A hydrophobic and tough sea mud concrete material and its preparation method and application

Abstract

The present invention belongs to the technical field of concrete compositions, and specifically relates to a hydrophobic and tough sea mud concrete material, a preparation method thereof, and an application thereof. The hydrophobic and tough sea mud concrete material provided by the present invention uses dredged sea mud and industrial solid waste as main raw materials, without the addition of traditional cement. Through the coordinated action of precursors, activators, hydrophobic materials, and fibers, dredged sea mud and industrial solid waste are synergistically stimulated to produce a dense structure with a significant hydrophobic effect. The obtained hydrophobic and tough sea mud concrete material is not only high in strength and toughness, but also has a structurally stable hydrophobic property, which can realize the efficient resource utilization of dredged sea mud and industrial solid waste, effectively reduce carbon emissions, and achieve good durability through the synergy of high strength and toughness and hydrophobicity.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete compositions, and in particular relates to a hydrophobic and tough sea mud concrete material, a preparation method thereof, and an application thereof. Background Art

[0002] Permanent formwork, as a structural system that can work in conjunction with concrete structures, does not need to be dismantled during construction. It can effectively simplify the construction process, shorten the construction period, and improve the structural integrity and service durability. It has been used in bridge engineering, marine engineering, underground structures and other fields.

[0003] However, existing permanent formwork is generally based on cement-based materials, which lack durability in complex environments such as high humidity and high salinity. For example, in marine and coastal areas, permanent formwork is exposed to adverse conditions such as seawater erosion and chloride ion penetration, leading to premature degradation, which seriously affects the durability and service life of engineering structures. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydrophobic and tough sea mud concrete material, a preparation method and application thereof. The hydrophobic and tough sea mud concrete material provided by the present invention can obtain a waterproof permanent formwork with excellent durability.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The invention provides a hydrophobic and tough sea mud concrete material, comprising the following components in parts by mass: 24-27 parts of blast furnace slag, 12-24 parts of fly ash, 3-13 parts of dredged sea mud, 2-4 parts of a microstructure densifier, 9-11 parts of an alkali activator, 16.3-18 parts of fine silica sand, 16.5-18.3 parts of a retarder, 0.7-1.2 parts of fibers, and a hydrophobic agent, wherein the ratio of the mass of the hydrophobic agent to the total mass of the blast furnace slag, fly ash, dredged sea mud and the microstructure densifier is 1-4:100; the particle size of the fine silica sand is 0.01-663.4 μm; the fibers include polyethylene fibers and polyvinyl alcohol fibers; the hydrophobic agent is a polysiloxane hydrophobic agent; and the polysiloxane hydrophobic agent has hydroxyl groups as terminal groups.

[0007] Preferably, the particle size of the blast furnace slag is not greater than 80 μm; the particle size of the fly ash is not greater than 300 μm; the particle size of the microstructure densifier is not greater than 150 μm; and the average particle size of the fine silica sand is not greater than 300 μm.

[0008] Preferably, the alkali activator is anhydrous sodium silicate powder; the modulus ratio of the anhydrous sodium silicate powder is 1.2 to 1.6.

[0009] Preferably, the retarder comprises borax and water; the mass ratio of the borax to water is 130-141:1000.

[0010] Preferably, the polysiloxane hydrophobic agent includes one or more of α,ω-dihydroxy polydimethylsiloxane, single-end hydroxy polydimethylsiloxane, α,ω-dihydroxy polyether modified polysiloxane and α,ω-dihydroxy amino modified polysiloxane; the molecular weight of the siloxane main chain in the polysiloxane hydrophobic agent is 400~1500.

[0011] Preferably, the volume percentage of the polyvinyl alcohol fibers is no less than 1 / 3 of the total fibers.

[0012] The present invention also provides a method for preparing the hydrophobic and tough sea mud concrete material described in the above scheme, comprising the following steps: mixing fly ash, dredged sea mud, alkali activator, blast furnace slag, microstructure densifier, fine silica sand, retarder, fiber and hydrophobic agent, forming the mixture and then thermally curing the mixture to obtain the hydrophobic and tough sea mud concrete material.

[0013] The present invention also provides a waterproof permanent formwork, comprising one or more unit formworks; the unit formworks comprise an outer shell layer, a fiber-reinforced composite material mesh and a filling layer arranged in sequence from the outside to the inside; the outer shell layer comprises a hydrophobic and tough sea mud concrete material; the filling layer comprises a hydrophobic and tough sea mud concrete material; the unit formworks are provided with fiber-reinforced composite material mesh connection holes or bolt connection holes; the unit formworks are connected by mechanical components and sealing cementitious materials; the hydrophobic and tough sea mud concrete material is the hydrophobic and tough sea mud concrete material described in the above scheme or the hydrophobic and tough sea mud concrete material obtained by the preparation method described in the above scheme.

[0014] Preferably, the surface of the fiber reinforced composite material mesh is also coated with epoxy resin.

