Flexural Strengthening for Busy Bridge with RenewWrap

Nov. 2, 2022
Busy bridge found with spalling concrete rehabilitated with GeoTree RenewWrap FRP

Project Overview

Engineers from the Louisiana Department of Transportation (LADOT) identified a bridge that required flexural strengthening and repair of spalling concrete on the underside. The busy bridge is raised and lowered around 800 times a month so they needed to find a repair solution which would cause the least disruption to the bridge’s operation as possible.


LADOT called on contractor C.E.C. to complete the repairs to the bridge, who in turn recommended the application of GeoTree’s RenewWrap CFRP system. Having previous experience using RenewWrap repair products, C.E.C knew it would be the ideal solution to repair the damage due to its high strength, ease of use, and the support provided by GeoTree. C.E.C. called on Durable Piling Restoration to carry out the install.

A 4-person installation team from Durable Piling Restoration was deployed to the site, and the application was observed by two LADOT representatives and one GeoTree product specialist. Taking three days to complete the work, the longest part of the repair involved the removal of spalling concrete. The largest area of spalling was of a 2ft by 2ft section of concrete which was crumbling and falling away. This portion was chipped away until all loose concrete was removed, a repair mortar was then used to patch the resulting hole.

Bugholes in the concrete were repaired with GeoTree’s EZ Paste repair putty and the RenewWrap material was then installed over this repair covering 18, 16ft-long spans using RenewWrap CF335 1x24”. Due to the large section being repaired, a dry lay-up technique was used. This involved a layer of resin being applied to the substrate at all locations where fabric was going to be installed. After approximately 15 minutes, once the resin was tacky, the dry fabric was rolled out onto the resin with a further layer of resin then coated onto the hung fabric.

The installation team faced the challenge of having to fit the RenewWrap product to the underside of the bridge in a cramped, overhead, and above water situation which was complicated by the rising and lowering tides. To manage variable elements, the repair was conducted from a boat anchored to the riverbed under the bridge.

GeoTree’s President John Hepfinger said: “GeoTree’s RenewWrap was definitely the ideal solution to this issue. The product is fast and easy to install and can be fit under the most challenging of conditions by experienced installers. LADOT can now have peace of mind that the bridge is safe and secure and will be for many years to come.”