What Is the Melting Point of Concrete? From many references and studied, I have a decision that Concrete does not actually have a melting point, but it decomposes into various components due to the makeup of concrete, which is mostly sand and gravel with Portland cement added. Melting point of Silica is around 1200°C and around 1550°C is the melting point of cement . Steel melts at around 1510 degrees C. Now my specific question is why concrete building is assumed more Safety than steel building.
Mr Alam, your question why concrete building is assumed more Safety than steel building. it has to be well interpreted. Two elements with the same dimensions, one made of steel and the other made of concrete, under fire, the concrete one will collapse before the steel one. However, this is not how both are found in civil construction. Concrete structures are larger than steel structures. This causes temperatures in concrete to be lower than in steel structures. That is why it appears that the concrete structure (not just a small concrete element) resists more than steel. However, in practice, codes require that the structures of both materials must be safe in a fire situation. That is, the reinforced concrete structure must be designed to withstand the fire, this means that the dimensions of the concrete and the position of the reinforcement in the concrete mass must be adequate so that the temperatures in the reinforcements are not too high. In turn, steel structures must be coated with thermal protection material. Thus, in the design practice, the structures of the two materials are equally resistant to fire. Just as it does at room temperature.
From the classical engineering point of view, the answer is no. But if you are talking about the possibility in terms of Geology, the answer would be yes. For more explanation I just want you to revise the Metamorphic Rocks.
You can see that the concrete is not melting in the fire. This is due to the presence of other circumstances such as the space around the buildings and existence of human beings that would reduce the danger of fire.
Dear Md. Shahrior Alam
Concrete structures perform well in fire. This is because of the combination of the inherent properties of the concrete itself, along with the appropriate design of the structural elements to give the required fire performance and the design of the overall structure to ensure robustness.
Fire performance is the ability of a particular structural element (as opposed to any particular building material) to fulfil its designed function for a period of time in the event of a fire.
Also, concrete has the highest fire resistance classification (class AI) under EN 13501-1:2007- A1:2009.
YES, concretes melt without problems!
There will be no distinctive melting point determinable (due to the various compositions of concretes). Concretes will go through different stages of thermal decomposition (dehydration, baking, sintering, melting) if heated > 1300°C. The brownish melt will harden to a glassy product (ceramic) when cooled down to room temperature.
Experiments with selective laser melting (SLM) have shown that i.e. concrete surfaces may be covered by a glassy ceramic coating or decorated by this laser technology.
Concrete is exploding not melting when heated.
This vedio will help to see that
https://youtu.be/NxJPX0lssIQ
Thank you
Don't get mislead! Under standard conditions for the determination of melting points, concrete will never explode, when heated!
Sure, under very special (extreme) thermal exposure, such as
- restricted escape of free or bound water and/or decomposition gases (creation
of a "pressurized vessel phenomena" due to encapsulation)
- partial / localized spot heating (extreme thermal gradient within a material)
concrete structures may tend to rapid spalling (mistakenly called/defined as "explosion"!) during a heating process prior to melting.
Unrealistic laboratory conditions/experiments are not suitable for determination of melting points/characteristics.
Mr Alam, your question why concrete building is assumed more Safety than steel building. it has to be well interpreted. Two elements with the same dimensions, one made of steel and the other made of concrete, under fire, the concrete one will collapse before the steel one. However, this is not how both are found in civil construction. Concrete structures are larger than steel structures. This causes temperatures in concrete to be lower than in steel structures. That is why it appears that the concrete structure (not just a small concrete element) resists more than steel. However, in practice, codes require that the structures of both materials must be safe in a fire situation. That is, the reinforced concrete structure must be designed to withstand the fire, this means that the dimensions of the concrete and the position of the reinforcement in the concrete mass must be adequate so that the temperatures in the reinforcements are not too high. In turn, steel structures must be coated with thermal protection material. Thus, in the design practice, the structures of the two materials are equally resistant to fire. Just as it does at room temperature.
I agree with @Valdir Pignatta Silva, who responded excellently!
As the melting points of concrete and steel are relatively close. However, when steel is under high temperatures, it loses a high quantity of its strength unlike concrete which doesn’t get affected. Losing strength could lower the safety factor of a building, which eventually causes failure of the system/building. This is all due to the steel’s joining system (welding or bolting) under heat either of these will fail, leading to unjointed steel members. Whereas, in concrete buildings the members are joined together in ways that they may not get affected by fire or high temperatures making them stronger.
Assuming that a building is exposed to fire and heat. The concrete component as a whole (all of its constituents will act as defence and not the cement itself. This is why steel members in steel-structured buildings are brushed with some protecting liquids.
and some studies are done ...
https://www.buildings.com/news/industry-news/articleid/2511/title/which-is-the-better-building-material-concrete-or-steel-
I hope that this helps
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