The Meiyu season, also known as the "plum rain" season, occurs annually from mid-June to mid-July in the middle and lower reaches of the Yangtze River in China. It is characterized by a period of continuous rainy weather. During this time, items are prone to mildew, hence the term "moldy rain," and it coincides with the ripening of yellow plums in the Jiangnan region, which is why it is also called "plum rain" or "yellow plum rain." The duration of the rain belt is referred to as the "Meiyu season." During this period, continuous overcast and rainy weather, along with high temperatures and humidity, pose many challenges for reinforcement work using adhesive anchors.
In the Meiyu season, humidity is almost omnipresent, with a very high level of moisture in the air. In such a humid environment, it is crucial to strictly control the environmental humidity when carrying out reinforcement construction. Excessive humidity can greatly affect the curing speed and quality of the adhesive anchors. Reinforcement under such conditions can significantly reduce the effectiveness of the work, and in severe cases, it may even threaten the safety of the building. Therefore, it is essential to accurately measure the environmental humidity before construction. If the humidity exceeds the standard, dehumidifying equipment should be used promptly to reduce the environmental humidity.
A humid environment can easily cause the surface of concrete to become damp, significantly increasing its water content. If the moisture on the surface of the concrete is not fully removed, the bonding strength between the adhesive anchor and the concrete will be weakened, leading to a reduction in the reliability of the reinforcement. Therefore, before starting the reinforcement work, the treatment of the base material surface must be handled with care and precision to ensure it is dry and clean. The "three blows and three brushes" process is indispensable.
In addition, in the humid environment of the Meiyu season, some conventional adhesive anchor materials may lose their original performance due to the damp conditions. Choosing the right product is crucial.
For example, the SHB-611 underwater-specific adhesive anchor, made from modified epoxy resin, has the advantages of high strength and strong bonding force, similar to pre-embedded anchors. It has excellent aging and heat resistance, no creep at room temperature, and can resist erosion from acids, alkalis, and salts. It also has good seismic and fatigue resistance, making it particularly suitable for anchoring in humid and clear water environments such as seawater and freshwater. Compared to conventional adhesive anchors, it performs more favorably in underwater projects, achieving breakthroughs in all performance parameters, truly realizing the concept of specialized use for specific purposes.
The Meiyu season is not only humid but also characterized by high temperatures, which require attention. When using injection-type adhesive anchors, it is important to control the speed of the injection.
Due to the principle of "thermal expansion and contraction," injecting too quickly can lead to the bursting of the adhesive tubes. Therefore, it is necessary to reasonably control the injection speed to avoid such occurrences.
After reinforcement in a damp environment, corresponding protective measures should be taken. If the reinforced structure is exposed to a damp environment for a long time, the curing quality of the adhesive anchor and the reinforcement effect may be affected. Measures such as constructing sunshades and covering with moisture-proof materials can provide effective protection for the reinforced structure, shielding it from the damage of the damp environment.
Underwater adhesive anchor construction process:
- Drill holes in the base material.
- Clean the holes thoroughly.
- Inject the adhesive anchor into the holes.
- Slowly screw in the bolt.
- Wait for the adhesive to cure.
- After curing, the structure can bear loads.
Despite the challenges brought by the Meiyu season to the reinforcement work with adhesive anchors, as long as we strictly control the relevant measures, including humidity control in the construction environment, treatment of the base material surface, selection of suitable adhesive anchor products, and subsequent reinforcement maintenance.
As long as these issues and details are given high importance, the performance and quality of reinforcement can be greatly improved, making the reinforcement work with adhesive anchors during the Meiyu season manageable.
