Masonry basics Flashcards
What type of material is masonry?
Composite - Bricks + Mortar
Masonry is a brittle material, but where is the weakness?
Mortar joints
How does masonry cope with tension vs compression?
Strong in compression
Weak in tension
What do masonry properties depend on?
Masonry is anisotropic
Properties depend on joint orientation
Varies failure modes
How strong is masonry and what happens when mortar strength increases?
Between mortar and unit strength
If mortar strength increases, brick strength increases
Is masonry elastic or non-linear?
Low stress, masonry is elastic F=kx
If cracks for, highly non-linear and redistribution of load throughout uncracked material
What can happen if you restrain masonry?
As brittle material, cracks form
What causes vertical cracks?
Flexure and tension
What causes horizontal cracks?
Shear and bending
What are benefits of masonry?
Versatile
Constructability is high
High performance
Durable
Energy efficient
Acoustic
Qualified labour
Describe the brick making process?
- Crush into powder
- Mix with water
- Dry
- Fire in kiln
What are the two types of unit shape?
Solid bricks
Frogged bricks
What are units typically constructed of and do they shrink or expand?
Clay or concrete
Clay expands
Concrete shrinks
What are the three types of masonry joints?
What is a course?
What is a stretcher course?
What is a header course?
What is a soldier course?
What is bonding?
Overlapping between courses to distribute load and provide stability
What is a stretcher bond?
What is a heading bond?
What is a flemish bond?
What is a stack bond?
What is a English bond?
What causes variability in masonry units?
Temp bricks are fired: High temp increases strength
Stone inclusions increase strength
Ageing
What causes variability of mortar joints?
Composition and quality
Interaction of mortar with adjacent units
Orientation of mortar joints
Ageing
How do you cure mortar optimally?
It doesn’t need heat to dry!
Moisture evaporates
Slower this process happens the stronger mortar is
What are the joint failure mechanisms?
What are unit failure mechanisms?
What are the combined failure mechanisms?
What are three failure mechanisms of masonry walls?
- Bed joint sliding
- Rocking (toe compression failure)
- Diagonal cracking
What is the solution to stresses exerted on walls?
Infill masonry (non-loadbearing wall)
What is the solution to vertical and horizontal eccentric loads?
Loadbearing walls thicker
What is the solution to buckling?
Thin walls with buttresses
What is the solution to uniform pressure of the wind?
Thin walls with ringbeam
What is the solution to concentrated pressure of earthquakes?
Reinforced masonry
