A template embedded dam face permanent thermal protection module and prefabrication and construction method

Abstract

The application discloses a template-embedded dam surface permanent heat preservation protection module and a prefabrication and construction method. The module comprises a heat preservation core layer, a facing anti-seepage protection layer is arranged on one side of the heat preservation core layer close to a concrete pouring template, an internal pressure bearing protection layer is arranged on the other side of the heat preservation core layer close to a dam surface layer crack limiting steel bar, a heat broken bridge support keel is arranged in the heat preservation core layer, and an anchoring device is arranged in a region between the internal pressure bearing protection layer and the dam surface layer crack limiting steel bar. The prefabrication and construction method is modular, the prefabrication and installation method of a single module is simple and efficient, details such as anchoring protection measures are fully considered, the engineering construction is high in operability, convenient and efficient, and the construction time of the heat preservation layer is greatly saved.

Description

Technical Field

[0001] This invention relates to the field of concrete thermal insulation and protection technology for water conservancy engineering dams, and in particular to a template-embedded permanent thermal insulation and protection module for dam surfaces, as well as its prefabrication and construction methods. Background Technology

[0002] When constructing concrete dams in frigid regions, it is necessary to promptly insulate the poured concrete to prevent large fluctuations in the surface temperature of the dam concrete caused by adverse factors such as cold waves, sudden drops in temperature, and large temperature differences between day and night. This will reduce the temperature difference between the inside and outside of the concrete and prevent the dam from cracking due to temperature stress caused by large temperature differences.

[0003] Traditional insulation techniques involve permanent insulation and protection of the concrete dam surface after the formwork is removed. For example, Chinese patent CN102505664B, "A Method for Anti-aging of Dam Concrete," firstly employs permanent insulation by covering with polyethylene foam, insulation cotton, and then attaching polystyrene boards or spraying rigid polyurethane foam. Then, an anti-aging paint, polyurea, or polymer mortar is applied to the surface of the insulation layer to resist the compression, pull-out, and impact caused by reservoir water freezing, aging and discoloration caused by solar radiation, and damage from impacts or fires caused by other construction work. Alkali-resistant fiberglass mesh or wire mesh is laid in the middle of the protective layer for reinforcement and anchored to the dam concrete using anchor bolts or other components. This achieves permanent insulation and protection for the concrete dam surface.

[0004] While traditional permanent thermal insulation and protection schemes for dam surfaces have provided some protection for dam concrete, evaluation based on engineering practice and effectiveness reveals several shortcomings that require improvement and optimization. These shortcomings are mainly reflected in three aspects:

[0005] (1) Thermal insulation and protection are delayed, and the dam concrete is at risk of cracking;

[0006] Traditional permanent insulation solutions rely on a clean dam surface after formwork removal. However, normal formwork removal can only proceed after the newly poured concrete has initially set and its strength has increased to meet the requirements for formwork removal, resulting in a certain lag in dam insulation. Furthermore, the early strength of dam concrete is relatively low, making it more susceptible to cracking due to temperature tensile stress, necessitating timely permanent insulation protection.

[0007] (2) The on-site thermal insulation and protection process involves many steps, requires high-altitude cross-operations, and is difficult to construct.

[0008] The traditional dam heat preservation protection system is composed of multiple processes to cope with the adverse effects of large temperature difference, high water pressure and ice formation in reservoir water. Different processes include multiple procedures, and the process is relatively complex. Secondly, there are many restrictions during construction, such as polyurethane spraying construction, or polyurea or anti-aging paint spraying construction, which requires a clean and dry base surface. On the other hand, heat preservation and protection construction and pouring cross operation interfere with each other, and the construction difficulty is relatively large, and there is a high safety risk.

[0009] (3) Complex construction environment, many interference factors, quality difficult to control;

[0010] The traditional dam surface heat preservation and protection construction is greatly influenced by human subjective factors, and the quality is difficult to control. Secondly, the wind is strong on the construction site all year round, and the polyurethane material is easily blown away and scattered everywhere during spraying operation on the dam surface, which not only wastes materials and pollutes the environment, but also makes the spraying thickness uneven and the quality difficult to control. When applying polymer mortar protective layer on the surface of the heat preservation layer, water flow should be avoided. After initial setting, timely watering and curing are required to ensure the overall quality of the dam concrete heat preservation and protection system. The construction site environment is complex, with many interference factors, and the quality is difficult to control.

[0011] As can be seen, the traditional heat preservation and protection construction of the heat preservation and protection scheme has a lag, which leads to the risk of cracking of the dam concrete; and the construction process and procedure are complex, and are greatly influenced by environmental interference factors, with great construction difficulty; most of the work needs high-altitude operation and cross operation, with high risk coefficient, which needs a new scheme to better protect the dam concrete.

[0012] In this context, some experts and scholars have proposed the concept of removable formwork, such as Chinese patent CN202222438817.X - thermal insulation structure integration removable formwork installation system in the field of building, which proposes to use thermal insulation board core material and composite lightweight mortar protective layer to form removable formwork, fix the removable formwork outside the inner membrane through a screw rod, and leave a gap between the inner form and the thermal insulation form; then cast in-situ concrete in the gap; finally remove the external limiting screw. This method is suitable for external wall engineering of civil building engineering, but not suitable for large volume concrete pouring of dam in water conservancy engineering. There is also a Chinese patent with application number CN202410402902.1 - a dam surface concrete permanent intelligent thermal insulation formwork and its manufacturing and construction method, which solves the problem that spraying or pasting thermal insulation materials cannot cover the dam concrete in time by sequentially arranging a steel formwork, a hydrophobic protective layer, a transition layer, and an intelligent thermal insulation layer from the outside to the inside. The focus of this method is to monitor the surface temperature of the dam concrete, the internal temperature of the intelligent thermal insulation layer, and the environmental temperature using temperature sensors, and then control the voltage adjustment device to output a certain voltage on both sides of the intelligent thermal insulation layer, convert the electrical energy into heat energy using conductive phase materials, and thus regulate the temperature of the intelligent thermal insulation layer. However, it does not provide specific parameters and solutions for how to achieve it. Similarly, Chinese invention CN 114892666 B - a dam concrete permanent thermal insulation formwork structure and its construction method, proposes a structure including a steel truss, a steel formwork, a thermal insulation formwork, and a reinforced beam, which arranges the steel truss and the steel formwork first, then fixes the thermal insulation formwork inside the formwork using the reinforcing rib, and removes the external support structure steel truss and steel formwork after the concrete pouring is completed.

[0013] Although the above-mentioned patents propose some solutions for removable formwork, they are still at the initial conceptual stage. The specific problems in engineering applications need further research, and there is no complete and effective technical system. For example, the dam has a large surface area, how to achieve seamless installation during arrangement; the thermal insulation performance of the thermal insulation material will be weakened after absorbing water, and there is no effective anti-seepage protection measure; the closed-cell structure of the thermal insulation material such as polyurethane rigid foam will be damaged after compression and deformation, and the thermal insulation performance will be significantly reduced, and the existing technology has defects in protecting the thermal insulation material. The dam concrete pouring process in water conservancy engineering is complex, and the above-mentioned solutions have great limitations, and there is no specific implementation plan for the material, structure, size, arrangement, and installation of removable formwork, which cannot adapt to the conditions and multiple demands of site construction, such as a castle in the air, which cannot be implemented in actual engineering at the moment. The main aspects are as follows:

[0014] (1)The material of the inner and outer protective layers directly affects the weight of the removable formwork structure. In a removable formwork field test carried out by a certain project, in order to ensure the strength and overall aesthetics of the panel, the weight exceeds 2000 kg. Due to the heavy weight of the self-formwork, the installation is difficult, slow, and even faces the scene of being unable to install and stopping work. Finally, during the concrete pouring, the connecting and fixing pull rod fell off and collapsed, which poses a great safety hazard.

[0015] (2) The compressive strength of the commonly used thermal insulation materials with excellent thermal insulation performance is relatively low compared to concrete. The single-bin pouring layer height of dam concrete is generally about 3m. When the concrete enters the bin and is vibrated, a large lateral pressure and impact force of coarse aggregate will be generated. If there is no effective protection, the concrete will be extruded and deformed. Although the existing technology such as Chinese invention CN 114892666B - A dam concrete permanent thermal insulation formwork structure and its construction method considers the protection problem of impact force by arranging a protective layer in the inner layer of the thermal insulation material to offset the impact force of coarse aggregate. However, it lacks consideration of lateral pressure. The lateral pressure of concrete first acts on the protective layer and then is directly transmitted to the intermediate thermal insulation material through the protective layer, which can cause compression deformation of the thermal insulation layer.

