Cooling towers at a processing facility had severe damage from corrosion. It was wondered whether structural integrity could be maintained while avoiding the cost of total replacement. Loose concrete was removed with jet blasting, and VpCI®-423 was used to remove heavy rust on rebar. MCI®-2023 was applied immediately to protect cleaned rebar. MCI®-2038 and MCI®-2039 were then used to repair concrete and restore structural integrity. Structurally sound areas that did not require concrete repair were treated with MCI®– 2020 surface applied corrosion inhibitor designed to migrate and protect the steel beneath the concrete. Using this process, the contractor was able to restore the structure’s integrity and aesthetics at a substantial cost savings to the owner.
Keywords: cooling tower restoration, case history spotlight, severe damage from corrosion, cost savings, concrete repair, MCI, SACI, surface applied corrosion inhibitor, VpCI, remove rust
Most of the concrete work was already done when a project in Saudi Arabia hit construction delays. This posed the problem of rusted rebar in concrete, as many rebars on in-fill beams and expansion joints were left exposed in a corrosive environment. Cortec® Middle East recommended treating preexisting rebar corrosion with CorrVerter® MCI® Rust Primer and applying MCI® CorShield® on all other exposed rebar for outdoor corrosion protection. These products provided an economical solution and satisfied the requirements of all involved.
A golf course owner wanted to clean up significant hydrocarbon oil stains on an outdoor concrete pad used to park equipment and machinery. MCI®-2061 concentrate was applied and brushed into the concrete. Water was used to activate microorganisms, and the “green” cleaning product was left overnight to allow biodegradation to occur. Treated areas were rinsed with water the next day. The customer was extremely happy with the results and the fact that MCI®-2061 was so easy to use as an alternative to blast cleaning.
As part of a balcony repair project, a condominium complex in Cincinnati needed overhead patching and caulking followed by a sealer. Cortec® MCI®-2019 was chosen for the latter as a two-in-one Migrating Corrosion Inhibitor™ / water repellent that could be applied in one step. The condominium owner ultimately expressed satisfaction with the application and performance of MCI®-2019 during the project.
To read the full case history, please visit:
In 1999, the Plankinton Avenue parking ramp in downtown Milwaukee was deteriorating and rebar had rusted in the concrete due to deicing salt. The city wanted an economical way to renovate and protect the ramp with minimal downtime while using the best products and procedures on this valuable source of revenue. The renovation contractor applied MCI®-2020 to the concrete decks as an important part of the concrete repair system to extend structural service life and reduce maintenance by forming a corrosion inhibitor barrier on steel reinforcement.
A major power supplier needed high quality repair materials to fix cooling towers that had been damaged by corrosion and contaminated by chlorides and carbonation. Prior to placing repair mortars, MCI®-2020 was sprayed into the area where concrete had spalled. The cavity was then filled in using MCI®-2038 and MCI®-2039. Surrounding areas were treated with MCI®-2020 to fight the ring-anode effect that can accelerate corrosion in concrete adjacent to repairs. In this way, the immediate repair was completed using a proven technology that would have ongoing effects to mitigate future corrosion and concrete damage.
Between October 1994 and October 1995, a unique bridge was under construction in North America. Of special note was the fact that the bridge was privately built and leased to the City of Winnipeg for approximately 20 years. Another special feature was the use of MCI®-2000 corrosion inhibiting admixture in the bridge decking, added to extend the service life of this private investment. MCI®-2020 was applied to sign-support columns aboveground. It was also slated for use in a number of Winnipeg bridges the following year, as provincial and civic engineers were recommending the use of MCI® Technology in all bridge projects at this time.
A processing facility faced the question of whether they could save the structural integrity of deteriorating, corrosion-damaged concrete cooling towers instead of replacing them at significant cost. The question was answered with an MCI® concrete repair. First, loose concrete was jet blasted off. Heavy corrosion was removed from rebar using VpCI®-423. MCI®-2023 was immediately applied to clean rebar for protection. MCI®-2038 and MCI®-2039 were used to repair concrete and restore structural integrity. Areas that did not need to be repaired were sprayed with MCI®-2020 to migrate and protect underlying steel from corrosion. The work restored the structural integrity and appearance of the concrete cooling towers at a significant cost savings compared to replacement.
The historic Alcatraz Federal Penitentiary is located on an island in San Francisco Bay. The perpetual environment of saltwater and fog has caused many corrosion problems for the National Park Service (NPS), who oversees the site. In 2008, the NPS realized something had to be done to slow down ongoing corrosion and remove loose concrete that could fall off high prison building walls and threaten visitor safety. The work was complicated by a limited budget and the designation of Alcatraz as a bird sanctuary where the bird habitat must not be disturbed by maintenance activity from February through September. NPS worked around the difficulties by contacting their Cortec® distributor for solutions. The repair ultimately involved removing spalled concrete, coating exposed steel with CorrVerter®, and applying MCI®-2020 to mitigate unseen corrosion beneath the surface. The products were easy to apply and cost-effective. Also, the fact that they could treat larger areas presented NPS with a potential cost savings on future repairs.
The Hakalau Bridge in Hawaii was suffering from steel girder corrosion caused by volcanic sulfuric dioxide as well as chloride enriched moisture from the Pacific Ocean. Some of the rusty areas on the bridge were especially hard to clean. CorrVerter® was used to prime the tight rust in these areas where good surface prep was difficult to achieve. MCI®-2005 NS was added to new concrete poured to cover the foundation and enhance the structural strength of first level bents in case of seismic activity. MCI® Mini Grenades were used in repair mortars for hand lay-up. The products’ ease of use and protective abilities made them excellent solutions to extend the expected service life of the structure.