621600 - Western IC entry slip road pavement - construction phase support

Description

A63 Western IC EB Entry Slip Road - 2000A63/443 (0.755km long) This is a single lane slip road which leads off the A15 SB. Records indicate this slip road was resurfaced in 2016 with some previous deeper targeted inlays completed in 2008. The current defects include surface course deterioration, joint deterioration and cracking. Some defects are present in the local authority owned section, 10m prior to the start of the slip road - the scheme has been extended to incorporate these defects. There are currently no concerns with regards to texture however, between Ch.0m and 150m SCRIM is as low as -.005. There are two isolated areas of rutting at 11.5mm and TSD Cat 3 has been recorded between Ch.0m and 150m. Deflectograph data is not currently available. Wholescale inlays of 90mm deep are proposed for the entire length of the slip road. This approach acknowledges the core findings and Cat 3 TSD readings however, there are no significant structural failures and this depth is deemed appropriate given the visual defects. The only other option would be to go much deeper (full depth reconstruction) and the low traffic figures and type of defects do not justify this. The chevron area between the slip road and mainline is to be resurfaced. The existing drainage channels are to be replaced as they are life-expired and difficult to maintain. It should be noted that slot drainage now requires a departure from standards, refer to Appendix G for alternative drainage system to be used. Additional information/survey data to be passed onto the Detail Designer as soon as it becomes available. The full extents of the slip road should be renewed - extend into lane 1 (full width) if necessary to ensure the narrow end is fully renewed. There are no structures affected by this scheme. Loops have not been identified within the scheme extent