News Abstract: in the case of basement leakage stoppage, the causes of reinforced concrete cracks encountered are summarized. Each crack has one or several main causes
In the case of basement leakage stoppage, the causes of basement reinforced concrete cracks are analyzed
In the case of basement leakage stoppage, the causes of reinforced concrete cracks are summarized. Each crack has one or several main causes, such as: the change of temperature and humidity, the brittleness and inhomogeneity of concrete, the unreasonable structure, unqualified raw materials, formwork deformation, uneven foundation settlement, etc.
The concrete crack causes are carefully analyzed and effective measures are taken to prevent concrete cracks.
There are many reasons for cracks, mainly including the following:
1. Design reasons, such as the shrinkage deformation of concrete structure is not fully considered in the design, or the configuration of structural reinforcement is too small or too thick, resulting in cracks in components.
2. The shrinkage of concrete will be intensified due to material reasons, such as excessive mud content in coarse and fine aggregates, wrong type of concrete admixtures and admixtures, etc.
3. Reasons for concrete mix proportion, such as excessive water cement ratio.
4. The reasons for construction and maintenance: the vibration is not dense during construction, resulting in honeycomb phenomenon and local cracks; improper heat dissipation measures of mass concrete cause excessive temperature difference inside the concrete, resulting in temperature difference cracks; for example, when pouring concrete, the wind speed is too high and the sun is exposed to the sun, causing the concrete to lose water too fast, resulting in excessive shrinkage of concrete; Concrete maintenance measures are not in place will also cause concrete early dehydration, shrinkage cracks; therefore, strengthening the construction site is particularly important.
5. The cracks of concrete wall will be caused by some reasons, such as excessive local load, rough decoration, random demolition of bearing wall or arbitrary opening.
6. During the hardening of concrete, a large amount of hydration heat is released from the cement, and the internal temperature rises continuously, causing tensile stress on the surface. In the later stage, due to the restriction of the foundation or the original concrete, the tensile stress will appear inside the concrete.
Temperature will also cause great tensile stress on the surface of concrete. Sometimes the temperature stress can exceed the stress caused by other external loads. When the tensile stress exceeds the crack resistance of concrete, cracks will appear.
Therefore, the variation law of temperature stress is very important for reasonable structural design and construction. Website: micheledimaio.com