[0016] (3) The thermal insulation materials such as polyurethane rigid foam are mostly closed-cell structures. The low-boiling-point gas in the cells generally has a lower thermal conductivity than air. The overall thermal conductivity is generally lower than air. Existing literature shows that when the density is 50 kg / m 3 , the gas phase thermal conductivity accounts for about 70% of the total thermal conductivity of polyurethane. If the thermal insulation layer is deformed under pressure, the closed-cell structure will be damaged, and its thermal insulation performance will be significantly reduced. Relevant test research shows that the reduction of thermal insulation performance is not linearly related to the thickness compression value. The existing technology lacks sufficient understanding of the weakening of the thermal insulation performance of the thermal insulation material after deformation, and the corresponding protection measures are also insufficient. A large-scale project in the northwest of China tried to use removable formwork ten years ago, but ultimately failed to achieve engineering application due to deformation and shedding of the thermal insulation layer.

[0017] (4) Thermal insulation materials have a certain water absorption, and the thermal conductivity increases significantly after absorbing water, greatly reducing the thermal insulation effect. Removable formwork is made by connecting and installing prefabricated blocks of different sizes in the bin. The joint part becomes a clear leakage channel. The existing technology does not provide effective structures and treatment methods. In addition, the outer protective layer of the existing removable formwork is relatively thin, and there is no effective anti-seepage measure. Under the action of high water pressure, it is easy to leak itself, which will weaken the protection ability of the dam thermal insulation layer.

[0018] In summary, the conventional dam concrete heat preservation protection technology has defects and needs to be improved. The existing formwork removal technology scheme has great limitations in structure and other aspects, which leads to failure in the test stage, only some preliminary ideas and frameworks are proposed, without providing specific implementation parameters, technical indicators and construction methods, which cannot meet the requirements of dam concrete pouring construction and cannot be applied in dam construction of water conservancy and hydropower projects. Therefore, it is particularly important to study the permanent heat preservation and anti-seepage protection technology suitable for dam concrete of water conservancy projects. SUMMARY

[0019] The purpose of the present application is to overcome the above-mentioned deficiencies, and to provide a formwork embedded dam surface permanent heat preservation and protection module and a prefabrication and construction method to solve the problems in the background art.

[0020] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a formwork embedded dam surface permanent heat preservation and protection module, comprising a heat preservation core layer, a facing anti-seepage protection layer is arranged on the side of the heat preservation core layer close to the concrete pouring formwork, an internal pressure bearing protection layer is arranged on the side of the heat preservation core layer close to the dam surface layer crack limiting steel bar, a heat broken bridge support keel is arranged inside the heat preservation core layer, and an anchoring device is arranged in the area between the internal pressure bearing protection layer and the dam surface layer crack limiting steel bar.

[0021] Preferably, the facing anti-seepage protection layer is sequentially provided with a hydrophobic anti-icing coating, a cement-based anti-seepage coating and a base protection layer from the side in contact with the concrete pouring formwork to the inside of the dam; the base protection layer comprises a first fiber cement board and a first steel mesh arranged in the first fiber cement board.

[0022] Preferably, the internal pressure bearing protection layer comprises a second fiber cement board and a second steel mesh arranged in the second fiber cement board.

[0023] Preferably, the heat broken bridge support keel comprises a first anchoring nut arranged in the facing anti-seepage protection layer and a second anchoring nut arranged in the internal pressure bearing protection layer, the first anchoring nut and the second anchoring nut are threadedly connected with both ends of the heat insulation screw rod, and the thread directions of the first anchoring nut and the second anchoring nut are opposite.

[0024] Preferably, a groove or a step is formed on the side of the heat insulation screw rod close to the first anchoring nut, an outer limiting flange plate in contact with the facing anti-seepage protection layer is arranged at the groove or the step; a groove or a step is formed on the side of the heat insulation screw rod close to the second anchoring nut, and an inner limiting flange plate in contact with the internal pressure bearing protection layer is arranged at the groove or the step.

[0025] Preferably, the anchoring device comprises an adjustable support rod arranged between the internal pressure bearing protection layer and the dam surface layer crack limiting steel bar, and an anchoring bar threadedly connected with the outside of the second anchoring nut.

[0026] Preferably, the concrete pouring formwork, the facing impermeable protection layer, the thermal insulation core layer and the internal pressure bearing protection layer are provided with insertion holes for mounting the concrete pouring formwork anchoring bolts and the concrete pouring formwork supporting legs, the concrete pouring formwork anchoring bolts are threadedly connected with one end of the positioning cone, and the other end of the positioning cone is connected with the dam surface crack limiting steel through the serpentine anchoring rib; the concrete pouring formwork supporting legs are fixedly connected with the concrete pouring formwork support.

[0027] Preferably, one end of the thermal insulation core layer is higher than the end plane of the facing impermeable protection layer and the internal pressure bearing protection layer, forming a tenon structure; the other opposite end of the thermal insulation core layer is lower than the end plane of the facing impermeable protection layer and the internal pressure bearing protection layer, forming a mortise structure; each two adjacent formwork embedded dam surface permanent thermal insulation protection modules are connected through the cooperation of the tenon structure and the mortise structure.

[0028] In addition, the application also discloses a prefabrication method of the formwork embedded dam surface permanent thermal insulation protection module.

[0029] Step 1: parameter determination;

[0030] Step 1.1: according to the equivalent heat release coefficient of the thermal insulation layer required by the dam design, the thickness of the thermal insulation core layer is determined;

[0031]

[0032] In the formula, δ is the thickness of the thermal insulation core layer, the unit is m; γ is the thermal conductivity, the unit is W / (m·K); β is the equivalent heat release coefficient, the unit is W / m 2 K; k is a correction value: k is 1-1.2, when the air tightness of the adhesive joint is poor, k=1.2;

[0033] Step 1.2: the lateral pressure during dam concrete pouring is calculated, and the shear strength of the fiber cement board of the facing impermeable protection layer and the internal pressure bearing protection layer is reviewed to determine the thickness of the fiber cement board;

[0034] The detection shows that the bending strength of the 1cm fiber cement board is 12MPa, when P max ×10 -3 <12, the thickness H of the fiber cement board is 1cm;

[0035] When P max ×10 -3 ≥12, the thickness H of the fiber cement board is calculated according to the following formula:

[0036]

[0037] In the formula, H is the thickness of the fiber cement board, the unit is m; P max: maximum lateral pressure of concrete, unit kPa;

[0038] Step 1.3: According to the thickness of the thermal insulation core layer δ and the thickness of the fiber cement board H, the total length of the heat insulation screw and the length of the middle thick segment are calculated according to the following formula:

[0039]

[0040] L 中 = (δ - h Ⅰ -h Ⅱ );

[0041] In the formula, L is the length of the heat insulation screw, unit m; δ is the thickness of the thermal insulation core layer, unit m; H Ⅰ is the height of the first anchor nut, unit m; H Ⅱ is the height of the second anchor nut, unit m; h Ⅰ is the thickness of the outer limiting flange, h Ⅱ is the thickness of the inner limiting flange;

[0042] Step 1.4: Determine the size and weight of a single module;

[0043] Step 2: Manufacturing of the decorative impermeable protective layer;

[0044] Step 2.1: Mix the XYPEX admixture, cement, fiber and filler raw materials in a certain proportion, and send them into the mixer for stirring to ensure that various raw materials are fully mixed to form a uniform paste;

[0045] Step 2.2: Pour the mixed paste into the mold to half the height, then place the steel wire mesh in the paste in the mold, keeping the steel wire mesh in the middle position of the paste; then arrange and fix the first anchor nut in a square four-corner shape on the steel wire mesh; finally, pour the mixed paste into the mold to the thickness of the fiber cement board determined in step 1.2, and use the flattening machine and pressing machine for flattening and pressing treatment, and curing forming;

