Attachment 4 - Site Investigation and Slab Report

Table 3 Suggested deflection ratios for reinforced masonry

                                      Absolute maximum deflection, ∆
                                      as a function of span, L             Absolute maximum deflection, ∆
Wall construction                     (mm)                                 (mm)

Reinforced masonry veneer             L/300                                40

Reinforced full masonry
   Sheet and/or faced finish          L/400                                30
   Rendered or painted finish         L/600                                20




on reinforced block walls refer to the Concrete          as doors and windows. However, small openings
Masonry Handbook10.                                      for air conditioners, toilet windows and the like are
     Reinforced masonry may also include reinforced      permissible provided that they do not interfere with
brick masonry containing bed joint reinforcement         the courses that contain the reinforcement.
and/or reinforced cavities within the brickwork.             Also, if more-flexible footings are used, the
Cavities may either be the cavities between two          recommended maximum spacing of articulation
leaves of brickwork or those within brick piers.         joints in reinforced brick masonry remains
The standard footing design in AS 2870 for a             similar to unreinforced masonry and should not
stiffened slab with deep edge beam is an example         exceed the values given in Table 2. The maximum
of reinforced brick masonry where a minimum              recommended spacing for expansion joints in
75-mm-wide cavity is reinforced with SL82 mesh           straight reinforced brick masonry walls without
or N12 bars at 400-mm centres each way and then          openings is 30 m11 , although they may be required
grout or concrete filled.                                to be as close as 10 m depending on conditions.
     Unlike reinforcing bars and meshes used                 Reinforced brick masonry used for structural
for structural applications, the lighter bed joint       applications (similar to unreinforced masonry) is
reinforcement (for brick or block walls) is usually      generally designed to span horizontally between
incorporated to assist with crack control in wall        vertical or lateral supports such as columns and
panels between articulation joints, and especially       cross/return walls. As such, if articulation joints are
around openings and above arches. In high-wind           required, they should be located at these points and
areas it may also be used to improve the structural      detailed such that loads can be transferred to the
performance of wall panels.                              supporting elements Figure 17. This does not apply
     Bed joint reinforcement typically consists          to masonry veneer construction as lateral support
of two 3-mm (minimum) diameter longitudinal              is provided by the structural framing to which it is
wires (galvanised or stainless steel depending on        attached.
durability requirements) welded into a cage for              The vertical spacing of reinforced bed joints
easier installation and more accurate positioning.       depends on the design requirements and openings
It typically comes in 3-m lengths and a range of         within the wall. If bed joint reinforcement is used for
standard widths to suit various masonry units. The       improved crack control between joints (articulation
maximum wire size should not exceed two thirds of        or other control joints), an appropriate location may
the design bed joint thickness and at least 15 mm of     be in the two courses above and below window/door
cover should be provided between embedded metal          openings and in the second or third course from the
wires and any exposed surface of the mortar joint.       bottom and top of the wall Figure 34. Where there
Light gauge wire products may also be used but           are no openings in the wall panel, reinforcement
will be less effective, may not be appropriate for the   would typically be provided at 600-mm centres. An
exposure conditions and as a consequence, result in      alternative arrangement in 2.4-m-high masonry
corrosion problems.                                      block walls is to reinforce the top and bottom
     Dwellings using bed-joint reinforcement to          3 courses and the middle course of the wall in lieu
reduce footing sizes should be designed such             of distributing reinforcement evenly over the height
that openings do not interfere with the reinforced       of the wall12. Concentrating the reinforcement
courses. In general, this will mean that most            at the extremities of the wall improves the wall’s
sections of reinforced brick masonry (being full-        resistance to in‑plane bending from footing
height infill sections) will not contain openings such   movements.


                                                                                            Articulated Walling Page 21