What aspects do I have to consider for the fire-protection of structures in a concrete and masonry mixture, reinforced or pre-stressed concrete?

The steel components present in reinforced or pre-stressed concrete, as in the masonry elements in mixed structures, lose their mechanical properties when the temperature rises, losing their load-bearing capacity.

These structures have their own intrinsic fire-resistance capacity, but if this is insufficient, it can be increased by the use of reactive paints or lightened fire-proofing plaster.

Why protect structures in a concrete and masonry mixture, reinforced or pre-stressed concrete

The concept of the concrete cover

Buildings for industrial use and also some other residential and other buildings are built using prefabricated systems or assembled on site. There is widespread use of reinforced or pre-stressed concrete, as is a masonry and concrete mix for flooring. The combination of steel and concrete and masonry makes these elements particularly sensitive to fire.

How are masonry and cement, reinforced or pre-stressed concrete protected?

It is sometimes necessary to adapt the fire-protection capacity of these construction elements, with their combined nature of metal, concrete and masonry parts. The methods for doing this vary in terms of both complexity and cost.

What is the regulatory framework?

The contribution made by a coating designed to protect a structural element from fire can be determined by analytical calculation, comparing tables and/or by experimental testing.

Amotherm brand reactive paints and varnishes undergo the rigorous testing prescribed by EU regulations to provide an unequivocal classification of their performance and effectiveness.

How is a reactive protective system for concrete and masonry, reinforced and pre-stressed concrete made?

Structures in concrete and masonry, reinforced or pre-stressed concrete are rarely subject to mechanical stress but they may be subject to harsh climatic agents. It is therefore essential for the correct procedure to be followed, from the base-coat or primer to the finishing coat, to ensure the system delivers effective fire protection.

What are compliance checks for?

To guarantee an intumescent coating’s fire-protection performance the application instructions must be scrupulously followed. In particular, it is necessary to refer to the product’s conditions of use and the instructions for applying it, carrying out the compliance checks before, during and after the intumescent system is applied. These checks are as follows.

Check the product
Check the surface
Check the application conditions and methods
Check the properties of the intumescent system used

The thickness of the coat of intumescent paint applied is an essential factor in ensuring the correct fire-protection performance of the construction element treated and therefore an adequate criterion must be used to check this system property.

What is meant by duration and durability and what is maintenance for?

Durability is defined as “The expected life of a protective paint system to the first major maintenance painting”.

Because the duration in service, or durability, of a protected surface is generally longer than the durability of the protective system used, a maintenance schedule must be prepared, in compliance with current technical standards, that makes it possible to use the structure for its nominal lifetime. The schedule must provide for routine maintenance, to be done at regular intervals, as well as special maintenance to be carried out whenever conditions lead to damage or degradation requiring partial or total replacement of the reactive paint. With proper maintenance the durability of the protective treatment will definitely be prolonged for the entire nominal lifetime of the protected structure. For information about proper maintenance, see the manufacturer’s manual.