[0015] The present invention also provides a method for preparing the waterproof permanent formwork described in the above scheme, comprising the following steps: preparing a hydrophobic and tough sea mud concrete material and an FRP reinforcement mesh, casting and then vibrating the concrete to form a unit formwork; using a post-tensioning method to connect the unit formwork through mechanical components and a sealing cementitious material, and then curing the unit formwork to obtain the waterproof permanent formwork.

[0016] The present invention provides a hydrophobic, strong-tough sea mud concrete material. This material uses dredged sea mud and industrial solid waste (blast furnace slag, fly ash, and a microstructure densifier) ​​as primary raw materials, eliminating the need for traditional cement. Through the coordinated action of precursors, activators, hydrophobic materials, and fibers, the dredged sea mud and industrial solid waste synergistically stimulate each other to produce a dense structure with a significant hydrophobic effect. The resulting hydrophobic, strong-tough sea mud concrete material is not only high in strength and toughness, but also possesses structurally stable hydrophobic properties. This allows for the efficient resource utilization of dredged sea mud and industrial solid waste, effectively reducing carbon emissions. The synergistic effects of high strength and toughness and hydrophobicity also provide excellent durability.

[0017] The specific mechanism of the present invention using dredged sea mud to obtain hydrophobic and tough sea mud concrete material is as follows: although dredged sea mud contains certain silicon and aluminum minerals, their activity is low and the alkali-induced reaction rate is slow; the present invention introduces highly active industrial solid waste, blast furnace slag, fly ash and microstructure densifier rich in amorphous SiO2, Al2O3 and CaO and other highly active components, which can quickly release Ca in an alkaline environment. 2+ 、SiO4 4- 、AlO4 5- Reactive ions such as C-(A)-SH and NASH can significantly increase the concentration of reactive ions in the system, thereby promoting the continued progress of the reaction, accelerating the dissolution and participation of low-activity minerals in the dredged sea mud in the reaction, and ultimately generating dense cementitious products mainly composed of C-(A)-SH, NASH, MSH, etc., giving the hydrophobic and tough sea mud concrete material good structural density and durability.

[0018] The present invention utilizes the cementitious material system formed by dredged sea mud, as well as hydrophobic agents and fibers, to obtain hydrophobic and tough sea mud concrete materials. The specific mechanism is as follows: Generally, directly adding hydrophobic agents to alkali-activated cement-based materials will significantly reduce the strength and toughness of the raw materials, and the hydrophobic performance is limited. The present invention utilizes the alkali activation effect of dredged sea mud and industrial solid waste to avoid the influence of hydrophobic agents on traditional cement hydration, and through the mutual coupling of polyvinyl alcohol fibers with hydroxyl-terminated hydrophobic materials (hydrophobic agents) and water in the cementitious products, the hydrophobic effect and the effect of the coupling agent are exerted at the same time, thereby improving the tightness between the fibers and the matrix and the overall hydrophobic modification effect inside the material, constructing an integrated synergistic performance system of "strong-tough-hydrophobic", achieving an overall hydrophobic effect, effectively resisting wear, and avoiding the reduction of the strength and toughness of the material by the hydrophobic agent.

[0019] The present invention is different from other geopolymer systems. The present invention does not only take strength or low carbon as a single goal, but takes the realization of the integrated synergistic performance of "strong-tough-hydrophobic" as the core orientation. It adopts a multi-component composite control strategy, utilizes specific raw materials, dosage ratios, particle size grading and interface control mechanisms, and conducts system optimization around engineering application requirements such as structural integration, waterproof durability and crack resistance control. Specifically, dredged sea mud and blast furnace slag and other raw materials synergistically provide multi-source calcium-silicon-aluminum active components, promote the formation of gel skeletons such as C-(A)-SH and NASH, and stimulate the development of overall strength; microstructure densifiers, as highly active ultrafine components, effectively control the microscopic pore structure and the density of the interface transition zone, and enhance the toughness foundation; hydrophobic agents participate in condensation reactions in an alkaline-excited environment to construct a stable hydrophobic silicon-oxygen network and form a continuous hydrophobic barrier; fibers construct a stress bridging mechanism to effectively improve fracture toughness and crack control capabilities. Through the synergy of multiple mechanisms, the present invention achieves the organic unity of mechanical properties, durability and hydrophobic properties, which is significantly better than geopolymer systems that aim at single performance optimization.

[0020] The present invention also provides a method for preparing the hydrophobic and tough sea mud concrete material described in the above solution. The preparation method provided by the present invention has simple steps, is environmentally friendly, and has low cost.

[0021] The present invention also provides a waterproof permanent formwork. This invention utilizes the aforementioned hydrophobic, tough marine mud concrete material combined with a highly corrosion-resistant fiber-reinforced plastic (FRP) reinforcement mesh structure. The two form a synergistically stressed composite system, integrating structural and construction functions. This waterproof permanent formwork exhibits excellent waterproofing and corrosion resistance, along with strong resistance to chloride ion attack. It can maintain long-term stability in harsh service environments such as high humidity and high salinity, achieving excellent durability and mechanical properties. This makes it technically and economically feasible for application in bridge structures, marine engineering (harbor projects, channel revetments, coastal structures), and underground structures. It is particularly suitable for marine or port projects requiring dredging. After hardening, the waterproof permanent formwork provided by the present invention forms a good interfacial bond with the structural concrete, exhibiting synergistic stress-bearing capabilities and overall structural integrity, significantly extending the service life of the structure. The waterproof permanent formwork provided by the present invention can be used directly as a structural component without dismantling, effectively simplifying the construction process, shortening the construction period, and reducing labor costs, achieving a green and low-carbon approach. It also significantly increases the concrete's bearing capacity, making it suitable for building structures in both conventional and special environments and possessing broad application prospects.

