A concrete corrosion-preventing admixture and method suitable for marine dry-wet cycle environment
By adding anti-corrosion admixtures A and B to concrete and utilizing the combination of triethanolamine and SAP, the problem of self-healing of concrete in marine wet-dry cycle environments was solved, achieving all-time self-repair and improved durability, and preventing structural damage.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QINGDAO HARBOR VOCATIONAL & TECH COLLEGE
- Filing Date
- 2023-06-14
- Publication Date
- 2026-07-21
AI Technical Summary
Existing anti-seepage and anti-corrosion admixtures have weak water molecule diffusion ability in marine wet-dry cycle environments, which makes the self-healing process difficult and the crystal repair ability limited, thus failing to effectively prevent corrosion and damage deterioration of concrete structures.
The concrete anti-corrosion admixture uses two components: component A and component B. Component A consists of silicate cement, quartz sand, silica fume, triethanolamine, and acrylic acid, while component B is superabsorbent polymer (SAP). By providing moisture during the dry period to support the hydration reaction, it prevents the formation of large pores and achieves self-healing throughout the entire time.
It improves the self-healing speed of concrete in marine wet-dry cycle environments, enhances the durability and corrosion resistance of structures, and reduces the risk of damage deterioration.
Smart Images
Figure CN116693258B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a concrete anti-corrosion admixture and method, and more particularly to a concrete anti-corrosion admixture and method suitable for marine wet-dry cycle environments. Background Technology
[0002] Reinforced concrete is the main structural material for marine engineering. Due to long-term exposure to seawater immersion, alternating wet and dry conditions, sunlight exposure, coastal salt spray, marine organisms, and humid air, the corrosive environment is quite harsh, which can easily cause internal steel reinforcement corrosion, external concrete spalling, and aggregate exposure, seriously affecting safety and usability.
[0003] The main working principle of existing anti-seepage and anti-corrosion admixtures used in marine concrete structures is to prevent chloride ion migration by blocking capillary pores through self-crystallization, thereby improving the overall protective capacity, self-healing performance, and durability of the structure while filling gaps. Water molecules are essential as an inducing condition in the self-healing process of concrete capillary pores and microcracks. However, due to the influence of wet-dry cycles in ocean tidal zones, the diffusion capacity of water molecules within the structure of existing anti-seepage and anti-corrosion admixtures is relatively weak, which limits the anti-corrosion induction conditions and makes self-healing difficult. Furthermore, continuous ocean wet-dry cycles coarsen the surface pores of the structure, and the repair capacity of crystals for large pores is very limited, posing a risk of deterioration due to untimely repair. Therefore, it is urgent to improve existing anti-seepage and anti-corrosion admixtures to address their shortcomings in improving the overall durability of marine engineering structures. Summary of the Invention
[0004] To address the shortcomings of the aforementioned technologies, this invention provides a concrete anti-corrosion admixture and method suitable for marine wet-dry cycle environments. It primarily addresses the problem that concrete structures are easily eroded and corroded by water, gas, and chemicals in harsh environments. Using the self-healing mechanism of concrete as a carrier, it adapts to the dependence of the self-healing hydration reaction of structures on water molecules in marine wet-dry cycle environments, accelerating the repair process and enhancing the durability and corrosion resistance of the structure.
[0005] To solve the above technical problems, the technical solution adopted by the present invention is: a concrete anti-corrosion admixture suitable for marine wet-dry cycle environment, the anti-corrosion admixture comprising two components, component A and component B;
[0006] Material A is obtained by uniformly dry-mixing the raw materials, including the following raw materials in the following weight ratios:
[0007] 30-50 parts silicate cement, 25-35 parts quartz sand, 5-20 parts silica fume, 5-8 parts triethanolamine, 15-30 parts acrylic acid, and 5-8 parts calcium hydroxide;
[0008] Component B is superabsorbent polymer (SAP).
[0009] When this anti-corrosion admixture is added to concrete, the amount of component A is 0.8% to 1.5% of the mass of the concrete gel material, and the amount of component B is 0.3% to 0.4% of the mass of the concrete gel material.
