Self-balancing method for wharf cast-in-place breast wall concrete temperature field

Abstract

The invention discloses a self-balancing method for a wharf cast-in-place breast wall concrete temperature field. The method comprises the steps that S1, a plurality of side wall lower water pipelines with lower water inlets and lower water outlets are arranged on the lower portion of a side wall; s2, concrete on the lower portion of the side wall is poured; s3, a plurality of side wall upper water pipelines with upper water inlets and upper water outlets are arranged on the upper portions of the side walls; s4, after the concrete at the lower part of the side wall is initially set, a plurality of upper water inlets are connected with a plurality of outlet pipes of a water segregator, each upper water outlet is connected with a corresponding lower water inlet, a plurality of lower water outlets are connected with a water return port of a water storage tank, and an outlet of the water storage tank is connected with an inlet of the water segregator through a water pump; a plurality of cooling water circulation loops are formed; and S5, concrete on the upper portion of the side wall is poured, a water pump is started, cooling water enters a cooling water circulation loop, hydration heat of new concrete on the upper portion of the side wall is absorbed, and the two-way effect of upper portion heat dissipation and lower portion heating is achieved.

Description

Technical Field

[0001] This invention relates to a self-balancing method for the temperature field of cast-in-place breast wall concrete in wharfs. Background Technology

[0002] Improving the durability of waterway infrastructure has long been a key concern in this field in my country, with concrete durability being particularly prominent, especially as cracks increasingly allow corrosive media to penetrate and damage the concrete. Cracks have become a critical issue in concrete durability research.

[0003] With the increasing scale and offshore nature of waterway engineering, gravity-type wharves are widely used, but cracking of their breast walls concrete is a frequent problem. Research indicates that the causes of these cracks involve multiple factors, including raw material quality, construction control, mix proportions, and structural design. Cracks not only affect the appearance of the concrete but also accelerate steel corrosion, endangering the overall structural safety and, in severe cases, potentially leading to damage to the concrete surface and functional degradation. Therefore, controlling cracking is a prerequisite for ensuring the normal use of concrete structures.

[0004] During the staged pouring of the concrete breast wall of a gravity wharf, numerous cracks can occur due to shrinkage caused by the asynchronous pouring of new and old concrete, as well as constraint stress and temperature stress resulting from temperature changes. Therefore, temperature control of the concrete during construction is crucial for crack control. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art and provide a self-balancing method for the temperature field of cast-in-place breast wall concrete in wharfs. It can effectively reduce the overall temperature difference between new and old concrete, adjust the difference in elastic modulus between the upper and lower concrete of the side wall, and reduce the influence of asynchronous shrinkage and temperature stress of concrete.

