Page 91 - Design of Reinforced Masonry Structures

MASONRY UNITS: APPLICATIONS, TYPES, SIZES, AND CLASSIFICATION 2.43

FIGURE 2.42 Tooling of masonry joints. (Courtesy: Author.)

2.10 TYPES OF WALL CONSTRUCTION

Columns and walls are examples of structural elements for which masonry construction
employed. Design of these two elements is presented in Chaps. 5 and 6, respectively. A very
brief summary of reinforced masonry construction is presented here.

2.10.1 Single and Cavity Walls

From the standpoint of construction, walls are commonly built in one of the two ways. The
most frequently built is the single wythe, single-block, or solid wall. The term solid is rather
a misnomer because the blocks may be cored or hollow. Figure 2.43 shows typical details

of a reinforced masonry foundation wall built from concrete blocks.
The other type of wall is the cavity wall which consists of two separate wythes, sepa-
rated by an air space and tied together with metal ties which are embedded in the horizontal
mortar joints. Figure 2.44 shows details of a cavity wall. The two wythes can also be held
together with bricks or blocks laid cross-wise between the two wythes at certain points.
Regardless of how the two wythes are tied together, the purpose of these connectors is to
transfer shear between the wythes. As a result of this inter-wythe shear transfer, if the two
wythes are spaced close together and bonded with the closely spaced units, the behavior of
a cavity wall approaches that of a single-wythe wall.
Cavity walls have several advantages. The continuous air barrier helps prevent moisture
and, to some extent, heat from penetrating the wall. The cavity can also be filled with insu-
lating material such as glass wool to give better insulating performance.