CASE HISTORY SPOTLIGHT #734: Best PT Mix Ever!

In 2021, a new mixed-use complex in Nebraska called for the construction of a four-level post-tension (PT) parking garage with a 100-year design life (before the first corrosion-related repair). Adding a corrosion inhibitor was essential because of the high corrosion risk from frequent winter freeze-thaw cycles, excessive ice, and heavy deicing salts.

Shortly before the first concrete pour, the contractor had a bad experience using a calcium nitrite corrosion inhibitor (CNI) in another PT parking garage. The PT mix had been difficult to place and finish because of set acceleration, stiffness, and a low slump. As a result, the contractor decided to try MCI®-2005 NS as an alternative in the next project.

The first pour took place in the middle of a July heat wave, with the heat index at 100 °F (38 °C) at 9:30 in the morning. Since heat can accelerate set time, the contractor wondered if they should wait until evening to pour the mix. Their Cortec® MCI® regional sales manager reassured them that they could go ahead and treat the mix as they normally would under these temperatures. They did so, and soon noticed how much easier it was to consolidate and place the mix than their last CNI batch. Even an interruption in the placement job left them with great results when they resumed and made their first finishing pass.
At the end of the pour, the contractor’s general superintendent commented that this was the best PT mix he had ever placed and that he never wanted to go back to CNI. In less than a week, his prediction that other local ready-mix suppliers would want to switch over, as well, came true when all ready-mixer bids for another parking garage included MCI
®-2005 NS as their corrosion inhibiting admixture.

To read more details in the full case history, please visit: https://www.corteccasehistories.com/?s2member_file_download=access-s2member-level1/ch734.pdf

Keywords: Case History Spotlight, Cortec, MCI, CNI, corrosion inhibiting admixture, set acceleration problems, corrosion, calcium nitrite alternative, deicing salt corrosion, pouring concrete in heat wave

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CASE HISTORY SPOTLIGHT: Case History #62: Concrete Cooling Tower Restoration

MCI®-2038 and MCI®-2039 were then used to repair concrete and restore structural integrity

 

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

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CASE HISTORY SPOTLIGHT: Case History # #694: Rebar Corrosion Protection During Construction Delay

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.

 

To read the full case history, please visit: https://www.corteccasehistories.com/?s2member_file_download=access-s2member-level1/ch694.pdf

Keywords: rebar protection, construction delays, exposed rebar, rusted rebar, corrosion protection, case history spotlight, Cortec, MCI, rusted rebar in concrete, rebar corrosion

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CASE HISTORY SPOTLIGHT: Case History #697: Concrete Oil Stain Cleanup at Golf Course

August 23, 2022

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.

To read the full case history, please visit: https://www.corteccasehistories.com/?s2member_file_download=access-s2member-level1/ch697.pdf

Keywords: concrete oil stain cleanup, case history spotlight, Cortec, MCI, alternative to blast cleaning, green cleaning products, oil stain cleanup, concrete cleanup, From Grey to Green

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CASE HISTORY SPOTLIGHT: Case History #253: Condo Balcony Repair

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.
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Keywords: balcony repair, corrosion inhibitor, water repellent, MCI-2019, Migrating Corrosion Inhibitors, Cortec, condominium repair

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CASE HISTORY SPOTLIGHT: Case History #121: Plankinton Avenue Parking Ramp Preservation

August 10, 2022

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.

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Keywords: rusted rebar in concrete, parking ramp preservation, deicing salt rust, concrete renovation, Cortec MCI, From Grey to Green, MCI-2020, concrete repair, corrosion inhibitor

CASE HISTORY SPOTLIGHT: Case History #102: Concrete Cooling Tower Repair

MCI®-2020 Concrete Cooling Tower Repair

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.

Read the full case history here.

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