Self-locking anti-cracking waterproof prefabricated hydraulic ecc panel

Abstract

The application belongs to the technical field of hydraulic engineering, and discloses a self-locking anti-cracking waterproof prefabricated hydraulic ECC panel. Through a material regulation and structure design cooperation method, a combination design of a low-shrinkage ECC main panel unit and a timely and quantitative expansion ECC self-locking assembly connection unit is used, so that volume deformation self-compensation high-precision assembly and self-locking anti-seepage improvement of the prefabricated ECC panel after assembly are realized. The panel has the advantages of high tensile anti-cracking, anti-seepage durability and the like, compared with a traditional hydraulic panel, has obvious improvement in mechanical properties, anti-seepage function and durability and safe service and the like, and solves the defects of insufficient durability of joint water stop of the existing steel-concrete panel. The method can be specifically applied to the fields of rockfill dam panels, pumped storage panels, water conveyance channel lining, hydraulic anti-seepage reinforcement and repair, fabricated buildings and the like.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering technology, and in particular to a self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel. Background Technology

[0002] Hydraulic panels are the main seepage-proof components of hydraulic structures, widely used in water conservancy projects such as rockfill dams and pumped storage power stations. Crack resistance and seepage prevention of hydraulic panels are crucial to the safety and efficiency of these projects, and crack resistance and seepage prevention are also among the major challenges currently facing hydraulic panels.

[0003] Traditional hydraulic engineering panels can be mainly divided into reinforced concrete rigid panels and asphalt concrete flexible panels. Asphalt panels have advantages such as strong deformation and foundation adaptability, and can be used to construct jointless hydraulic engineering panels due to their inherent crack resistance. However, asphalt concrete has disadvantages such as low stiffness / strength, performance sensitivity to service temperature, and significant durability and aging issues, which to some extent restricts its application in hydraulic engineering under harsh service environments.

[0004] Concrete panels have high stiffness and strength, but poor tensile strength. To mitigate cracking due to deformation caused by temperature and shrinkage, concrete panels must be designed with joints during construction, with horizontal / longitudinal joints connected by waterproofing structures for seepage prevention. Commonly used hydraulic waterproofing materials include copper, rubber, asphalt, and plastic fillers. Under the influence of water loads, dam deformation, settlement, and voiding, panel cracking and waterproofing failure are bottlenecks restricting the safe service life of hydraulic panels.

[0005] Engineered Cementitious Composite (ECC), a high-ductility cement-based composite material, exhibits tensile ductility exceeding 30,000 με through multi-slit microcracks after being subjected to tension, and also demonstrates tensile hardening capacity. Due to different translation and nomenclature, ECC is also often referred to as High-Ductility Concrete (HDC), Strain-Hardening Cement-Based Composite (SHCC), Flexible Concrete, and Ultra-High Toughness Cement-Based Composite (UHTCC), among other names. Compared to traditional concrete and asphalt concrete, ECC materials have compressive strength comparable to concrete, while their tensile strength and tensile deformation capacity are significantly superior, possessing the advantage of both rigidity and flexibility, and hold promise for overcoming the challenges of crack resistance and seepage prevention in hydraulic engineering panels.

[0006] Traditional ECC materials exhibit shrinkage deformation of 1500-3000 με, which is 3-6 times that of traditional concrete. Hydraulic panels, being ultra-thin layer structures subjected to strong external constraints, are prone to multi-crack formation due to shrinkage deformation before the water storage period. Furthermore, the high fiber content required in ECC necessitates high slurry fluidity to facilitate fiber dispersion. Given the steep slope of the hydraulic panels, the high fluidity of the ECC panels makes it difficult to maintain their shape on steep slopes during construction, posing a high risk of flow problems.