[0022] The waterproof principle of the waterproof permanent formwork provided by the present invention is as follows: the interior of the waterproof permanent formwork of the present invention uses a dense, hydrophobic, and tough sea mud concrete material as the main filling material, which significantly improves the overall waterproof performance and prevents moisture from penetrating into the interior of the formwork or the structural interface. Specifically:

[0023] (1) Multi-layer composite structure extends the water seepage path: The waterproof permanent formwork is composed of three layers of filling layer, FRP mesh and outer shell layer, forming a continuous laminated structure, which significantly extends the water penetration path through the waterproof permanent formwork, thereby improving the water blocking efficiency.

[0024] (2) Double protection of node sealing and secondary sealing: The unit templates are closed by bolts and anchors, and grouting holes are reserved at key connection nodes and injected with bonding materials to further seal the micro-cracks at the interfaces, effectively preventing leakage hazards caused by splicing gaps.

[0025] (3) The waterproof permanent formwork has load-bearing and protective functions: The waterproof permanent formwork of the present invention not only serves as the outer formwork of the concrete component, but also as the permanent main skeleton to participate in the load-bearing. Its waterproof function does not rely on additional coatings or membranes, and its overall performance will not deteriorate due to long-term water immersion or interface peeling, ensuring the long-term service performance of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a schematic cross-sectional view of the main elevation of the structure of the waterproof permanent formwork of the present invention;

[0028] Figure 2 This is a schematic diagram of the main elevation of the "T"-shaped unit formwork of the waterproof permanent formwork of the present invention;

[0029] Figure 3 This is a schematic diagram of the main elevation of the middle unit formwork of the waterproof permanent formwork of the present invention;

[0030] Figure 4 This is a schematic diagram of the main elevation of a rectangular unit formwork of a waterproof permanent formwork of the present invention;

[0031] Figure 5 This is a water contact angle diagram of the hydrophobic and tough sea mud concrete material of Example 1;

[0032] Figure 6 This is a water contact angle diagram of the hydrophobic and tough sea mud concrete material of Example 2;

[0033] Figure 7 This is the axial tensile strain curve of the hydrophobic and tough sea mud concrete material of Example 1;

[0034] Figure 8This is the axial tensile strain curve of the hydrophobic and tough sea mud concrete material of Example 2;

[0035] Figure numerals: 1 is the "T"-shaped unit formwork of the waterproof permanent formwork, 2 is the middle unit formwork of the waterproof permanent formwork, 3 is the rectangular unit formwork of the waterproof permanent formwork, 4 is the fiber reinforced composite material mesh connection hole, 5 is the fiber reinforced composite material mesh, and 6 is the bolt connection hole. DETAILED DESCRIPTION

[0036] The present invention provides a hydrophobic and tough sea mud concrete material, comprising the following components in parts by mass:

[0037] 24-27 parts of blast furnace slag, 12-24 parts of fly ash, 3-13 parts of dredged sea mud, 2-4 parts of microstructure densifier, 9-11 parts of alkali activator, 16.3-18 parts of fine silica sand, 16.5-18.3 parts of retarder, 0.7-1.2 parts of fiber, and a hydrophobic agent, wherein the ratio of the mass of the hydrophobic agent to the total mass of blast furnace slag, fly ash, dredged sea mud and microstructure densifier is 1-4:100; the particle size of the fine silica sand is 0.01-663.4 μm; the fibers include polyethylene fibers and polyvinyl alcohol fibers; the hydrophobic agent is a polysiloxane hydrophobic agent; and the polysiloxane hydrophobic agent has hydroxyl groups as terminal groups.

[0038] In parts by mass, the hydrophobic and tough sea mud concrete material provided by the present invention includes 24 to 27 parts of blast furnace slag, specifically 25 parts or 26 parts.

[0039] In the present invention, the components of the blast furnace slag may include CaO, Al2O3 and SiO2; the particle size of the blast furnace slag may be no greater than 80μm, specifically 0.17μm, 1μm, 5μm, 10μm, 20μm, 40μm or 68.95μm.

[0040] Based on the mass fraction of the blast furnace slag, the hydrophobic and tough sea mud concrete material provided by the present invention includes 12 to 24 parts of fly ash, specifically 15 parts, 17 parts, 19 parts, 21 parts or 23 parts.

[0041] In the present invention, the particle size of the fly ash may be no greater than 300 μm, specifically 0.4 μm, 1 μm, 5 μm, 10 μm, 20 μm, 40 μm, 80 μm, 127 μm, 170 μm, 210 μm or 270 μm.

[0042] Based on the mass fraction of the blast furnace slag, the hydrophobic and tough sea mud concrete material provided by the present invention includes 3 to 13 parts of dredged sea mud, specifically 5 parts, 7 parts, 9 parts or 11 parts.

