Crack control method based on wharf cast-in-place breast wall concrete

Abstract

The invention relates to the field of infrastructure construction of water transportation engineering, in particular to a crack control method based on cast-in-place breast wall concrete of a wharf, which comprises the following steps: S1, arranging a water cooling system consisting of a reservoir, a water pump, a hose, a flow meter and a plurality of cooling water pipes; s2, breast wall concrete is poured for three times, and a first-layer breast wall, a second-layer breast wall and a third-layer breast wall are arranged; s3, a cooling water pipe in first pouring is arranged; s4, a cooling water pipe in secondary pouring is arranged; s5, pouring the thoracic cavity concrete for the third time; s6, three layers of basalt fiber grids are laid in different pouring sections of the breast wall in order to prevent the concrete from cracking under the internal and external temperature difference and the self-constriction effect; s7, laying a first layer of basalt fiber grids; s8, laying a second layer of basalt fiber grids; and S9, laying a third layer of basalt fiber grids. The purpose of the invention is to ensure the structural safety of the whole project.

Description

Technical Field

[0001] This application relates to the field of waterway engineering infrastructure construction, and in particular to a crack control method based on cast-in-place breast wall concrete of a wharf. Background Technology

[0002] Improving the durability of waterway infrastructure has always been a key focus in my country's waterway construction industry. Concrete durability is a crucial issue for engineering structures, particularly important for hydraulic concrete structures. In particular, cracking in structural concrete allows external corrosive media to penetrate the concrete, directly causing increasingly frequent durability problems in hydraulic concrete. Therefore, "cracks" are an unavoidable issue when studying concrete durability.

[0003] In related technologies, the trend of large-scale and offshore infrastructure development in water transport engineering is evident, and gravity wharves, as an important structural form of port terminals, are increasingly being used in engineering practice. Current investigations have revealed some problems in the application of gravity wharves. Among these, the cracking of the wharf breast wall concrete, a concrete structure with a large exposed area, is becoming increasingly common. The breast wall is typically cast-in-place and embedded within a caisson, forming the vertical wall required for ship mooring, blocking backfill material behind it, bearing various external forces acting on the wharf, and transferring these forces to the foundation and subgrade. The breast wall is a crucial structural component of a gravity wharf. To accommodate foundation settlement, it is usually constructed in layers along its height, pouring the first and second layers first, and then proceeding to the next stage after the settlement has stabilized. Numerous engineering cases have shown that cracks of varying degrees often appear in the breast wall during construction or for a period after construction. Numerous scientific studies and engineering practices indicate that factors causing cracks in the wharf breast wall concrete include raw material quality, construction quality control, concrete mix proportions, and structural design.

[0004] Due to the long time interval between the pouring of new and old concrete, cast-in-place breast walls are highly susceptible to developing uniform through-cracks and deep cracks along their length under the strong constraint of the old concrete at the bottom. Influenced by factors such as structure, materials, and construction techniques, cracking in cast-in-place breast wall concrete structures is a persistent problem that plagues all parties, often resulting in the embarrassing situation of "the more you try to control it, the more it cracks." Summary of the Invention

[0005] This application provides a crack control method based on cast-in-place breast wall concrete in wharfs. The purpose is to effectively control the cracking of concrete, thereby effectively ensuring the appearance quality of the concrete breast wall structure and ensuring the structural safety of the entire project.

[0006] This application provides a crack control method based on cast-in-place breast wall concrete of a wharf, which adopts the following technical solution: A method for crack control based on cast-in-place breast wall concrete in wharfs includes the following steps: S1. Install a water cooling system, which consists of a water storage tank, water pump, hoses, flow meter and multiple cooling water pipes; S2. The breast wall concrete is poured in three stages; S3. Lay out the cooling water pipes for the first pouring; S4. Lay out the cooling water pipes for the second pouring; S5. Third pouring of thoracic cavity concrete; S6. To prevent concrete from cracking due to internal and external temperature differences and autogenous shrinkage, three layers of basalt fiber mesh are laid in different pouring sections of the breast wall. S7. Lay the first layer of basalt fiber mesh; S8. Lay the second layer of basalt fiber mesh; S9. Lay the third layer of basalt fiber mesh.