[0046] Step 2.3: Cut the fiber cement board into shape according to the size determined in step 1.4, and reserve the insertion holes of the concrete pouring mold anchor bolt and the concrete pouring mold support leg at the corresponding positions to obtain the base protective layer;

[0047] Step 2.4: Apply a layer of XYPEX impermeable material on the smooth surface of the base protective layer to obtain a cement-based impermeable coating;

[0048] Step 2.5: Apply a layer of hydrophobic coating on the surface of the cement-based impermeable coating to obtain a hydrophobic anti-icing coating;

[0049] Step 3: Manufacturing of the internal pressure-bearing protective layer:

[0050] Step 3.1: Mix the XYPEX admixture, cement, fiber and filler raw materials in a certain proportion, and send them into a mixer for stirring to ensure that the raw materials are fully mixed to form a uniform slurry;

[0051] Step 3.2: Pour the mixed slurry into the mold to half the height, then place the steel mesh in the slurry in the mold, keeping the steel mesh in the middle of the slurry; then arrange and fix the second anchor nut in a square four-corner shape on the steel mesh, with the arrangement position corresponding to the first anchor nut one by one; finally, pour the mixed slurry into the mold to the thickness of the fiber cement board determined in step 1.2, and use a flattening machine and a pressing machine for flattening and pressing treatment, and curing forming;

[0052] Step 3.3: Cut the fiber cement board according to the size determined in step 1.4, and reserve the insertion holes of the concrete pouring mold anchor bolt and the concrete pouring mold support leg at the corresponding positions to obtain an internal pressure-bearing protective layer;

[0053] Step 4: Pouring and extruding the thermal core layer;

[0054] Step 4.1: Thread the two limiting flanges into the two ends of the heat insulation screw respectively;

[0055] Step 4.2: Place the rough surface of the facing impermeable protective layer parallel to the rough surface of the internal pressure-bearing protective layer, and thread the threaded segments at the two ends of the plurality of heat insulation screws into the first anchor nut and the second anchor nut respectively, to connect the facing impermeable protective layer and the internal pressure-bearing protective layer to form a whole; then seal the four sides with a formwork, leaving only one pouring opening to form a 6-sided closed pouring mold;

[0056] Step 4.3: Use the pouring and extruding one-step forming process to fill and compact the polyurethane rigid foam thermal insulation material inside the mold; after setting, remove the formwork around the four sides;

[0057] Step 4.4: Drill the thermal core layer through the concrete pouring mold anchor bolt and the concrete pouring mold support leg insertion hole reserved on the facing impermeable protective layer and the internal pressure-bearing protective layer using tools;

[0058] Step 4.5: Cut and trim the four sides according to the principle of upper and lower correspondence and left and right correspondence to form a son-mother mortise and tenon structure, so as to form a seamless connection when multiple modules are spliced and installed.

[0059] The application also discloses a construction method of the dam surface permanent thermal insulation protective module embedded in the formwork, and has the characteristics that it comprises the following steps:

[0060] Step 1: Transportation and hoisting;

[0061] According to the dam concrete pouring progress, the prefabricated formwork embedded dam face permanent thermal protection module in the factory is transported to the site warehouse in batches; then according to the daily concrete storage area, these modules are transported to the storage face by cable crane hoisting;

[0062] Step 2: formwork embedded splicing installation:

[0063] Step 2.1: After the completion of the concrete pouring formwork erection, the above-mentioned module facing seepage prevention protection layer is arranged close to the pouring formwork, and a balance cushion layer is laid between the inside of the concrete pouring formwork and the outer surface of the module, which has two functions: first, it plays a buffering role for the facing protection layer of the module during concrete pouring, preventing it from being crushed; second, it prevents the release agent, oil stains on the concrete pouring formwork from polluting the facing seepage prevention protection layer, avoiding the adhesion of the two during form removal; when arranging, the concrete pouring formwork anchor bolts and concrete pouring formwork support legs are pulled out from the reserved insertion hole into the warehouse, and the concrete pouring formwork anchor bolts and the positioning cone are threadedly connected at one end, at this time the other end of the positioning cone is connected with the dam surface layer crack limiting steel through the serpentine anchor;

[0064] Step 2.2: According to the corresponding principle of the sub-mother mortise and tenon structure, the splicing and installation of adjacent modules are carried out; before splicing, adhesive is uniformly applied on the surface of the tenon, then the tenon is inserted into the corresponding mortise, ensuring seamless connection between the adjacent modules above, below and on both sides;

[0065] Step 2.3: Between the spliced and installed multiple modules and the dam surface layer crack limiting steel, the length of the adjustable support rod is adjusted according to the actual distance and is installed and fixed in contact, preventing the modules from shifting or deviating from the concrete pouring formwork and falling into the warehouse during concrete pouring and vibrating;

[0066] Step 2.4: The threaded ends of multiple anchor bars are screwed into the second anchor nuts of the internal pressure bearing protection layer, and the other ends face the warehouse; when the concrete is poured, the anchor bars form a whole with the dam body, thereby firmly fixing the formwork embedded dam face permanent thermal protection module;

[0067] Step 2.5: The top surface of the uppermost module is temporarily sealed and protected by using an edge sealing protection cover, which prevents the concrete slurry from polluting the sub-mother mortise and tenon structure of the module during pouring, and also prevents damage to the thermal core layer during the pouring;

[0068] Step 3: inspection and plugging;

[0069] Step 3.1: When the concrete pouring formwork is removed after concrete pouring, the concrete pouring formwork anchor bolts connected with the positioning cone on the outside are unscrewed, and the concrete pouring formwork is lifted upwards along the surface of the module; after the upper formwork support and panel installation is completed, the concrete pouring formwork support legs of the lowermost formwork support are taken out from the insertion hole, and finally the facing seepage prevention protection layer of the concrete dam face in the warehouse is exposed.

[0070] Step 3.2: the tool is hung on the support of the upper formwork, and a person goes down to the dam surface along the tool to check and seal;

[0071] Step 3.3: when the formwork of the next bin is erected, the protective cover on the top of the installed module is removed, and the new module is spliced and installed on the top of the installed module according to the sub-mother mortise and tenon structure, and then the above steps are repeated, when the dam pouring is completed, the formwork-embedded permanent thermal protection module of the dam surface is also arranged, and the protection of the dam concrete throughout the life cycle is realized.

[0072] The present application has the following advantages:

[0073] 1. The structure of the present application is scientific and reasonable, and the lateral pressure and coarse aggregate impact force during the pouring and vibrating of the concrete are fully considered, the load is uniformly transmitted from the internal pressure bearing layer to the facing impermeable protection layer through the hot broken bridge support keel, and then transmitted to the outside pouring formwork, and the internal thermal core layer will not be extruded and deformed.

[0074] 2. The size, thickness and other parameters of the single module can be calculated according to the actual situation of the project, which not only meets the load bearing capacity requirement, but also takes into account the structure and characteristics of the dam pouring formwork, and has good engineering adaptability.

[0075] 3. The present application can avoid the joints existing in the modular construction through the mortise and tenon structure, and can realize seamless splicing and installation of the modules, so that the dam thermal impermeable protection layer becomes a whole, prevents the joints from becoming a weak link of thermal protection, and has better thermal insulation and impermeability, and better protects the dam.

[0076] 4. The system adopts the modular prefabrication and construction method, the prefabrication and installation method of the single module is simple and efficient, and the details such as anchoring protection measures are fully considered, the engineering construction has strong operability, and is convenient and efficient, which greatly saves the construction time of the thermal insulation layer.

[0077] 5. The present application has many functions, in addition to the main thermal insulation function, by adding cement-based admixture in the facing impermeable protection layer, arranging an impermeable coating on the surface, and adding a hydrophobic ice prevention layer in the water level change area, the system has a thermal insulation impermeable protection integrated structure and function.

[0078] 6. The formwork-embedded permanent thermal protection module of the dam surface has high structural strength and good bending resistance, can withstand the lateral pressure generated during the pouring and vibrating of the dam concrete, and the impact force of the coarse aggregate in the four-grade concrete, and prevent damage to the system.

