Case Study - Spray Injection Patching

Spray Injection Patching is a patching solution which has been around for a number of years. Generally used in rural locations, this latest package of works shows the flexibility of the process and how it can be used in a variety of locations if managed well. This system offers an economical alternative to conventional solutions.

 

What we did

 

North Yorkshire’s inspectors routinely identify carriageway defects, that require reactive maintenance. The inspections generally take place at six monthly intervals. On completing the repairs, it was clear to the onsite team that there were further defects that had not been present or had worsened since the inspections. In this instance the threshold was defects with a depth greater than 40mm. With a large number of defects recorded the client were looking for a reactive process that could quickly and effectively remove these safety critical defects. Following discussion with the local inspector and the client it was agreed that any defect found to meet the intervention criteria should be repaired while the team were on site, removing the costly exercise of returning to the site a second time, to complete additional repairs.

 

 

This initial programme of works took place around Harrogate town centre and the surrounding suburbs and although this was challenging due to the traffic volumes and parked cars, the flexibility of the process meant the team could keep moving and manage the programme to suit the individual site requirements without work coming to a standstill.

 

Results

 

EST prides itself on attention to detail, this was evident throughout this package of works. The crew ensured that Kerbs were protected from over spray, all patches were compacted to tie in the material and prevent early life aggregate shedding, all loose materials were swept and removed before the crew opened the sites to traffic. The end result was a repair that not only offered the best chance of longevity but was also pleasing to the eye.

The works were completed over a period of 31 days. The crew visited 73 locations and repaired 725 defects, a total of 1611.97 m2. This equates to an average of 52 m2 per day. Indications from our Ringway Colleagues show that a general maintenance gang would average 16m2 per day on similar work.

 

 

When taking into account all costs of the recent programme delivered including traffic management, against the predicted costs of a general maintenance gang completing the same work. The spray injection patching system demonstrated a financial saving of 48% and a time saving of 69%.