[0010] Preferably, material A comprises the following raw materials in the following weight ratios:
[0011] 30 parts silicate cement, 25 parts quartz sand, 5 parts silica fume, 5 parts triethanolamine, 15 parts acrylic acid, and 5 parts calcium hydroxide.
[0012] Preferably, material A comprises the following raw materials in the following weight ratios:
[0013] Material A is obtained by uniformly dry-mixing various raw materials, including the following raw materials in the following weight ratios:
[0014] 50 parts silicate cement, 35 parts quartz sand, 20 parts silica fume, 8 parts triethanolamine, 30 parts acrylic acid, and 8 parts calcium hydroxide.
[0015] Preferably, material A is obtained by uniformly dry-mixing the raw materials, including the following raw materials in the following weight ratios:
[0016] 40 parts silicate cement, 30 parts quartz sand, 12.5 parts silica fume, 6.5 parts triethanolamine, 22.5 parts acrylic acid, and 6.5 parts calcium hydroxide.
[0017] Preferably, the particle size of the quartz sand in material A is between 70 mesh and 140 mesh.
[0018] Preferably, the superabsorbent polymer (SAP) resin used has the following properties: particle size of 30–80 mesh and density of 0.8 g / cm³. 3 Water absorption rate is 250-600 g / g, and water absorption rate is 30 s.
[0019] A method for using a concrete anti-corrosion admixture suitable for marine wet-dry cycles, the method comprising the following steps:
[0020] Step 1: Preparation of Materials A and B: Prepare materials A and B of the anti-corrosion additive according to the required weight proportions.
[0021] Step 2: Uniform mixing of dry powder materials: Add cement, fly ash, material A, material B, and silica sand to the mixer and mix at a speed of 100 rpm to 200 rpm for 2 to 3 minutes.
[0022] Step 3: Prepare cement slurry without coarse aggregate: Add water to the mixed dry powder in Step 2 above and stir at a speed of 100-200 rpm for 1-2 minutes. After the solution has settled, continue stirring at a speed of 400-500 rpm for 3-5 minutes.
[0023] Step 4: Preparation of impermeable and corrosion-resistant concrete: Add the aggregate to the cement slurry without coarse aggregate from Step 3 and stir thoroughly for 2-3 minutes until uniformly mixed to prepare impermeable and corrosion-resistant concrete suitable for marine wet-dry cycle environments.
[0024] Preferably, the mass of each component in the mixed dry powder is as follows:
[0025] Cement 200-250kg, fly ash 20-30kg, A component 1.76-4.2kg, B component 0.66-1.12kg, silica sand 800-900kg.
[0026] Preferably, in step three, a water-reducing agent is added to the water at a ratio of 1.5% to 2% of the mass of the cementitious material; the weight of the cementitious material refers to the total mass of cement and fly ash.
[0027] A test method for concrete anti-corrosion admixtures applicable to marine wet-dry cycles, the test process is as follows:
[0028] Anticorrosive concrete specimens were prepared using this anticorrosive admixture. The specimens were cured in a standard curing chamber for 28 days. Microcracks were generated by splitting preloading of the specimens. A permeability test was conducted under a water pressure of 0.2 MPa. A wet-dry cycle was performed in 12-hour intervals, including 6 hours of immersion in seawater and then 6 hours of exposure to ambient air. The degree of self-healing of the concrete was determined by the permeability ratio (RSR).
[0029] This invention discloses a concrete anti-corrosion admixture and method suitable for marine wet-dry cycle environments, and explores a detection method for the anti-corrosion and repair functions of the concrete anti-corrosion admixture. The main reason for this is the simultaneous addition of an early-strength agent (triethanolamine), an anti-permeability agent (acrylate), and a superabsorbent polymer (SAP) to the concrete. This research addresses the mechanism by which the self-healing performance of concrete structures in marine wet-dry cycle environments is limited. During the dry period, the water required for the hydration of the structural repair material (acrylate) can be provided by SAP, achieving uninterrupted self-repair during the dry period. Simultaneously, it prevents the formation of harmful large pores, avoids the coarsening of voids due to wet-dry cycles, and reduces the risk of damage deterioration due to untimely repair, thus fundamentally optimizing the self-healing performance of marine concrete. Attached Figure Description
[0030] Figure 1 This is a microscopic image of the concrete repair sample of the present invention.