[0079] 7、The hot broken bridge support keel structure can evenly conduct the load of the concrete from the inner protective layer to the outer protective layer through the hot broken bridge support keel structure during pouring, and further conduct to the concrete pouring formwork, prevents extrusion deformation of the intermediate thermal core layer, and avoids the phenomenon that the thermal performance of the thermal core layer is weakened after compression deformation, and the high water head pressure in the reservoir area can be reversely conducted to the dam concrete after the dam is completed and put into operation, thereby protecting the thermal core layer.

[0080] 8、Compared with the existing formwork removal technology, the material and structure adopted by the present application cannot penetrate to the outer surface, and a good broken bridge can be formed between the dam concrete and the external environment, thereby reducing the adverse effects of the environmental temperature on the dam concrete temperature.

[0081] 9、The modular prefabrication and installation technical scheme can not only move the dam thermal protection workload forward and complete the module prefabrication in the factory building, but also has the advantages of light weight, modular installation, convenient and efficient construction, good adaptation to the dam concrete pouring construction, and realization of permanent thermal insulation and dam concrete pouring synchronization.

[0082] 10、The prefabrication of the module in the factory building avoids the interference of the complex construction environment during on-site operation, has better quality control and lower cost, avoids high-altitude cross operation, has high safety factor, can greatly reduce the thermal protection workload, promotes the individuality of the technology, and has remarkable economic and social benefits. BRIEF DESCRIPTION OF DRAWINGS

[0083] Figure 1 is a structural schematic view of a formwork embedded dam surface permanent thermal protection module;

[0084] Figure 2 is Figure 1 is an enlarged structural schematic view of the middle surface seepage protection layer;

[0085] Figure 3 is Figure 1 is an enlarged structural schematic view of the middle internal pressure bearing layer;

[0086] Figure 4 is Figure 1 is an enlarged structural schematic view of the hot broken bridge support keel;

[0087] Figure 5 is a structural schematic view of the connection of the concrete pouring formwork, the concrete pouring formwork support and the formwork embedded dam surface permanent thermal protection module;

[0088] Figure 6 is a schematic view of the cooperation and connection of the upper and lower two layers of formwork embedded dam surface permanent thermal protection modules through the tenon structure and the mortise structure. DETAILED DESCRIPTION

[0089] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0090] Example 1:

[0091] like Figures 1-6 As shown: A template-embedded permanent thermal insulation and protection module for dam surfaces includes a thermal insulation core layer 4. The side of the thermal insulation core layer 4 near the concrete pouring template 6 is provided with a decorative anti-seepage protective layer 1. The side of the thermal insulation core layer 4 near the crack-limiting steel bars 7 on the dam surface is provided with an internal pressure-bearing protective layer 2. The thermal insulation core layer 4 is provided with a thermally broken bridge support keel 3. An anchoring device 5 is provided in the area between the internal pressure-bearing protective layer 2 and the crack-limiting steel bars 7 on the dam surface.

[0092] Preferably, the decorative anti-seepage protective layer 1 is provided with a water-repellent and anti-icing coating 1.1, a cement-based anti-seepage coating 1.2 and a substrate protective layer 1.3 in sequence from the side in contact with the concrete pouring formwork 6 toward the inner side of the dam; the substrate protective layer 1.3 includes a first fiber cement board 1.3.1 and a first wire mesh 1.3.2 disposed in the first fiber cement board 1.3.1.

[0093] In this embodiment, the substrate protective layer is a fiber cement board made from raw materials such as fiber and cement, with a thickness of 10-50 mm. The thickness of the substrate protective layer in the finishing waterproof protective layer is the same as the thickness of the inner pressure-bearing protective layer, and the thickness of the inner pressure-bearing protective layer is calculated based on the lateral pressure of the concrete.

[0094] XYPEX admixture is added to the slurry during pressing, at a ratio of 1% to 3% of the cement content, which can achieve a good seepage prevention effect.

[0095] Preferably, the interior of the substrate protective layer is provided with one or more layers of wire mesh, the mesh size of which is 2 to 4 cm and the wire diameter is 0.8 to 1.5 mm.

[0096] Multiple first anchor nuts, made of stainless steel, carbon steel, or nylon, are arranged at 500mm intervals inside the substrate protective layer. The inner diameter of each first anchor nut is 10mm, and its height is half the thickness of the fiber cement board. One side of the first anchor nut is flush with the inner surface of the substrate protective layer, while the other side is located in the center of the fiber cement layer, pressing against the wire mesh. This design serves several purposes: first, it ensures that the force borne by the first anchor nut is more evenly transmitted to the fiber cement board, preventing damage from excessive localized stress; second, the height of the first anchor nut is only half that of the fiber cement board, leaving the outer surface of the substrate protective layer undamaged, maintaining aesthetics and overall protective performance; and third, the inner surface is also free of protrusions, facilitating the batch stacking and transportation of prefabricated modules and reducing transportation costs.

[0097] The base protection layer has a rough surface on one side and a smooth surface on the other side. The smooth surface faces outward, which can increase the flatness and beauty of the dam surface, reduce ice formation and reduce the pulling force of the ice layer on the base protection layer. The rough surface faces inward, which can increase the adhesion between the base protection layer and the thermal insulation core layer and enhance the durability of the overall structure.

[0098] A cement-based anti-seepage coating is coated on the outer side of the base protection layer. The material of the cement-based anti-seepage coating is XYPEX concentrate, and the thickness of the anti-seepage layer is 1-2 mm. This further enhances the anti-seepage ability and prevents high water pressure from penetrating the base protection layer into the thermal insulation core layer when used on the upstream face of the dam, thereby weakening the thermal insulation performance of the thermal insulation core layer.

[0099] For the surface anti-seepage protection layer in the water level change area, in order to deal with the pulling damage caused by ice formation in cold regions, a hydrophobic coating is coated on the outer side of the anti-seepage layer. The material of the hydrophobic coating is organic fluorocarbon resin or organic silicon oligomer, and the thickness of the hydrophobic coating is 0.1-0.5 mm. Through the penetration of the hydrophobic coating, a protective film can be formed on the surface of the base protection layer, preventing water penetration and protecting it from damage by the reservoir water, preventing and reducing surface icing, and improving its freeze-thaw resistance.

[0100] Preferably, the internal pressure-bearing protection layer 2 comprises a second fiber cement board 2.1 and a second steel wire mesh 2.2 arranged in the second fiber cement board 2.1.

[0101] The main function of the internal pressure-bearing protection layer is to protect the thermal insulation core layer from lateral extrusion force and impact force of aggregates during concrete pouring and vibration, which requires the base protection layer itself to have good bending strength and impact resistance.

[0102] The internal pressure-bearing protection layer is a fiber cement board made of fiber, cement and other raw materials. A XYPEX admixture is added to the slurry during pressing, with a mixing ratio of 1%-3% of the cement amount, which can achieve good anti-seepage effect.

[0103] The thickness of the fiber cement board determines its bending strength and impact resistance, which must be greater than the lateral pressure during dam concrete pouring. The thickness of the fiber cement board is 20-50 mm, and the specific thickness is obtained by calculation.

[0104] According to the concrete pouring template guide ACI 347-04, when the concrete slump value is ≤175 mm and the placement height is ≤4.2 m under normal vibration, and the placement rate is <21 m / h, the lateral pressure of the concrete is calculated according to the following formula.

[0105]

[0106] P max : maximum lateral pressure of concrete, unit kPa; C w : unit weight coefficient, w: density of concrete, unit kg / m 3 ; C c : chemical coefficient, taking 1.2; R: pouring rate of concrete, unit m / h; T: temperature of concrete during placement, unit ℃; and through detection, the performance indicators of 10mm thick fiber cement board are as follows:

[0107] Table 1 related technical parameters of 10mm fiber cement board

[0108]

[0109] As can be seen from Table 1, the fiber cement board of 10mm thickness has a bending strength of 12MPa.

[0110] Working condition 1: when P max ×10 -3 < 12, the thickness H of the fiber cement board is 10mm;

[0111] Working condition 2: when P max ×10 -3 ≥ 12, the thickness H of the fiber cement board is calculated according to the following formula,

[0112]

[0113] In the formula, H: thickness of fiber cement board, unit m; P max : maximum lateral pressure of concrete, unit kPa.

[0114] The internal pressure bearing protective layer is internally arranged with one or more layers of steel wire mesh, the mesh of the steel wire mesh is 2-4cm, and the wire diameter of the steel wire mesh is 0.8-1.5mm.