[0007] To overcome the adverse effects of shrinkage cracking on panels, researchers have invented low-shrinkage ECC, zero-shrinkage ECC, expanding ECC, and self-stressing ECC. Hydraulic panels have a large seepage prevention area, and construction cold joints are unavoidable during ECC construction; in particular, the expanding agent in expanding ECC and self-stressing ECC accelerates ECC setting, significantly increasing the number of construction cold joints. Under high water pressure and foundation deformation, construction cold joints remain a weak point in crack resistance and seepage prevention.

[0008] While prefabricated ECC panels for hydraulic engineering can overcome the problem of cold joints during construction, they still face several challenges. First, the volume deformation of the ECC material must be sufficiently small, ideally approaching zero, to ensure that the dimensions of the prepared ECC panels are not affected by volume deformation. Second, sufficient gaps must be reserved at the assembly and connection points of the hydraulic panels to facilitate construction and assembly. Finally, after panel assembly, gaps should be sealed or eliminated to achieve seepage prevention. However, current technology cannot simultaneously solve all three challenges.

[0009] In summary, there is an urgent need for a hydraulic panel with high crack resistance and impermeability, which has excellent mechanical and durability properties and solves the shortcomings of insufficient durability of existing panel joint sealing. Summary of the Invention

[0010] This invention addresses the shortcomings of existing hydraulic engineering panels in terms of crack resistance and seepage prevention by proposing a self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel. Through a collaborative design approach combining materials and structure, this invention overcomes the challenges of precise assembly and crack / seepage prevention in prefabricated hydraulic engineering panels.

[0011] First, this invention proposes a self-compensation method for volume deformation of ECC materials in hydraulic engineering prefabricated panels. Through the collaborative design of low-shrinkage ECC materials and timely quantitative expansion ECC materials, high-precision geometric design of the hydraulic engineering panel is ensured. Second, the geometrical relationship between the low-shrinkage main panel unit and the timely quantitative expansion self-locking assembly connection unit is determined through theoretical calculations. Finally, the timely quantitative expansion ECC, through controlled design, achieves adjustable assembly and installation gaps, and achieves self-locking seepage prevention after assembly. Compared with traditional concrete hydraulic engineering panels, ECC panels have significant advantages in terms of tolerance, tensile and crack resistance, seepage resistance and durability, and timely quantitative volume control. This method can be specifically applied to rockfill dam panels, pumped storage panels, water conveyance channel lining, hydraulic engineering seepage prevention reinforcement and repair, and prefabricated buildings.

[0012] The technical solution of this invention is as follows: a self-locking, crack-resistant, waterproof precast hydraulic ECC panel, wherein the self-locking, crack-resistant, waterproof precast hydraulic ECC panel is made of high-ductility cement-based material ECC; the self-locking, crack-resistant, waterproof precast hydraulic ECC panel includes two parts: a main panel unit and a self-locking assembly connection unit, which are integrally formed; adjacent self-locking, crack-resistant, waterproof precast hydraulic ECC panels are assembled through the self-locking assembly connection unit.

[0013] The main panel unit is composed of low-shrinkage ECC material, and the self-locking assembly connection unit is composed of timely quantitative expansion ECC material; the length of the self-locking assembly connection unit / the length of the main panel unit is equal to the total volume expansion deformation of the timely quantitative expansion ECC after preparation and assembly control / the total shrinkage deformation of the low-shrinkage ECC before assembly; the main panel unit and the self-locking assembly connection unit satisfy the volume deformation self-compensation relationship.

[0014] The average thickness of the self-locking assembly connection unit is 50% of the average thickness of the main panel unit; the unidirectional extension dimension of the self-locking assembly connection unit along the length direction of the main panel unit is 4%-20% of the length of the main panel unit; the unidirectional extension dimension along the width direction of the main panel unit is 4%-20% of the width of the main panel unit.