[0007] By adopting the above technical solution, this setup combines two protective measures—a water cooling system and a basalt fiber mesh—into the concrete structure of the wharf breast wall. This effectively controls concrete cracking, ensures the appearance quality of the concrete breast wall structure, and guarantees the structural safety of the entire project.

[0008] Preferably, the cooling water pipe is composed of multiple horizontal water pipes connected in series, and the multiple horizontal water pipes are evenly distributed at intervals, and a protective layer is provided between the horizontal water pipes and the breast wall low formwork.

[0009] By adopting the above technical solution, the side wall water pipes are each 83.5m long, and each pipe consists of multiple horizontal pipes connected in series. The spacing between the water pipes is 60cm or 50cm, and the water pipes are 100cm away from the protective layer at both ends of the breast wall. To dissipate heat collected at the bottom of the breast wall, the water pipes are 35cm away from the protective layer of the lower formwork. To increase heat exchange with subsequent pours, the water pipes are 45cm away from the protective layer of the top surface of the first pour. The bottom slab water pipes are 133.8m long and are arranged in the bottom slab to effectively reduce the center temperature of the bottom slab.

[0010] Preferably, during the second concrete pouring process, multiple horizontal water pipes are arranged in the concrete poured in the first pour, and then multiple horizontal water pipes are connected in series and arranged in the second concrete pouring.

[0011] By adopting the above technical solution, the length of a single water pipe in this process is 168m. The cooling water first cools the second pour of concrete before entering the pipes in the first pour, thus achieving the function of heat exchange between the two pours. The new series water pipes are spaced 50cm apart, and the top has good air heat dissipation and does not support large-volume concrete pours; the protective layer thickness is 75cm.

[0012] Preferably, the first layer of basalt fiber mesh is arranged in the area of ​​the breast wall sidewall, and the first layer of basalt fiber mesh is arranged on the sea side, land side and top surface of the sidewall.

[0013] By adopting the above technical solution, the thickness of the protective layer from the side grid to the concrete surface is 20mm. Furthermore, to ensure the integrity of the side grid in the second layer of poured concrete above the upper side wall, the grid height should be at least three grid openings higher than the elevation of the first layer, extending beyond the top surface of the poured concrete to facilitate subsequent binding and overlapping of the upper grid. To prevent damage to the top grid during the roughening process, the protective layer thickness is 50mm.

[0014] Preferably, the second layer of basalt fiber mesh is arranged on the bottom surface of the second layer of concrete in the side wall, and a protective layer is provided between the second layer of basalt fiber mesh and the bottom surface of the second layer of concrete.

[0015] By adopting the above technical solution, a protective layer thickness of 20mm is used to prevent cracking between the protective layer and the first layer of concrete. Basalt fiber mesh is also arranged on both the seaside and landside sides of the sidewalls, and is tied and overlapped with the first layer of basalt fiber mesh. Given that the third layer of concrete is relatively thin and has no risk of lateral cracking, no basalt fiber mesh is needed; therefore, the second layer of basalt fiber mesh does not extend upwards further, and the protective layer thickness is 20mm.

[0016] Preferably, the basalt fiber mesh of the third layer is arranged on the top surface of the third layer of concrete, and a protective layer is provided between the basalt fiber mesh of the third layer and the top surface of the third layer of concrete.

[0017] By adopting the above technical solution, in order to prevent cracking of the top surface of the breast wall, which would affect its durability and aesthetics, a basalt fiber mesh is laid on the top surface of the third layer of concrete, with a protective layer thickness of 20mm.

[0018] Preferably, a temperature monitoring system is installed inside the breast wall concrete. The temperature monitoring system includes multiple temperature measuring points, which are respectively arranged in the corresponding concrete during the three pouring processes of the breast wall.

[0019] By adopting the above technical solution, temperature monitoring points are set up at different locations on the breast wall during the three-stage concrete pouring process, and the temperature changes before and after concrete pouring are monitored in a tiered manner, thereby effectively ensuring comprehensive monitoring of the concrete.