[0115] The internal pressure bearing protective layer is internally arranged with a plurality of second anchor nuts at intervals of 500mm, and the positions and quantities of the second anchor nuts one-to-one correspond to the first anchor nuts in the surface impermeable protective layer.

[0116] The material of the second anchor nut is stainless steel, carbon steel or nylon material. The inner diameter of the second anchor nut is 10mm, and the height is the same as the thickness of the fiber cement board. The second anchor nut is arranged in the internal pressure bearing protective layer in a through arrangement, one side of the second anchor nut is flush with the inner surface of the internal pressure bearing protective layer, and the other side is flush with the outer surface. There is no protrusion on both sides, which facilitates batch stacking and transportation of prefabricated modules.

[0117] The rough surfaces on both sides of the fiber cement board are convenient for good bonding with the polyurethane material of the thermal insulation core layer, and can uniformly distribute the extrusion and impact force generated during concrete pouring and vibrating, so that the overall pressure bearing of the thermal insulation and protection system is more uniform, and the compression resistance and durability are increased.

[0118] Preferably, the thermal broken bridge support furring 3 comprises a first anchoring nut 3.1 arranged in the surface anti-seepage protection layer 1 and a second anchoring nut 3.2 arranged in the internal pressure bearing protection layer 2, the first anchoring nut 3.1 and the second anchoring nut 3.2 are threadedly connected with both ends of the thermal insulation screw 3.3, and the thread directions of the first anchoring nut 3.1 and the second anchoring nut 3.2 are opposite.

[0119] Preferably, a groove or a step is arranged on one side of the thermal insulation screw 3.3 close to the first anchoring nut 3.1, and an outer limiting flange plate 3.4 in contact with the surface anti-seepage protection layer 1 is arranged at the groove or the step; a groove or a step is arranged on one side of the thermal insulation screw 3.3 close to the second anchoring nut 3.2, and an inner limiting flange plate 3.5 in contact with the internal pressure bearing protection layer 2 is arranged at the groove or the step.

[0120] The thermal insulation screw is a double-thread structure with thin ends and a thick middle part, the diameters of the two ends are 10 mm, and the diameter of the middle part is 20 mm. The misalignment formed by the change of the diameter is used to clamp the limiting flange plate on the surface of the surface anti-seepage protection layer and the internal pressure bearing protection layer, and the stress area is increased to prevent local damage.

[0121] The material is nylon or basalt fiber composite rib, which has the advantages of high strength, good thermal insulation performance and strong corrosion resistance, forms a broken bridge structure, and prevents external temperature changes from being conducted to the inside of the concrete through the screw.

[0122] The limiting flange plate is an iron or steel O-shaped gasket with an inner diameter of 10 mm, an outer diameter of 100 mm and a thickness of 5 mm. The limiting flange plate can prevent the thermal insulation core layer from deforming under pressure through limiting; secondly, the diameter of the gasket is obviously larger than the diameter of the thermal insulation screw, and the stress area is increased to prevent the inner and outer fiber cement boards from being damaged under local pressure.

[0123] A plurality of thermal insulation screws are first inserted into the limiting flange plates at both ends, and then screwed into the nuts of the surface anti-seepage protection layer and the internal pressure bearing protection layer respectively, so as to connect the inner and outer layers to form a whole as a support framework.

[0124] The length of the thermal insulation screw is calculated as follows: according to the thickness δ of the thermal insulation core layer and the thickness H of the fiber cement board, the total length of the thermal insulation screw and the length of the thicker middle part are calculated according to the following formula.

[0125]

[0126] L 中= (δ - h Ⅰ -h Ⅱ );

[0127] In the formula: L is the length of the heat insulation screw, in meters; δ is the thickness of the heat preservation core layer, in meters; H Ⅰ is the height of the first anchor nut, in meters; H Ⅱ is the height of the second anchor nut, in meters; h Ⅰ is the thickness of the outer limiting flange, h Ⅱ is the thickness of the inner limiting flange, h Ⅰ = h Ⅱ = 0.005 m.

[0128] When the concrete is poured, the lateral extrusion force and impact force generated by the vibration first act on the internal pressure bearing protective layer; when the heat preservation core layer is subjected to a larger load and is likely to produce compression deformation, the limiting flange close to the internal pressure bearing protective layer begins to bear stress, first transmitting the load of the internal pressure bearing protective layer to the heat insulation screw; then transmitting the load to the limiting flange close to the outer facing impermeable protective layer through the heat insulation screw; and finally transmitting the load to the facing impermeable protective layer uniformly through the limiting flange. Through the heat break bridge support keel structure, the heat preservation core layer in the middle can be well protected.

[0129] Preferably, the anchoring device 5 comprises an adjustable support rod 5.1 arranged between the internal pressure bearing protective layer 2 and the dam surface crack limiting steel bar 7, and an anchor bar 5.2 threadedly connected with the outer side of the second anchor nut 3.2.

[0130] The adjustable support rod is used to temporarily fix the dam surface permanent heat preservation impermeable protection module arranged close to the inner side of the concrete pouring formwork, one end of the adjustable support rod is supported on the internal pressure bearing protective layer of the module, and the other end of the adjustable support rod is supported on the concrete base surface or the crack limiting steel bar in the warehouse. The length of the adjustable support rod is adjusted to keep the module close to the formwork, so as to prevent the module from being displaced or overturned due to the pouring and vibration of the concrete. When the concrete in the warehouse is poured to a certain height, the module is kept close to the formwork by the lateral pressure of the concrete itself, and then the adjustable support rod is recycled and fixed by the next layer of module. In the embodiment, the adjustable support rod can be a spring buckle type telescopic rod, and after each length adjustment, the length is locked through the cooperation of the spring buckle and the corresponding hole.

[0131] The anchor bar is a serpentine structure with a threaded end, the diameter of the thread matches the second anchor nut, and the length of the anchor bar is 15 cm to 50 cm. The material can be steel, iron, nylon, basalt fiber and other high-strength materials.

[0132] After the dam surface permanent thermal insulation anti-seepage protection module is fixed, the threaded end of the anchor bar is screwed into the second anchor nut, and the serpentine tail end faces the bin. When the concrete in the bin is poured to the height of the anchor bar, the serpentine anchor bar is completely wrapped by the concrete. After the concrete solidifies, the serpentine anchor bar firmly fixes the dam surface permanent thermal insulation anti-seepage protection module on the surface of the dam.

[0133] Preferably, the concrete pouring formwork 6, the facing anti-seepage protection layer 1, the thermal insulation core layer 4 and the internal pressure bearing protection layer 2 are provided with insertion holes for installing the concrete pouring formwork anchor bolts 8 and the concrete pouring formwork support legs 9. The concrete pouring formwork anchor bolts 8 are threadedly connected with one end of the positioning cone 10, and the other end of the positioning cone 10 is connected with the dam surface layer crack limiting steel bar 7 through the serpentine anchor bar 11. The concrete pouring formwork support legs 9 are fixedly connected with the concrete pouring formwork support 12. The current dam concrete pouring formwork must be fixed by anchor bolts, positioning cones and anchor bars. The concrete pouring formwork support legs 9 and the concrete pouring formwork support 12 can bear the weight of the entire formwork and module, and the concrete pouring formwork anchor bolts 8 can fixedly connect the module and the formwork, thereby playing a certain supporting role and preventing the module from falling into the bin. In order to make the formwork embedded dam surface permanent thermal insulation protection module better adapt to the dam concrete pouring, according to the structural characteristics of the construction steel formwork, the concrete pouring formwork anchor bolt insertion holes and the concrete pouring formwork support leg insertion holes are reserved in each module, and the size and number thereof are determined according to the structure of the external formwork.

[0134] Preferably, as shown in Figure 6 Preferably, as shown in

[0135] In this embodiment, the thermal insulation core layer is a polyurethane rigid foam thermal insulation material or a polystyrene board material or a polyethylene foam material, which is formed by a pouring and extruding one-step forming process. The thickness of the thermal insulation core layer is determined according to the design requirements of the dam, and the thickness can be 3-15 cm.

[0136] The thickness of the thermal insulation core layer is determined according to the equivalent heat release coefficient of the thermal insulation layer required by the design of the dam.