[0015] The self-locking assembly connection unit is provided with a key or groove to achieve self-locking assembly of adjacent self-locking crack-resistant waterproof precast hydraulic ECC panels. A reserved gap is provided after the key and groove of adjacent self-locking assembly connection units are assembled. The gap dimension along the thickness direction of the main panel unit is 0.2%-0.6% of the thickness of the main panel unit, and the gap along the length direction of the main panel unit is 0.2%-0.6% of the effective width of the adjacent keyway. The shape of the key or groove is square, rectangular, trapezoidal, or triangular. The height of the key or the depth of the groove is 1 / 3-1 / 2 of the thickness of the self-locking crack-resistant waterproof precast hydraulic ECC panel, and the bottom width is 1-5 times the height. The spacing between the keys or grooves is 1-5 times the height of the key or the depth of the groove.

[0016] After the self-locking assembly connection unit is prepared and molded by timely and quantitative expansion ECC material, it is only kept moist for 1 day and then placed in the air for drying. After the self-locking assembly connection unit is assembled, it is then cured with water for 2-7 days, resulting in an expansion volume deformation of 2000με-6000με.

[0017] The timely quantitative expansion ECC material is composed of 150-300 parts by mass of volume expansion component, 100-500 parts of cement, 400-1200 parts of supplementary cementitious material, 400-800 parts of aggregate, 200-400 parts of water, 0-30 parts of water-reducing agent, 0-50 parts of shrinkage-reducing agent, 0-10 parts of thickener, and 10-40 parts of fiber. The timely quantitative expansion ECC material has a direct tensile ductility of not less than 4%, a cubic compressive strength of 40-200 MPa, a direct tensile strength of 5-15 MPa, a flexural strength of 10-25 MPa, and a permeability coefficient of less than 10 after 0.5% deformation. -9 m / s.

[0018] A self-waterproof sealing unit is also provided between adjacent self-locking assembly connection units. It is arranged in the gap between the protrusion and groove of the adjacent self-locking assembly connection unit. When it comes into contact with water, the self-waterproof sealing unit will undergo a sealing and expansion reaction. Combined with timely quantitative expansion of ECC material, the volume deformation of the self-locking assembly connection unit is regulated, thereby enhancing the self-locking and seepage prevention effect after the self-locking crack-resistant and waterproof prefabricated hydraulic ECC panel is assembled.

[0019] The self-waterproof sealing unit is one or more of the following: expansive cement, steel slag powder, blast furnace slag powder, highly active fly ash, plastic filler, bentonite, asphalt, water-absorbing resin, penetrating crystallizing material, and hydraulic material.

[0020] The low-shrinkage ECC material is composed of 30-50 parts by mass of volume expansion component, 100-800 parts of cement, 400-1200 parts of supplementary cementitious material, 400-800 parts of aggregate, 200-400 parts of water, 0-30 parts of water-reducing agent, 0-50 parts of shrinkage-reducing agent, 0-10 parts of thickener, and 10-40 parts of fiber. The low-shrinkage ECC material has a direct tensile ductility of not less than 2%, a cubic compressive strength of 20-50 MPa, a direct tensile strength of 2-5 MPa, a flexural strength of 8-15 MPa, and a permeability coefficient of less than 10 after 0.5% tensile deformation. - 9 m / s.

[0021] After the main panel unit is made of low-shrinkage ECC material, it is maintained under high humidity for at least 14 days to allow the expansion components to fully react; the free shrinkage of the self-locking, crack-resistant, and waterproof prefabricated hydraulic ECC panel is less than 500με after 90 days, and the total shrinkage volume deformation after 90 days is stable within 200με.

[0022] The transition area between the main panel unit and the self-locking assembly connection unit is locally reinforced; the self-locking assembly connection unit is cast simultaneously with the main panel unit, and wet connection is achieved through local reinforcement, forming an integral panel load-bearing structure after hardening.

[0023] The thickness of the self-locking, crack-resistant, and waterproof precast hydraulic ECC panel is 0.2 meters to 0.6 meters, preferably 0.3 to 0.5 meters; the length of the self-locking, crack-resistant, and waterproof precast hydraulic ECC panel is 10 to 100 meters, preferably 40 to 60 meters; and the width of the self-locking, crack-resistant, and waterproof precast hydraulic ECC panel is 5 to 30 meters, preferably 10 to 20 meters.