[0006] The objective of this invention is achieved as follows: a self-balancing method for the temperature field of cast-in-place breast wall concrete in a wharf, performed after the bottom slab concrete of the breast wall has been poured, the self-balancing method comprising the following steps: S1. Arrange several rows of lower sidewall water pipes along the width of the sidewall, between a distance of at least 50cm from the top of the base plate of the breast wall and at least 50cm from the top of the lower part of the sidewall. Connect each row of lower sidewall water pipes in a serpentine pattern to form several lower sidewall water pipe systems, each with a lower inlet and a lower outlet. Arrange three layers of lower temperature monitoring points on the lower part of the sidewall, with each monitoring point corresponding to a location 5-10cm from the top of the base plate, at the midpoint of the lower part of the sidewall, and... The distance to the top of the lower part of the side wall is 5-10cm; each layer of lower temperature monitoring points includes one internal lower temperature monitoring point and two surface lower temperature monitoring points; the internal lower temperature monitoring point is located in the middle of the thickness of the lower part of the side wall; the two surface lower temperature monitoring points are located correspondingly at a distance of 5-10cm from the inner surface of the lower part of the side wall and a distance of 5-10cm from the outer surface of the lower part of the side wall; each of the internal lower temperature monitoring point and the two surface lower temperature monitoring points is equipped with two temperature sensors; all temperature sensors are connected to the PLC controller through signal lines; S2. Pour the concrete at the bottom of the side wall; S3. Along the width of the side wall, within a distance of at least 50cm from the top of the lower part of the side wall and at least 50cm from the top of the side wall of the breast wall, arrange several rows of upper side wall water pipes corresponding one-to-one with the rows of lower side wall water pipes. Connect each row of upper side wall water pipes in a serpentine pattern to form several upper side wall water pipe routes with one upper inlet and one upper outlet. Arrange three upper temperature monitoring points on the upper side wall, each located at the interface between the lower and upper parts of the side wall, and at the midpoint of the upper side wall height. The distance from the top of the upper side wall to the inner surface is 5-10cm; each layer of temperature monitoring points includes one internal upper temperature monitoring point and two surface upper temperature monitoring points; the internal upper temperature monitoring point is located in the middle of the thickness of the upper side wall; the two surface upper temperature monitoring points are located correspondingly at a distance of 5-10cm from the inner surface of the upper side wall and a distance of 5-10cm from the outer surface of the upper side wall; each of the internal upper temperature monitoring point and the two surface upper temperature monitoring points is equipped with two temperature sensors; all temperature sensors are connected to the PLC controller through signal lines; S4. After the concrete at the bottom of the side wall has initially set, connect the upper inlets of several upper water pipes on the side wall to several outlet pipes of the distributor one by one. Install a control valve and a flow meter on each outlet pipe of the distributor. Connect the upper outlet of each upper water pipe on the side wall to the lower inlet of the corresponding lower water pipe on the side wall. At the same time, connect the lower outlets of several lower water pipes on the side wall to the return outlet of the water storage tank. The outlet of the water storage tank is connected to the inlet of the distributor through a water pump, forming several cooling water circulation loops. The water pump, as well as all the control valves and flow meters on the distributor, are connected to the PLC controller through signal lines. S5. Pour the concrete on the upper part of the side wall, start the water pump at the same time, and open the control valves on several cooling water circulation loops so that the cooling water in the storage tank enters the cooling water circulation loop from the upper inlet of the water pipe on the upper part of the side wall. After absorbing the hydration heat of the new concrete on the upper part of the side wall, it flows back to the storage tank from the lower outlet of the water pipe on the lower part of the side wall. S6. Continuously circulate water through several cooling water loops, and pour the top slab concrete of the breast wall after the concrete on the upper part of the side wall has initially set. S7. Continuously circulate water through several cooling water loops, and monitor the temperature difference between the lower and upper parts of the sidewall in real time through the three lower and upper temperature monitoring points, as well as the temperature difference between the interior and surface of the sidewall. If the temperature difference between the inner surface of the concrete at the top of the sidewall is 23℃, the PLC controller will issue a warning 2℃ in advance. The PLC controller will increase the speed of the water pump, i.e., increase the water flow rate by 10% to 20%, and at the same time increase the opening of all control valves on the distributor. If the interface temperature difference between the lower and upper parts of the sidewall is >8℃, the PLC controller will slow down the speed of the water pump or decrease the opening of all control valves on the distributor to reduce the flow rate of the cooling water. When the inner surface temperature difference of the sidewall is >25℃ or the interface temperature difference between the lower and upper parts of the sidewall is >10℃, the system will trigger an audible and visual alarm.

[0007] The above-mentioned self-balancing method for the temperature field of cast-in-place breast wall concrete of the wharf, wherein the horizontal and vertical spacing of the water pipes at the bottom and top of the side wall are both 0.5m to 1.5m.

[0008] The above-mentioned self-balancing method for the temperature field of cast-in-place breast wall concrete of the wharf, wherein steel reinforcement supports are used for fixing when installing the water pipes at the bottom and top of the side wall.

[0009] The above-mentioned self-balancing method for the temperature field of cast-in-place breast wall concrete at the wharf includes the following: a liquid level sensor is installed inside the water storage tank at 1 / 3 of its height; a filter is installed between the outlet of the water storage tank and the inlet of the water pump.