[0137]

[0138] In the formula, δ is the thickness of the thermal insulation core layer, in meters; γ is the thermal conductivity, in W / (m·K); and β is the equivalent heat release coefficient, in W / m 2K; k is a correction value: k takes 1~1.2, when the air leakage of the pasting joint is not obvious, k=1.2 is taken.

[0139] According to the equivalent heat release coefficient required by the dam design, the thickness δ of the heat preservation core layer can be calculated by the above formula.

[0140] The heat preservation core layer, the surface anti-seepage protection layer and the internal pressure bearing protection layer form an integral whole, and a mortise and tenon structure is formed around the four sides, and the depth of the groove and the length of the tenon are both 5 cm.

[0141] When the on-site modular splicing and installation is carried out, first of all, the adhesives such as foam glue and structural glue are brushed on the surface of the tenon and the mortise, then the tenon and the mortise of the adjacent modules are spliced one by one to realize the seamless connection of multiple modules, and the adverse effects of the temperature amplitude of the environment on the dam concrete through the joint are prevented.

[0142] Preferably, the top surface of the uppermost heat preservation core layer 4, the surface anti-seepage protection layer 1 and the internal pressure bearing protection layer 2 is also provided with an edge sealing protection cover 13. The edge sealing protection cover 13 is used to temporarily seal and protect the top surface of the uppermost module, which can prevent the concrete slurry from polluting the mortise and tenon structure of the module during pouring, and can also prevent the heat preservation core layer from being damaged during the pouring. The groove structure of the edge sealing protection cover corresponds to the tenon of the module, and after all the modules in the chamber are spliced, installed and fixed, the tenon of the module is covered with the edge sealing protection cover, which can prevent the concrete slurry from polluting the mortise and tenon structure of the module during pouring, and can also prevent the heat preservation core layer from being damaged during the pouring. When the next chamber is poured, the edge sealing protection cover is removed.

[0143] Embodiment 2: A prefabrication method of a formwork embedded dam surface permanent heat preservation protection module, which comprises the following steps:

[0144] Step 1: parameter determination;

[0145] Step 1.1: according to the equivalent heat release coefficient of the heat preservation layer required by the dam design, the thickness of the heat preservation core layer is determined;

[0146]

[0147] In the formula: δ is the thickness of the heat preservation core layer, unit m; γ is the thermal conductivity, unit W / (m·K); β is the equivalent heat release coefficient, unit W / m 2 K; k is a correction value: k takes 1~1.2, when the air leakage of the pasting joint is not obvious, k=1.2 is taken.

[0148] Step 1.2: the lateral pressure during the pouring of the dam concrete is calculated, and the shear strength of the fiber cement board of the surface anti-seepage protection layer and the internal pressure bearing protection layer is checked, so as to determine the thickness of the fiber cement board;

[0149] According to the concrete pouring formwork guide ACI 347-04, when the concrete slump value is ≤175 mm, and the placement height is ≤4.2 m under normal vibration, and the placement rate is <21 m / h, the lateral pressure of the concrete is calculated according to the following formula:

[0150]

[0151] P = 0.5CwRT max : maximum lateral pressure of the concrete, unit kPa; C w : unit weight coefficient, w: density of the concrete, unit kg / m 3 ; C c : chemical coefficient, taking 1.2; R: pouring rate of the concrete, unit m / h; T: temperature of the concrete during placement, unit ℃;

[0152] The test shows that the flexural strength of the 1 cm fiber cement board is 12 MPa, when P max ×10 -3 < 12, the thickness H of the fiber cement board is 1 cm;

[0153] When P max ×10 -3 ≥ 12, the thickness H of the fiber cement board is calculated according to the following formula:

[0154]

[0155] H = 0.005P max : maximum lateral pressure of the concrete, unit kPa; Step 1.3: according to the thickness δ of the thermal insulation core layer and the thickness H of the fiber cement board, the total length of the heat insulation screw and the length of the middle thick segment are calculated according to the following formula.

[0156]

[0157] L 中 = (δ-h Ⅰ -h Ⅱ );

[0158] L = (δ-h Ⅰ -h Ⅱ ) = (δ-h Ⅰ -h Ⅱ ) = (δ-h Ⅰ -h Ⅱ = 0.005 m.

[0159] Step 1.4: Single module size and weight determination.

[0160] The formwork used in dam concrete pouring is 80% large steel formwork with standard size such as multi-card formwork. For this part of the modular design calculation, according to the structural characteristics of the large formwork (size, size and number of positioning cone, position and length of support leg, etc.), the single module is controlled to be a square or rectangle with a side length of 1000mm-3000m according to the principle of equal division of single formwork, and the weight of single formwork is controlled to be 50-500kg. The size of the single heat preservation and anti-seepage protection module matched with the large formwork, the size and number of the reserved positioning cone hole, the size and position of the reserved formwork support leg insertion hole, etc. are obtained, so that large-scale installation in batches can be realized on the construction site.

[0161] For the remaining part of the small formwork, special-shaped formwork, etc., according to the size, position and number of this part of the formwork, for the large number and consistent size, the module is designed and produced according to the size of the small formwork, and then transported to the site for installation. For the small amount and different size, the standard module is cut on site with cutting machine and other tools to realize the installation and fixation inside the special-shaped formwork.

[0162] Step 2: Manufacturing of the decorative anti-seepage protection layer

[0163] Step 2.1: Mix the raw materials such as XYPEX admixture, cement, fiber and filler according to a certain proportion, and send them into the mixer for stirring to ensure that the various raw materials are fully mixed to form a uniform slurry.

[0164] Step 2.2: Pour the mixed slurry into the mold to half the height, then put the steel mesh into the slurry in the mold, keeping the steel mesh in the middle position of the slurry; then arrange and fix the first anchor nut in a square four-corner shape on the steel mesh, and ensure that the distance between adjacent bolts is 500mm; finally, pour the mixed slurry into the mold to the standard height (the thickness of the fiber cement board determined in step 1.2), and use a 7000-ton flattening machine and a pressing machine for flattening and pressing treatment, and curing.

[0165] Step 2.3: According to the size determined in step 1.4, cut the fiber cement board into shape, and reserve the insertion holes of the concrete pouring formwork anchor bolt and the concrete pouring formwork support leg at the corresponding position to obtain the base protection layer.

[0166] Step 2.4: Apply 1-2mm XYPEX anti-seepage material on the smooth surface of the base protection layer to obtain the cement-based anti-seepage coating.

[0167] Step 2.5: A layer of hydrophobic coating is applied on the surface of the impermeable coating, the material of the hydrophobic coating is organic fluorocarbon resin or organic silicon oligomer, the thickness of the hydrophobic coating is 0.1-0.5 mm, and a hydrophobic anti-icing coating is obtained.

[0168] Step 3: Manufacturing of internal pressure bearing protective layer

[0169] Step 3.1: The raw materials such as XYPEX admixture, cement, fiber and filler are mixed in a certain proportion and sent to the mixer for stirring to ensure that the various raw materials are fully mixed to form a uniform slurry.

[0170] Step 3.2: The mixed slurry is poured into the mold to half the height, then the steel wire mesh is placed in the slurry in the mold, keeping the steel wire mesh in the middle position of the slurry; the second anchor nut is arranged in a square four-corner manner on the steel wire mesh, and the spacing between adjacent bolts is 500 mm, and the arrangement position corresponds to the first anchor nut one by one; finally, the mixed slurry is poured into the mold to the standard height (the thickness of the fiber cement board determined in step 1.2), and a 7000 ton pressing machine and a pressing machine are used for pressing and pressing treatment, and curing is performed.

[0171] Step 3.3: The fiber cement board is cut according to the size determined in step 1.4, and the insertion holes of the concrete pouring formwork anchor bolts and the concrete pouring formwork support legs are reserved at the corresponding positions, and the internal pressure bearing protective layer is obtained.

[0172] Step 4: Pouring and extruding of thermal core layer

[0173] Step 4.1: Two limiting flanges are respectively inserted into the two ends of the heat insulation screw.

[0174] Step 4.2: The rough surface of the finishing impermeable protective layer is placed in parallel with the rough surface of the internal pressure bearing protective layer, the threaded segments at both ends of the plurality of heat insulation screws are screwed into the first anchor nut and the second anchor nut respectively, and the finishing impermeable protective layer is connected with the internal pressure bearing protective layer to form a whole. Then the template is sealed around, only one pouring port is left, and a 6-face sealed pouring mold is formed.

