1、 二 一 四 届毕业设计 外 文 翻 译 学 院： 工程机械学院 专 业： 工程机械 姓 名： 学 号： 指导教师： 完成时间： 2014 年 3 月 28 日 1 Recommendations for Paving / Points to Note 1.1 Basic Principles Before starting work, the minimum and maximum pave widths should be established and the paver be set up accordingly. The paving sequence should be co-or
2、dinated with the other teams on site in order to assure the supply of material and prevent the hot mix being driven over too soon. The feed vehicles must be organized in such a way as to ensure a continuous supply of mix with as few paver stops as possible. Check with the mixing plant(s) to ensure t
3、hat mix will be supplied as planned. Check serviceability of the road paver (filling levels, electrical and hydraulic functions, etc.). The feed vehicles tarpaulin cover should only be removed just before dumping the hot mix in order to prevent it cooling. The pave speed should be as constant as pos
4、sible. If mix can only be supplied to a limited extent, it is better to continue paving slowly and uniformly than to interrupt the process by paver stops. In the event of prolonged disruptions in the supply of mix and in cool weather, it is advisable to use up the entire mix stored in the paver and
5、then to lift up and clean the screed. The screed can be re-lowered and the work continued when the supply of mix is resumed. The composition and temperature of the mix should be checked regularly. The layer thickness should be checked regularly while paving in order to avoid errors. When using Autom
6、ated Grade and Slope Control, the sensors must be checked to ensure that they are operating correctly. Paving by hand should only be done in exceptional cases, such as on small surfaces or in corners inaccessible to the paver. The rollers used for subsequent compaction must be dimensioned in accorda
7、nce with the mix (compactability), paved area in square metres, temperature of the mix, surroundings and base so that roller compaction is completed before the mix has cooled. The pavement should only be re-opened to traffic when the temperature of the mix has dropped below 40 C in order to prevent
8、any risk of deformation. The pave speed should be kept constant throughout the paving job, if possible. At the end of the day or between paving sessions, a transverse joint is to be installed. Adjustments on the screed while paving should be kept to a minimum. The pavers material hopper should not b
9、e run empty (to avoid segregation). If no kerbstones are installed, wearing course should always be paved with the screed in Screed Float mode. Do not use Automated Grade and Slope Control. 2 Imperfect Paving 2.1 Paving Problems /Paving Errors 2.1.1 Irregularities when Passing Over Mix Fault/Cause U
10、nless compensated by movement of the tow point rams, mix which has spilled into the area of the wheels or crawler tracks will lead to a change in the screed planing angle when passed over and cause irregularities to appear in the pavement. Remedy - Avoid spilling mix in the area of the wheels or cra
11、wler tracks and remove any mix which has spilled. - For tracked pavers, fit baffle plates in front of crawler tracks. 2.1.2 Pavement Irregularities due to Large Screed Planing Angle Fault/Cause When paving mix of poor bearing capacity (e.g. base course), the screed adopts a too large planing angle w
12、hile paving to reach the specified layer thickness. A too large screed planing angle promotes irregularities in the pavement. Remedy - Use the Screed Assist function. - Set a low, constant pressure. - Increase tamper speed and reduce the pave speed. - Increase the tamper stroke length. Recommendation The Screed Assist function shall not be used when paving wearing course. 2.1.2 Buldge Formed when Resuming Paving
