Columns

Question 1

Define a column

Answer 1

A column is a structural member, which transmits
a compressive force along a straight path in the
direction of the member. Columns are usually
thought of as being vertical, but any structural
member, which is comparatively loaded, is governed
by the laws of columns, despite its attitude

Question 2

What is the function of a column

Answer 2

The function of a column is to carry part of the
weight of the building where an internal wall
would interfere with the designed use or where a
large open space is needed. A column is often
designed to withstand only vertical loads and any
eccentric loading greatly increases the stress.

Question 3

The fire resistance of a concrete

column depends on:

Answer 3

(a) The applied load;
(b) The type and strength of the concrete;
(c) The dimensions of the column;
(d) The method of reinforcement;
(e) Its resistance to collapse.

Question 4

Structural steelwork has the disadvantage of
being unable to withstand the high temperatures
generated under fire conditions and it will quickly
loose its strength, buckle and fail. It must, therefore,
usually be protected where fire resistance is
required and the type of protection can be either

Answer 4

“solid” or “hollow”.

Question 5

Solid protection of a structural steel column

is achieved by

Answer 5

(a) Concrete encasement; or
(b) Spraying with different types of mineral fibre
vermiculite cements, magnesium oxychlorides
etc., or
(c) Application, either by spray or brush, of
intumescent paints.

Question 6

What is hollow protection of steelworks

Answer 6

This is the encasement of steelworks (Figure 5.9)

by fire-resistant boards