【作者】 潘赏；

【导师】 姜志国；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2010， 硕士

【摘要】 高速铁路是现代化科学技术成就的总体表现,是铁路进入现代化的重要标志,且已经成为了许多国家客运发展的共同趋势。高速铁路桥梁大多采用的是钢筋混凝土结构,在使用过程中,受到以下外界因素的影响,例如车辆高频冲击震动、温度和气候变化引起膨胀收缩等,使得钢筋混凝土桥梁表面产生许多裂纹,随着外界水分和二氧化碳的侵入,将引起混凝土强度下降、钢筋锈蚀、混凝土断裂等严重问题,影响桥梁的使用寿命,威胁运行安全,增加运营维护成本。虽然在设计和施工上采用了多种混凝土防护措施,但不能从根本解决问题。从工程实践看,桥面上喷上一层防水涂料,是解决上述问题的可行办法。按照中国《综合交通网中长期发展规划》的要求,已经规划了“四横四纵”等客运专线以及人口稠密和经济发达地区的城际客运系统,预计到2020年会有1.6万公里的高速客运专线建成投产。并且防水层的面积可达到1亿多平方米,这就会给防水行业带来了巨大市场。按设计要求,中国高速铁路桥梁具有以下要求：列车运行速度250km／h-300 km／h,使用寿命100年。在高速铁路桥梁中,防水层处于特殊的位置,对新的防水层材料提出了更高的要求,表现为材料强度高、伸长大、耐老化、耐酸碱、耐日晒和耐撕裂等性能指标。现有国家标准的防水材料不能满足设计要求,研究高性能的专用防水涂料已成为铁路建设迫切解决的问题。铁路桥梁防水是一个系统防水工程,不仅关系到不同部位和不同产品,而且与桥面施工的相关工序和相关部件有关。涉及到的防水产品有桥面防水涂料层、梁端伸缩缝、排水坡落水口等构件；相关工序有桥面六面坡层、滑动层、轨道板、扣件总成等。桥梁防水存在的主要问题是：1.防水层与混凝土基层浸润性差,与混凝土脱层严重；2.防水层强度低,在后续工序碾压下破坏损害；3.运营中,梁端伸缩缝脱落达严重。为了解决以上问题,本课题研制出了高铁桥梁用的防水体系系列产品,包括高性能聚氨酯防水材料、低模量高伸长聚氨酯伸缩缝和混凝土界面处理剂,分别用于桥面、梁端和混凝土表面。应用粘弹性理论,论文设计了全新的聚氨酯弹性分子结构,研究了原材料、合成工艺对材料性能的影响,制备了二中种聚氨酯新材料,形成了三种新防水产品,达到了铁道部相关产品技术规范的要求,通过了中试和现场使用评价,取得了良好的效果。更多还原

【Abstract】 High-speed railway which has developed in many countries is the result of achievements owning to modern science and technology, and also is an important symbol of railway modernization. More and more countries have chosen it as the most important way of passenger transport. In order to protect bridges made of reinforced concrete used in the railway from corrosion, a variety of measures have been taken. Duing to the high frequency impact vibration of vehicles, expansion-shrinkage caused by all kinds of climate fators, defects are inevitable. With external water entering the cracks appearing on the surfaces of bridges, a lot of problems need solving such as strength degradation and frature of reinforced concrete and reinforcement corrosion. It is high time that meaurses be taken to prolonge service life, keep running safe and reduce operation maintenance cost. Spraying waterproof material on the serface of the bridge deck is a better way according to engineering practice than thickening concrete during the design and construction.According to the layout of Chinese government, passenger dedicated lines named "four vertical and four horizontals" and intercity passenger travel system in the densely populated area have been planed.16,000 km high-speed passenger line will be put into operation in 2020 as planed. The area of waterproof layer can reach over 100 million square meters and a huge market will appear.The designed life of the high-speed railway is as long as 100 yuears. On the purpose of ensuring safety and durability of the high-speed railway the speed of which is as high as 250 km/h-300 km/h, waterproof layer is very important.Therefore, a kind of dedicated high-performance coating used in waterproof is needed urgently. It should satisfy all kinds of standards such as high strength, high elongation,aging resistance,acid and alkali resistance, light fastness and high tear strength.Bridge waterproof is a system engineering which is not only related to different positions and products, but also related to construction procedures and different components. Waterproof products involve deck waterproof coating, beam-end expansion joint, drainage slope inlet and so on.Related operations include installing bridge deck with six-face slope layer, sliding layer, rail plate and fastener.The difficulties of bridge waterproof mostly involve: 1. Because wettability between waterproof layer and concrete base is low, abscission is common.2. The strength of waterproof layer is not high enough to afford the rolling of follow-up process.3. The waterproof material in expansion joint comes off easilyThe subject aims to develop a series of products about waterproof system used in high-speed railway bridges, including polyurethane waterproof material used on bridge decks, polyurethane expansion joint filler with low modulus and high elongation used on beam-end and surface treatment agent of concrete. With the use of viscoelastic theory, a novel elastic molecular structure of polyurethane is designed,and the affects of raw material and synthesis technologis are also studied. Two new kinds of polyurethane material and three new sorts of products are got which have satisfied related standards of Ministry of Railway and also experienced pilot test and field applications.更多还原