropriate dosage of PAN fiber and gelatine powder selected properly was confirmed. Based on this, further study on adhesive property, dry-shrinkage performance and frost resistance of fiber polymer cement-mortar were taken and related mechanisms were analyzed.The results showed that the polymer gelatine powder could increase the flexural strength of mortar, improve the flexibility but decrease the compressive strength of mortar. P1 improved with a better effect and its appropriate dosage was between 1.0% and 1.5%. Adding PAN fiber to the polymer mortar could make a further improvement to the construction workability of the fresh mixed mortar. In addition, the water holding capacity became better when the fiber dosage increased, with no bleeding phenomenon. When the dosage was at a suitable range, PAN fiber could improve the flexural strength and flexibility of the polymer mortar, but had little effect to the compressive strength. When the dosage of gelatine powder was between 1.0% and 1.5%, the dosage of PAN fiber was between 0.8% and 1.0%, the fiber polymer cement-mortar had the best comprehensive performance. Polymer gelatine powder could also improve the tensile adhesive strength of mortar and obviously improved when its dosage was between 1.0% and 2.0%. Compound doped the polymer gelatine powder and PAN fiber, the adhesive property of mortar became better. Besides, the adhesive strength improved as the dosage of fiber increased. Polymer gelatine powder and PAN fiber could also reduce the dry-shrinkage rate and improve the frost resistance of mortar. The dry-shrinkage rate reduced by 16.7% of the polymer mortar while 25.1% of the fiber polymer mortar, compared with ordinary mortar. After 30 freeze-thaw cycles, the flexural strength lost 28.9% of ordinary mortar,12.8% of mortar single-doped polymer gelatine powder with 1.5% dosage, while just 7.8%-10.1% of mortar double-doped polymer gelatine powder and PAN fiber.更多还原