[0024] The beneficial effects of this invention: The self-locking, crack-resistant, and waterproof precast hydraulic ECC panel of this invention achieves a self-locking assembly design for the precast hydraulic ECC panel through a combination design of a low-shrinkage ECC main panel unit and a timely quantitative expansion ECC self-locking assembly connection unit. The invented self-locking, crack-resistant, and waterproof precast hydraulic ECC panel has advantages such as high tensile strength, crack resistance, impermeability, and durability. Compared with traditional hydraulic concrete panels, its tensile deformation capacity is increased by more than 300 times, its bending deformation capacity is increased by more than 10 times, and its 0.5% horizontal crack permeability coefficient is reduced by two orders of magnitude. It exhibits significant improvements in mechanical properties, impermeability, and durable service life. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of a self-locking, crack-resistant, waterproof precast hydraulic ECC panel.

[0026] Figure 2 This is a top view of a self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel.

[0027] Figure 3 This is a partial view of the self-locking assembly connection unit.

[0028] Figure 4 Here is a schematic diagram of the keyway of the self-locking assembly connection unit; (a) is a square keyway; (b) is a triangular and trapezoidal keyway; (c) is a rectangular keyway. Detailed Implementation

[0029] Unlike traditional prefabricated buildings, the assembly process of prefabricated hydraulic panels must meet three basic conditions:

[0030] Requirement 1: Precise assembly of geometric dimensions, meaning that the actual geometric dimensions of the panel must meet the high-precision requirements of the design geometric dimensions; the ECC panel must not have its dimensions affected by volume deformation of the ECC material.

[0031] Requirement 2: Sufficient clearance must be reserved between the assembled structures to facilitate construction and assembly.

[0032] Requirement 3: After the panel is assembled, the gaps should be sealed or eliminated to achieve the purpose of preventing water seepage.

[0033] To address the aforementioned triple challenges, this invention utilizes a collaborative design approach combining materials and structure to develop a self-locking, crack-resistant, and waterproof prefabricated hydraulic ECC panel, achieving both high-precision assembly and post-assembly self-locking impermeability.

[0034] 1. The concept of self-compensation for volume deformation in high-precision panel assembly and panel geometric dimension design;

[0035] Traditional ECC materials shrink by about 2000 με. Hydraulic panels are usually quite large. For example, a 50-meter long ECC panel will have a volumetric deformation of 10 cm after fabrication (50 meters * 2000 με). This means that the ECC panel will have a volumetric deformation error of 10 cm compared to the design size before assembly.

[0036] This invention proposes a design concept for self-compensation of volume deformation of hydraulic panels. For example... Figure 1 As shown, the hydraulic panel consists of a main panel unit and a self-locking assembly connection unit; the main panel unit is made of low-shrinkage ECC material, and the self-locking assembly unit is made of timely quantitative expansion ECC material. The geometric dimensions of the main panel unit and the self-locking assembly connection unit satisfy the requirements of equation (1):

[0037] (1)

[0038] L1 and L2 are the lengths of the main panel unit and the self-locking assembly connection unit, respectively. The free volume deformation of the low-shrinkage ECC material of the main panel unit before assembly; The total volumetric expansion deformation of the ECC material for the self-locking assembly connection unit, from preparation to assembly control, is described in Table 1. Table 1 lists the material ratios and volumetric deformation control methods for low-shrinkage ECC and timely quantitative expansion ECC.

[0039] Table 1. ECC materials with different ratios (unit: kg / m²) 3 )

[0040]

[0041] This example, based on ASTM C490 / C490M–17, tests the free volume deformation of a 25mm*25mm*300mm ECC sample. The earliest permissible demolding time is selected as the starting point for the volume deformation test. Table 2 lists the free volume deformation under different initial curing conditions and different sulfoaluminate expansive cement (CSA) admixtures.