[0020] Preferably, a strain monitoring system is installed inside the breast wall concrete. The strain monitoring system includes multiple strain measuring points, which are respectively arranged in the corresponding concrete during the three pouring processes of the breast wall.

[0021] By employing the above technical solution, the strain development of concrete in different parts of the breast wall was compared under different crack control measures by monitoring the strain. All stress testing sensors were connected to the reinforcing steel bars under test using a binding method. After each sensor was installed, the test lead was extended and a number was affixed to the lead wire exit end. The test leads were protected with flexible PVC sleeves and fixed along the longitudinal reinforcing steel bars using binding straps.

[0022] If strain monitoring points are placed at stress concentration points in the concrete pouring body, such as slab joints and beam tops, then strain data will mainly be distributed at stress concentration points, and primarily in the middle and top of the structure.

[0023] A construction process for basalt fiber mesh, employing the crack control method based on cast-in-place breast wall concrete of a wharf as described in any one of claims 1-8, includes the following steps: S1. Arrange the padding blocks; S2. Install steel reinforcement; S3. Install the grid positioning device; S4. Concrete pouring; S5. Concrete vibration; S6. Lay basalt fiber mesh; S7. Smooth and level the surface; S8. Concrete curing.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. By combining water cooling system and basalt fiber mesh as protective measures and applying them to the concrete structure of the wharf breast wall, the cracking of concrete can be effectively controlled, thereby ensuring the appearance quality of the concrete breast wall structure and ensuring the structural safety of the entire project. 2. Temperature monitoring points are set up at different locations on the breast wall during the three-stage concrete pouring process to monitor the temperature changes before and after concrete pouring in a tiered manner, thereby effectively ensuring comprehensive monitoring of the concrete. 3. By monitoring the strain of concrete at different locations in the breast wall, the strain development of the breast wall concrete under different crack control measures was compared. All stress test sensors were connected to the reinforcing steel bars under test by binding. After each sensor was installed, the test lead was extended and a number was affixed to the lead wire exit end. The test leads were protected by flexible PVC sleeves and fixed along the longitudinal reinforcing steel bars using binding straps.

[0025] If strain monitoring points are placed at stress concentration points in the concrete pouring body, such as slab joints and beam tops, then strain data will mainly be distributed at stress concentration points, and primarily in the middle and top of the structure. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is a structural schematic diagram illustrating the positional relationship of the cooling water pipes in a specific embodiment of this application; Figure 3 This is a structural schematic diagram illustrating the positional relationship of basalt fiber mesh in a specific embodiment of this application; Figure 4 This is a structural schematic diagram illustrating the positional relationship of temperature measuring points in a specific embodiment of this application; Figure 5 This is a structural schematic diagram illustrating the positional relationship of strain measurement points in a specific embodiment of this application.

[0027] Attached diagram labels: 1. First layer of breast wall; 2. Second layer of breast wall; 3. Third layer of breast wall; 4. Cooling water pipe; 5. Basalt fiber mesh; 6. Temperature measuring point; 7. Strain measuring point. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1 -Appendix Figure 5 This application will be described in further detail below.

[0029] Example: This application discloses a crack control method based on cast-in-place breast wall concrete in wharfs, referring to... Figure 1 This includes the following steps: Reference Figure 1 and Figure 2 , S1. Install a water cooling system; The water cooling system consists of a water storage tank, a water pump, hoses, a flow meter, and a cooling water pipe 4. Water in the water storage tank is pumped into the inlet of the cooling water pipe 4 by the water pump, flows through the interior of the concrete through the cooling water pipe 4, and then flows back to the water storage tank from the outlet of the cooling water pipe 4. This cycle forms the water cooling system. S2. The breast wall concrete is poured in three stages; The breast wall is set as the first layer breast wall 1, the second layer breast wall 2 and the third layer breast wall 3. First, the base plate and the side wall 1.5m are poured, then the side wall 3m is poured, and finally the top surface of the side wall 0.4m is poured. S3. Lay out the cooling water pipes for the first pouring; The side wall water pipes are each 83.5m long, and each pipe consists of multiple horizontal pipes connected in series. The spacing between the pipes is 60cm or 50cm, and the distance between the pipes and the protective layer at both ends of the breast wall is 100cm. To dissipate heat collected at the bottom of the breast wall, the distance between the pipes and the protective layer of the lower formwork is 35cm. To increase heat exchange with subsequent pours, the distance between the pipes and the protective layer of the top surface of the first pour is 45cm.