[0010] The self-balancing method for the temperature field of cast-in-place breast wall concrete in wharfs of this invention employs a novel water pipe layout process and a cooling circulating water system. This system connects the concrete poured in two stages, upper and lower, and fully utilizes the heat of hydration generated by the newly poured concrete at the upper part of the side wall. Through the circulation of water in the cooling circulating water loop, the heat is heated to the older concrete at the lower part of the side wall, achieving a two-way effect of "heat dissipation from the upper part + heating from the lower part." This balances the temperature field of the asynchronously poured concrete, reduces the overall temperature difference between the new and old concrete, adjusts the difference in elastic modulus between the upper and lower parts of the side wall concrete, significantly reduces the constraint effect of the lower part of the side wall concrete on the upper part, reduces the impact of asynchronous shrinkage and temperature stress, effectively controls the cracking problem of gravity-type wharf breast wall concrete, thereby improving the performance of the wharf breast wall concrete and reducing its potential hazards. The effect is significant. Attached Figure Description

[0011] Figure 1 This is a cross-sectional view of the wharf breast wall during step one of the self-balancing method for the temperature field of the cast-in-place wharf breast wall concrete of the present invention. Figure 2 This is a front view of the wharf breast wall during step one of the self-balancing method for the temperature field of the cast-in-place wharf breast wall concrete of the present invention. Figure 3 This is a cross-sectional view of the wharf breast wall during step three of the self-balancing method for the temperature field of the cast-in-place breast wall concrete of the present invention. Figure 4 This is a front view of the wharf breast wall during step three of the self-balancing method for the temperature field of the cast-in-place wharf breast wall concrete according to the present invention. Figure 5 This is a schematic diagram of the cooling water circulation loop during step four of the self-balancing method for the temperature field of the cast-in-place breast wall concrete of the wharf in this invention. Figure 5a This is a front view of the water distributor used in the cooling water circulation loop of the present invention; Figure 5b yes Figure 5a Top view. Detailed Implementation

[0012] The invention will now be further described with reference to the accompanying drawings.

[0013] Please see Figures 1 to 5b The self-balancing method for the temperature field of the cast-in-place breast wall concrete of the present invention is carried out after the bottom slab concrete of the breast wall is poured. The total height of the breast wall is 6.4m, of which the bottom slab 100 of the breast wall is 1.5m high, the lower part 101 and the upper part 102 of the side wall of the breast wall are both 2.225m high, and the top slab 103 of the breast wall is 0.45m high. The thickness of the side wall of the breast wall is 4.5m.

