Some useful construction tips to enhance the fire resistance capacity of concrete

The concrete materials with their property provide a significant impact in controlling fire that may occur in a building. In some cases, the temperature of concrete enhances quickly and leads to spalling.

To make the fire resistance capacity of concrete better, the following steps should be undertaken.

• While forming concrete with ordinary Portland cement, the fire is required in excess of 300 degrees Celsius; therefore, most of the crucial properties of concrete will be lost. The concrete can decline its structural performance for a temperature more than 600 degrees Celsius.
• The depth of the feeble region of the concrete will vary from small thickness from millimeters to several centimeters because the fire can raise the temperature of the concrete.
• It is recommended to use high alumina cement to safeguard the refractory linings above the temperature of 1600 degree Celsius. This is considered to retain higher performance in fire. An outstanding resistance to fire is exposed for a temperature exceeding 1000 degree Celsius.

A better performance is ensured with carbonate type aggregates like limestone, lime rock and dolomite. These have good resistance capacity against fire because if these are vulnerable to heat, the calcine will be heated up and will release carbon di oxide. Therefore, heat is essential to sustain such a reaction.

Image Source : precast.org

So, this reaction consumes some heat from the exothermic energy. Those aggregates containing silica provide poor performance in fire. Heat performance is associated with the thermal conductivity of concrete. Therefore, light weight aggregates in concrete is suitable to provide best resistance in fire.

Spalling in concrete because of high temperatures can be minimized by applying polymers or polypropylene monofilament fibers. It is an effective way to enhance the fire resistance capacity of the concrete.



These polymers will dissolve at temperature approx 160 degrees celsius and create channels to allow the consequential water vapors to outflow. This method is useful for minimizing the pore pressures and as a result the risk is decreased for spalling.

Other fruitful alternatives to safeguard the structural system from fire will comprise of the following:

• Applying heat shields coated with intumescent paint
• Spray used with lightweight mortars
• The application of preventive board systems

These are known as passive structural systems which are applied for fire resistance of concrete structures.