The construction of natural stones is one of the oldest in history, and continues to this day.
Due to the availability of stones from the mountains and quarries, and because most of the old buildings required pressure-bearing buildings, the building is characterized by a sense of luxury and poverty.
Historical development of stone construction
At the beginning of creation, man lived in caves that were naturally carved in the mountains, such as the Tigris valley in Egypt. The man used it as a shelter for him from animals and weather fluctuations.
After that, the man began to build houses of straw in the shape of a cone on top, trying to imitate the shape of the cave.
Then it develops and covers and supports the base of the house with clay so as to avoid collapse and to heat the house from the outside.
Then they began to use broken stone stones from the mountains for the durability of stones, and began to build houses, temples, castles and fences.
These stone buildings were a key factor in the defense of cities.
All ancient civilizations are considered as stone civilizations, from Pharaonic civilization, through Babylonian, Chinese, Assyrian, Greek, Roman, Indian, and Japanese civilizations.
Types of stones and their distinction
The natural stones used in construction are cut from different quarries and fall under the types of sedimentary rocks, namely limestone, sandstone, and granite stones, which are now little used in the construction of our country.
Limestone: These stones are composed of calcium carbonate, and may sometimes exist pure and sometimes mixed with other metal jewels such as silice, aluminum, magnesium and some other metal oxides.
The types of limestone are:
Ordinary limestone: This stone is in the form of layers that sometimes have a large thickness separated from each other by stratified levels and may be light blue, and are soft and fragile, most of which are broken into a molasses that burn to lime.
Cochlear Stone: The limestone type used in construction is a harder stone than before.
Dolomite stone: a manganese limestone made up of calcium carbonate and manganese.
Sandstones: These stones are made up of quartz atoms that are joined together by adhesive such as silice, alumina or lime carbonate. The adhesive may not exist in some stones but its granules are very compact and cohesive. Since quartz is not affected by weather factors, the durability of the stone Sanding depends on the type of adhesive and the shape of quartz atoms and the amount of its ability to absorb water.
The red, yellow or brown color of the sandstone is only due to the presence of iron oxide in these stones as an adhesive. The softness of these stones arises from the presence of alumina, but if they contain mica, they are layers between the quartz grains and some of them. Class.
The sandstone particles are gravitationally resistant to atmospheric impacts and are resistant to sudden changes in temperature and cold.
The presence of iron and iron carbonate in these stones affects the purity of the stones.
Sandstones are used in many facilities, such as reservoirs with hubs, bridges, dams, etc.
We can distinguish the types of stones each other with the following specifications:
Granular accuracy: that is, the granules of these stones are small. The smaller the granule the stronger the stone.
Homogeneity: that is, all parts are of one kind so that the mass is solid one.
Easy to form: It is difficult to form solid stones according to will, becoming expensive after the operation because they need to spend a lot like stone flint.
If the stone is easy to sculpt, it can be operated for the desired purpose easily and a few expenses.
Clarity of palms: Stone surfaces are rough to accept adhesion with the mortar layers used against the soft stones that do not have this property.
Resistance to fracture and fragmentation: The more rigid the stone, the more cohesive the parts are used to be safe to withstand the great pressures that may be exposed to it.
Not affected by fluctuations and effects of air: Some of the stones of the effects of air to a large degree, long life, while others are affected by fragmentation parts and be of little value.
The substances circulating in the atmosphere contains some acids such as carbonic acid, sulfuric acid and azotec acid, which spread in the atmosphere of industrial cities, causing a lot of decomposition and disintegration of stones building in the atmosphere of those cities.
Carbon dioxide in the atmosphere affects stones containing low amounts of iron, and the same effect as acids does. This can be seen by looking at the old stone buildings in these cities.
If the air is pure, these stones are preserved and preserved for a long time.
The sand also affects the stones, and the heavy winds that may carry some sand materials, especially in the vicinity of the mountains and the desert, the sandy material works sandpaper, removing layer after layer of stones, but if the wind is nice it removes the dust on the façades of buildings.
Change in temperature and cold: If this change does not occur a stretch or a significant contraction, but the stones exposed to the sun live more than exposed to moisture. Therefore, the stone should not be used in the construction of any walls, one of which is exposed to great heat and the other to extreme cold.
Stone resistance: The stone resistance of the affected loads depends on their hardness. The effective pressure on any type of stone should not exceed 1/10 the crushing pressure of the stone, bearing in mind that the limestone blocks bear pressure between 30 and 150 kg per square centimeter.