BS III - Fire

FIRE RESISTANT BUILDINGS AND FIRE FIGHTING

  • Instructor: Prof. Rakhee Kulkarni

  • Course: T. Y. B. Arch. JNEC, MGMU, Chh. Sambhajinagar

FIRE RESISTING BUILDING

Introduction

  • Fire-resisting buildings are designed to:

    • Resist fire spread and maintain structural integrity during fire events.

Purpose

  • Protect human life by providing safe escape routes.

  • Prevent or delay the spread of fire to adjacent buildings.

  • Minimize property damage and business disruptions.

  • Support firefighting efforts by maintaining stability.

Case Study: One Meridian Plaza Fire

Background

  • Location: Philadelphia, USA

  • Date: 1991

  • Structure:

    • High-rise building, 38 floors.

    • Fire started on the 22nd floor and spread to 11 floors.

Fire Management

  • Fire-resistant design features:

    • Use of fire-resistant materials and compartmentalization.

    • Enabled:

      • Safe evacuation of occupants.

      • Containment of the fire within a single zone.

      • Minimal structural damage.

      • Successful firefighting operations.

Technical Aspects of Fire Safety

Fire Safety Definition

  • Conveys fire resistance in terms of hours when subjected to fire.

Fire Safety Concerns

  1. Fire prevention and reduction of outbreaks.

  2. Internal and external fire spread management.

  3. Safe exit routes for occupants.

  4. Availability of fire extinguishing equipment.

Understanding Fire

Characteristics of Fire

  • Described as a rapid oxidation process producing:

    • Heated gaseous combustion products.

    • Emission of visible and invisible radiation.

Causes of Fire

  • Carelessly discarding ignited materials.

  • Inadequate machinery maintenance.

  • Negligence in cleanliness and safety protocols.

  • Faulty installations and unapproved equipment use.

Fire as a Hazard

Overview

  • Identified as a major hazard per the UN Global Assessment Report 2018.

  • Defined by the Emergency Management Division as uncontrolled burning.

  • Fire's dangers include:

    • Oxygen depletion leading to asphyxiation.

    • Release of toxic gases causing respiratory issues.

    • Heating effects may cause explosions.

Types of Fire Hazards

  1. Personal Hazard: Risk of loss or damage to life.

  2. Internal Hazard: Potential for fire spreading within the building.

  3. Exposure Hazard: Fire spreading to adjacent buildings.

Fire Load Classification (IS 1641-1988)

  • Fire Load: Weight x calorific value / floor area.

  • Classified into:

    • Low (<275,000 kcal/m²) - e.g., residential buildings.

    • Moderate (>275,000 & <550,000 kcal/m²) - e.g., retail shops.

    • High (>550,000 & <1,100,000 kcal/m²) - e.g., warehouses.

Fire Resistant Construction Practices

Materials and Construction

Characteristics of Fire Resisting Materials

  1. Must not disintegrate under heat.

  2. Should not lead to structural instability when expanded.

  3. Should withstand sudden cooling from water.

Fire Resistant Construction Elements

  1. Walls and columns:

    • Thicker sections for longer resistance.

    • Brick preferred over stone.

    • RCC preferred to steel structures.

  2. Floors and roofs:

    • Slab roofs preferred over sloping.

    • Use of fire-resistant flooring materials.

  3. Wall openings:

    • Minimized openings to prevent spread.

    • Properly protected escape routes.

  4. Escape elements:

    • Stairways and corridors constructed with fire-resistant materials.

  5. Strong room construction:

    • 300mm thick cement concrete walls and floors.

General Fire Safety Requirements (IS:1641-1988)

  • Buildings must have:

    • Safe and accessible fire exits.

    • Fireproof doors and properly maintained exits.

    • Floors and roofs capable of withstanding fire effects for rated periods.

Fire Fighting System

Components of Fire Fighting

  1. Fire Alarm:

    • Manual and automatic systems to alert occupants and call for help.

  2. Fire Extinguishing Equipment:

    • Portable extinguishers, water buckets, and other tools for initial reactions to fire.

  3. Fire Hydrant:

    • Connected to an underground water supply, offering sufficient pressure.

  4. Wet Riser System:

    • Vertical piping system providing water for firefighting.

  5. Automatic Sprinkler System:

    • Network of pipes with heat-activated sprinklers to control fire quickly.

Fire Fighting Equipment

  • Includes:

    • Fire alarm systems.

    • Fire hoses and hydrants.

    • Fire extinguishers and sprinklers.