[0030] The water pipes in the base plate are 133.8m long and are arranged in the base plate to effectively reduce the temperature at the center of the base plate.

[0031] S4. Lay out the second pouring cooling water pipe 4; During the second concrete pour, multiple horizontal water pipes are laid within the first pour. These pipes are then connected in series and placed within the second pour, with each pipe measuring 168m in length. Cooling water first cools the second pour before entering the piping in the first pour, thus achieving heat exchange between the two pours. The newly connected water pipes are spaced 50cm apart. Due to good airflow at the top, no large-volume concrete is being poured, and the protective layer thickness is 75cm.

[0032] S5. The third pour of chest cavity concrete is carried out. Cooling water pipes 4 are not required for this pour. Reference Figure 1 , Figure 2 as well as Figure 3 , S6. To prevent concrete from cracking due to internal and external temperature differences and autogenous shrinkage, three layers of basalt fiber mesh were laid in different pouring sections of the breast wall. S7. Lay the first layer of basalt fiber mesh 5; The grid is installed on the breast wall sidewalls, on the sea side, land side, and top surface of the sidewalls. The side grid is 20mm above the concrete surface cover. To ensure the integrity of the side grid in the second layer of poured concrete above the current side grid, the grid height should be at least three grid openings above the first layer, extending beyond the top surface of the poured concrete to facilitate subsequent overlapping and binding of the upper grid. To prevent damage during the roughening process, the top grid has a 50mm thick protective layer.

[0033] S8. Lay the second layer of basalt fiber mesh 5; To prevent cracks from spreading between the second and first layers of concrete, a basalt fiber mesh 5, with a protective layer thickness of 20mm, is laid on the bottom surface of the second layer of concrete in the sidewall. Basalt fiber mesh 5 is also laid on both the sea and land sides of the sidewall, and is tied and overlapped with the first layer of basalt fiber mesh 5. Given that the third layer of concrete is relatively thin and there is no risk of lateral cracking, there is no need to lay basalt fiber mesh 5; therefore, the second layer of basalt fiber mesh 5 does not extend upwards further, and the protective layer thickness is 20mm.

[0034] S9. Lay the third layer of basalt fiber mesh 5; To prevent cracking of the top surface of the breast wall, which would affect its durability and aesthetics, basalt fiber mesh 5 was laid on the top surface of the third layer of concrete, with a protective layer thickness of 20mm.

[0035] When installing cooling water pipe 4, it must be securely fixed to the steel reinforcement frame or supporting truss to prevent deformation of the pipe or detachment of joints during concrete pouring, which could lead to blockage or leakage. During pipe laying, the pipes should be staggered from the main reinforcement of the foundation. If staggering is difficult in some sections, the positions can be adjusted appropriately. Simultaneously, a pressure test should be conducted on cooling water pipe 4 before use to prevent leakage or blockage. After each layer of circulating cooling water pipe 4 is covered and vibrated with concrete, water can be circulated through the pipes in that layer. Water discharged from the circulating cooling pipes must not be discharged onto the top surface of the concrete. Before concrete pouring, cooling water pipe 4 should be pre-filled with cooling water. The concrete cooling process can be controlled by adjusting the inlet and outlet water flow rates of the cooling system. The inlet water flow rate in each water pipe loop can be controlled using a flow meter. By adjusting the inlet water flow rate, the temperature difference between the inlet water and the center temperature of the concrete should be maintained at (15-25)℃ to prevent shrinkage cracks in the concrete around the cooling pipes due to excessively low cooling water temperature. The cooling water temperature should be monitored daily; if the water temperature is too high, it needs to be cooled down or replaced promptly.

