In real life, we can see the phenomenon of cracks in some walls. Many people may think that this is caused by problems with the construction project. In fact, this is not the case. Buildings made of reinforced concrete are subject to external forces. Cracks will appear more or less under the action. So what causes cracks? What types of cracks generally appear? Let’s take a look!
1. Uneven settlement of buildings
When uneven settlement occurs in a building, the overall hardness and stiffness of the building will become worse, resulting in irregular vertical and horizontal patterns. Deformation. At the same time, the entire base cannot withstand its variable force, causing shear forces to occur in some parts of the brickwork. When the deformation ability is not enough to resist, cracks will occur.
Cracks in houses caused by uneven settlement generally appear as horizontal or vertical cracks. Such cracks can cause wall cracks in mild cases, or can cause house collapse in severe cases. They usually occur on the first floor. In special circumstances, It happens on other floors too.
2. Temperature difference within the building
Cracks caused by this factor mostly occur in brick-concrete multi-story houses. For example, if the roof of a house is made of reinforced concrete panels and the walls are made of bricks, cracks will easily occur due to temperature differences, not least because the linear expansion coefficients of the roof and wall materials are doubled. , and also because the solar radiation area received by the roof is much larger than the irradiation area of ??the wall.
Summer and winter are easily affected by temperature, causing wall cracks. In the early stages, temperature is the dominant factor in crack formation, and it will take a period of time for the cracks to stabilize and not continue to develop. This type of cracks generally appear as horizontal cracks, straight splayed cracks, and inverted splayed cracks.
3. Other reasons during the decoration process
Some problems that occur during the decoration may also cause wall cracks. For example: when applying cement plaster, improper proportion of cement slurry will cause wall cracks; uneven scraping of wall putty; improper proportion of water and latex paint, etc. These non-compliant decoration operations can lead to cracks.
Generally, such cracks show irregular linearity, with little overall impact. They do not affect the safety of living, but only affect the aesthetics of home decoration.
4. Extra long concrete structures
With the improvement of concrete strength level, the development of large-scale buildings and the application of mercury feeding concrete technology in construction, the floors continue to increase, making Temperature differences within overlong concrete structures become larger, causing shrinkage cracks.
Generally, such cracks appear as horizontal cracks, straight splayed cracks and inverted splayed cracks. However, such cracks will not have any immediate impact, nor will they affect the overall structural safety and load-bearing capacity, but they will endanger the durability and integrity of the overall structure and bring a very bad life experience to users. .