7-8 Stone Decay & Weathering Flashcards
It is a naturally occurring solid aggregate of one or more minerals (silicates and non-silicates).
Stone
It is usually used as a building material because of its great durability and superior artistic quality.
Stone
It is a branch of geology that studies the origin,
composition, distribution and structure of rocks
Petrology
It is a branch of petrology that focuses on detailed description of rocks (shape and cleavage relief).
Petrography
Causes of Stone Decay:
- Earthquake
- Fire
- Terrorism
- Vandalism
- Neglect
- Tourism
- Previous Treatment
- Wind
(Other Factors) Causes of Stone Decay:
- Flood
- Rain
- Frost
- Temperature Fluctuations
- Chemical Attack
- Salt Growth
- Pollution
- Bio-deterioration
- Intrinsic Factors
- Maintenance
This significantly contribute to masonry decay by causing structural damage, mortar deteriorations and foundation issues.
Earthquake
High temperatures during a this can cause chemical changes in masonry materials.
Fire
This contribute masonry decay by causing physical damage, exposing structures to harsh environmental conditions.
Terrorism
This action involving deliberate destruction of or damage to public or private property, is willful or malicious destruction or defacement of public or private property.
Vandalism
This pertains of failure to care for properly, to pay no attention or too little attention to; disregard.
Neglect
Heavy tourist traffic may lead to wear and tear of the concrete floor surface, pollution caused by increase vehicular traffic, vandalism and theft.
Tourism
The harmful intervention or prior restoration works.
Previous Treatment
These forces can break the building’s load path or punch a hole in the building envelope. Can even pick debris up and projects it against the building envelope.
Wind
The process that breaks rocks apart without changing their chemical composition.
Physical Weathering
Physical Weathering is caused by factors such as:
- Thermal expansion & compression
- Frost disintegration
- Salt crystallization
- Biogenic physical impact
This factor in physical weathering means change in temperature where the rock expands when temperature is increases, and rock contracts when temperature is decreases.
Thermal expansion and compression
This factor of physical weathering means repeated cycle of ice formation and ice melt in the pore spaces and fractures of rocks; water freezes, volume increases by about 10%.
Frost disintegration
This factor of physical weathering means groundwater moves into pores of rock by capillary action; water evaporates, salt crystals grow and accumulate, putting pressure on the rock; common in drier climates.
Salt crystallization
This factor of physical weathering means plants can grow in cracks; the pressure of a confined growing root can make cracks in the rocks larger, and as roots grow they can break rocks apart.
Biogenic physical impact
It is the weakening and subsequent disintegration of rock by chemical reactions; also known as decomposition or decay.
Chemical Weathering
Chemical Weathering is caused by factors such as:
- Oxidation
- Carbonation
- Hydrosis
- Hydration
- Dehydration
Reaction of rock minerals with Oxygen, changing the mineral composition of the rocks
Oxidation
The process of rock minerals reacting with carbonic acid; carbonic acid dissolves or breaks down minerals in the rock
Carbonation
