How to be an excellent contractor?

Bros! Look at it!

When it comes to the male god on the construction site, the contractor is not allowed. But it is not that simple to be an excellent contractor. In addition to leading everyone to work hard, various stunts are very necessary. For example: how to add steel bars to concrete. First of all, let's take a look at the origin of concrete.

5000 years ago, the "Roman Mortar", the use of lime mortar, established a pyramid of the seven miracles of the world. By 1756, when the British J. Smith built a lighthouse, the lime stone contained in clay was burned and burned through After the fine grinding treatment, mixes with water and solidifies, obtained a mortar that is much higher than the "Roman mortar", and establishes the big lighthouse of Eddystone, which is well -known in the world.

This kind of mortar will have water hard characteristics after adding water, but unfortunately it is not widely used. Until 1796, the British J. Parker invented "Roman Cement", and he directly burned naturally mud and tattoo. In 1815, Berlin Chemist John Friedrich John determined that the effect of gloom in the cement was silicate. In 1824, the British construction worker Joseph Aspatin adjusted the proportion of limestone and clay to burn and grind, and obtained the "Portland Cement". At this point, the real cement appeared in the world. Subsequently, in 1849, the French gardener Joseph Monier invented the "reinforced concrete" and combined the wire with concrete to make flower pots to solve the problem of low concrete tensile strength, which also provided a huge source of inspiration for the design of modern architecture.

In China, the concrete abbreviation is "concrete", that is, "artificial stone". The common concrete is formed by gel material (cement), rough aggregate (stone) and fine aggregate (sand) mixed solidification according to a certain proportion. Of course, some concrete may add some additives to improve certain properties in it, thereby changing the strength, color, and anti -seepage of the concrete.

After pouring concrete, the water contained in it will be combined with the cement, which occurs in hydration to form colloids. At the same time, it automatically fills the stone gaps and sand gaps in the concrete. You can withstand dozens or even hundreds of tons of pressure. In addition, concrete also has a low price advantage, so it is widely used in various buildings.

Since the concrete is so solid, why does the packaging head add steel bars to the concrete to increase the cost of building? What can reinforcement play?

The concrete can withstand a lot of pressure, that is, the so -called "pressure resistance" is strong, because the characteristics of the concrete itself are inevitable during the solidification process. When the concrete is under pressure, these tiny cracks tend to be closed, so they can withstand great pressure.

However, when they are pulled, these cracks will begin to expand and extend, resulting in crushing concrete, so the concrete "tensile resistance" is relatively poor. As architectural materials, we must not only consider compressiveness, but also consider "tensile resistance" and "shear resistance". May wish to think about it, there are only pillars in the construction of houses and bridges, and there will be beams and covers. At the same time, it is also affected by natural disasters such as strong winds, rain and snow, and earthquakes. Therefore, in the case of ensuring the safety of the building, the capacity of concrete and shearing must be increased.

Reinforcement has strong tensile, shear, and bending force. For example, when the tension is tensile, the reinforcement can show a good plasticity.

Since the performance of the steel bars is so good, why not build a house with reinforced bars? This is because the price of steel materials is very expensive. If all steel bars are used to build high -rise buildings and bridges, it will be a very expensive expense. In addition, the reinforced bars are easy to rust and need to be maintained frequently after the outdoor meridian is winding and sunburn, otherwise the construction equipment will collapse. Therefore, even if the Baodou is willing to use the reinforcement to build a house, the developer and the owner are not stupid, and of course they disagree.

Therefore, the smart contractor puts the reinforcement to the concrete, so that the two materials have the same force in the building, coordinate and deform, and have the ability to resist tensile and pressure resistance. Under the influence, the two are deformed consistent; reinforced and concrete also have good adhesion; at the same time, concrete can also provide a protective layer for reinforced steel to prevent rust of reinforcement; when a fire occurs The first layer of protective effects prevent the heating of the steel bars. In addition, in order to increase the binding force between reinforced and concrete, the reinforced bars will add ribs during the production process to form "rib steel". The combination of the two truly achieves both fish and bear's paw, which has both pressure resistance and tensile resistance, thereby ensuring that the building materials are more secure and reliable.

Of course, the use conditions for buildings are different, and the choice of concrete and steel bars is also very different. The concrete can be divided into heavy concrete, ordinary concrete, and light concrete according to density; according to gel materials, it can be divided into cement concrete, polymer concrete, resin concrete, gypsum concrete, asphalt concrete, water glass concrete, silicate concrete, etc. It can be divided into structural concrete, waterproof concrete, heat -resistant concrete, acid -resistant concrete, decorative concrete, large -volume concrete, expansion concrete, radiation -proof concrete, road concrete, etc. Reinforcement also has many classifications, which can be divided into chemical composition, production process, rolling shape, supply form, diameter size, and use. It can be divided into force tendons, distributed tendons, stirrups, standing ribs, penetrating tendons, negative tendons, tensile tendons, and abdominal tendons. Therefore, learning how to choose the right steel concrete is also a very important knowledge, which can make you an excellent contractor and the male god of the construction site! Well, ok, wipe

Now everyone understands why the excellent contractor should add steel bars to the concrete. We must give full play to the advantages of the two, combine the concrete with strong pressure resistance with the steel bars with strong tensile capacity, and use the opponent's advantages to make up for their own defects to make up for their own defects Realize the maximum resources and optimal use. If you encounter difficulties in your life, you can take advantage of it and coordinate and win a win -win situation.

references

World Cement History

https://www.sohu.com/a/411457148_806515

The previous life of concrete

https://zhuanlan.zhihu.com/p/100404078

Who invented reinforced concrete?

https://www.awhouse.art/%E9%92%E7%AD%8B%E6%B7%B7%E5%8%9d%9C%9F%E688%AF%E8%B0 %81%e5%8F%91%E6%98%8E%E7%84%EF%BC%9F

What are the types of concrete?

https://zhidao.baidu.com/question/562003666425434812.html

Do you divide the 8 types of reinforcement on the construction site? https://baijiahao.baidu.com/sid=1711837868065485086WFR=spor=pc

What age is the invention of cement? Why does cement contribute so much to modern society?

https://baijiahao.baidu.com/sid=16219189737580926wfr=spiderFor=pc

(Article pictures are derived from the Internet, only for science popularization for reference)

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