[0042] For the initial 14-day wet curing period, the shrinkage rate after 90 days of ECC decreased with increasing CSA content. Specifically, the CSA content in C20 was only 20 kg / m³. 3The expansion effect is limited, with a shrinkage of 910 με after 90 days. The shrinkage values ​​of C_30 and C_50 ratios after 90 days are between 0 and 500 με. After 14 days of wet curing, the free volume deformation of the C_60 ratio shows an expansion of 160 με after 90 days.

[0043] Extending the early wet curing time helps reduce later shrinkage. With the same C_50 ratio, without early wet curing, the free volume deformation value at 90 days is 860με shrinkage; with early wet curing for 7 days, the free volume deformation shrinkage is 325με, slightly lower than the 210με shrinkage after 14 days of wet curing; and with 28 days of wet curing, the 90-day shrinkage value is further reduced to 180με.

[0044] Both high CSA content and extended wet curing time can reduce material shrinkage. This invention recommends a CSA content of 30-50 parts and an early wet curing period of at least 14 days, which can control the free shrinkage deformation to be less than 500 με after 90 days.

[0045] Table 2. Free shrinkage volumetric deformation values ​​(με) of low-shrinkage ECC under different curing conditions

[0046]

[0047] Note: The default value is the shrinkage value.

[0048] Table 3 lists the results of free expansion deformation under different curing conditions and different sulfoaluminate expansive cement (CSA) dosages. The results show that wet curing is beneficial to improving the expansion deformation after CSA reaction, but the timing of curing and the dosage of CSA are more important for the timely and quantitative control of expansion deformation.

[0049] Due to the initial 2-day wet curing period, the CSA reaction in C_150 was relatively complete, resulting in an expansion deformation of 3510 με after 90 days. However, after a second wet curing period following 90 days, the expansion deformation only increased by 190 με. For the initial 1-day wet curing, the expansion deformation after 90 days was 2100 με. The expansion deformation controlled in the later stages increased with the extension of the wet curing time; after 90 days, the expansion deformation increased by 1100 με, 2000 με, and 2050 με after 1, 2, and 7 days of wet curing, respectively.

[0050] For the initial curing condition of 1 day of wet curing followed by 7 days of wet curing after 90 days, the expansion deformation showed a significant increasing trend with the increase of CSA content. The 90-day free expansion deformation of C_300 and C_400 were 4420 με and 5100 με, respectively. After 7 days of controlled wet curing after 90 days, the free expansion deformation of C_300 was 10420 με, while C_400 exhibited expansion cracking failure.

[0051] In conclusion, the following conclusions can be drawn:

[0052] Excessive early curing time leads to premature consumption of CSA, affecting later expansion control. Based on the results of this example, it is recommended that the early wet curing time be 1 day.

[0053] With the extension of the wet curing time after 90 days and the increase of CSA dosage, the corresponding adjustable expansion deformation is greater. Before panel installation, the expansion deformation is not controlled, leaving sufficient gaps to ensure smooth assembly; after panel assembly: the expansion deformation is controlled to be as large as possible, and the reserved gaps are self-locked, thereby achieving the purpose of impermeability and crack resistance.

[0054] Based on the results of this demonstration, it is recommended that the wet curing time after 90 days be 2-7 days, and the CSA content be 150-300 parts. Below this range, the later control of expansion and deformation will be insufficient; excessive CSA content will cause the ECC material itself to expand and crack.

[0055] Table 3. Free expansion volumetric deformation values ​​(με) of ECC under different curing conditions.

[0056]

[0057] Note: The default value is the expansion value.

[0058] According to the low-shrinkage ECC in Table 2 and the timely quantitative expansion ECC free volume deformation in Table 3, under the requirements of high-precision assembly criteria, the length design requirements of the main panel unit and self-locking assembly connection unit under different material and maintenance combination conditions must meet the proportional limit of equation (1). The specific combination of panel geometry design under the high-precision assembly requirements is shown in Table 4. It should be noted that in addition to meeting the high-precision assembly requirements, the panel geometry design must also meet the crack resistance and seepage resistance design requirements in the subsequent demonstration examples. High-precision assembly is only one of the panel design criteria.

