Page 524 - Design of Reinforced Masonry Structures

7.86 CHAPTER SEVEN

3. Minimum area of sum of horizontal and vertical reinforcement should be 0.002 times
the gross cross-sectional area of the wall.
4. Minimum area of reinforcement in each direction should be 0.0007 times the gross
cross-sectional area of the wall.
5. The minimum area of vertical reinforcement should be one-third of required shear rein-
forcement.
6. Maximum spacing of both horizontal and vertical reinforcement should be limited to the
smallest of
(a) One-third of the height of wall
(b) One third the length of wall
(c) 48 in.
7. Shear reinforcement should be anchored around vertical reinforcing bars with a stan-
dard hook (MSJC-08 Section 3.3.3.3.2.1).
MSJC specifies additional special requirements when shear wall masonry is laid in other
than running bond (e.g., in stack bond):
1. The maximum spacing of reinforcement is 24 in.
2. Wythes of stack bond masonry shall be constructed of fully grouted hollow open-end
units, or two wythes of solid units.

Figure 7.33 shows minimum detailing requirements for special reinforced masonry
shear walls.
In a building, often there are other walls that are not a part of SFRS of the building.
These include such walls as partition walls, screen walls, and other masonry elements not
designed to resist gravity or lateral forces other than those induced by their own gravity
loads and inertia forces. Such masonry elements must be isolated from the building so that
gravity and lateral forces from the building are not imparted to these elements. Isolation
joints and connectors between these elements and the structure must be designed to accom-
modate the design story drift.

FIGURE 7.33 Minimum detailing requirements for special reinforced masonry shear walls [7.16].
(Courtesy: CMACN.)