| 5 great groups of materials used in the construction exist, that are
Ceramic and glasses.
First they obtain when cooking the mud in special furnaces. Examples of ceramic are the roofing tiles (left photo) or the brick.
| The glasses are obtained from the silica (earth) next to other components to improve their properties. They are material very hard or fragile
| Natural elements as the marble, the sand or the slate. They are used of natural form without hardly treatment To the left, a marble sample. To the right a granite stone. The marble is but delicate that the granite (ray more easily)
| Starting off of certain minerals, a great variety of pure metals is obtained (aluminum, the iron), that when uniting it to other metals and metals does not obtain alloys (case of the steel, that it is the mixture of iron and carbon) a pure metal as aluminum (left) and a stainless steel (mixture of iron, carbon and chromium)
| They are a mixture of materials to create another material with an improvement in certain properties, as for example asphalt (tar mixture and burdens) or the concrete (cement mixture, burdens, sand and water) the concrete to the left becomes in small amounts in the concrete mixer but for great amounts they are necessary to bring it in trucks. To the right, asphaltBinders
The cement and plaster use in bulk in the form of dust, but with the water mixture, it hardens to form a hard compound. To this process setting is called to him.2º Main constructive elements of the building
It has been the part in charge to support the weight of the building and for of reinforced concrete. Some good foundations are fundamental because if fails, the building will be affected very
2. The Structure. Formed by the pillars (vertical), the beams and joists (horizontal)
3. Grounds and ceilings. Between joist and joist it is placed the curved parts of the stern. The spaces that are free are made level with concrete to finish them with the wood or ceramics ground.
4. Outer wall. Usually it is a double brick wall with a space between which one fills up with an insulator as the fiber glass, the polyurethane foam or expanded polystyrene laminae.
5. Windows. Formed by a frame of wood, PVC or aluminum and its corresponding glass. Necessary for “opening itself to the deep space”, but it is a place by where much heat enters summer and it escapes in winter. The glasses multilayers (glass layer next to another one of air) are better for the heat insulation.
In the part superior usually one puts a joist (threshold) so that the bricks do not fall
6. Cover. It protects to us of rain. Normally it is realised with joists that support the curved parts of the stern, a layer of reinforced concrete and the roofing tiles. He is advisable to add an insulator to avoid losses of heat
7. Inner walls. They can be of pladur (stuffed very slight metallic structure with of cardboard and plaster) or of bricks
3º Properties of the materials
At the time of making a building it is important to know as they are going away to tolerate the materials. For that reason we are going to see some of the most important properties, as they are the density, the compression and the traction
The density is the relation between the weight and the volume and is moderate in kg between .
The formula that there is to use to calculate it is:
where M is the mass and V the volume.
Activity 1: To calculate the density of a beam that weighs 400 kg if it measures 5 meters in length X 20 cm of stop and 30 cm in width.
Activiadad 2: In the image inferior we have three I sweep equal with different weights. To calculate the density for each of them
We will see anow to determine whichever kg is to castrate to hold a deformed material before it is broken or. For it we must consider the magnitude physical of pressure, that measures the force to us between surface and whose unit is Mpa (megapascal) that is 1 million pascales. The pascal as pressure exerted by a force of 1 Nw in 1 meter squared is defined, that is In the following image we have the behavior of the steel, the glass and the concrete. The S glass with difference the winner of this test but its fragility does not allow him to be used as load element
4º Since a brick becomes?
If we want that it holds much the heat can be added special substances to him to turn it into refractory ceramics.
5º Since the flat glass becomes?
We are going to now see how make the glass of the windows. We have already seen that very it is used for being I am transparent (entered of the light), duros, fragile and resistant to corrosive agents.
They are even used as supports of cables of high voltage by his resistance to the current. We see an example above where glass discs are used to isolate the cable of the iron turret.
The glass is obtained from the fusion of sand, alkali and metallic oxides (it is added to give to color and stability).
To emphasize that when coming out of the main furnace the decreasing glass is very hot reason why is necessary to warm up it to temperature again so that it is not broken.
very used in the construction due to the price, ease of use, etc. The way to improve its properties is to add iron to him in its interior. This is especially important when it is put under bending stress. We appreciate in the figure that shoots with an arrow orange (flexion) causes that the face superior shrinks (compression) and the inferior dilates (traction). When adding to him the iron, is avoided this problem giving greater robustness to the beam.