[0014] The self-balancing method for the temperature field of cast-in-place breast wall concrete in wharfs according to the present invention includes the following steps; S1. Seven rows of lower sidewall water pipes 201 are arranged at a distance of not less than 50cm from the top of the base plate 100 of the breast wall and not less than 50cm from the top of the lower sidewall 101 of the breast wall, along the width direction of the sidewall. The horizontal spacing of the seven rows of lower sidewall water pipes 201 is L=0.5m, and the vertical spacing of each row of lower sidewall water pipes 201 is H=0.5m (see...). Figure 1 The lower water pipes 201 of the side wall are fixed with steel supports during installation to ensure accurate horizontal and vertical spacing and prevent displacement of the lower water pipes 201 when pouring the concrete of the lower side wall 101. Each row of lower water pipes 201 is connected in series in a serpentine pattern to form seven lower water pipe circuits with one lower water inlet 20a and one lower water outlet 20b. All lower water inlets 20a and all lower water outlets 20b extend beyond the top surface of the breast wall (see...). Figure 2 The length of the water pipe at the bottom of each side wall shall not exceed 200m; three layers of lower temperature monitoring points shall be arranged at the bottom of the side wall 101, with each layer corresponding to a distance of 5-10cm from the top of the bottom plate 100, at the middle of the height of the bottom of the side wall 101, and at a distance of 5-10cm from the top of the bottom of the side wall 101; each layer of lower temperature monitoring points shall include one internal lower temperature monitoring point and two surface lower temperature monitoring points; the internal lower temperature monitoring point shall be located at the middle of the thickness of the bottom of the side wall 101; the two surface lower temperature monitoring points shall be corresponding to a distance of 5-10cm from the inner surface of the bottom of the side wall 101 and a distance of 5-10cm from the outer surface of the bottom of the side wall 101; each internal lower temperature monitoring point and each of the two surface lower temperature monitoring points shall be equipped with two temperature sensors (average value shall be taken to reduce monitoring error); all temperature sensors shall be connected to the PLC controller via signal lines. S2, Pour concrete at the lower part of the side wall 101; S3. Seven rows of upper sidewall water pipes 202, corresponding one-to-one with the seven rows of lower sidewall water pipes 101, are arranged on the upper sidewall 102 of the breast wall, within a distance of not less than 50cm from the top of the lower sidewall 101 and not less than 50cm from the top of the breast wall. The horizontal spacing of the seven rows of upper sidewall water pipes 202 is L=0.5m, and the vertical spacing of each row of upper sidewall water pipes 202 is H=0.5m (see...). Figure 3The upper water pipes 202 on the side wall are fixed with steel supports during installation to ensure accurate horizontal and vertical spacing and prevent displacement of the upper water pipes 202 when pouring the upper concrete of the side wall 102. Each row of upper water pipes 202 on the side wall is connected in series in a serpentine pattern to form seven upper water pipe circuits on the side wall, each with one upper water inlet 20c and one upper water outlet 20d. All upper water inlets 20c and all upper water outlets 20d extend beyond the top surface of the breast wall (see...). Figure 4 The length of the upper water pipe on each side wall shall not exceed 200m; three layers of upper temperature monitoring points shall be arranged on the upper part 102 of the side wall, with each layer corresponding to a point at the interface between the lower part 101 and the upper part 102 of the side wall, at the midpoint of the height of the upper part 102 of the side wall, and at a distance of 5-10cm from the top of the upper part 102 of the side wall; each layer of upper temperature monitoring points shall include one internal upper temperature monitoring point and two surface upper temperature monitoring points; the internal upper temperature monitoring point shall be located at the midpoint of the thickness of the upper part 102 of the side wall; the two surface upper temperature monitoring points shall be corresponding to a point at a distance of 5-10cm from the inner surface of the upper part 102 of the side wall and a point at a distance of 5-10cm from the outer surface of the upper part 102 of the side wall; each internal upper temperature monitoring point and each of the two surface upper temperature monitoring points shall be equipped with two temperature sensors (average value shall be taken to reduce monitoring error); all temperature sensors shall be connected to the PLC controller via signal lines. S4. After the concrete at the lower part 101 of the side wall has initially set, connect the upper inlets 20c of the seven upper water pipes on the side wall to