刚性路面路肩设毕业论文文献翻译.docVIP

外文资料 DESIGN OF RIGID PAVEMENT SHOULDERS Most of the information presented in Section 11 .4 on the design of flexible pavement shoulders is also applicable to the design of rigid pavement shoulders . Some of the features of rigid pavement shoulders that are different from those of flexible pavemen t shoulders are presented here . PCC shoulders have been used in urban expressways for many years, but their use on rural highways began only in the mid 1960s . The good performance of thes epavements has made it the standard practice of many agencies to utilize PCC shoulders for rigid pavements . Advantages of Tied Concrete Shoulders Concrete shoulders must be tied to the mainline concrete pavements. The advantages of tied concrete shoulders are as follows : 1. The placement of a tied concrete shoulder next to the mainline pavement can substantially increase the load-carrying capacity of the pavement . The tied concrete shoulder provides support to the edge of the pavement and reduces stresses and deflections in the mainline slab . The shoulder is also benefited by receivin gsupport from the mainline slab, so the damage due to encroaching traffic can be greatly reduced . 2. A tied longitudinal joint between mainline and shoulder pavements can be easily sealed to reduce the amount of surface runoff infiltrating into the pavemen tstructure . Field studies conducted in Georgia and Illinois showed that sealing the longitudinal joint greatly reduced the amount of inflow from rainfall into the pavement structure (Dempsey et al., 1982). 3. Pumping beneath the mainline slab is reduced through the reduction of edge an d corner deflections, the reduction of water infiltration through the longitudinal joint, and the draining of water far away from the traffic lane . 4. Tied concrete shoulders can reduce differential movements at the longitudinal shoulder joint and do not experience the lane/shoulder dropoff type of distress that occurs so frequently in flexible shoulders . Types of