Vector Corrosion Services – Post Tension Impregnation Rawcliffe Bridge
Vector provided material, equipment and technical services to impregnate post-tensioned tendons on the Rawcliffe Bridge over Dutch River in Yorkshire. The work was completed over 5 weeks with support from the main contractor.
Bonded post-tensioned cables can experience corrosion and reduced durability when grouting problems such as voids or defective grout are present. The Post-Tech Tendon Impregnation approach utilizes the interstitial spaces between the individual wires to transport corrosion inhibiting material along a length of the tendon which is then available to impregnate into the surrounding grout or concrete. The impregnation material is intended to reduce on-going corrosion and to mitigate the initiation of corrosion activity. The mechanism of protection includes impregnation / waterproofing of the grout around the cables to create a corrosion resistant environment around the cables as well as creating a corrosion resistant film on exposed steel surfaces such as sections of tendons which pass through voids in the grout.
On this project the PT tendons were located using a combination of methods including GPR, exploratory drilling and photos from previous inspections.