Page 48 - Design of Reinforced Masonry Structures

CHAPTER 2
MASONRY UNITS:

APPLICATIONS, TYPES, SIZES,

AND CLASSIFICATION

2.1 INTRODUCTION

Whereas masonry construction can be truly claimed as the oldest building art practiced by
humans since the dawn of history, both stones and bricks can be considered as two of the
oldest building materials—stone the oldest natural material, and the brick the oldest man-
made material. A brief description of the historical development of masonry construction
was presented in Chap. 1.
Masonry is typically laid of prefabricated units of different materials, shapes, and sizes.
The common types of masonry units, typically rectangular, are clay bricks, clay tiles, con-
crete blocks, lightweight cellular concrete blocks, sand-lime bricks, and natural building
stones. Units of shapes other than rectangular, particularly bricks, are also available. Both
clay and concrete masonry units (referred to as CMU hereafter) are available in several
colors, textures, and profiles to suit practically every conceivable need and convenience,
visual effect, and aesthetic appeal as desired by engineers and architects. There is a world
of masonry units out there.
This chapter discusses various types of clay units (bricks) and CMU which are referred
to throughout this book. Masonry construction typically involves placement of masonry
units one by one which, like any other type of construction such as steel, concrete, and
wood, is a time-consuming and weather-dependent process. To reduce construction time,
the concept of prefabricated masonry was developed, which is becoming increasingly pop-
ular. Research and advancement in technology of masonry construction led to the develop-
ment in the 1980s of mortarless block systems in the United States. Both the prefabricated

masonry and mortarless block systems are discussed briefly in this chapter.

2.2 APPLICATION OF MASONRY UNITS
IN CONSTRUCTION

Both clay units and CMU offer themselves as versatile construction materials to be used
for load-carrying elements of a structure. Bricks in particular can be used for both the
building’s exterior skin as wall and load-carrying elements as in a single-wythe bearing
wall system. A major advantage of using bricks is that, with their many hues and colors,
they can be used to create many attractive patterns and designs for architectural treatments

2.1