[0043] In the present invention, the dredged sea mud can come from domestic or foreign offshore waters.

[0044] Based on the mass fraction of the blast furnace slag, the hydrophobic and tough sea mud concrete material provided by the present invention includes 2 to 4 parts of a microstructure densifier, specifically 3 parts.

[0045] In the present invention, the microstructure densifier may include one or more of silica fume, ground metakaolin and hollow glass microspheres.

[0046] In the present invention, the particle size of the microstructure densifier may be no greater than 150 μm, specifically 0.04 μm, 0.1 μm, 1 μm, 5 μm, 10 μm, 20 μm, 40 μm, 60 μm, 88.58 μm, 110 μm or 130 μm, preferably 2-4 μm.

[0047] Based on the mass fraction of the blast furnace slag, the hydrophobic and tough sea mud concrete material provided by the present invention includes 9 to 11 parts of an alkali activator, specifically 10 parts.

[0048] In the present invention, the alkali activator may be anhydrous sodium silicate powder; the particle size of the anhydrous sodium silicate powder may be no greater than 600 μm, specifically 0.04 μm, 0.1 μm, 0.5 μm, 1 μm, 5 μm, 10 μm, 20 μm, 40 μm, 80 μm, 120 μm, 160 μm, 200 μm, 275 μm, 325 μm, 375 μm, 425 μm, 525 μm or 575 μm.

[0049] In the present invention, the modulus ratio of the anhydrous sodium silicate powder can be 1.2 to 1.6, specifically 1.4. By regulating the type and ratio of the alkali activator, the present invention achieves rapid hardening and early strength development of the hydrophobic and tough sea mud concrete material at room temperature, making it suitable for various construction processes such as spraying, laying, and prefabrication.

[0050] Based on the mass fraction of the blast furnace slag, the hydrophobic and tough sea mud concrete material provided by the present invention includes 16.3 to 18 parts of fine silica sand, specifically 17 parts.

[0051] In the present invention, the particle size of the fine silica sand is 0.01 to 663.4 μm, specifically 1 μm, 10 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, or 600 μm, and the average particle size may be no greater than 300 μm, specifically 30 μm, 100 μm, 200 μm, or 250 μm. The present invention uses fine silica sand of the above particle size to improve the compactness of the slurry.

[0052] Based on the mass fraction of the blast furnace slag, the hydrophobic and tough sea mud concrete material provided by the present invention includes 16.5 to 18.3 parts of retarder, specifically 17 parts or 18 parts.

[0053] In the present invention, the retarder can include borax and water; the mass ratio of borax to water can be 130-141:1000, specifically 133:1000, 136:1000, or 140:1000; and the purity of the borax can be no less than 95%. By adding borax, the present invention optimizes the excitation reaction performance of the hydrophobic and tough sea mud concrete material, extending the workability and improving fluidity.

[0054] Based on the mass fraction of the blast furnace slag, the hydrophobic and tough sea mud concrete material provided by the present invention includes a hydrophobic agent, and the ratio of the mass of the hydrophobic agent to the total mass of the blast furnace slag, fly ash, dredged sea mud and microstructure densifier can be 2~4:100, specifically 3:100.

[0055] In the present invention, the polysiloxane hydrophobic agent may include one or more of α,ω-dihydroxy polydimethylsiloxane, single-end hydroxy polydimethylsiloxane, α,ω-dihydroxy polyether modified polysiloxane and α,ω-dihydroxy amino modified polysiloxane, specifically dihydroxy-terminated polydimethylsiloxane or monohydroxy-terminated polydimethylsiloxane; the molecular weight of the siloxane main chain in the polysiloxane hydrophobic agent may be 400~1500, specifically 700, 1000 or 1200; the viscosity of the hydrophobic agent may be 500~1000 Pa·s, specifically 500Pa·s, 700Pa·s or 850Pa·s.

[0056] In the present invention, the hydrophobic and tough sea mud concrete material includes 0.7 to 1.2 parts of fiber, specifically 0.8 parts or 1 part.

[0057] In the present invention, the fibers may also include one or more of basalt fibers, steel fibers, and polypropylene fibers.

[0058] In the present invention, the volume percentage of the polyvinyl alcohol fiber in the total fiber volume is not less than 1 / 3, specifically 50% or 88%.

[0059] In the present invention, the length of the non-metallic fiber can be 12-25 mm, specifically 15 mm, 18 mm or 21 mm, the diameter can be 14-35 mm, specifically 20 μm, 24 μm, 28 μm or 32 μm, and the density can be 0.97 g / cm 3 , the tensile strength can be 3000MPa.

[0060] The present invention also provides a method for preparing the hydrophobic and tough sea mud concrete material described in the above scheme, comprising the following steps:

[0061] The hydrophobic and tough sea mud concrete material is obtained by mixing fly ash, dredged sea mud, alkali activator, blast furnace slag, microstructure densifier, fine silica sand, retarder, fiber and hydrophobic agent (referred to as the first mixing), molding and then heat curing.

