Passive fire protection for steel structures

Wacker VINNAPAS LL 3112 Lab testLab test of a dispersion: Depending on the formulation, VINNAPAS® LL 3112 allows highly fire-resistant coatings with fire resistance class F120 to be achieved, which means heat protection for up to two hours. (Image source: Wacker Chemie AG)Extensive testing by Wacker Chemie has shown that copolymers based on vinyl acetate and ethylene produce a stable and eco-friendly matrix for carrying the reactive components of intumescent coatings

Tall steel structures of the type so widely seen in the Gulf today rapidly lose their strength when the temperature exceeds 5,000°C or so. Special ‘intumescent’ coatings that swell up to 100 times when exposed to fire and are applied in thin coats like paints during construction can protect them for a while, allowing time for the affected building to be safely evacuated. This is achieved by the rapid formation of an insulating foam ‘jacket’.

Without such fireproofing-coating protection being built in the weakened steel girders can collapse within a mere ten minutes or so of a serious incident breaking out, with disastrous consequences.

These protective intumescent coatings encase the structural members of the building and expand in the event of fire breaking out. The heat barrier thus created delays the weakening of the whole structure, thereby providing a measure of passive protection that ‘buys time’ for adequate response by the fire crews sent to the scene.

The coatings now available consist of a special organic binder and various reactive fillers which release phosphoric acid esters which in turn expand to form the vital insulating foam layer.

Water-based organic binders such as Wacker’s new VINNAPAS* LL 3112, based on vinyl acetate-ethylene-vinyl ester copolymers and seen at the European Coatings Show/Congress in March, ensure the protective foam remains thick (6cm or more) and resilient (i.e. not brittle when expanded), with a dense pore structure, and adhering firmly to the building’s steel structure.

Hauptverwaltung Wacker HQ GermanyWacker Chemie AG Headquarter in Munich. Founded in 1914, the Group has a global network of 25 production sites, 20 technical competence centres and 53 sales offices. (Image source: Wacker Chemie AG)Thinner coats can be efficiently and economically applied, and this improved binder can also be stored for extended periods at high ambient temperatures to provide the required fire resistance as and when required, and to meet local Leadership in Energy & Environmental Design sustainability certification requirements.

Effective heat protection for up to two hours is claimed by the manufacturers, the Polymers Division of Wacker Chemie AG, headquartered in Munich (pictured above).

This environmentally-friendly binder is free of organic solvents and plasticizers and is produced without any materials that contain damaging alkylphenol ethoxylates (APEOs). Thereby compliance with ever-tightening regulations on volatile organic compounds (VOCs) and LEED requirements – now widely recommended in the Gulf by organisations like the Emirates Green Building Council - are achieved.

In a complementary move the manufacturers recently expanded the services offered by their Technical Centre in Dubai. This now includes a dedicated laboratory for paints and coatings such as this new VINNAPAS-branded product, comprising applications technology and test equipment for the specialised dispersions needed as binders for advanced interior and exterior paints and coatings.

Said local MD Cyril Cisinski at the opening last November, “The expansion of our Technical Centre helps us to further strengthen our leading market position in the promising growth segment of paints and coatings in the Middle East … Our Technical Centre is top notch-equipped and unique in the region.”

By establishing this new laboratory for the local construction industry the company is meeting the growing demand for consulting and service for paints and coatings applications, throughout the Gulf and further afield. It is thereby helping to formulate quality standards as well as to introduce technologies that are both economical and environmentally friendly to the region. The next European Coatings event will be held in Nuremberg from 21-23 April 2015.

Taken from Technical Review Middle East Vol 29/Issue Three 2013

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