Concrete Column Fire Resistance (FRP) Calcolatrice

The SkyCiv Fire Resistance Calculator calculates the Fire Resistance Period (FRP) achieved by a reinforced concrete section. Whilst reinforced concrete is a fire-resistant material, prolonged exposure to high temperature causes a reduction in the strength of a concrete section, which will eventually lead to structural failure. Building codes require structural concrete elements to have a minimum fire resistance period during which the element will maintain its structural integrity.

SkyCiv offers tools to calculate concrete FRP in accordance with the following codes:

  • NEL 1992.1.2.2004 - Progettazione di strutture in calcestruzzo
  • COME 3600:2018 Strutture in cemento

The below calculator allows engineers to calculate fire resistance periods, and provides detailed, relazioni di calcolo con riferimento al codice che spiegano i risultati.

Avvio del calcolatore di resistenza al fuoco SkyCiv RC...

About Concrete Fire Resistance

What is Fire Resistance Period (FRP)?

When subjected to fire, reinforced concrete can react in several ways which reduce its structural integrity:

  • Cracking and spalling of concrete at the faces of the element.
  • Debonding of concrete from reinforcement, reducing composite action (and overall strength).
  • Reduction in yield stress and stiffness of reinforcement.

Fire resistance is the ability of a structural element to maintain its integrity when subjected to fire. This is typically described using a Fire Resistance Period (FRP), misurato in minuti. Building codes mandate minimum FRP values for structural elements depending on the building classification. FRP requirements can range from 30-240 minuti. Some codes split FRP requirements into distinct categories relating to methods of fire suppression. These categories include:

  • Structural Adequacy: Ability to maintain structural capacity.
  • Integrità: Ability to prevent the transfer of fire through the element.
  • Insulation: Ability to prevent heat transfer through the element.

Depending on the classification, some codes may require different FRP values for each category.

What Factors Contribute to FRP?

The Fire Resistance Period of a concrete section is influenced by the following factors:

  • Dimensione: Larger concrete sections typically have a higher FRP.
  • Coperchio: Increased cover to reinforcement can reduce the potential of concrete spalling/debonding.
  • ACI-Verifica-Libri-Anteprima: Higher concrete strengths have increased fire resistance.
  • Load Level: Heavily loaded concrete sections typically have a lower FRP.
  • Reinforcement Ratio: Increasing section reinforcement can increase FRP.
  • Esposizione: Elements exposed all sides will have a lower FRP than sections protected on one side.

It is also possible to increase the FRP of concrete elements through the application of protective coatings such as vermiculite or intumescent paint.

How is FRP Calculated?

FRP is calculated differently depending on the design code adopted. When using NEL 1992-1-2, the below process is followed:

  1. Determine the isotherm of 500°C for the specified fire exposure, standard fire or parametric fire.
  2. Calculating new cross-section dimensions by excluding the concrete outside the 500 tu. isotherm.
  3. Determine the temperature of reinforcing bars in the tension and compression zones.
  4. Determine the reduced strength of reinforcement.
  5. Calculate the reduced ultimate load bearing capacity.

When using AS 3600:2018, the process is as follows:

  1. Determine effective length and slenderness.
  2. Calculate loading eccentricity based on design moment/axial force.
  3. Calculate load level and mechanical reinforcement ratio.
  4. Use tabulated values to determine minimum section width and reinforcement cover.

Domande frequenti sul calcolatore della resistenza al fuoco

1. What does the SkyCiv RC Fire Resistance Calculator do?

Il calcolatore della resistenza al fuoco SkyCiv RC calcola la dispersione della temperatura sviluppata durante l'incendio all'interno dell'armatura e del calcestruzzo di un membro. Quindi calcola la sezione trasversale ridotta delle aste, ovvero. la sezione trasversale ottenuta rimuovendo parti della sezione trasversale con resistenza e rigidezza pari a zero. It then estimates the axial and flexural force carrying capacity in its combined form and finally compares the capacity with the actual forces to which the member is being subjected.

Per eseguire il modulo sono necessari i seguenti input:

  • Tipo di sezione (circolare o rettangolare).
  • Dimensioni della sezione.
  • Durata della resistenza al fuoco in ore.
  • Disposizione dei rinforzi (diametro della barra e spaziatura della barra) per i lati laterali e longitudinali.
  • Carichi di progettazione (flessione sull'asse maggiore e sull'asse minore e forza assiale).
  • Coperchio laterale.
  • Proprietà dei materiali per calcestruzzo e acciaio per cemento armato.

2. Su quale standard di progettazione si basa il calcolatore della resistenza al fuoco SkyCiv RC?

SkyCiv offers tools to calculate concrete FRP in accordance with the following codes:

  • NEL 1992.1.2.2004 - Progettazione di strutture in calcestruzzo
  • COME 3600:2018 Strutture in cemento

Ottieni un calcolatore personalizzato unico come la tua attività

Esplora la possibilità del tuo calcolatore SkyCiv personalizzato
per tempi di progettazione più rapidi e risparmi significativi in ​​termini di tempo e costi.

Mettiti in contatto oggi stesso