Page 360 - Design of Reinforced Masonry Structures
P. 360

6.12                       CHAPTER SIX

             Curtain and panel (or filler) walls (Fig. 6.1) are nonload-bearing walls which have
           been used as building systems for decades. They are used to enclose structural frames
           of steel or concrete. Curtain and panel walls differ slightly in that a panel wall is wholly
           supported at each story, but a curtain wall is not. However, both must be capable of
           resisting lateral loads (due to wind or earthquakes) and transmitting these forces to
           adjacent structural members. They are designed to meet the requirements of exterior
           walls, which include providing a durable, attractive, and economical finish; control of
           heat flow; water penetration; noise; and fire.
             Prevention of damage due to dimensional changes in walls and adjacent structural
           frames is one of the most important considerations in design of a building system.
           Differential movement occurs as a result of stresses caused by many factors such as
           temperature variations, moisture, loading, and the like. Temperatures vary throughout
           buildings depending on locations and time. Masonry walls may be exposed to wide
           variations in temperatures. An exterior wall may have an outside surface temperature as
           high as 150°F when exposed to hot summer sun, while the temperature on the interior
           wall may be about 70°F. Also, during winter, the temperature on an exterior wall me be
           as low as 20°F. Variations in moisture content also cause masonry materials to expand
           and contract. Possible damage to curtain and wall panels can be avoided by anticipating
           stresses that may be caused by these factors.
             Screen walls (Fig. 6.10) are constructed from specially manufactured screen units.
           They are used in buildings for many purposes. They provide privacy with observation,
           interior light with shade and solar heat reduction, and airy comfort with wind control.
           Curtain walls, fence walls, sun screens, decorative veneers, and room dividers are some
           of the many applications of screen walls. Screen units are manufactured in a wide vari-
           ety of shapes and sizes so that the screen walls can be advantageously used to enhance
           aesthetic qualities of a building. Screen walls are designed as nonload-bearing wall
           elements. As such, they are designed to support their own dead weight, and they should
           exhibit stability and safety.
             Design of the screen walls depends on several factors such as function, location (exte-
           rior or interior), aesthetic requirements, and local building codes. They are extensively
           used for the following types of construction: (1) interior partitions, (2) free-standing
           walls supported on their foundations, (3) veneers, and (4) enclosed panels in masonry
           walls. As partitions, they are designed as nonload-bearing wall panels with primary





















            FIGURE 6.10  Screen walls [6.8].
   355   356   357   358   359   360   361   362   363   364   365