Why do concrete cracks occur ?
Writer： admin Time：2024-07-19 11:53 Browse：
Concrete cracks are one of the common diseases, and the occurrence of cracks not only affects the appearance of concrete, but also affects its service life.
There are many factors that can cause concrete cracks, and the main reasons are:
1. Poor quality of raw materials, such as unqualified cement stability, poor aggregate quality, and unqualified mixing water and additives.
2. Improper construction techniques, such as template not being moistened, improper treatment of construction joints, improper maintenance, and insufficient compaction during vibration.
3. Structural design defects, such as sudden changes in cross-section and improper prestressing.
4. Temperature changes, different heat dissipation conditions inside and on the surface of concrete, lead to temperature gradients, resulting in temperature deformation and temperature stress.
5. Shrinkage, including plastic shrinkage and shrinkage shrinkage (dry shrinkage), especially during the construction process of large volume concrete or high-strength concrete, due to the high hydration heat of concrete, the internal temperature differs greatly from the surface temperature of concrete and the external environmental temperature, coupled with the presence of constraints, resulting in hydration heat cracks.
6. Foundation subsidence, especially in adverse sites such as severely collapsible loess, frost heave soil, etc., when the foundation treatment does not meet the requirements of the specifications, the ability of concrete structure and foundation stiffness to resist foundation subsidence is still strong. However, when the foundation treatment does not meet the requirements of the specifications, foundation subsidence (expansion) cracks still often occur.
The methods for dealing with concrete cracks include filling method, grouting method, structural reinforcement method, concrete replacement method, electrochemical protection method, etc. Preventive measures involve correct material selection, optimization of construction processes, appropriate maintenance measures, and addition of crack resistant fibers, such as polypropylene fiber FD9130 to reduce the occurrence of microcracks in concrete, and coarse fiber FD600T to improve the crack resistance of concrete in the later stage. Federal Fiber can supply many different type fibers for concrete reinforcement . Welcome to inquiry.
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