EXTENDING THE SERVICE LIFE OF A REINFORCED CONCRETE RAILROAD BRIDGE
Two railroad bridges in the Midwest US were showing signs of chloride-included corrosion and becoming a local eye-sore and a safety concern.
The columns were heavily chloride-contaminated from years of de-icing chemical exposure and suffering from extensive concrete cracking, spalling and delamination. In addition to shotcrete repairs and epoxy injection crack repairs of the abutments, the columns were repaired and protected by Vector Construction’s Cedar Rapids, Iowa office using Octaform’s ColumnArmor™.
Project Partners
- Vector Corrosion Technologies
As part of the concrete preservation process, an evaluation consisting of a combination of non-destructive and destructive testing was conducted to determine the condition of the structures, including corrosion potentials, chloride profile and cover depth as determined by ground penetrating radar. Together, this information revealed that significant chloride concentrations existed at the level of the reinforcing steel and that corrosion was active throughout the columns.
The deteriorated concrete was first removed and the rebar cleaned of corrosion byproducts. Then, galvanic anode strips were distributed around the column and connected to the existing reinforcing steel. Once the anodes are secured to the existing concrete structure, the ColumnArmor™ PVC forms are fitted around the columns and filled with concrete.
Octaform Advantages
Cost Savings
Octaform’s solution provided decreased total costs compared to traditional methods involving concrete and polyurethane applied membrane coatings. This cost efficiency was instrumental in keeping the project within budget.
Construction Effieciency
Octaform’s system significantly reduced construction time and labor requirements. The ease of installation contributed to a streamlined construction process, saving valuable time and resources.
Built-In Insulation
Octaform’s system incorporated insulation directly into the structure. This ensured optimal thermal performance, with the thermal mass of concrete on the interior of the structure and insulation on the exterior, reducing operating costs.
Simplified Maintenance
The durability of Octaform’s tank interior was a crucial factor. The system resists corrosion and requires no mid-life servicing or re-coating, further reducing long-term maintenance costs.
Corrosion Resistance
Octaform’s PVC stay-in-place forming system offered superior corrosion resistance compared to traditional concrete and membrane systems. This durability ensures a longer service life for the infrastructure.
Outcomes
Aside from the dramatic aesthetic improvement, the rehabilitated structure will have decades of galvanic protection to allow the bridges to remain in service for decades to come, a significant improvement over regular concrete repairs that do not address the fundamental problem, corrosion.
Vector Corrosion Technologies
Vector Corrosion Technologies is a leading full-service supplier of corrosion mitigation products and services for reinforced concrete and masonry structures including bridges, parking garages, buildings, marine structures, and industrial facilities.
