How many years does concrete last and how long does concrete last?

Concrete works with cracks. There are cracks in any concrete after the reconstruction, and the crack width of the general component is less than millimeter. Reinforced concrete structure.

The fair use period is 50 years. But it's not like it's going to break down in 50 years. After identification and reinforcement, it can continue to be used.

There are various reasons why cracks occur in concrete, but the root cause is that the tensile stress in the concrete exceeds the tensile strength of the concrete. Specifically, it can be attributed to three reasons: temperature and humidity changes, excessive deformation due to external loads, and improper construction methods. The specific types are:

1.Cracks caused by cement shrinkage. This crack appears on the surface of the concrete and is relatively small. Cement is a hydraulic material with dry shrinkage, and cracks may occur if there is not enough water due to improper maintenance in the early stage of hardening.

2.Temperature differences, cracks caused by thermal expansion and contraction effects. This kind of crack generally appears in the environment with large temperature difference and on the component or structure with a large area or length, and there is no expansion joint in the appropriate part.

3.Cracks caused by stress concentrations. This kind of crack generally appears at the yin and yang corners of the concrete slab or at the support. It is caused by insufficient reinforcement of negative moment reinforcement on the plate surface or excessive spacing of thick reinforcement.

4.Cracks caused by overload and excessive deformation caused by improper use. This type of crack usually occurs in the tension zone of the concrete flexural member.

5.Cracks caused by tensile force. In the tensioning process of prestressed reinforced concrete components after tensioning, cracks may be caused if they are not well controlled. This type of crack usually occurs at the end of the prestressed member or at the corner of the upper surface of the slab.

6.Cracks caused by uneven settlement. Due to the uneven settlement of the foundation, the foundation or ring beam, girder and other components are too tensile and cracks appear.

7.During construction, cracks will occur in the structure due to the vibration, deformation or displacement of the formwork in the initial setting stage of concrete.

8.Cracks created prematurely by loading. During construction, due to the early removal of the formwork, the concrete strength did not meet the design requirements and the load was added in advance, which caused the components to be overloaded and cracks appeared.

9.If the construction joint is not treated well, cracks may appear in the construction joint.

10.In the process of demoulding, transportation, stacking and lifting, the compression area of the component is in a tensile state due to various reasons, which may cause cracks in the component.

Thanks to the invitation, the life of concrete is mainly determined by the design and the environment in which it is used. The natural decomposition time of concrete is equivalent to weak weathering stone, in the process of use, the pavement concrete is finished in more than ten years, the concrete of housing construction projects has 50 years, 70 years, and the concrete life of our Three Gorges Project should be hundreds of years.

Generally speaking, the life of concrete is about 10 to 20 years, which can be said to be very long.

The life span of concrete is generally about 100 years, and this life is also very long. And at present, the quality of concrete on the market is getting better and better, and the life will be longer.

It has a long lifespan, and while it is matched with steel bars, the buildings it constructs can reach more than 80 years.

How long does it take for concrete to crack Hello dear, the concrete with a large water-mill balance ash ratio will produce cracks within the age () months due to drying and shrinking. Blind to make the correct answer] D [Answer analysis] This question examines the analysis of the causes of structural cracks in reinforced concrete structures. Concrete with a large water-cement ratio, due to drying shrinkage, cracks occur within 2 to 3 months of age.

Commercial housing can not be guaranteed, the Internet often breaks the news that the walls of commercial housing fall off, cracking, and even with your hands can pinch a handful of concrete down, more cruel is that some walls are mixed with straw, linen, plastic nylon, straw mats, in short, in my opinion, the normal is generally in 30-40 years, abnormal years, in recent years, I often see some places bridge collapse, building collapse, highway doll pits, there are many reasons for this phenomenon, or commercial bribery in the middle of the link, kickbacks, These are caused by the developer's cost is too high or the contractor is pinched by the profit is too low or irresponsible some profiteers, the house has a foundation to build its own value is reliable, the quality will not be bad, commercial housing in addition to speculation, ** and high, the quality can not be guaranteed, even if Beijing, Shanghai and Guangzhou?

There should be no possibility of satisfying the theoretical value, because the product cannot meet the standard. But if you use it as waste, you can leave it behind for 10,000 years!

When conditions are poor and maintenance is lacking, concrete alone can be weathered over the course of a few decades. And the road surface is so bad that it may not last for a few years. Do you know how long the life of concrete is? Let our pchouse answer for you.

