Page 80 - Design of Reinforced Masonry Structures

MASONRY UNITS: APPLICATIONS, TYPES, SIZES, AND CLASSIFICATION 2.33

FIGURE 2.30 Special pilaster units in various shapes and sizes. (Courtesy: PCA.)

of reinforcement and/or grouting as necessary. The partition between the cells is called
web. The two parts of the block perpendicular to the web are called the face shells (oriented
along the length of a wall); those parallel to the web (or webs) are called the ends (oriented
perpendicular to the wall).
Common concrete masonry unit nominal widths are 4, 6, 8, and 12 in.; common nomi-
nal heights are 4 and 8 in., and the common nominal length 16 in. Other sizes may be
available on special order, depending on the producer. Also available are special blocks for
columns and pilasters (Fig. 2.30). Figure 2.31 shows some sizes and shapes of concrete
masonry units for sills, copings, bond beams, and lintels.

2.6.9 Surface Texture of Concrete Masonry Units
Concrete masonry units are produced with a variety of surface textures to satisfy the
desired architectural requirements (Fig. 2.18). Textures are classified somewhat loosely,
and with considerable overlapping, as open, tight, fine, medium, and coarse. Various
degrees of smoothness (or roughness) can be achieved with any aggregate by changes
in aggregate grading, mix proportions, wetness of mix, and the amount of compaction in
molding. [2.1].
For example, slump blocks (or units) are produced by using a concrete mixture finer
and wetter than usual. The units are squeezed to develop a bulging effect; the bulging faces