[0059] Table 4. Panel length ratios for achieving high-precision assembly under different combinations of materials and control measures.

[0060]

[0061] 2. Panel geometry design under crack resistance and impermeability standards;

[0062] like Figure 1 The self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel shown consists of a main panel unit and a self-locking assembly connection unit. The thickness of the main panel unit is twice the average thickness of the self-locking assembly connection unit. Keyways are provided on the self-locking assembly connection unit, and the assembly of hydraulic panels is achieved by the interlocking of the keyways.

[0063] The main panel unit and the self-locking assembly connection unit are formed by wet casting with reinforced steel bars, and the deformation coordination control equations they satisfy are as follows:

[0064] (2)

[0065] L1 and L2 are the lengths of the main panel unit and the self-locking assembly connection unit, respectively. and These refer to the deformations that occur after the main panel unit and the self-locking assembly connection unit are assembled.

[0066] The main panel unit is relatively large, typically reaching 30-80m or even longer in length. Excessive shrinkage deformation could cause cracking of the main panel. Therefore, the shrinkage deformation of the assembled main panel unit is limited. The initial crack deformation of ECC material is generally around 200με. This invention limits the total shrinkage deformation of the main panel unit to stabilize within 200με after 90 days, i.e., controls... Therefore, D5 and D6 in Table 2 do not meet the requirements. In order to achieve the goal of smaller shrinkage in the later stage, sufficient wet curing in the early stage (at least 14 days) is required. Formula (2) can be used to further derive the length relationship between the main panel unit and the self-locking assembly connection unit.

[0067] (3)

[0068] Table 5 lists the relationship between the permeability coefficient and deformation cracking level of the typical ECC formulation in this example. The data in the table show that when the direct tensile deformation is less than 0.5%, the permeability coefficient is less than 10. -10 The deformation rate is m / s, meeting the design requirements for impermeability of hydraulic panels. When the direct tensile deformation exceeds 0.5%, the permeability coefficient increases significantly, leading to increased permeability loss. Therefore, this invention recommends controlling the deformation of the self-locking assembly connection unit to 0.5%, i.e. .

[0069] Under the design criterion of deformation compatibility control equation (3), when When the main panel undergoes a 200με shrinkage deformation, it can induce a 0.5% deformation in the self-locking assembly connection unit. The permeability coefficient of the self-locking assembly connection unit after cracking will exceed 10. -10 The flow rate (m / s) is insufficient to meet the anti-seepage requirements of hydraulic panels.

[0070] To meet the deformation compatibility control equations and crack resistance and impermeability requirements, it is necessary to control This also indicates that the D3-P5 working conditions in Table 4 do not meet the design requirements.

[0071] Table 5 Relationship between ECC permeability coefficient and deformation cracking level

[0072]

[0073] Because the average thickness of the self-locking assembly connection unit is only 50% of the thickness of the main panel unit, it is easily damaged during construction processes such as preparation, transportation, hoisting, and assembly. Furthermore, due to its special material design, the self-locking assembly connection unit is relatively expensive. Therefore, it is not recommended that the size of the self-locking assembly connection unit be too large; based on existing research experience, this invention suggests controlling the size... This indicates that the operating conditions D1-P3 and D1-P4 in Table 4 do not meet the design requirements.

[0074] Similarly, the outward extension of the panel along the width direction also satisfies the 4%-20% proportional relationship, which can be seen in the top view along the length and width of the panel. Figure 2 .

[0075] 3. The self-locking assembly connection unit has a reserved gap design;

[0076] Figure 3 A partial view of the self-locking assembly connection unit is provided for this example. To ensure that the panel has a certain degree of adjustability during assembly, a certain gap is preset between the keyways of the self-locking assembly connection unit, specifically the gap in the length direction. and thickness direction gap .

[0077] The self-locking assembly connection unit is composed of ECC material that expands quantitatively at appropriate times after panel assembly, and can expand and deform quantitatively at appropriate times to self-adjust and fill the gap reserved in the keyway.