[0036] When the temperature difference between the core and surface of the concrete is less than 15°C, water cooling can be suspended. If the core temperature rises to a temperature difference greater than 25°C, the water cooling system should be restarted. After cooling is complete, the cooling water pipe 4 should be grouted and sealed promptly. The grouting material should be cement mortar of the same strength grade. After the mortar hardens, cut or remove all pipes and fittings used for cooling on the exterior of the concrete structure. The surface of the concrete should be kept moist during water cooling, and the insulation material covering should meet the requirement that the temperature difference between the surface and the interior of the concrete is less than 25°C. If the flow direction is always maintained, the concrete temperature at the outlet end will be higher than that at the inlet end after cooling. To ensure that the concrete temperature is as uniform as possible at the end of cooling, the water flow direction should be changed continuously during the cooling process. It is advisable to change the water flow direction once a day to minimize the hydration heat rise at each cross-section.

[0037] This design combines a water cooling system and basalt fiber mesh 5 as protective measures and applies them to the concrete breast wall structure of the wharf. This effectively controls concrete cracking, ensures the appearance quality of the concrete breast wall structure, and guarantees the structural safety of the entire project.

[0038] Furthermore, referring to Figure 1 and Figure 4 Temperature monitoring is installed within the breast wall concrete, including multiple temperature measuring points. The measuring points are arranged according to a half-axis of the symmetrical axis of the concrete casting plan, with the monitoring points layered within the test area. Measuring points are also set on the outer surface of the concrete casting to observe the surface temperature. The specific locations of the measuring points are as follows: The center of the concrete block; Location of the axis of symmetry of the concrete block; 5cm from the concrete surface (representing the surface concrete temperature); Temperature within the concrete surface covering layer; In the air (ambient temperature).

[0039] Specifically, during the initial concrete pouring, the measuring points adjacent to the breast wall were adjusted inwards by 5cm from the concrete edge, with the corresponding points positioned at the upper surface corners of the breast wall to monitor the lowest temperature. Additionally, additional measuring points were placed at the center of the side wall during the first pouring of the breast wall.

[0040] When setting up measuring points for the second concrete pour, the adjacent measuring points are adjusted inward by 5cm from the concrete edge, and additional measuring points are set up on the vertical axis of the center of the side wall and on the vertical edge of the side wall during the second pour.

[0041] When setting up the measuring points during the third concrete pour, a measuring point was placed at the center of the top surface of the breast wall.

[0042] Temperature monitoring points were set up at different locations on the breast wall during the three concrete pouring processes to monitor the temperature changes before and after concrete pouring in a tiered manner, thereby effectively ensuring comprehensive monitoring of the concrete.

[0043] Furthermore, referring to Figure 1 and Figure 5 Strain monitoring was installed within the concrete breast wall, including multiple strain measurement points 7. By monitoring the strain of the concrete in different parts of the breast wall, the strain development of the breast wall concrete under different crack control measures was compared.

[0044] All stress testing sensors are connected to the reinforcing steel bars under test using a binding method. After each sensor is installed, the test lead is extended and a number is affixed to the lead end. The test leads are protected with flexible PVC conduit and secured along the longitudinal reinforcing steel bars using cable ties.

[0045] If strain monitoring points are placed at stress concentration points in the concrete pouring body, such as slab joints and beam tops, then strain data will mainly be distributed at stress concentration points, and primarily in the middle and top of the structure. Specifically, the sensor cable extends directly from the top of the breast wall and connects to the automated data acquisition device, which is placed in a nearby safe location and protected from damage.

[0046] A basalt fiber mesh construction process: S1. Arrange the padding blocks; Mark the positions of the reinforcing bars at the bottom using a stone pencil, and lay down standard thickness protective layer spacers at 1m x 1m intervals. Adjust the height and spacing of the reinforcing bar spacers appropriately according to the slope of the breast wall to ensure that the reinforcing bar protective layer meets the design requirements.

[0047] S2. Install steel reinforcement; After the reinforcing bars are transported to the site, they are tied and formed according to the design drawings, with neat spacing and sufficient protective layer. The number and length of the reinforcing bar joints are strictly welded or tied according to the specifications or design requirements based on the location. Flash welding is prohibited for reinforcing bar joints, and the quality of the joints must meet the specifications.

