My Coursework About Starrfa

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  • Topic: Concrete, Construction aggregate, Metakaolin
  • Pages : 2 (521 words )
  • Download(s) : 60
  • Published : March 24, 2013
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Q3: Describe and discuss the durability properties of hardened concrete.

Durability is the ability of concrete to handle deterioration from the surroundings or at the service in which it is placed. The most important things that cause rust could be divided into two chemical and physical causes. The Chemical durability complications are disturbed with countless formulae reactions of cement-aggregate. On the other hand In the physical durability aspect problems are concerned from the aggregates that are susceptible to thawing or drying or freezing and wetting, in addition to physical wear.

Durability of concrete is measured by the ability of concrete to resist many characteristics such as chemical assault, bad weather, and abrasion while maintaining its desired engineering properties. Concretes vary for its requirements of durability having different degrees of durability relying on the properties that are desired and disclosure to the environment. For example, the indoor concrete floor having different requirements from the concrete that is exposed to tidal seawater. Concrete ingredients, they’re proportioning, interactions between them, placing and curing practices, and the service environment determine the ultimate durability and life of concrete

Physical Durability:
Aggregates are said to be unsound if volume changes that accompany environmental changes lead to the deterioration of concrete. Repeated freezing and thawing or wetting and drying cycles can cause volume changes. Rocks that undergo sizable volume change on wetting and drying are very rare; therefore, soundness is primarily a question of freeze-thaw resistance. Freeze-thaw resistance of an aggregate depends on whether high internal stresses develop when the water inside the aggregate freezes and causes a volume increase. This stress is a function of the porosity of the aggregate, its permeability, the degree of saturation, and size.

Aggregates play an important role in determining the...
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