Strength of Bricks ~ due to the wide variation of the raw
materials and methods of manufacture bricks can vary greatly in
their compressive strength. The compressive strength of a
particular type of brick or batch of bricks is taken as the
arithmetic mean of a sample of ten bricks tested in accordance
with the appropriate British Standard. A typical range for clay
bricks would be from 20 to 170 MN/m^2 the majority of which
would be in the 20 to 90 MN/m^2 band. Generally calcium silicate
bricks have a lower compressive strength than clay bricks with a
typical strength range of 10 to 65 MN/m^2.Strength of Mortars ~ mortars consist of an aggregate (sand) and
a binder which is usually cement; cement plus additives to improve
workability; or cement and lime. The factors controlling the
strength of any particular mix are the ratio of binder to aggregate
plus the water:cement ratio. The strength of any particular mix
can be ascertained by taking the arithmetic mean of a series of
test cubes or prisms † see page 357.
Wall Design Strength ~ the basic stress of any brickwork depends
on the crushing strength of the bricks and the type of mortar used
to form the wall unit. This relationship can be plotted on a graph
using data given in BS 5628 as shown below:-Principles of Calculated Brickwork