[0062] In the present invention, the first mixing method can be: premixing fly ash, dredged sea mud and alkali activator to obtain a dry premix, preliminarily mixing the dry premix with blast furnace slag, microstructure densifier and fine silica sand to obtain a dry mixture, and mixing the dry mixture with a retarder, fiber and a hydrophobic agent.

[0063] In the present invention, the premixing may be grinding and mixing; the grinding and mixing time may be 20 to 30 minutes; the grinding and mixing may include sequentially rotating forward at 250 rpm for 10 minutes, resting for 5 minutes, and then rotating backward at 250 rpm for 10 minutes.

[0064] In the present invention, the initial mixing may be grinding mixing; the grinding mixing time may be 20 to 30 minutes; the grinding mixing may include sequentially rotating forward at 250 rpm for 10 minutes, resting for 5 minutes, and then rotating backward at 250 rpm for 10 minutes.

[0065] In the present invention, the mixing may be stirring mixing; the rotation speed of the stirring mixing may be 150-250 rpm, and the mixing time may be 3-5 minutes.

[0066] In the present invention, the temperature of the first mixing may be room temperature.

[0067] In the present invention, the molding can be carried out in a mold; the molding temperature can be 14-30°C, specifically 20°C or 25°C, and the molding time can be 36-54 hours, specifically 45 hours or 50 hours; and the molding can also include demolding the obtained product.

[0068] In the present invention, the thermal curing temperature may be 60-120° C., specifically 80° C. or 100° C., and the heat preservation time may be 65-85 hours, specifically 72 hours (3 days) or 78 hours.

[0069] The present invention also provides a waterproof permanent formwork, comprising one or more unit formworks; the unit formworks comprise an outer shell layer, a fiber-reinforced composite material mesh and a filling layer arranged in sequence from the outside to the inside; the outer shell layer comprises a hydrophobic and tough sea mud concrete material; the filling layer comprises a hydrophobic and tough sea mud concrete material; the unit formworks are provided with fiber-reinforced composite material mesh connection holes or bolt connection holes; the unit formworks are connected by mechanical components and sealing cementitious materials; the hydrophobic and tough sea mud concrete material is the hydrophobic and tough sea mud concrete material described in the above scheme or the hydrophobic and tough sea mud concrete material obtained by the preparation method described in the above scheme.

[0070] In the present invention, the material of the fiber reinforced composite material mesh may include one or more of glass fiber reinforced plastic (GFRP), carbon fiber reinforced plastic (CFRP), aramid fiber reinforced plastic (AFRP) and basalt fiber reinforced plastic (BFRP).

[0071] In the present invention, the surface of the fiber reinforced composite material mesh can also be coated with epoxy resin. The present invention utilizes the good corrosion resistance of epoxy resin to stagger and fix the fiber reinforced composite material mesh layer by layer, and combines it with the extrusion process to form an integral body.

[0072] In the present invention, the thickness ratio of the outer shell layer and the filling layer can be 30~40:60~80, specifically 1:1.5 or 1:2; the thickness of the outer shell layer can be 30~40mm, specifically 35mm; the thickness of the filling layer can be 60~80mm, specifically 70mm.

[0073] In the present invention, the thickness ratio of the fiber reinforced composite material mesh and the filling layer can be 1~3:30~90, specifically 1:30 or 1:60; the thickness of the fiber reinforced composite material mesh can be 1~3 mm, specifically 2 mm; the thickness of the filling layer can be 30~90 mm, specifically 50 mm or 70 mm.

[0074] In the present invention, the shape of the unit formwork can include rectangular, T-shaped, I-shaped or box-shaped. The unit formwork of the present invention can be designed according to the project requirements and is suitable for structural members such as plates, beams, and walls under different spans and load conditions, with good construction adaptability.

[0075] The present invention also provides a method for preparing the waterproof permanent template described in the above scheme, comprising the following steps:

[0076] Prepare hydrophobic and tough sea mud concrete material and FRP reinforcement mesh, cast and vibrate to form a unit formwork;

[0077] The unit formwork is connected by mechanical components and sealing cementitious materials using a post-tensioning method and then cured to obtain the waterproof permanent formwork.

[0078] The present invention prepares a hydrophobic and tough sea mud concrete material and an FRP reinforcement mesh, casts the concrete, and then vibrates the concrete to form a unit formwork. In the present invention, the FRP reinforcement mesh can be pre-treated to remove impurities before use.

[0079] In the present invention, the casting may include: embedding the FRP mesh into a mold and positioning it, while controlling the positions and numbers of the reserved fiber reinforced composite material mesh connection holes and bolt connection holes through the mold.

[0080] In the present invention, the vibration molding time may be 2 to 5 minutes, specifically 3 minutes.

[0081] After obtaining the unit formwork, the present invention uses post-tensioning to connect the unit formwork with mechanical components and a sealing cementitious material, followed by curing to obtain the waterproof permanent formwork. In the present invention, the connection can be achieved by splicing and butting the unit formwork together, aligning the reserved fiber-reinforced composite material reinforcement mesh connection holes with the bolt connection holes, and then using post-tensioning to thread the FRP reinforcement mesh and mechanical components through the post-tensioning method. The tensioning and anchoring are then secured to form an integrated connection. The present invention uses sealing cementitious material to fill gaps, further enhancing the overall waterproofing effect.

