432 Park Avenue, NYC

Applying Iso-Tek 8501 to 432 Park Avenue

How One Developer
Solved an Absorption Challenge

Ghostshield® Iso-Tek™ 8501 offers an effective solution for architects, engineers, and builders looking to protect vertical high-density concrete commonly used in commercial and industrial construction. This technology is used on some of the most iconic structures — including the Big Dig, the Channel Tunnel, Bjarke Ingels Group’s Grove at Grand Bay, Water Street Development, Notre Dame, and the Zakim Bridge. Here is how Macklowe Properties utilized Iso-Tek™ 8501 to provide an unsurpassed level of protection on the 432 Park Ave project in New York City.

Top Challenges

14,000 PSI
High-Density Concrete
1,396 Feet
Vertical Surface Height
20 Years
Long-Term Protection

Stratospheric Ambitions

The goal: provide an invisible, protective barrier on vertical ultra high density concrete without any aesthetic alteration.

For many investors, asset protection is just as important as the asset itself. When Macklowe Properties set out to develop the tallest residential building in the Western Hemisphere, protecting it became a top priority.

Macklowe commissioned WJE (Wiss, Janney, and Elstner Associates) and Simpson Gumpertz & Heger to find the right solution; To provide years of protection against weather and the natural elements that contribute to concrete erosion. Silanes are known for this type of protection, but traditional liquid silanes have low viscosity and do not penetrate deep enough into high density concrete or vertical surfaces.

By using Iso-Tek™ 8501, you can protect vertical high density concrete and achieve deep penetration without loss of material.

Here’s why Macklowe selected Iso-Tek™ 8501 to protect 432 Park Avenue located in New York City:

432 Park Avenue Photo

A Penetration Predicament

Consumption is directly related to time of contact. Penetration depth of silane is dependent on porosity, time of contact, and degree of saturation.*

For silanes to work effectively, they must be absorbed deep into the substrate where they react with silica in the concrete. The deeper the silanes penetrate, the better protection they can provide. Instead of experiencing excessive material loss, vertical run-off, and shallow penetration levels with traditional liquid silanes, Iso-Tek 8501™ high-viscosity gel sealer defies gravity to deliver astounding absorption.

* A. Johansson, M. Janz, J. Silfwerbrand & J. Trägårdh; Swedish Cement and Concrete Research Institute, Stockholm, Sweden

Silane runoff on vertical surface
Traditional silanes on vertical surfaces are prone to excessive run-off.

Penetration Depth
in Carbonated Concrete Cubes

Showing greater absorption in high-density (lower water-to-cement ratio) concrete

0 2 4 6 8 12 10 14 16 18 PENETRATION DEPTH (mm) Liquid “pure” silane Iso-Tek 8501 Solvent-based silane (30% active content) Solvent-based siloxane Water-based silane (40% active content) in g/m 3 100 250 400 100 250 400 100 250 400 100 250 400 100 250 400 W/C = 0.70 W/C = 0.45

Tested in the Lab, Proven in the Field

Iso-Tek 8501's raison d'être: Depth of penetration was significant, material loss was insignificant.

Core samples taken from the 432 Park Ave structure were used to independently test Iso-Tek™ 8501 against traditional liquid silanes. Tests showed a single coat of Iso-Tek™ 8501 out-performed all other liquid sealers and provided significantly better depth of penetration on the 14,000 PSI vertical high-density concrete.

The thixotropic consistency of Iso-Tek™ 8501 allowed active silanes to remain on vertical surfaces longer and it increased the degree of saturation. The temporary gel coating provided a shield against premature drying or “flash-off”, giving the silanes more time to penetrate into the substrate.

To achieve similar performance, four coats of pure 100% liquid silane was needed. The advantage over traditional liquid was considerable.

Iso-Tek 8501 cream / gel on vertical surface
Iso-Tek™ 8501 adheres to the surface of the concrete allowing for greater absorption of the silane.

Concrete Results

"An ounce of prevention is worth a pound of cure."

In the 5 years since 432 Park Ave was treated, moisture level readings have varied between 3-4%. No visual or structural defects are known and micro-cracking remains well below expected.

There’s real power in knowing which sealer performs best, especially when the materials used on a project push the boundaries of construction. When you can see which sealer provides the best protection, you can use that insight to make the best investment for the future.

Iso-Tek™ 8501 was designed for high-density vertical concrete and continues to outperform when put to the test.

Ready to use Iso-Tek™ 8501 on your project?

Iso-Tek 8501 on palettes

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