Introduction Flashcards
How is sand formed?
Of particles of quartz or feldspar formed by mechanical erosion
What is clay?
Silicates and aluminates resulting from weathering of parent rocks under conditions of high temperatures and humidity
How does clay react to heavy loads?
Clay has low permeability, therefore the water/air between the particles moves out slowly. The clay will compress, but this can take a long time (possibly centuries).
What do you call the compression of soils?
Consolidation
What happens when timber is pulled apart from the side?
Timber is made of layers of fibres and those are individually very strong, but can be pulled apart, i.e. become delaminated.
What is corbelling?
When blocks are placed on top of each other gradually closer together until it is closed by a stepped roof
What are voussoirs?
Carefully prepared wedge shaped stones used for semicircular arches
Flying buttresses have pinnacles on top of their ends, what is their function?
To push the load more effectively into the masonry
What is wrought iron?
Iron with a low proportion of carbon.
This can be stretched without losing all its strength and can be beaten or rolled (wrought) into simple shapes
What is steel?
Iron with a higher proportion of carbon and with other elements mixed within (such as manganese, titanium or chromium)
What is tensile strength?
How much a material can be stretched and pulled apart
What is prestressed concrete?
When the steel inside reinforced concrete is first stretched before the concrete hardens in order to strengthen the material even further.
(If the steel is not stretched beforehand it could stretch the concrete with it which would break it)
What are designer soils?
Materials from the ground which are modified in order to give particular mechanical properties.
Used for making roads
What are the three layers of roads, which have existed for millennia?
- a strong running surface, resistant to wear
- underlying support, to prevent the top layer from spreading
- a drainage layer to draw rainwater into lateral ditches to prevent the formation of a morass in wet weather
What is an aquifer?
A geological layer in which water is stored and through which the water is able to flow
What is the difference between old and young water?
Old water is water from deep below
Young water is rainfall or rivers