[0082] In the present invention, the mechanical parts may include bolts, washers and nuts.

[0083] In the present invention, the sealing gelling material may include one or more of polyurethane sealant, epoxy resin sealant and silicone sealant.

[0084] In the present invention, after the connection, the method may further include pouring a sealing cementitious material into the connection holes of the fiber reinforced composite material rib mesh to ensure that the joints are waterproof.

[0085] In the present invention, the curing may further include demoulding.

[0086] The outer shell layer of the waterproof permanent formwork provided by the present invention is formed of an ecological, low-carbon, high-performance alkali-activated cementitious material to form a dense, waterproof, inorganic non-metallic hardened body with both mechanical properties and durability. The FRP reinforcement mesh is arranged inside the outer shell layer in a three-dimensional spatial grid arrangement. It serves as the main load-bearing skeleton of the formwork and is fixed to the outer shell layer through mechanical connection, pre-embedded anchoring, and interface agent coating. During the pouring process, it is formed together with the ecological, low-carbon, high-performance alkali-activated cementitious material slurry to form a stable skeleton, achieving coordinated force with the substrate, and can effectively improve the overall bending resistance, crack resistance and durability of the waterproof permanent formwork. The filling layer is formed by the ecological, low-carbon, high-performance alkali-activated cementitious material filled between the FRP reinforcement meshes. The ecological, low-carbon, high-performance alkali-activated cementitious material completely covers the FRP reinforcement mesh, and forms an integrated composite structure through physical coating and chemical bonding to ensure structural integrity, waterproofness and durability.

[0087] In order to further illustrate the present invention, the scheme of the present invention is described in detail below with reference to the accompanying drawings and embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0088] Example 1

[0089] This embodiment provides a hydrophobic and tough sea mud concrete material, comprising the following components in parts by mass: 26 parts blast furnace slag, 13 parts fly ash, 13 parts dredged sea mud, 3.8 parts silica fume, 9.9 parts anhydrous sodium silicate powder, 17 parts fine silica sand, 17.3 parts retarder (borax and water in a mass ratio of 130:1000), 1.5 parts hydrophobic agent (α,ω-dihydroxy polydimethylsiloxane with a siloxane main chain molecular weight of 400 and a viscosity of 500 Pa·s), and polyethylene (PE) fiber (diameter of 12 μm, length of 35 mm, and density of 0.97 g / cm 3 , tensile strength is 3000MPa) 0.8 parts.

[0090] This embodiment uses dredged sea mud to prepare a hydrophobic and tough sea mud concrete material, including the following steps:

[0091] (1) Weigh fly ash, dredged sea mud and anhydrous sodium silicate powder in proportion, grind and dry mix at room temperature, rotate forward at 250 rpm for 10 minutes, pause for 5 minutes, and reverse at 250 rpm for 10 minutes to obtain a dry premix;

[0092] (2) Weigh blast furnace slag, silica fume and fine silica sand (particle size of 0.01 to 663.4 μm, average particle size <300 μm) in proportion, grind and dry mix with the dry premix obtained in step (1) at room temperature, rotate forward at 250 rpm for 10 minutes, pause for 5 minutes, and reverse at 250 rpm for 10 minutes to obtain a dry mixture;

[0093] (3) adding a retarder, a hydrophobic agent and PE fiber in proportion to the dry mixture obtained in step (2), and stirring in a mixer at 250 rpm for 3 minutes to obtain a wet material;

[0094] (4) The wet material obtained in step (3) is filled into a mold, molded at 15°C for 54 hours, and then demolded. The mold is then heat-cured at 80°C for 3 days to obtain a hydrophobic and tough sea mud concrete material.

[0095] Example 2

[0096] This embodiment provides a hydrophobic and tough sea mud concrete material, comprising the following components in parts by mass: 26 parts blast furnace slag, 20.8 parts fly ash, 5.2 parts dredged sea mud, 3 parts silica fume, 9.9 parts anhydrous sodium silicate powder, 17 parts fine silica sand, 17.3 parts retarder (borax and water in a mass ratio of 141:1000), 2.3 parts hydrophobic agent (single-end hydroxyl polydimethylsiloxane with a siloxane main chain molecular weight of 1500 and a viscosity of 1000 Pa·s), and polyethylene (PE) fiber (diameter 24 μm, length 18 mm, density 0.97 g / cm 3 , tensile strength is 3000MPa) 0.8 parts.

