Diseases of concrete
Writer： admin Time：2024-08-29 13:30 Browse：
1、 The main types of disease in concrete
1. Cracks: Cracks are one of the most common quality problems in concrete, which may occur due to temperature stress, shrinkage, settlement, stress release, and other reasons.
2. Honeycomb rough surface: Honeycomb rough surface refers to the appearance and durability of concrete surfaces affected by potholes and pits.
3. Exposed reinforcement: Exposed reinforcement refers to steel bars exposed outside the concrete, which may cause corrosion of the steel bars and affect structural safety.
4. Insufficient strength: Insufficient concrete strength may lead to a decrease in structural bearing capacity, affecting its functional use.
5. Matte surface and insufficient smoothness: The concrete surface may have pockmarks, potholes, or insufficient smoothness, which affects the appearance and user experience.
2、 Cause of occurrence
1. Raw material issues: Poor cement quality, inaccurate sand and gravel grading, and quality problems with admixtures may lead to poor concrete performance.
2. Mixing ratio issue: Inaccurate mixing ratios may lead to poor workability, low strength, and large shrinkage of concrete.
3. Mixing and transportation: Uneven mixing and segregation during transportation may lead to a decrease in concrete quality.
4. Construction issues: Improper pouring process, untimely maintenance, and formwork leakage may all cause concrete quality problems.
5. Design issues: Unreasonable structural design, irregular component cross-sections, and other design problems may also lead to concrete quality issues.
3、 Prevention and solutions
*** Adding polypropylene fiber is one way to control the cracking
1. Strictly control the quality of raw materials to ensure that the quality of cement, sand and gravel, admixtures,like Polypropylene fiber,steel fiber, etc. meets the regulatory requirements.
2. Accurately calculate the mix proportion to ensure that the concrete meets the design requirements in terms of workability, strength, etc.
3. Standardize the mixing and transportation process to ensure stable concrete quality.
4. Standardize the construction process, ensure correct pouring technology, timely maintenance, and avoid problems such as template leakage.
5. Strengthen construction management to ensure that construction quality meets regulatory requirements.
For crack problems, crack sealants or cement-based waterproof materials can be applied at the crack location. For wider cracks, cement mortar or rigid repair materials can be used for filling and repair.
7. For the problem of honeycomb and rough surface, a deep groove in the shape of a circular arc can be chiseled on the surface, and then protected with a polymer anti cracking plaster, or the surface can be chiseled and supported with a template, poured with a higher grade of fine aggregate concrete and vibrated.
8. For the problem of exposed reinforcement, cushion blocks can be added between the reinforcement and the formwork to ensure the thickness of the reinforcement protection layer, or a layer of interface agent can be applied to the surface and the reinforcement can be tied, and then poured with a higher grade of concrete and vibrated.
9. For the problem of insufficient strength, early strength agents or early strength antifreeze agents can be used for treatment. For already formed structures, electric heating rods or plates can be used for heating and curing to enhance the development of early strength.
Summary: Common quality problems in concrete cannot be completely avoided to a certain extent, but the above methods can effectively reduce the frequency of such problems. In the actual operation process, it is necessary to strictly follow the relevant regulatory requirements and continuously improve the construction quality and management level.
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