[0078] The keyway clearance and real-time quantitative expansion ECC of the self-locking assembly connection unit must satisfy formula (3-4) to achieve the self-locking effect.

[0079] (3)

[0080] (4)

[0081] Where W is the effective width of adjacent keyways, such as Figure 3 As shown, this represents the center-to-center distance between adjacent protrusions and grooves, where H is the panel thickness. The expansion volume deformation of the ECC is measured and adjusted in a timely manner after panel assembly. As shown in Table 3 (P6 condition), excessive volume expansion control in the later stages may cause ECC cracking. Therefore, this example limits the upper limit of the later expansion control level to 6000 με (P5 condition). If the volume deformation control level is too small, the panel will be unable to achieve a self-locking effect through its own volume deformation control after assembly, thus creating seepage channels. Based on existing experience, if the gap is less than 0.2%, it may cause assembly difficulties and construction inconvenience. Therefore, this example limits the lower limit of the later expansion control level to 2000 με (P3 condition). Finally, this invention recommends a gap in the length direction. The clearance must meet the requirement of 0.2%-0.6% of the effective width of adjacent keyways, i.e., 0.2%-0.6% of the center distance between adjacent keyways and grooves; the clearance dimension along the panel thickness direction. The thickness is 0.2%-0.6% of the main panel unit thickness. That is, the working conditions P3-P5 in Table 4 all meet the self-locking gap design requirements, while P1, P2, and P6 do not meet the design requirements.

[0082] 4. Keyway and self-locking design;

[0083] In addition to the trapezoidal keyway form mentioned in Example 3, the convex key or groove form of the self-locking assembly connection unit also includes square, rectangular, or triangular (e.g.) Figure 4 (As shown). The height of the convex key or the depth of the groove is 1 / 3 to 1 / 2 of the thickness of the self-locking, crack-resistant, waterproof precast hydraulic ECC panel, and the bottom width is 1 to 5 times the height; the spacing between the convex keys or grooves is 1 to 5 times the height of the convex key or the depth of the groove.

[0084] In addition to regulating the volume deformation through timely and quantitative expansion ECC, the self-locking assembly connection unit can also incorporate self-waterproofing sealing units in the gap between the key and the groove. Materials for these self-waterproofing sealing units include, but are not limited to, expanded cement, steel slag powder, blast furnace slag powder, highly reactive fly ash, plastic fillers, bentonite, asphalt, water-absorbing resin, penetrating crystallizing materials, and hydraulic materials. Upon contact with water, the self-waterproofing sealing unit expands, achieving a waterproof and seepage-proof effect. Combined with timely and quantitative expansion ECC material to regulate the volume deformation of the self-locking assembly connection unit, the self-locking and seepage-proof effect after panel assembly is enhanced.

[0085] In summary, the self-locking, crack-resistant, and waterproof prefabricated hydraulic ECC panel in this invention must simultaneously meet the requirements of high-precision assembly and post-assembly crack resistance and seepage prevention. To achieve these requirements, this invention proposes three design principles through coordinated material and structural control design: a self-compensation concept for high-precision assembly volume deformation of the panel, a coordinated control equation for panel resistance, seepage prevention, and deformation, and a pre-reserved gap assembly and self-locking control equation. Guided by these three design principles, the self-locking, crack-resistant, and waterproof prefabricated hydraulic ECC panel achieves both high-precision assembly and anti-crack properties.