the seven outlet pipes 30 of the distributor 300 one by one. Install a control valve 301 and a flow meter 302 on each outlet pipe 30 of the distributor 300. Connect the upper outlet 20d of each upper water pipe on the side wall to the lower inlet 20a of the corresponding lower water pipe on the side wall. At the same time, connect the lower outlets 20b of the seven lower water pipes on the side walls to the return outlet of the water storage tank 500. The outlet of the water storage tank 500 is connected to the inlet of the distributor 300 through the water pump 400, forming seven cooling water circulation loops (see...). Figure 5 , Figure 5a and Figure 5b All seven cooling water circulation loops use stainless steel pipes with an outer diameter of 50mm and a wall thickness of 3mm. A liquid level sensor 501 is installed in the water storage tank 500 at 1 / 3 of its height. When the water level in the water storage tank 500 is lower than 1 / 3, the liquid level sensor 501 automatically triggers the water supply switch to replenish water, preventing the circulation from being interrupted due to water shortage in the water storage tank 500. A Y-type filter 600 is installed between the outlet of the water storage tank 500 and the inlet of the water pump 400 to prevent impurities in the water from clogging the water pipes. All control valves 301 and all flow meters 302 on the water pump 400 and the water distributor 300 are connected to the PLC controller via signal lines. S5. Pour the concrete for the upper part 102 of the side wall, and at the same time start the water pump 400 and open the control valve 301 on the seven cooling water circulation loops. This allows the cooling water in the storage tank 500 to enter the cooling water circulation loop from the upper inlet of the water pipe on the upper part of the side wall. After absorbing the heat of hydration of the new concrete in the upper part 102 of the side wall, the water flows back to the storage tank 500 from the lower outlet of the water pipe on the lower part of the side wall, thus achieving the dual effect of heat dissipation from the upper part of the side wall and heating from the lower part of the side wall. S6. Continuously supply water to the seven cooling water circulation loops, and pour the top slab concrete of the breast wall after the concrete at the upper 102 of the side wall has initially set. S7. Continuously circulate water through the seven cooling water loops, and monitor the temperature difference between the lower part 101 and the upper part 102 of the side wall in real time using temperature sensors at the lower and upper temperature monitoring points of the three floors; simultaneously monitor the temperature difference between the inside and outside of the side wall; the temperature sensors collect data every hour (increased to every 30 minutes within 72 hours after the concrete pouring of the upper part 102 of the side wall), and transmit the data in real time to the PLC controller in the control room to generate a "temperature-time" curve; if the temperature difference between the inside and outside of the concrete of the upper part 102 of the side wall is 23℃, the PLC controller will issue a warning 2℃ in advance, and the PLC controller will increase the speed of the water pump by 400, that is, increase the water flow. The flow rate is increased by 10% to 20%, and the opening of all control valves 301 on the distributor 300 is increased to accelerate the heat dissipation of the concrete in the upper part 102 of the side wall. If the temperature difference between the interface between the lower part 101 and the upper part 102 of the side wall is greater than 8℃ (the target is to control it at around 5℃), the PLC controller will slow down the speed of the water pump 400 or reduce the opening of all control valves 301 on the distributor 300 to reduce the flow rate of the cooling water, allowing the warm water in the lower part 101 of the side wall to stay longer to heat the old concrete in the lower part 101 of the side wall. When the temperature difference between the inner surface of the side wall is greater than 25℃ or the temperature difference between the interface between the lower part 101 and the upper part 102 of the side wall is greater than 10℃, the PLC controller will trigger an audible and visual alarm and send a text message to the mobile phone of the on-site management personnel. The flow meter (accuracy ±2%) on each cooling water circulation loop collects the flow data of the circulating cooling water in real time and displays it synchronously with the temperature data on the control interface. If the flow rate of the circulating cooling water in each cooling water circulation loop suddenly drops by more than 50% (such as pipe blockage) or suddenly increases by more than 30% (such as valve failure), the PLC controller will immediately alarm and mark the number of the faulty cooling water circulation loop, such as "abnormal flow rate of the 3rd cooling water circulation loop", so as to facilitate workers to quickly locate and troubleshoot.

