Stone

Why are stones used in construction?
Stone is a natural material usually used in architecture with constructive purporses because of its resistant and longevity. There are some many types of stone related with the size, the porosity, their chemical position and the hardeness, but they are formaly classificad in three types, the igneous, the sedimentary and the metamorphic, that are subdivided into many groups. Rocks have some positives characteristics like adaptavility, naturality and resistance that had caught the attention and they are use in some constructions, although they have some negative ones.

The igneous rocks are formed when the magma gets cool.

The metamorphic rocks are formed by any kind of rock subjected to different conditions of temperature and pressure that it was originally formed.

The sedimentary rocks are composite by sediments, organic or chemical precipitates || Paragraph
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Stones have some advantages and disadvantages. They are used in construction because are durable, can adapt to sculptural treatment and can be used in their naturally form, although they are difficult to quarry, transport and cut, weakness in tension, expensive and unstable with load pushing at angles.

In the work area, we can find two types of stones that have different characteristics:

1.**The simplest and the cheapest one is ** Rubble, roughly broken stones bounded in mortar 2.**The strongest and most suitable for monumental architecture is ** Ashlars-Masonry, regularly cut blocks (e.g. entablatures, **the upper sections of a classical order that rest on the capital of a column) **

Despite of the characteristics that we mentioned before, the rocks can link with other materials barely bonded. T**he best way that the stones can bond is when blocks are placed in a way that the vertical joints don’t mach with the instants rows. **


 * The stones have been used in the construction of buildings since the Stonehenge, in England, because they are strong enough to provide monolithic supports and beams. **