Rapidly dispatched to the scene. Sealing the leak is crucial. After on-site consultation, only divers can be sent underwater to investigate before proceeding with the underwater sealing. Upon Director Gong's immediate order for divers to arrive overnight, four divers arrived and dived in. Amidst strong currents, the divers descended but struggled to stay steady, ultimately successfully sealing the underwater leak.
Operate according to modern enterprise management models. Comply with the requirements of the Provincial Construction Department, the Municipal Construction Committee, the client unit, and environmental protection authorities, ensuring civilized construction, quality follow-up, and lifelong responsibility. We are willing to contribute to the innovation and application of waterproofing and leakage prevention technology along with our domestic peers. We sincerely welcome enterprises, institutions, and individuals to consult and negotiate by phone or in person.
In major and medium-sized hydropower and water conservancy projects such as the Yangtze River Three Gorges, the Yellow River Xiaolangdi, and the Wanzhai, despite employing various construction techniques and having stringent quality assurance systems and control measures, various cracks have been found to a certain degree during concrete construction.
Various cracks that form in concrete not only have adverse effects on its structure but may also pose direct hazards to the entire building, particularly water structures. The formation of cracks in concrete, such as those beneath the water surface, can lead to water leakage along the cracks. For cracks above the waterline, the repeated temperature changes can cause capillary water within the cracks to further damage the structure, potentially leading to structural failure.
1. Project Manager 1 2. Manager 1 3. Safety Officer 1 4. Diving Team Leader 2 5. Divers 10 6. Crane Operator 2 Underwater Recovery and Underwater Object Recovery Engineering. Hot Searches: Construction teams specializing in underwater work, with strong capabilities, serving in rivers, lakes, seas, reservoirs, and other underwater engineering projects. Possesses a positive corporate image and strong competitive advantages. Since its establishment, it has adhered to a people-oriented approach, honest operation, and relies on high-quality, efficient, and dynamic services.
Underwater cutting for bridges, concrete, and more, providing diving services for port, bridge, shipyard, power plant, reservoir, and various construction owners. With an inclusive spirit and an indomitable spirit, Hua Hang Company is dedicated to the diving engineering industry. The company has always adhered to the diving operation philosophy of "people-oriented, diving expertise, continuous improvement, and customer satisfaction." Our diving service undertakes local diving work and arrives on-site within one hour. Before diving construction, it is essential to understand the water depth, current speed, weather, and ensure safety with no obstructions for upstream and downstream underwater operations. Our diving team is skilled, strictly follows operational procedures, and quickly resolves various underwater tasks. Trust us, and we guarantee to deliver the underwater engineering services you desire.
Surface treatment is required for cracks in areas with requirements for anti-weathering, anti-seepage, anti-erosion, and abrasion resistance. Services include: basement leak sealing, tunnel leak sealing, sewage pool leak sealing, culvert repair, pond leak sealing, underwater leak sealing, dock leak sealing, mine leak sealing, cable trench leak sealing, civil air defense project leak sealing, expansion joint leak sealing, junction joint leak sealing, crack leak sealing, pump house leak sealing, settlement joint leak sealing, dam leak sealing, underground engineering leak sealing, elevator shaft leak sealing, junction joint leak sealing projects, cooling tower leak sealing, construction joint leak sealing, underwater leak sealing, and various waterproofing and leak sealing projects!
1. Temperature difference variation
The basement construction spanned the summer and autumn, with the focus on the transition period between the two seasons. The construction and backfilling schedules indicate that the basement concrete was significantly affected by seasonal temperature differences and internal-external temperature differences during this period, with significant temperature variations of up to 33°C. It can be concluded that the primary cause of the expansion joint deformation is the horizontal contraction induced by the temperature differences.
2. Waterstop placement is inaccurate
Misalignment detected; the water stop belt installed at the basement expansion joint is twisted and misaligned, severely off-center. The hollow circular ring in the middle of the water stop belt does not align with the center of the expansion joint, affecting the belt's ability to adapt to deformation. Additionally, improper fixing methods often lead to the water stop belt not being securely fastened.
3. The waterstop does not combine tightly with the concrete on both sides.
When installing the horizontal waterstop on the base plate, it is difficult to compact the concrete below the waterstop, often resulting in honeycomb or rough surfaces. Additionally, after the moisture between the waterstop and concrete evaporates, gaps are left, forming water seepage channels. When pouring concrete on both sides of the vertical expansion joint, inadequate compaction occurs.
