手机版

道路路桥工程毕业论文中英文资料外文翻译文献(3)

发布时间:2021-06-06   来源:未知    
字号:

中英文资料of a pavement failure and which is to be avoided if possible

. Compressive deformation of the pavement results in a dimensional change in the pavement, and with this change come a loss of resiliency and usually a degree of roughness. This deformation is less serious than the one just described, but it, too, leads to pavement failure. The desirable type of deformation is an elastic one, which actually is beneficial to flexible pavements and is necessary to their long life. The pavement should be durable and should offer protection to the subgrade. Asphalt cement is not impervious to the effects of weathering, and so the design must minimize weather susceptibility. A durable pavement that does not crack or ravel will probably also protect the roadbed. It must be remembered that flexible pavements transmit loads to the subgrade without significant bridging action, and so a dry firm base is absolutely essential. Rapidly moving vehicles depend on the tire-pavement friction factor for control and safety. The texture of the pavement surfaces must be such that an adequate skid resistance is developed or unsafe conditions result. The design procedure should be used to select the asphalt material and aggregates combination which provides a skid resistant roadway. Design procedures which yield paving mixtures embodying all these properties are not available. Sound pavements are constructed where materials and methods are selected by using time-tested tests and specifications and engineering judgments along with a so-called design method. The final requirement for any pavement is one of economy. Economy, again, cannot be measured directly, since true economy only begins with construction cost and is not fully determinable until the full useful life of the pavement has been recorded. If, however, the requirements for a stable, durable, and safe pavement are met with a reasonable safety factor, then the best interests of economy have probably been served as well. With these requirements in mind, the functions of the constituent parts can be examined with consideration give to how each part contributes to now-established objectives or requirements. The functions of the aggregates is to carry the load imposed on the pavement, and this is accomplished by frictional resistance and interlocking between the individual pieces of aggregates. The carrying capacity of the asphalt pavement is, then, related to the surface texture (particularly that of the fine aggregate) and the density, or “compactness,”, of the aggregates. Surface texture varies with different aggregates, and while a rough surface第 3 页 共 12 页

道路路桥工程毕业论文中英文资料外文翻译文献(3).doc 将本文的Word文档下载到电脑,方便复制、编辑、收藏和打印
×
二维码
× 游客快捷下载通道(下载后可以自由复制和排版)
VIP包月下载
特价:29 元/月 原价:99元
低至 0.3 元/份 每月下载150
全站内容免费自由复制
VIP包月下载
特价:29 元/月 原价:99元
低至 0.3 元/份 每月下载150
全站内容免费自由复制
注:下载文档有可能出现无法下载或内容有问题,请联系客服协助您处理。
× 常见问题(客服时间:周一到周五 9:30-18:00)