[0175] Step 4.3: The inside of the mold is filled and compacted with polyurethane rigid foam insulation material using a pouring and extruding one-step forming process; after setting, the template around is removed.

[0176] Step 4.4: Using power station, electric saw and other tools, the thermal core layer is drilled through the concrete pouring formwork anchor bolt and concrete pouring formwork support leg insertion hole reserved on the finishing impermeable protective layer and the internal pressure bearing protective layer, and the hole diameter is the same as the protective layer.

[0177] Step 4.5: Cut the four sides with tools such as electric saws and hand saws, and form a sub-mother mortise and tenon structure according to the principle of upper and lower correspondence and left and right correspondence, so as to form a seamless connection when multiple modules are spliced and installed.

[0178] Embodiment 3: A construction method of a template-embedded dam face permanent thermal protection module, comprising the following steps:

[0179] Step 1: Transportation and hoisting;

[0180] According to the dam concrete pouring progress, the template-embedded dam face permanent thermal protection module prefabricated in the factory is transported to the site warehouse in batches. Then according to the daily concrete storage area, these modules are transported to the storage surface by cable crane hoisting.

[0181] Step 2: Template-embedded splicing and installation;

[0182] Step 2.1: After the concrete pouring formwork is erected, the above-mentioned module's decorative impermeable protection layer is arranged closely against the pouring formwork, and a balance pad layer is laid between the inner side of the concrete pouring formwork and the outer surface of the module. The balance pad layer can be foam rubber pad, plywood, polyethylene film, PET film and EVA film, etc. Firstly, it plays a buffering role for the decorative protection layer of the module during concrete pouring, preventing it from being broken under pressure; secondly, it prevents the decorative protection layer from being contaminated by the release agent and oil stains on the concrete pouring formwork, avoiding the adhesion of the two during form removal. When arranging, the positioning cone and the formwork support leg are pulled out from the reserved hole into the warehouse.

[0183] Step 2.2: According to the principle of corresponding sub-mother mortise and tenon structure, the splicing and installation of adjacent modules are carried out. Before splicing, adhesive such as structural adhesive and foam adhesive is uniformly brushed on the surface of the tenon, and then the tenon head is inserted into the corresponding mortise to ensure seamless connection between the adjacent modules above, below, left and right.

[0184] Step 2.3: Use support rods, pads, etc. to fix the spliced and installed multiple modules on the concrete surface or surface layer of the crack control reinforcement in the warehouse, preventing the modules from shifting or deviating from the concrete pouring formwork and falling into the warehouse when the concrete is poured and vibrated.

[0185] Step 2.4: Screw the threaded end of the multiple serpentine anchor bars into the second anchor nut of the internal pressure-bearing protection layer, and the other end faces the warehouse. When the concrete is poured, the serpentine anchor bars form a whole with the dam body, firmly fixing the template-embedded dam face permanent thermal impermeable protection integrated system module.

[0186] Step 2.5: Use edge sealing protection cover to temporarily seal and protect the top surface of the uppermost module, which can prevent the concrete slurry from contaminating the sub-mother mortise and tenon structure of the module during pouring, and can also prevent the thermal core layer from being damaged during the concrete pouring.

[0187] Step 3: Inspection and plugging;

[0188] Step 3.1: When the concrete pouring form is removed after the concrete pouring, the concrete pouring form anchor bolt connected with the positioning cone is unscrewed, and the concrete pouring form is lifted upwards along the module surface; after the upper formwork support and panel are installed, the concrete pouring form support leg of the lowermost formwork support is taken out of the insertion hole, and finally the finishing impermeable protective layer of the concrete dam surface of the bin is exposed.

[0189] Step 3.2: Use a hanging ladder and other tools to hang on the support of the upper formwork, and then go down to the dam surface for inspection and plugging. First, use polyurethane foaming material to plug the positioning cone hole and the formwork support leg insertion hole, and when the plugging is 1cm away from the surface, use polymer mortar to plug it, then brush 1-2mm of XYPEX impermeable material on the surface, and finally brush a layer of 0.1-0.5mm thick hydrophobic material, and the permanent thermal insulation and impermeable protective layer of the concrete dam surface of the bin is arranged.

[0190] Step 3.3: When the formwork of the next bin is erected, remove the protective cover on the top of the installed module, and then splice and install the new module on the top of the installed module according to the sub-mother mortise and tenon structure, and then repeat the above steps, and when the dam pouring is completed, the permanent thermal insulation and impermeable protective module of the formwork embedded dam surface of the entire dam surface is also arranged, realizing the protection of the entire life cycle of the dam concrete.

[0191] The above embodiments are only preferred technical solutions of the present application, and should not be regarded as a limitation of the present application. The protection scope of the present application should be based on the technical solutions recited in the claims, including equivalent replacement solutions of the technical features recited in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present application.

Claims

1. A prefabrication method of a formwork-embedded dam surface permanent thermal protection module, the formwork-embedded dam surface permanent thermal protection module comprising a thermal core layer (4), a facing impermeable protection layer (1) provided on one side of the thermal core layer (4) close to a concrete pouring formwork (6), an internal pressure-bearing protection layer (2) provided on one side of the thermal core layer (4) close to a dam surface crack-limiting steel bar (7), a hot broken bridge support keel (3) provided inside the thermal core layer (4), and an anchoring device (5) provided in a region between the internal pressure-bearing protection layer (2) and the dam surface crack-limiting steel bar (7); the hot broken bridge support keel (3) comprises a first anchoring nut (3.1) provided in the facing impermeable protection layer (1) and a second anchoring nut (3.2) provided in the internal pressure-bearing protection layer (2), the first anchoring nut (3.1) and the second anchoring nut (3.2) are threadedly connected with both ends of a heat insulation screw rod (3.3), the first anchoring nut (3.1) and the second anchoring nut (3.2) have opposite thread directions; the heat insulation screw rod (3.3) is provided with a groove or a step on one side close to the first anchoring nut (3.1), an outer limiting flange plate (3.4) in contact with the facing impermeable protection layer (1) is provided in the groove or the step; the heat insulation screw rod (3.3) is provided with a groove or a step on one side close to the second anchoring nut (3.2), an inner limiting flange plate (3.5) in contact with the internal pressure-bearing protection layer (2) is provided in the groove or the step; the method is characterized in that: It comprises the following steps: Step 1: parameter determination; Step 1.1: according to the equivalent heat release coefficient of the heat preservation layer required by the design of the dam, the thickness of the heat preservation core layer is determined; ； In the formula: is the thickness of the heat preservation core layer, unit m; is the thermal conductivity, unit W / (m·K); is the equivalent heat release coefficient, unit W / m²·K; is the correction value: Take 1~1.2, when the paste joint is not air permeable, take =1.2; Step 1.2: the lateral pressure of the dam concrete pouring is calculated, and the shear strength of the fiber cement board of the surface anti-seepage protection layer and the internal pressure protection layer is checked to determine the thickness of the fiber cement board; The 1cm fiber cement board was detected to have a bending strength of 12MPa, and when x 10 -3 <12, the thickness of the fiber cement board was 1cm. 1cm. When x 10 -3 ≥ 12, the thickness of the fiber cement board is calculated as follows: In the formula : thickness of the fiber cement board, unit m; : maximum lateral pressure of the concrete, unit kPa; Step 1.3: Calculate the total length of the heat preservation screw and the length of the thicker middle section according to the thickness of the heat preservation core layer and the thickness of the fiber cement board The total length of the heat preservation screw and the length of the thicker middle section are calculated according to the following formula: ； ； In the formula: is the length of the heat-insulating screw, in m; is the thickness of the heat-insulating core, in m; is the height of the first anchor nut, in m; is the height of the second anchor nut, in m; is the thickness of the outer limiting flange plate, is the thickness of the inner limiting flange plate; Step 1.4: single module size and weight determination; Step 2: surface anti-seepage protection layer manufacturing; Step 2.1: mix XYPEX admixture, cement, fiber and filler raw materials in a certain proportion, and send them into the mixer for stirring to ensure that various raw materials are fully mixed to form a uniform paste; Step 2.2: pour the mixed paste into the mold to half the height, then put the steel wire mesh into the paste in the mold, keep the steel wire mesh in the middle position of the paste; then arrange and fix the first anchor nut in a square four corners on the steel wire mesh; finally, pour the mixed paste into the mold to the thickness of the fiber cement board determined in step 1.2, and use the flattening machine and the pressing machine for flattening and pressing treatment, and curing forming; Step 2.3: cut the fiber cement board into shape according to the size determined in step 1.4, and reserve the insertion holes of the concrete pouring formwork anchor bolt and the concrete pouring formwork support leg at the corresponding position to obtain the base protection layer; Step 2.4: apply a layer of XYPEX anti-seepage material on the smooth surface of the base protection layer to obtain a cement-based anti-seepage coating; Step 2.5: apply a layer of hydrophobic coating on the surface of the cement-based anti-seepage coating to obtain a hydrophobic anti-icing coating; Step 3: internal pressure protection layer manufacturing: Step 3.1: mix XYPEX admixture, cement, fiber and filler raw materials in a certain proportion, and send them into the mixer for stirring to ensure that various raw materials are fully mixed to form a uniform paste; Step 3.2: pour the mixed paste into the mold to half the height, then put the steel wire mesh into the paste in the mold, keep the steel wire mesh in the middle position of the paste; then arrange and fix the second anchor nut in a square four corners on the steel wire mesh, which corresponds one to one with the first anchor nut; finally, pour the mixed paste into the mold to the thickness of the fiber cement board determined in step 1.2, and use the flattening machine and the pressing machine for flattening and pressing treatment, and curing forming; Step 3.3: cut the fiber cement board into shape according to the size determined in step 1.4, and reserve the insertion holes of the concrete pouring formwork anchor bolt and the concrete pouring formwork support leg at the corresponding position to obtain the internal pressure protection layer; Step 4: heat preservation core layer pouring and extrusion; Step 4.1: pass two limiting flanges into the two ends of the heat insulation screw respectively; Step 4.2: place the rough surface of the surface anti-seepage protection layer and the rough surface of the internal pressure protection layer in parallel, screw the threaded segments of the multiple heat insulation screws into the first anchor nut and the second anchor nut respectively, connect the surface anti-seepage protection layer and the internal pressure protection layer to form a whole; then seal the four sides with a template, leaving only one pouring port to form a 6-sided closed pouring mold; Step 4.3: The inside of the mold is filled and compacted with polyurethane rigid foam insulation material; after setting, the surrounding mold plate is removed; Step 4.4: The tool is inserted into the concrete pouring mold anchor bolt and concrete pouring mold support leg insertion hole reserved on the surface of the dam and the inner pressure bearing protective layer, and the insulation core layer is drilled through; Step 4.5: Cut around, form a mother-in-law mortise structure according to the principle of up and down correspondence and left and right correspondence, so as to form a seamless connection when multiple modules are spliced and installed.

