MASONRY - Materials for Civil and Construction Engineers - page 310

Specified length 390 mm (15 5/8 in.)

Nominal length 400 mm (16 in.)

FIGURE 8.3 Nominal dimensions
and specified (modular) dimensions.

masonry units are available in nominal widths of 100 mm, 150 mm, 200
mm, 250 mm, and 300 mm (4 in., 6 in., 8 in., 10 in., and 12 in.), heights of
100 mm and 200 mm (4 in. and 8 in.), and lengths of 300 mm, 400 mm, and
600 mm (12 in., 16 in., and 24 in.). Common load-bearing blocks are
whereas non-load-bearing blocks are
as shown in Figure 8.4. Also, depending on
the position within the masonry wall, they are manufactured as stretcher,
single-corner, and double-corner units, as depicted in Figure 8.5.
Solid concrete masonry units (concrete bricks) are manufactured in two
grades (N and S) based on strength and absorption requirements. Grade N
units have higher compressive strength, resistance to moisture penetration,
and resistance to frost action than grade S. According to ASTM C55, the
minimum compressive strength of individual units is 20.7 MPa (3000 psi)
for grade N, and 13.8 MPa (2000 psi) for grade S. Grade N bricks are typi-
cally used as architectural veneers and facing units in exterior walls. Grade
S bricks are for general use where moderate strength and resistance to frost
action and moisture penetration are required.

200 mm * 200 mm

200 mm * 400 mm, 100 mm * * 400 mm,

FIGURE 8.4 Concrete masonry units:
(a) Non-load-bearing and (b) load-bearing.

(a) (b)

(a) (b) (c)

FIGURE 8.5 Concrete masonry units: (a) stretcher, (b) single-
corner, and (c) double-corner.