Brickwork
Bond strength – is a measure of the strength of the bond between brick and mortar.
- It is measured by constructing nine brick high piers for testing beams in bending or single joints can be broken using the bond wrench apparatus.
- AS 3700 assumes all normal brickwork will have characteristic bond strength of not less than 0.2 MPA.
- brickwork should be laid to a standard gauge.
- For standard/traditional bricks (and all other bricks which are 76mm high) the gauge is seven courses 600mm of wall height.
- Is dependent on the properties of the bricks and the mortar.
- The property is determined by testing four-brick high piers laid up using the mortar intended for the construction.
- Slenderness ratio & robustness requirements
- Walls and columns subjected to compressive loads must be designed to satisfy the requirements for slenderness ratio set out in AS 3700
- Masonry members that are not subjected to loads must satisfy the robustness requirements of AS 3700. Requirements limit the height and length of walls of a given thickness according to support conditions.
- Fire resistance levels (FRL)
- These are specified in the Building Code of Australia
- It provides an accurate method of predicting the ability of a wall to maintain strength in a fire and to resist its spread.
- It depends on the thickness, height and length of a wall. Also how the top, bottom and ends of the walla are connected to the other building elements.
- A typical fire resistence level for a wall would be FRL 90/90/90 – 90 minutes for each of the following
- Structural adequacy – ability of wall to continue to perform its structural function
- Integrity – ability of wall to prevent the passage of flames and hot gases
- Insulation – ability of wall to provide sufficent insulation, the side of the wall away from the fire does not exceed pre-defined rise in temperature.
- Single leaf masonry is not water proof
- Damp proof detailing, using membranes, flashings and good workmanship aid in keeping water out of buildings.
- Cavity wall construction prevents water from reaching the internal leaf of brickwork. Free water in the cavity drains to the cavity flashing and out through a weep hole.
- To perform satisfactorily it is essential that all joints are properly filled with mortar/
- Must be sealed using two or three coats of acrylic paint on the outside to prevent water penetration