[0048] S3. Install the grid positioning device; Based on the design dimensions of the fiber mesh distance from the concrete cover thickness, welding fixing bars are installed on the reinforcing steel to ensure the mesh position during subsequent laying of the basalt fiber mesh 5. The diameter of the welding fixing bars should not be less than 6mm. Considering a mesh width of 1.5m, the horizontal spacing of the fixing bars is set to 0.75m, and the vertical spacing is set to 1~2m.

[0049] S4. Concrete pouring; Before pouring concrete, clean the panel surface of gravel, wood chips, and other debris, and thoroughly moisten the panel surface, but avoid water accumulation, to ensure a tight bond between the breast wall concrete and the panel surface. After removing the side formwork, if there is excessive concrete seepage from the bottom wire mesh, cut it off before pouring adjacent panels to reduce cracks at the edges.

[0050] S5. Concrete vibration; The vibration time should not be too long, otherwise the sand and cement paste will separate, the aggregate will sink, and a sand layer will form on the concrete surface, affecting the quality of the concrete. During vibration, the vibrator should be inserted 10cm into the lower layer of concrete to strengthen the bond between the upper and lower layers. The spacing between the vibrator insertion points is generally 30-50cm to prevent missed vibration.

[0051] S6. Lay basalt fiber mesh 5; Basalt fiber mesh 5 should be stored in areas protected from rain and moisture, avoiding impacts, oil stains, direct sunlight, rain, and immersion in water. Keep it away from heat and fire sources. The mesh can be cut directly on-site using an angle grinder; operators should wear work gloves to prevent cuts. The mesh is transported in a curved manner; caution should be exercised during laying, and personal safety measures should be taken in advance to prevent injury from the mesh's excessive elasticity. Assuming a basalt fiber width of 1.5m, the basalt fiber mesh 5 should be laid after the concrete area exceeding 1.5m in width has been vibrated. Place the basalt fiber mesh 5 on top of the fixing bars, ensuring the mesh extends beyond both ends. After confirming the distance between the ends and the top of the concrete is approximately 2cm, the surface can be smoothed. Direct footsteps on the mesh are strictly prohibited to prevent bending and damage.

[0052] S7. Smooth and level the surface; Once a basalt fiber mesh 5 has been laid, a trowel can be used to smooth and level the surface. The first troweling will squeeze the concrete surface into a tight cavity, press out the cement slurry, and make the surface smooth. One hour before the concrete sets, a power trowel will be used to smooth and finish the surface.

[0053] S8. Concrete curing; After the concrete surface is finished, it should be covered with plastic film immediately for moisture retention and heat preservation. The plastic film should be airtight and adhere tightly to the exposed concrete surface, and condensation should be maintained inside the plastic film.

[0054] The implementation principle of a crack control method based on cast-in-place breast wall concrete in a wharf, as described in this application, is as follows: S1. Install a water cooling system; The water cooling system consists of a water storage tank, a water pump, hoses, a flow meter, and a cooling water pipe 4. Water in the water storage tank is pumped into the inlet of the cooling water pipe 4 by the water pump, flows through the interior of the concrete through the cooling water pipe 4, and then flows back to the water storage tank from the outlet of the cooling water pipe 4. This cycle forms the water cooling system. S2. The breast wall concrete is poured in three stages; The breast wall is set as the first layer breast wall 1, the second layer breast wall 2 and the third layer breast wall 3. First, the base plate and the side wall 1.5m are poured, then the side wall 3m is poured, and finally the top surface of the side wall 0.4m is poured. S3. Lay out the cooling water pipes for the first pouring; The side wall water pipes are each 83.5m long, and each pipe consists of multiple horizontal pipes connected in series. The spacing between the pipes is 60cm or 50cm, and the distance between the pipes and the protective layer at both ends of the breast wall is 100cm. To dissipate heat collected at the bottom of the breast wall, the distance between the pipes and the protective layer of the lower formwork is 35cm. To increase heat exchange with subsequent pours, the distance between the pipes and the protective layer of the top surface of the first pour is 45cm.