[0097] This embodiment uses dredged sea mud to prepare a hydrophobic and tough sea mud concrete material, including the following steps:

[0098] (1) Weigh fly ash, dredged sea mud and anhydrous sodium silicate powder in proportion, grind and dry mix at room temperature, rotate forward at 250 rpm for 10 minutes, pause for 5 minutes, and reverse at 250 rpm for 10 minutes to obtain a dry premix;

[0099] (2) Weigh blast furnace slag, silica fume and fine silica sand (particle size of 0.01 to 663.4 μm, average particle size <300 μm) in proportion, grind and dry mix with the dry premix obtained in step (1) at room temperature, rotate forward at 250 rpm for 10 minutes, pause for 5 minutes, and reverse at 250 rpm for 10 minutes to obtain a dry mixture;

[0100] (3) adding a retarder, a hydrophobic agent and PE fiber in proportion to the dry mixture obtained in step (2), and stirring in a mixer at 150 rpm for 5 minutes to obtain a wet material;

[0101] (4) The wet material obtained in step (3) is filled into a mold, molded at 25°C for 36 hours, and then demolded. The mold is then heat-cured at 80°C for 3 days to obtain a hydrophobic and tough sea mud concrete material.

[0102] Example 3

[0103] This embodiment prepares a waterproof permanent template, the structure of which is as follows Figures 1 to 4As shown, it is composed of three unit templates, which are assembled and combined according to different structural parts to obtain a waterproof permanent template. Specifically including:

[0104] (1) The outer shell is made of the hydrophobic and tough sea mud concrete material prepared in Example 1 of the present invention.

[0105] (2) FRP mesh, the main load-bearing frame, presents a three-dimensional grid structure and is made of glass fiber reinforced plastic (GFRP).

[0106] (3) The filling layer is made of the hydrophobic and tough sea mud concrete material of Example 2 of the present invention, which is filled between the FRP reinforcement meshes and completely covers the FRP reinforcement meshes, and forms an overall composite structure through interface bonding.

[0107] The specific construction steps of this embodiment are:

[0108] (1) Prepare hydrophobic and tough sea mud concrete materials in proportion at the construction site to ensure fluidity and workability; pretreat the FRP bars to remove surface impurities, and mesh the FRP bars to obtain an FRP bar mesh.

[0109] (2) Press Figures 2-4 Design, cast "T"-shaped unit formwork, middle unit formwork and rectangular unit formwork respectively, the FRP mesh is embedded in the mold and positioned, and the position and number of reserved FRP mesh connection holes and bolt connection holes are controlled by the mold. After the slurry is poured, it is vibrated and formed for 3 minutes to form an integrated structure of the filling layer and the outer shell layer.

[0110] (3) First, the two "T"-shaped unit templates are spliced ​​and connected with the middle unit template on site, aligned with the FRP reinforcement mesh connection holes, and the FRP reinforcement mesh is passed through the post-tensioning method. The FRP reinforcement mesh is fixed with the anchor to form an integrated connection, ensuring that the splicing connection is tight and the force transmission is stable.

[0111] (4) Then install two rectangular unit templates, use bolt connection to embed high-strength bolts through the bolt connection holes and use washers, nuts and the middle unit template to form a fastening connection; at the same time, use the post-tensioning method to penetrate the FRP reinforcement mesh and connect the two "T"-shaped unit templates through the FRP reinforcement mesh connection holes to form a connection.

[0112] (5) Pour sealing cementitious material into the connection holes of the FRP mesh to ensure that the joints are waterproof.

[0113] (6) Mechanical connections are made at the joints, and sealing cementitious materials are used to fill the gaps to enhance the overall waterproof effect.

[0114] (7) After curing, the formwork is removed to obtain an integrated, dense, durable and waterproof permanent formwork.

[0115] Test Example 1

[0116] The compressive strength of the hydrophobic, strong-tough sea mud concrete materials prepared in Examples 1 and 2 was tested. Three groups of hydrophobic, strong-tough sea mud concrete materials were prepared according to Examples 1 and 2. The compressive strength tests were conducted using cubic specimens measuring 150 mm × 150 mm × 150 mm, in accordance with the requirements of GB / T 50081-2019, "Standard for Test Methods for Physical and Mechanical Properties of Concrete." The specimens were placed in a compression testing machine and continuously loaded at a rate of 1 MPa / s until failure. The maximum failure load was recorded, and the compressive strength was calculated. The results are shown in Table 1.

[0117] Table 1 Compressive strength (MPa)

[0118]

[0119] It can be seen from Table 1 that the compressive strength of the hydrophobic and tough sea mud concrete materials prepared in Examples 1 and 2 is greater than 50 MPa, which meets the basic requirements for the mechanical properties of high-performance concrete, proving that the hydrophobic and tough sea mud concrete material prepared in the present invention has good bearing capacity.

[0120] Test Example 2

[0121] The water contact angle and axial tensile ultimate strain tests were performed on the hydrophobic and tough sea mud concrete materials prepared in Examples 1 and 2. The test methods were based on GB / T 30693-2014 "Measurement of the contact angle of plastic film with water" and GB / T 50081-2019 "Standard for test methods of physical and mechanical properties of concrete". The results are shown in Table 2 and Figures 5 and 6 shown.

[0122] Table 2 Water contact angle and axial tensile limit strain

[0123]

[0124] According to Table 2 and Figures 5 and 6 It can be seen that the tensile strain of the hydrophobic and tough sea mud concrete materials prepared in Examples 1 and 2 is greater than 2%, which is significantly higher than the typical value of ordinary brittle materials (0.01-0.02%), and the water contact angle of ordinary concrete is within the hydrophilic range of only 20°-30°, which proves that the hydrophobic and tough sea mud concrete material provided by the present invention has high toughness and ultra-high hydrophobic properties, and is used for the service requirements of structural components under tension or combined action.

