预应力混凝土的广泛应用外文翻译(编辑修改稿)

预应力混凝土的广泛应用外文翻译(编辑修改稿)内容摘要：

elopment, horizontal cracks are internal (priestesses reinforced, section And concrete strength) and external factors (loading and sleeper boundary conditions) caused by a bination. 2. cracks in the concrete sleeper durability of the structure (1) sleeper in the openair environment, because of dense concrete, water, gas will not infiltrate into the internal, but cracks in to a certain width and depth of cracks at the 西南交通 大学本科 毕业设计 第 4 页 protection layer, water, gas will reach the peration along the cracks gradually reinforced , Caused steel corrosion and rust, rust is a pound of iron (iron oxide), four times its volume expansion in the concrete caused internal stress, leading to further cracking concrete, reinforced and priestesses concrete and Bonding of lower Thus affecting the sleeper of the carrying capacity. (2) Study shows that only cracks in the concrete structure of a certain width, water, gas can be infiltrated, from steel corrosion. Domestic and international norms, reinforced concrete structure to allow the crack width of ~ (depending on the media environment), priestesses concrete structure does not allow even a crack, its purpose is to ensure that no reinforcement corrosion. However, many times at home and abroad for the investigation and trial, and that crack width and not directly related to steel corrosion. (3) Research also shows that the vertical cracks on the durability of the general structure than the horizontal cracks serious. Reinforced concrete structures due to the longitudinal cracks will cause the steel corrosion protection layer peeling off。 cracking concrete expansion will cause osteoporosis, swap block. The author had been taken from different routes 16, with a different state of the sleeper Split 11, the normal sleeper 5, casebytrack roots are cracking under section static strength and fatigue strength test. Table 3 from the test results can be seen: ① through cracks in the sleeper, most of the rail section under static load cracking strength obviously lower。 ② end of the fracture or cracking of the sleeper, static cracking strength And fatigue, pared with the normal sleeper, in general there was no significant difference. This shows that the end of the rail fracture and multiple cracks from the surface, not to influence the development of concrete and steel of the Bonding. 3. concrete sleeper cracks in the prevention and control Sleeper as a priestess’s concrete structure, in order to pletely eliminate cracks is very difficult to do. After all, but the crack is harmful. For this reason, every effort should be made to prevent the emergence of crack. Prevention and control of cracks, you can start with a threepronged: 西南交通 大学本科 毕业设计 第 5 页 First, from the mechanical point of view, in order to prevent horizontal cracks, except in accordance with the greatest possible load, the rational allocation of priestesses reinforced, we must also strengthen the end of the stirrups and the spiral reinforcement clip bolt whole configuration. In addition, to strengthen the conservation line maintenance so that the sleeper is in a good state support under the track and prevent the sleeper pillow horizontal cracks appeared in the major conditions. Stirrups and spiral reinforcement of the settings and prevent sleeper End and central fracture cracks and nail holes, but not the overall stirru。