Claims

1. A self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel, characterized in that, The self-locking, crack-resistant, and waterproof prefabricated hydraulic ECC panel is made of high-ductility cement-based material ECC; the self-locking, crack-resistant, and waterproof prefabricated hydraulic ECC panel includes two parts: a main panel unit and a self-locking assembly connection unit, which are integrally formed; adjacent self-locking, crack-resistant, and waterproof prefabricated hydraulic ECC panels are assembled through the self-locking assembly connection unit. The main panel unit is composed of low-shrinkage ECC material, and the self-locking assembly connection unit is composed of timely quantitative expansion ECC material; the length of the self-locking assembly connection unit / the length of the main panel unit is equal to the total volume expansion deformation of the timely quantitative expansion ECC after preparation and assembly control / the total shrinkage deformation of the low-shrinkage ECC before assembly; the main panel unit and the self-locking assembly connection unit satisfy the volume deformation self-compensation relationship. The average thickness of the self-locking assembly connection unit is 50% of the average thickness of the main panel unit; the unidirectional outward extension dimension of the self-locking assembly connection unit along the length direction of the main panel unit is 4%-20% of the length of the main panel unit; the unidirectional outward extension dimension along the width direction of the main panel unit is 4%-20% of the width of the main panel unit. The self-locking assembly connection unit is provided with a key or groove to realize the self-locking assembly of adjacent self-locking crack-resistant and waterproof prefabricated hydraulic ECC panels; the key and groove of adjacent self-locking assembly connection units are provided with a reserved gap after assembly; wherein the gap dimension along the thickness direction of the main panel unit is 0.2%-0.6% of the thickness of the main panel unit, and the gap along the length direction of the main panel unit is 0.2%-0.6% of the effective width of the adjacent keyway; A self-waterproof sealing unit is also provided between adjacent self-locking assembly connection units. It is arranged in the gap between the protrusion and groove of the adjacent self-locking assembly connection unit. When it comes into contact with water, the self-waterproof sealing unit will undergo a sealing and expansion reaction. Combined with timely quantitative expansion of ECC material, the volume deformation of the self-locking assembly connection unit is regulated, thereby enhancing the self-locking and seepage prevention effect after the self-locking crack-resistant and waterproof prefabricated hydraulic ECC panel is assembled.

2. The self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel according to claim 1, characterized in that, After the self-locking assembly connection unit is prepared and molded by timely and quantitative expansion ECC material, it is only kept moist for 1 day and then placed in the air for drying. After the self-locking assembly connection unit is assembled, it is then cured with water for 2-7 days, resulting in an expansion volume deformation of 2000με-6000με.

3. The self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel according to claim 2, characterized in that, The timely quantitative expansion ECC material is composed of 150-300 parts volume expansion component, 100-500 parts cement, 400-1200 parts supplementary cementitious material, 400-800 parts aggregate, 200-400 parts water, 0-30 parts water-reducing agent, 0-50 parts shrinkage-reducing agent, 0-10 parts thickener, and 10-40 parts fiber by mass fraction.

4. The self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel according to claim 1, characterized in that, The self-waterproof sealing unit is one or more of the following: expansive cement, steel slag powder, blast furnace slag powder, highly active fly ash, plastic filler, bentonite, asphalt, water-absorbing resin, penetrating crystallizing material, and hydraulic material.

5. The self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel according to claim 1, characterized in that, The low-shrinkage ECC material is composed of 30-50 parts by mass of volume expansion component, 100-800 parts of cement, 400-1200 parts of supplementary cementitious material, 400-800 parts of aggregate, 200-400 parts of water, 0-30 parts of water-reducing agent, 0-50 parts of shrinkage-reducing agent, 0-10 parts of thickener, and 10-40 parts of fiber.

6. The self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel according to claim 5, characterized in that, After the main panel unit is made of low-shrinkage ECC material, it is maintained under high humidity for at least 14 days to allow the expansion components to fully react; the free shrinkage of the self-locking, crack-resistant, and waterproof prefabricated hydraulic ECC panel is less than 500με after 90 days, and the total shrinkage volume deformation after 90 days is stable within 200με.

7. The self-locking, crack-resistant, waterproof prefabricated hydraulic ECC panel according to claim 1, characterized in that, The transition area between the main panel unit and the self-locking assembly connection unit is locally reinforced; the self-locking assembly connection unit is cast simultaneously with the main panel unit, and wet connection is achieved through local reinforcement, forming an integral panel load-bearing structure after hardening.

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