Masonry Magazine April 1988 Page. 19
15 IN.
15 IN.
A) LADDER TYPE
B) 3-WIRE LADDER TYPE
16 IN.
C) TRUSS TYPE
D) 3-WIRE TRUSS TYPE
15 ΤΟ 16 ΙΝ.
16 IN.
E) TAB TYPE
Continuous Joint Reinforcement
FIG. 3
Structural testing performed in the early 1960's indicated that multi-wythe walls tied with joint reinforcement performed as well as walls tied with unit ties or masonry bonders. Test results also indicated that truss-type joint reinforcement, in cavity wall systems, helped to develop a degree of composite action in the horizontal span, but did not contribute to any composite action in the vertical span.
Joint reinforcement may be used in multi-wythe solid walls, masonry cavity walls and grouted masonry walls (see Fig. 4). Truss-type joint reinforcement is not recommended for use in insulated cavity walls. The configuration of the truss diagonals can restrain differential movement between wythes and possibly result in bowing of the walls.
Adjustable Ties
Adjustable tie systems were initially developed to accommodate the use of face brick that did not course out vertically with interior masonry wythes. This concept has been extended to ties used to attach brick to backup systems other than masonry (concrete, steel frames and steel studs), resulting in the use of both adjustable unit ties and adjustable joint reinforcement.
The use of adjustable ties has increased rapidly for a number of reasons: 1) Adjustable ties permit the construction of interior masonry wythes prior to the construction of exterior facing wythes, permitting the structure to be enclosed faster. 2) Adjustable ties are two-piece systems. One piece is installed as the backup is constructed and
১০০
CAVITY
BRICK
100000 00 000 00 TL
BRICK
A) TRUSS-TYPE CAVITY WALL
COLLAR JOINT
BRICK
১০০
60000 900000 OETL
BRICK
B) TRUSS-TYPE SOLID WALL
CMU
5/8 IN.
MIN OR
T/2 MAX
5/8 IN.
MIN OR
T/2 MAX
000
00 000 TL 5/8 IN.
BRICK
MIN OR
T/2 MAX
CAVITY
C) TAB-TYPE CAVITY WALL
COLLAR JOINT
REINFORCING STEEL
BRICK
১০০০০০.....OOOC T
BRICK
D) LADDER-TYPE REINFORCED WALL
Joint Reinforcement Details
FIG. 4
5/8 IN.
MIN OR
T/2 MAX
3