The basic principle of waterproofing and leak plugging is chemical grouting. Sealing expansion joints through chemical grouting involves manually or mechanically injecting a specially formulated chemical grouting material into the cracks of the building structure under pressure, causing the grout to solidify within the cracks. The purpose of this is to fill the gaps and stop the leakage. For贯穿cracks, methods such as sealing, embedding pipes, and chemical grouting can be adopted. For non-penetrating cracks, due to the closed-air condition, it is difficult to inject slurry into the tip area of the cracks, thus unable to eliminate the stress concentration zone formed in the tip area. Therefore, various factors should be carefully considered during treatment to improve the filling rate of the slurry. For temperature cracks, considering the concrete structure's sensitivity to temperature changes,“Lag effect”Generally, grouting is performed at the lowest temperature point of the concrete mass for better results.
What to do if the expansion joints in the building leak?
If there are leakage issues in the expansion joints between buildings, it may be due to the failure of the waterproofing material. A new waterproofing job is required, choosing a temporary waterproofing material to lay down can effectively alleviate the trouble of leakage.
Firstly, the original waterproofing layer must be completely removed. Then, use cement mortar to level the surface, ensuring it is flat. Strengthen the waterproofing at the roots where pipelines pass through the floor by first applying a sealing膏 for closure.
Once dried, apply the waterproofing material first to the facade. Each coat must be applied only after the previous one is completely dry. And then...2When applying waterproof materials, ensure the second coat is perpendicular to the first to prevent missed spots. With proper maintenance afterward, it will effectively serve as a waterproofing solution.
Why is there water leakage in the expansion joint?
Expansion joints may leak if the initial positioning of the waterproofing strip was inaccurate, so precision in placement is crucial. Severe misalignment or distortion may prevent it from aligning with the center of the joint later on, affecting its waterproofing effectiveness. Therefore, the initial fixation method must be mastered properly.
Another reason is that during the installation of the water stop, if there are issues with the concrete not being properly sealed on both sides, it becomes difficult to properly compact the concrete being poured below, leading to a surface strength that doesn't meet standards and resulting in honeycomb-like structures. Because gaps are formed, water will gradually leak through these gaps, and the leakage problem will gradually worsen over time.
Additionally, after the concrete pouring, due to varying pouring times and lack of adequate protection, the concrete strength may not be sufficient. Or, during construction, if the waterstop is cut by rebar, these issues can lead to future leakage problems.
What is the main function of expansion joints?
The primary function of expansion joints is to prevent cracks in buildings due to climatic changes. This method involves leaving a gap at regular intervals along the length of the building, and then completely disconnecting all above-ground components of the building, such as the roof, walls, and floors. Since the building foundation is buried underground, it is less affected by temperature changes and does not need to be disconnected. The width of expansion joints is generally20-30Within centimeters, the seam must be filled with insulating material. The spacing between the two expansion joints is clearly specified in the building structure regulations and cannot be altered arbitrarily.
If the building plan is excessively long and due to thermal expansion and contraction, it could also lead to significant temperature stresses in the structure. Therefore, gaps need to be set at certain lengths within the structure to divide the building into several sections. This gap is what we refer to as a expansion joint. For different building structural systems, it's important to note that the spacing of these expansion joints varies.