Ordinary concrete is composed of cement and fine aggregate.

1. Cement. Cement plays a cementing role in concrete and is the most important material. Correct and reasonable selection of cement varieties and strength grades is an important factor to ensure the quality of concrete.

When preparing concrete, ordinary Portland cement, ballast Portland cement, pozzolana Portland cement, and fly ash Portland cement are generally used. The quality of cement should meet the requirements of the current national standards and specifications.

2. Fine aggregate ((sand)

The aggregate with a particle size is called fine aggregate, which is referred to as sand. Natural sand is generally used for concrete, such as river sand, mountain sand, sea sand, etc., among which river sand has the best quality and the most application. Artificial sand is obtained by crushing and screening rocks.

The house we usually buy, in fact, can only buy the right to use the house for about 70 years, is it not 70 years after the concrete used to build the house will die. So the house can't be lived in anymore? In fact, this is not the case, ideally, the life of concrete can be said to be permanent, but in actual life affected by various factors, the life of concrete will be greatly reduced, the reinforced concrete commonly used in construction is a mixture of Portland cement, stone aggregate and steel skeleton, this mixture has good compressive and tensile capacity, so it is suitable for many projects.

The life of the concrete itself can be compared with the rock, but if it is exposed to the air all year round, it has to consider the weathering problem, if it is not well maintained, it will be weathered very seriously within a few decades, and the steel bar is easy to be oxidized, the concrete is originally alkaline, but it is affected by carbon dioxide, it will gradually become acidic, although this process can enhance the strength of the concrete, but it is easy to corrode the steel bar, if the protective layer of the concrete is not thick enough, Rebar can also lose its tensile resistance due to corrosion, which can cause the building to collapse.

So now the service life of concrete is generally 50-70 years. If the materials are regular and well maintained, the life will be extended, and the actual service life of concrete will generally be longer than theoretical, so you don't have to worry about the house suddenly collapsing after living for a long time.

The basic structure of the house is the columns, walls, beams, etc., which are also very important structures of the house. Because these structures not only guarantee the safety of the house, but also extend the life of the house.

For example, it can withstand the load and deformation within the scope of the house, and can maintain the overall stability of the house. Secondly, under normal maintenance, the house will not affect its service life due to the aging of concrete.

1. Steel structure.

As the name suggests, the steel structure is a reed trace made of steel materials, including a suspension structure, and it is also one of the types of building structures. The overall weight of the steel structure is relatively light, and the construction is relatively simple, generally suitable for steel workshops and large gymnasiums, etc., such as the Bird's Nest in Beijing is built of steel structure.

2. Steel-concrete structure.

The main structure of the steel-concrete structure is built with reinforced concrete, and the materials are a mixture of cement, steel bars and so on. For example, a house is partly made of steel and partly made of reinforced concrete, and many high-rise houses are built with this structure, but this method is more complex and more expensive.

3. Frame shear wall structure.

The shear wall is to replace the beams and columns in the frame structure with reinforced concrete wall panels, which can bear different inner linings and effectively control the horizontal force of the structure, which is widely used in high-rise houses.

100 years of good luck means 100 years.

The service life should be based on the specific situation, first of all, the design standard, the general civil building is 50 years, and the reinforced concrete structure is 80 years or more for large or more important buildings.

Of course, its service life will definitely be greater than the design life, if the natural life is closely related to the characteristics of concrete materials, structural design, and the influence of natural conditions, its life is relatively not very long, mainly due to the construction time will be defective, such as concrete cracking to reduce the protection of steel bars, resulting in accelerated damage, so that the life is greatly reduced, as well as natural erosion and weathering, but its service life is definitely greater than the design life, if there is later maintenance, those defects can be compensated, its service life will be greatly improved.

The building will be regularly inspected, and the hidden dangers must be dealt with in a certain amount of technology, early detection and early treatment, so that the life of the building will be greatly improved, the service life of the building refers to the life of the house in physical wear and tear can maintain normal use, and the natural life span is determined by the structure and quality of the house.

The depreciation life of a dwelling refers to the number of years of transfer of the value of the dwelling, which is determined by the socio-economic conditions in the process of use, and is also called the economic lifespan. The useful life of a dwelling is generally greater than the depreciation life. The depreciation period of different building structures is stipulated by the state is:

60 years for reinforced concrete structures; 50 years of brick-concrete structure.