[0055] The water pipes in the base plate are 133.8m long and are arranged in the base plate to effectively reduce the temperature at the center of the base plate.

[0056] S4. Lay out the second pouring cooling water pipe 4; During the second concrete pour, multiple horizontal water pipes are laid within the first pour. These pipes are then connected in series and placed within the second pour, with each pipe measuring 168m in length. Cooling water first cools the second pour before entering the piping in the first pour, thus achieving heat exchange between the two pours. The newly connected water pipes are spaced 50cm apart. Due to good airflow at the top, no large-volume concrete is being poured, and the protective layer thickness is 75cm.

[0057] S5. The third pour of chest cavity concrete is carried out. Cooling water pipes 4 are not required for this pour. S6. To prevent concrete from cracking due to internal and external temperature differences and autogenous shrinkage, three layers of basalt fiber mesh were laid in different pouring sections of the breast wall. S7. Lay the first layer of basalt fiber mesh 5; The grid is installed on the breast wall sidewalls, on the sea side, land side, and top surface of the sidewalls. The side grid is 20mm above the concrete surface cover. To ensure the integrity of the side grid in the second layer of poured concrete above the current side grid, the grid height should be at least three grid openings above the first layer, extending beyond the top surface of the poured concrete to facilitate subsequent overlapping and binding of the upper grid. To prevent damage during the roughening process, the top grid has a 50mm thick protective layer.

[0058] S8. Lay the second layer of basalt fiber mesh 5; To prevent cracks from spreading between the second and first layers of concrete, a basalt fiber mesh 5, with a protective layer thickness of 20mm, is laid on the bottom surface of the second layer of concrete in the sidewall. Basalt fiber mesh 5 is also laid on both the sea and land sides of the sidewall, and is tied and overlapped with the first layer of basalt fiber mesh 5. Given that the third layer of concrete is relatively thin and there is no risk of lateral cracking, there is no need to lay basalt fiber mesh 5; therefore, the second layer of basalt fiber mesh 5 does not extend upwards further, and the protective layer thickness is 20mm.

[0059] S9. Lay the third layer of basalt fiber mesh 5; To prevent cracking of the top surface of the breast wall, which would affect its durability and aesthetics, basalt fiber mesh 5 was laid on the top surface of the third layer of concrete, with a protective layer thickness of 20mm.

[0060] When installing cooling water pipe 4, it must be securely fixed to the steel reinforcement frame or supporting truss to prevent deformation of the pipe or detachment of joints during concrete pouring, which could lead to blockage or leakage. During pipe laying, the pipes should be staggered from the main reinforcement of the foundation. If staggering is difficult in some sections, the positions can be adjusted appropriately. Simultaneously, a pressure test should be conducted on cooling water pipe 4 before use to prevent leakage or blockage. After each layer of circulating cooling water pipe 4 is covered and vibrated with concrete, water can be circulated through the pipes in that layer. Water discharged from the circulating cooling pipes must not be discharged onto the top surface of the concrete. Before concrete pouring, cooling water pipe 4 should be pre-filled with cooling water. The concrete cooling process can be controlled by adjusting the inlet and outlet water flow rates of the cooling system. The inlet water flow rate in each water pipe loop can be controlled using a flow meter. By adjusting the inlet water flow rate, the temperature difference between the inlet water and the center temperature of the concrete should be maintained at (15-25)℃ to prevent shrinkage cracks in the concrete around the cooling pipes due to excessively low cooling water temperature. The cooling water temperature should be monitored daily; if the water temperature is too high, it needs to be cooled down or replaced promptly.

[0061] When the temperature difference between the core and surface of the concrete is less than 15°C, water cooling can be suspended. If the core temperature rises to a temperature difference greater than 25°C, the water cooling system should be restarted. After cooling is complete, the cooling water pipe 4 should be grouted and sealed promptly. The grouting material should be cement mortar of the same strength grade. After the mortar hardens, cut or remove all pipes and fittings used for cooling on the exterior of the concrete structure. The surface of the concrete should be kept moist during water cooling, and the insulation material covering should meet the requirement that the temperature difference between the surface and the interior of the concrete is less than 25°C. If the flow direction is always maintained, the concrete temperature at the outlet end will be higher than that at the inlet end after cooling. To ensure that the concrete temperature is as uniform as possible at the end of cooling, the water flow direction should be changed continuously during the cooling process. It is advisable to change the water flow direction once a day to minimize the hydration heat rise at each cross-section.

