Fire Protection Methods for Structural Steel | Report

FIRE PROTECTION METHODS FOR STRUCTURAL STEEL
Abstract: Structural steel has one problem- how to increase and improve its fire resistance. Most
times structures build by steel face challenges of catching and spreading fire easily. This is due
the inability of steel to contain high fire resistance. Various techniques have been invented to
improve the fire resistance of structural steel. They are both passive and active methods. This
article focusses on fire protection methods for structural steel, merits and demerits of each
method and how each method can be performed and implemented.
Keywords: Beams. Structural steel. Active methods. Passive methods. Steel columns. Cellular
steel.
Table of Contents
Introduction 3
1

Methods of Structural steel fire protection 3
Active methods 3
Passive methods 4
Passive Methods of structural steel fire protection 4
Use of boards and blanket coating method 4
Intumescent coating method 5
Cement/Gypsum based spray coating method 7
Concrete encasement 8
Protecting cellular beams 8
References 11
Table of Figures
Figure No. Description Page No.
1 Shows protection of steel structure against fire using boards
and blankets method
4
2 This show two pictures of the intumescent coating applied
to steel structure; before exposure to fires and how it is
expands to protect the steel after exposure to fires
6
3 Intumescent coating is applied to a steel structure in the off-
construction site
6
4 Intumescent coating is applied to a steel structure in the
construction site
7
5 Application of intumescent coating to steel structures
(beams) of regular and irregular shapes
7
6 Cement-based spray on the steel structure 8
7 How cement-based coating is sprayed on steel structures 8
8 Steel structure protected from fires by concrete covering 9
9 Thin-film intumescent coating applied to cellular beams 10
INTRODUCTION
2

Fire protection techniques are systems that have been designated to guard and protect the steel
structure against fire for a certain period of time. There are various systems that are now
available to be used for steel structure fire protection. Each system of fire protection has
specifications and conditions under which it is suitable to be used for steel structure protection.
The systems for protection of steel structures against are very important in building and
construction field as they enhance structural safety. In incidences of fire accidents, the fires can
destroy structures thus weakening the stability of the building and other structures (Structural
Engineering Institute. Special Design Issues--Fire Protection Committee, 2009).
Therefore the fire protection systems are meant to slow down the combustion process and thus
delay energy transfer. This energy transfer delay will afford the audience time to run to safety
before the failure of the structure or whole building. Structural failure of a building structure is
brought by fire loading and the only way to remedy this is by compartmentation.
Compartmentation brings about fire localization thus lowering the rate of which fire will spread
to other areas. The objectives of this study includes; study of various methods of steel structures
fire protection, and investigate merits and demerits of each discussed method of fire protection.
FIRE PROTECTION SYSTEMS
Fire protection methods are classified into two groups, namely;
1. Active methods
2. Passive methods
1. Active methods
Active fire protection involve systems which are activated in the event of occurrence of fire.
Active methods of protecting the structural steel against fire encompass systems of putting out
fire that are designed to protect the structural steel by preventing fire at its genesis. It is basically
an alarm detecting or sprinkling techniques that raises alertness in the outbreak of fire and may
also initiate fire extinguishing processes such as sprinkling of water to put out fires in buildings
(Guoqiang Li, 2013).
Active fire protection systems are designed mainly to control small-scale fires or contain fires at
the genesis before the fire spreads to other areas. In addition, it works to contain fires before
elaborate firefighting processes are put in place. This active systems works by installing a sealed
bulb of water sprinkler with fire/smoke detector on ceiling of rooms in buildings. In the event of
fire accident, the sealed bulb breaks and the head of the sprinkler releases water sprays which
extinguishes fires. Building regulations requires all building structures that have are over 30
metres high to have the water sprinkler systems. This technique is one of the best systems of fire
inhibitions as besides putting off small fires, it makes other materials in the room wet thus
preventing further spreading of fires. It is both economical in terms of the cost and can save lives
because it reduces amount of smoke-which is the main cause of human deaths in cases of fire
accidents (Edward Allen, 2016).
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2. Passive methods
Passive techniques involve all applications designed to protect structural steel against fires by
taking into consideration the possibility of fire occurring.
FIRE PROTECTION METHODS
1. Use of boards and blanket coating method
It is a passive method
Effectiveness
This method of protecting steel structures against fires is the most widely used system of fire
protection. Reasons why it is the most preferred include; this method is clean when used, it is
relatively cheap to purchase, install and maintain this system as compared to other methods of
structural steel fire protection, it is water resistant and can be used to protect non-painted steel
beams and columns.
Figure 1: Shows protection of steel structure against fire using boards and blankets method
(Veljkovic, 2016)
In addition, this method of using boards and blankets very strong and durable technique of steel
structure fire protection. Moreover, this method is compatible with any decorative finishing as it
is available in almost all colours.
How the fire protection is achieved
For the case of boards when used as fire protection technique, they are mostly preferred to be
used in steel columns and beams that have regular shapes. Various fire resistant materials are
used to make the boards and the selection of the board to be used is based on the thickness of the
board and recommended fire rating required for the steel structures.
Construction of the components utilised
4