2. A method of precasting a form-liner dam permanent protection module according to claim 1, characterised in that: The surface impermeable protective layer (1) is provided with a hydrophobic anti-icing coating (1.1), a cement-based impermeable coating (1.2) and a base protective layer (1.3) from the side in contact with the concrete pouring mold (6) to the inside of the dam.

3. A method of precasting a form-liner dam permanent protection module according to claim 1, wherein: The inner pressure bearing protective layer (2) includes a second fiber cement board (2.1) and a second steel wire mesh (2.2) arranged in the second fiber cement board (2.1).

4. The method of claim 1, wherein the method further comprises: providing a plurality of precast panels; and positioning the plurality of precast panels in a predetermined pattern on the foundation to form a dam surface. The anchoring device (5) includes an adjustable support rod (5.1) arranged between the inner pressure bearing protective layer (2) and the dam surface crack limiting steel bar (7), and an anchor bar (5.2) threadedly connected with the outer side of the second anchor nut (3.2).

5. The prefabrication method of a template-embedded permanent thermal insulation and protection module for dam surfaces according to claim 1, characterized in that: The concrete pouring mold (6), the surface impermeable protective layer (1), the insulation core layer (4) and the inner pressure bearing protective layer (2) are provided with insertion holes for installing concrete pouring mold anchor bolts (8) and concrete pouring mold support legs (9), the concrete pouring mold anchor bolts (8) are threadedly connected with one end of the positioning cone (10), the other end of the positioning cone (10) is connected with the dam surface crack limiting steel bar (7) through the serpentine anchor bar (11), and the concrete pouring mold support leg (9) is fixedly connected with the concrete pouring mold support (12).

6. A method of precasting a form-liner dam permanent protection module according to claim 1, wherein: The insulation core layer (4) is higher than the end plane of the surface impermeable protective layer (1) and the inner pressure bearing protective layer (2) at one end, forming a tenon structure; the other opposite end of the insulation core layer (4) is lower than the end plane of the surface impermeable protective layer (1) and the inner pressure bearing protective layer (2), forming a mortise structure; each two adjacent template embedded dam surface permanent thermal insulation protection modules are connected through the cooperation of the tenon structure and the mortise structure.

7. A method of precasting a form-liner dam permanent protection module according to claim 1, wherein: It also includes a construction method, which includes the following steps: Step 1): Transportation and hoisting; According to the dam concrete pouring progress, the template embedded dam surface permanent thermal insulation protection modules prefabricated in the factory are transported to the site warehouse in batches; then according to the daily concrete storage area, these modules are transported to the storage surface by cable crane; Step 2): Template embedded splicing and installation: Step 2.1): After the concrete pouring formwork is erected, the facing impermeable protective layer of the above module is arranged close to the pouring formwork, and a balance cushion layer is laid between the inside of the concrete pouring formwork and the outer surface of the module. Firstly, the facing protective layer of the module serves as a buffer during concrete pouring, preventing it from being crushed. Secondly, it prevents the release agent and oil stains on the concrete pouring formwork from contaminating the facing impermeable protective layer, avoiding adhesion between the two during form removal. When arranging, the concrete pouring formwork anchor bolts and concrete pouring formwork support legs are passed out of the reserved insertion holes into the warehouse, and the concrete pouring formwork anchor bolts and the positioning cone are threadedly connected at one end. At this time, the other end of the positioning cone is connected to the surface layer of the dam through the serpentine anchor. Step 2.2): The adjacent modules are spliced and installed according to the corresponding principle of the mortise and tenon structure. Before splicing, adhesive is evenly applied to the surface of the tenon, and then the tenon is inserted into the corresponding mortise to ensure seamless connection between the adjacent modules above, below, and on both sides. Step 2.3): Between the spliced and installed multiple modules and the surface layer of the dam, the length of the adjustable support rod is adjusted according to the actual distance and is installed and fixed in contact to prevent the modules from shifting or deviating from the concrete pouring formwork and falling into the warehouse during concrete pouring and vibration. Step 2.4): The threaded ends of multiple anchor bars are screwed into the second anchor nuts of the internal pressure-bearing protective layer, and the other ends face the warehouse. When the concrete is poured, the anchor bars form a whole with the dam, thereby firmly fixing the formwork-embedded dam face permanent thermal protection module. Step 2.5): The top surface of the uppermost module is temporarily sealed and protected using an edge protection cover, which prevents the concrete slurry from contaminating the mortise and tenon structure of the module during pouring and prevents damage to the thermal core layer during the warehouse. Step 3): Inspection and plugging; Step 3.1): After the concrete is poured, the concrete pouring formwork is removed by first unscrewing the concrete pouring formwork anchor bolts connected to the positioning cone on the outside and then lifting the concrete pouring formwork upwards along the surface of the module. After the upper formwork support and panel are installed, the concrete pouring formwork support legs of the lowermost formwork support are removed from the insertion holes, finally exposing the facing impermeable protective layer of the concrete dam face of the warehouse. Step 3.2): A tool is hung on the support of the upper layer of the formwork, and a person goes down to the dam face along the tool for inspection and plugging. Step 3.3): When the next warehouse module is erected, the protective cover on the top of the installed module is removed, and the new module is spliced and installed on top of the installed module according to the mortise and tenon structure. Then the above steps are repeated. When the dam pouring is completed, the formwork-embedded dam face permanent thermal protection module of the entire dam face is also arranged, achieving protection of the dam concrete throughout its life cycle.

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