[0015] The self-balancing method for the temperature field of cast-in-place breast wall concrete in wharfs of the present invention adopts a novel water pipe layout process and a cooling circulating water system to connect the concrete poured in two steps. It makes full use of the heat of hydration generated by the newly poured upper concrete, which is heated by the water circulation of the cooling circulating water system to balance the temperature field of the concrete poured at different times, reduce the overall temperature difference between the new and old concrete, adjust the difference in elastic modulus between the upper and lower concrete, significantly reduce the restraining effect of the lower concrete on the upper concrete, and reduce the influence of asynchronous shrinkage and temperature stress of the concrete.

[0016] The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions should also fall within the scope of the invention and should be defined by the claims.

Claims

1. A self-balancing method for the temperature field of cast-in-place breast wall concrete at a wharf, which is carried out after the bottom slab concrete of the breast wall is poured, characterized in that... The self-balancing method includes the following steps: S1. Arrange several rows of lower sidewall water pipes along the width of the sidewall, between a distance of at least 50cm from the top of the base plate of the breast wall and at least 50cm from the top of the lower part of the sidewall. Connect each row of lower sidewall water pipes in a serpentine pattern to form several lower sidewall water pipe systems, each with a lower inlet and a lower outlet. Arrange three layers of lower temperature monitoring points on the lower part of the sidewall, with each monitoring point corresponding to a location 5-10cm from the top of the base plate, at the midpoint of the lower part of the sidewall, and... The distance to the top of the lower part of the side wall is 5-10cm; each layer of lower temperature monitoring points includes one internal lower temperature monitoring point and two surface lower temperature monitoring points; the internal lower temperature monitoring point is located in the middle of the thickness of the lower part of the side wall; the two surface lower temperature monitoring points are located correspondingly at a distance of 5-10cm from the inner surface of the lower part of the side wall and a distance of 5-10cm from the outer surface of the lower part of the side wall; each of the internal lower temperature monitoring point and the two surface lower temperature monitoring points is equipped with two temperature sensors; all temperature sensors are connected to the PLC controller through signal lines; S2. Pour the concrete at the bottom of the side wall; S3. Along the width of the side wall, within a distance of at least 50cm from the top of the lower part of the side wall and at least 50cm from the top of the side wall of the breast wall, arrange several rows of upper side wall water pipes corresponding one-to-one with the rows of lower side wall water pipes. Connect each row of upper side wall water pipes in a serpentine pattern to form several upper side wall water pipe routes with one upper inlet and one upper outlet. Arrange three upper temperature monitoring points on the upper side wall, each located at the interface between the lower and upper parts of the side wall, and at the midpoint of the upper side wall height. The distance from the top of the upper side wall to the inner surface is 5-10cm; each layer of temperature monitoring points includes one internal upper temperature monitoring point and two surface upper temperature monitoring points; the internal upper temperature monitoring point is located in the middle of the thickness of the upper side wall; the two surface upper temperature monitoring points are located correspondingly at a distance of 5-10cm from the inner surface of the upper side wall and a distance of 5-10cm from the outer surface of the upper side wall; each of the internal upper temperature monitoring point and the two surface upper temperature monitoring points is equipped with two temperature sensors; all temperature sensors are connected to the PLC controller through signal lines; S4. After the concrete at the bottom of the side wall has initially set, connect the upper inlets of several upper water pipes on the side wall to several outlet pipes of the distributor one by one. Install a control valve and a flow meter on each outlet pipe of the distributor. Connect the upper outlet of each upper water pipe on the side wall to the lower inlet of the corresponding lower water pipe on the side wall. At the same time, connect the lower outlets of several lower water pipes on the side wall to the return outlet of the water storage tank. The outlet of the water storage tank is connected to the inlet of the distributor through a water pump, forming several cooling water circulation loops. The water pump, as well as all the control valves and flow meters on the distributor, are connected to the PLC controller through signal lines. S5. Pour the concrete on the upper part of the side wall, start the water pump at the same time, and open the control valves on several cooling water circulation loops so that the cooling water in the storage tank enters the cooling water circulation loop from the upper inlet of the water pipe on the upper part of the side wall. After absorbing the hydration heat of the new concrete on the upper part of the side wall, it flows back to the storage tank from the lower outlet of the water pipe on the lower part of the side wall. S6. Continuously circulate water through several cooling water loops, and pour the top slab concrete of the breast wall after the concrete on the upper part of the side wall has initially set. S7. Continuously circulate water through several cooling water loops, and monitor the temperature difference between the lower and upper parts of the sidewall in real time through the three lower and upper temperature monitoring points, as well as the temperature difference between the interior and surface of the sidewall. If the temperature difference between the inner surface of the concrete at the top of the sidewall is 23℃, the PLC controller will issue a warning 2℃ in advance. The PLC controller will increase the speed of the water pump, i.e., increase the water flow rate by 10% to 20%, and at the same time increase the opening of all control valves on the distributor. If the interface temperature difference between the lower and upper parts of the sidewall is >8℃, the PLC controller will slow down the speed of the water pump or decrease the opening of all control valves on the distributor to reduce the flow rate of the cooling water. When the inner surface temperature difference of the sidewall is >25℃ or the interface temperature difference between the lower and upper parts of the sidewall is >10℃, the system will trigger an audible and visual alarm.

2. The self-balancing method for the temperature field of the cast-in-place breast wall concrete of a wharf according to claim 1, characterized in that, The horizontal and vertical spacing between the water pipes at the bottom and top of the side wall is 0.5m to 1.5m.

3. The self-balancing method for the temperature field of the cast-in-place breast wall concrete of a wharf according to claim 1 or 2, characterized in that, The water pipes at the bottom of the side wall and at the top of the side wall are both fixed with steel reinforcement brackets.

4. The self-balancing method for the temperature field of the cast-in-place breast wall concrete of a wharf according to claim 1, characterized in that, A level sensor is installed inside the water storage tank at 1 / 3 of its height; a filter is installed between the outlet of the water storage tank and the inlet of the water pump.

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