[0062] This design combines a water cooling system and basalt fiber mesh 5 as protective measures and applies them to the concrete breast wall structure of the wharf. This effectively controls concrete cracking, ensures the appearance quality of the concrete breast wall structure, and guarantees the structural safety of the entire project.

[0063] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for crack control based on cast-in-place breast wall concrete in wharfs, characterized in that: Includes the following steps, S1. Install a water cooling system, which consists of a water storage tank, water pump, hose, flow meter and multiple cooling water pipes (4). S2. The breast wall concrete is poured in three stages, namely the first layer of breast wall (1), the second layer of breast wall (2) and the third layer of breast wall (3); S3. Lay out the cooling water pipes during the first pouring (4); S4. Lay out the cooling water pipes (4) during the second pouring; S5. Third pouring of thoracic cavity concrete; S6. To prevent concrete from cracking under the effects of internal and external temperature differences and autogenous shrinkage, three layers of basalt fiber mesh were laid in different pouring sections of the breast wall (5). S7. Lay basalt fiber mesh (5) first layer; S8. Lay the second layer of basalt fiber mesh (5); S9. Lay basalt fiber mesh (5) Third layer.

2. The crack control method based on cast-in-place breast wall concrete of a wharf according to claim 1, characterized in that: The cooling water pipe (4) is composed of multiple horizontal water pipes connected in series, and the multiple horizontal water pipes are evenly distributed at intervals. A protective layer is provided between the horizontal water pipes and the breast wall low formwork.

3. The crack control method based on cast-in-place breast wall concrete of a wharf according to claim 2, characterized in that: During the second concrete pouring process, multiple horizontal water pipes are placed in the concrete poured in the first pour. Then, multiple horizontal water pipes are connected in series and placed in the second concrete pouring process.

4. The crack control method based on cast-in-place breast wall concrete of a wharf according to claim 3, characterized in that: The first layer of basalt fiber mesh (5) is arranged in the area of ​​the breast wall sidewall, on the sea side and land side of the sidewall and on the top surface.

5. A crack control method based on cast-in-place breast wall concrete in a wharf according to claim 4, characterized in that: The second layer of basalt fiber mesh (5) is arranged on the bottom surface of the second layer of concrete on the side wall, and a protective layer is provided between the second layer of basalt fiber mesh (5) and the bottom surface of the second layer of concrete.

6. A crack control method based on cast-in-place breast wall concrete in a wharf according to claim 5, characterized in that: The basalt fiber mesh (5) of the third layer is arranged on the top surface of the third layer of concrete, and a protective layer is provided between the basalt fiber mesh (5) of the third layer and the top surface of the third layer of concrete.

7. A crack control method based on cast-in-place breast wall concrete in a wharf according to claim 6, characterized in that: Temperature monitoring is installed inside the breast wall concrete. The temperature monitoring includes multiple temperature measuring points (6), which are arranged in the corresponding concrete during the three pouring processes of the breast wall.

8. A crack control method based on cast-in-place breast wall concrete in a wharf according to claim 7, characterized in that: Strain monitoring is installed inside the breast wall concrete. The strain monitoring includes multiple strain measuring points (7), which are arranged in the corresponding concrete during the three pouring processes of the breast wall.

9. A construction process for basalt fiber mesh (5), characterized in that: The crack control method based on cast-in-place breast wall concrete of a wharf, as described in any one of claims 1-8, includes the following steps: S1. Arrange the padding blocks; S2. Install steel reinforcement; S3. Install the grid positioning device; S4. Concrete pouring; S5. Concrete vibration; S6. Lay basalt fiber mesh (5); S7. Smooth and level the surface; S8. Concrete curing.

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