[0125] Test Example 3

[0126] The hydrophobic and tough sea mud concrete materials prepared in Examples 1 and 2 were subjected to axial tensile tests according to the CECS 13-2009. Figures 7 and 8 shown.

[0127] according to Figures 7 and 8 It can be seen that the hydrophobic and tough sea mud concrete materials prepared in Examples 1 and 2 all exhibited obvious tensile strain hardening behavior, and the tensile strain rate all reached more than 5%, proving that the hydrophobic and tough sea mud concrete material provided by the present invention has high toughness characteristics.

[0128] As demonstrated in the examples above, the hydrophobic, tough marine mud concrete material provided by the present invention achieves breakthrough performance in all three key areas: strength, toughness, and hydrophobicity. These three attributes are not independently enhanced, but rather exhibit a significant synergistic relationship through material design and interface structure. This collaborative performance design ensures the material's stability and reliability in extreme environments such as high loads, high humidity, and high corrosion, meeting the long-term service requirements of permanent formwork.

[0129] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A hydrophobic and tough sea mud concrete material, characterized in that: The composition includes the following parts by weight: 24-27 parts of blast furnace slag, 12-24 parts of fly ash, 3-13 parts of dredged sea mud, 2-4 parts of microstructure densifier, 9-11 parts of alkali activator, 16.3-18 parts of fine silica sand, 16.5-18.3 parts of retarder, 0.7-1.2 parts of fiber, and a hydrophobic agent, wherein the ratio of the mass of the hydrophobic agent to the total mass of the blast furnace slag, fly ash, dredged sea mud, and microstructure densifier is 1-4:100; The particle size of the fine silica sand is 0.01 to 663.4 μm; the fibers include polyvinyl alcohol fibers and polyethylene fibers; The hydrophobic agent is a polysiloxane hydrophobic agent; the polysiloxane hydrophobic agent has a hydroxyl group as the terminal group; The microstructure densifier includes one or more of silica fume, ground metakaolin and hollow glass microspheres.

2. The hydrophobic and tough sea mud concrete material according to claim 1, characterized in that: The particle size of the blast furnace slag is not greater than 80 μm; The particle size of the fly ash is not greater than 300 μm; The particle size of the microstructure densifier is not greater than 150 μm; The average particle size of the fine silica sand is no more than 300 μm.

3. The hydrophobic and tough sea mud concrete material according to claim 1, characterized in that: The alkali activator is anhydrous sodium silicate powder; The modulus ratio of the anhydrous sodium silicate powder is 1.2 to 1.

6.

4. The hydrophobic and tough sea mud concrete material according to claim 1, characterized in that: The retarder includes borax and water; The mass ratio of the borax to water is 130-141:1000.

5. The hydrophobic and tough sea mud concrete material according to any one of claims 1 to 4, wherein the polysiloxane hydrophobizing agent comprises one or more of α,ω-dihydroxy polydimethylsiloxane, monohydroxy-terminated polydimethylsiloxane, α,ω-dihydroxy polyether-modified polysiloxane, and α,ω-dihydroxyamino-modified polysiloxane; The molecular weight of the siloxane main chain in the polysiloxane hydrophobic agent is 400-1500.

6. The hydrophobic and tough sea mud concrete material according to claim 1, characterized in that: The volume percentage of the polyvinyl alcohol fibers in the total fiber volume is no less than 1 / 3.

7. The method for preparing the hydrophobic and tough sea mud concrete material according to any one of claims 1 to 6, characterized in that: The following steps are involved: The hydrophobic and tough sea mud concrete material is obtained by mixing fly ash, dredged sea mud, alkali activator, blast furnace slag, microstructure densifier, fine silica sand, retarder, fiber and hydrophobic agent, molding and then heat curing.

8. A waterproof permanent formwork, characterized in that: Includes more than one unit template; The unit template comprises an outer shell layer, a fiber reinforced composite material rib mesh and a filling layer arranged in sequence from the outside to the inside; The outer shell layer comprises a hydrophobic and tough sea mud concrete material; The filling layer comprises a hydrophobic and tough sea mud concrete material; The unit template is provided with fiber reinforced composite material rib mesh connection holes or bolt connection holes; The unit templates are connected by mechanical components and sealing gelling materials; The hydrophobic and tough sea mud concrete material is the hydrophobic and tough sea mud concrete material according to any one of claims 1 to 6 or the hydrophobic and tough sea mud concrete material obtained by the preparation method according to claim 7.

9. The waterproof permanent formwork according to claim 8, characterized in that: The surface of the fiber reinforced composite material mesh is also coated with epoxy resin.

10. The method for preparing a waterproof permanent formwork according to any one of claims 8 to 9, characterized in that: The following steps are involved: Prepare hydrophobic and tough sea mud concrete material and FRP reinforcement mesh, cast and vibrate to form a unit formwork; The unit formwork is connected by mechanical components and sealing cementitious materials using a post-tensioning method and then cured to obtain the waterproof permanent formwork.

Images