Construction Flashcards
Structural Matters (Loads and Stability 3 Each)
Load
- Live and Dead Loads
- Lateral Loads - Bracing
- Torsion
Stability
- Anchorage - Foundations
- Height - Vibrations in tall buildings
- Cantilever principles - Center of gravity/Counterbalance
Examples of Loads (Imposed Loads and Dead Loads) (6 Each)
Imposed Loads (Live Loads)
- People
- Furniture
- Movable Partitions
- Vehicles Materials
- Stored Materials
- Snow
Dead Loads
- Beams
- Columns
- Floors
- Roofs
- Cladding
- Permanent Partitions
Example of lateral Loads (2)
- Wind
- Earthquakes
Internal Forces (6)
Compression
Tension
Shear
Torsion
Bending
Fatigue
Stress?
Forces acting on a material.
- Compressive force
- Tensile force
Strain?
Material or structural response to stress.
-Shorten
- Lengthen
Properties to be aware of when using materials in construction
Elasticity
Stiffness
Strength (30N/mm^2 – 250 N/mm^2)
Flexibility
Material Technology - Timber
Rough sawn timber –
straight from the logging
mill used as structure.
* Hardwoods (deciduous
trees)
* Softwoods (coniferous
trees)
* Prone to decay - moisture
and inadequate ventilation
can lead to rot or fungal
and insect attack
* Tanalith-E (applied under
pressure most common
treatments for against
wood decay and insect
attack
Material Technology - Steel
- Steel is a product of coal,
iron ore and limestone. - Sections can be
connected by drilling and
bolting or by brazing and
gluing. - Welding is the only way
of joining two pieces of
steel and make them act
as a single piece. - Corrosion (oxidation of
iron will produce rust)
can be prevented by
plating, painting,
application of coatings or
galvanization
Material Technology - Stone
- Low Tensile Strength
(strong in compression, weak
in tension) - Traditionally used to form
LOAD bearing walls,
columns and arches - Excavated from both
underground quarries and
open cast mines - Stone can be split,
chiseled, cropped and even
sawed into shapes - Oldest building material?
How is today’s CONCRETE made?
Portland Cement
Coarse aggregates of stone
Fine aggregates of sand, and
Water
Admixture are chemicals that can be added to the concrete to mix to control its setting properties and are used primarily when placing concrete during environmental extremes.
How to make general use concrete. (4 things totaling 6.5 parts)
One part Portland cement.
Two parts dry sand.
Three parts dry stone/aggregate
Half part clean water.
What is cement?
A binder which sets and hardens independently and can bind other materials together. When water is added to the cement powder mixture it is referred to as concrete.
(Cement should not be confused with concrete as the term cement explicitly refers to the dry powder substance.)
What are aggregates?
Sand, gravel and crushed stone.
Recycled aggregates (from construction, demolition and excavation waste) are increasingly used as partial replacement of natural aggregates.
Decorative stones can also be used to make the concrete more visually appealing.
What is Hydration in (Concrete)
Combining water with cementitious materials form a cement paste by the process of hydration.
This paste glues the aggregates together, fills voids within and allows it to flow more easily.
What is CURING?
The hardening process of concrete. (Chemical process not drying)
What will happen if less water is used to make concrete?
This can cause problems when setting or can also result in premature failure of the structure.
How do you test the consistency of Concrete? (Test name)
Slump Test
Forms of concrete? (3)
Reinforced concrete (Reinforced with steel rebar)
In-situ Concrete (Concrete cast on site in its final location, e.g. foundation)
Precast Concrete - Concrete elements cast elsewhere for subsequent assembly on-site.
What is formwork?
Formwork is the box into which concrete is poured to make required shapes.
Is Concrete strong or weak in tensile strength?
Weak.
The addition of steel means that the tensile forces will transfer to the steel. The concrete resists compressive forces and the steel resists tensile forces.
Tutorial 5 Construction Look at the diagrams
What is the function of a foundation?
To act as the interference between the building and the ground which supports it.
To spread the load over a sufficiently large area.
What are foundations made of?
Foundations are almost always made of concrete.