4. Lacking effective protection for rubber water stop belts
When there is a difference in concrete pouring time on both sides of the expansion joint in the basement, there is a lack of an effective protective structure for the exposed part of the waterproofing strip to be embedded in the subsequent concrete, or the protective structure may be damaged during construction due to collisions. Moreover, the waterproofing strip may also be damaged or cut by nails, rebars, and other sharp tools during construction.
5. Construction Tolerance
Base, wall, and ceiling expansion joints are all designed with corresponding nodes. During construction, these nodes were not completed as per design, resulting in dimensions and structures that meet design requirements.
Section 2: Repair Plan for Waterproofing of the Basement Expansion Joints
1. Construction Preparation
(1) Conduct on-site inspection of the basement expansion joint leakage location, quantity, and flow rate, and select an appropriate waterproofing structure based on the severity of the leakage.
(2) If the water volume is substantial, pre-grouting to seal leaks can be done first, followed by removing or dismantling decorative layers after reducing the water flow path; for lesser water volume, dismantling the decorative layers can be done initially for easier subsequent construction.
(3) Select qualified materials and components according to the established detailed plan.
(4) Surface to be cleaned, swept, and thoroughly washed, ensuring the base layer is of concrete structure, free of loose mortar, and flat; if not flat, local sanding or high-performance composite cement mortar can be used to level it. In case of local seepage or leakage during cleaning, perform grouting treatment, extending the grout into the rubber waterstop facing the leakage point to ensure no seepage or leakage during construction.
2. Set post-tensioned reinforcing steel with non-adhesive coating
In the concrete structure of the expansion joints in the basement, unbonded post-tensioned tendons are installed, applying the prestress after the structure is completed and reaches its strength. This preloads the concrete structure, enabling it to resist tensile stresses due to shrinkage and temperature deformation, thereby reducing and preventing cracks in the concrete.
3. Concrete Repair
During the reinforcement and repair of basement expansion joints, oblique injection holes are reserved in the concrete on both sides of the joint. Detachable waterstop bands are installed on the floor and wall panels, reinforced concrete挡板and joint materials are set on the outside of the wall joint, a water curtain wall is installed on the top plate, the embedded waterstop band on the top plate is located above the water curtain wall, and a gutter is set at the bottom of the top plate joint.
4. Concrete utilizes compensating shrinkage
Compensating shrinkage concrete is a type of concrete that incorporates an expansive agent or expansive cement, resulting in a self-stress of 0.2MPa to 0.7MPa. This type of concrete can generate a pre-compression stress of 0.2MPa to 0.7MPa through hydration and hardening within the concrete. This pre-compression stress can completely or partially offset tensile stresses caused by concrete shrinkage, creep, and temperature changes, thereby enhancing the crack resistance of the concrete in the expansion joint area of basements.
Additionally, self-compensating shrinkage concrete expands during hydration, which reduces the pores in cement stone, effectively filling them, and significantly enhances the overall impermeability of the project. The main applications of self-compensating shrinkage concrete in construction structures include: self-waterproofing of structures, seamless construction without post-construction strips in ultra-long reinforced concrete structures, and control of cracking and seepage in mass concrete. In actual engineering, these three situations may exist singly or interactively. By using the construction technology of self-compensating shrinkage concrete, these technical challenges can be addressed collectively.
Over 20 years of practice and experience in underwater diving operations such as shipwreck and debris recovery, underwater cutting, welding, dredging, gate repair, municipal pipeline sealing and demolition, well sinking construction, and various other underwater projects have gradually accumulated rich experience. Our efforts have been recognized and praised by departments such as China Railway, China Communications Construction, Bridge Bureau, Water Conservancy and Hydropower. Before diving, our construction team at Hua Hang Company ensures thorough preparation, which is crucial for the safety of divers and the successful completion of diving tasks. Detailed and meticulous preparation guarantees diver safety and facilitates smoother diving operations. The analysis of the diving site and the formulation of diving plans are essential. The recovery team ensures that each diver participating in the underwater operations is well-informed, confident, uses the correct methods, works efficiently, and achieves good results. Before departure, all diving equipment and accessories must be prepared and ready on the surface, and factors such as the conditions of the diving area and potential damage during the operation are carefully considered. Our accumulated instincts, strict workmanship, and a strong sense of responsibility have been consistent requirements at Hua Hang. We maintain high standards for underwater operations and continuously improve the quality of our diving services. Trust us to provide you with exceptional underwater services, and we can arrive at the scene within 2 hours for special circumstances.