[0031] Figure 2 This is a microscopic image of the concrete repair as a control in this invention. Detailed Implementation
[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0033] Anti-seepage and anti-corrosion concrete uses relatively strong cement and other materials, so its plasticity is not as good as ordinary concrete. It requires strong support and is not suitable for high-temperature environments. Furthermore, because a series of anti-corrosion and anti-seepage materials are added to anti-seepage and anti-corrosion concrete, its service life will be affected when used in high-temperature environments.
[0034] Based on this, the present invention proposes a concrete anti-corrosion admixture suitable for marine wet-dry cycle environments. Its key components are triethanolamine (early strength agent) and acrylic acid (anti-permeability agent) in component A, and superabsorbent polymer (SAP) in component B. This anti-corrosion admixture mixture takes into account the influence of wet-dry cycles in marine tidal zones, primarily addressing the limitation of self-healing performance in these cycles. Under dry conditions, triethanolamine improves the fluidity of cement, and the water required for the hydration of the active substance acrylic acid can be provided by SAP, achieving continuous self-repair throughout the wet-dry cycle. It also prevents the formation of harmful large pores due to slow repair, reduces the risk of damage deterioration due to untimely repair, and avoids the coarsening of pores caused by wet-dry cycles.
[0035] The corrosion inhibitor disclosed in this invention comprises two components, component A and component B.
[0036] Material A is obtained by uniformly dry-mixing various raw materials, including the following raw materials in the following weight ratios:
[0037] 30-50 parts silicate cement, 25-35 parts quartz sand, 5-20 parts silica fume, 5-8 parts triethanolamine, 15-30 parts acrylic acid, and 5-8 parts calcium hydroxide;
[0038] Component B is superabsorbent polymer (SAP).
[0039] When adding the anti-corrosion admixture to concrete, the amount of component A added is 0.8% to 1.5% of the mass of the concrete gel material, and the amount of component B added is 0.3% to 0.4% of the mass of the concrete gel material. Gel material refers to cement, aggregate, fly ash, and other materials that act as binders in concrete. In this invention, the weight of the gel material mainly refers to the total mass of cement and fly ash.
[0040] Furthermore, the quartz sand in component A has a particle size of 70-140 mesh. Component B uses SAP, a superabsorbent polymer powder with the following properties: particle size of 30-80 mesh and density of 0.8 g / cm³. 3It has a water absorption rate of 250–600 g / g and an absorption rate of 30 s. Adding SAP-containing anti-corrosion admixtures to ordinary concrete forms impermeable and corrosion-resistant concrete. By adjusting the internal moisture and pore distribution structure of the concrete, it achieves impermeability and corrosion resistance, effectively preventing damage to concrete in highly corrosive environments, ensuring the safety and stable operation of the structure, and exhibiting higher durability and weathering resistance in extreme climates, high humidity, and high temperature environments. This is reflected in:
[0041] 1) Prevent leakage: High-strength, impermeable and corrosion-resistant concrete prevents leakage and cracking by controlling the pore structure and moisture distribution in the concrete.
[0042] 2) Chemical corrosion resistance: With the addition of corrosion inhibitors, SAP anti-permeability and anti-corrosion concrete can enhance its chemical corrosion resistance and extend its service life.
[0043] 3) The SAP powder added to SAP anti-seepage and anti-corrosion concrete has water absorption and expansion properties. When the concrete is subjected to water pressure, SAP can expand and fill the capillary pores in the concrete, thereby enhancing the anti-seepage performance of the concrete.
[0044] 4) The SAP powder in SAP anti-seepage and anti-corrosion concrete is also hydrophilic, which can form a fine "isolation zone" that provides good protection for the steel bars in the concrete and extends the service life of the concrete.
[0045] Furthermore, the concrete anti-corrosion admixture proposed in this invention, suitable for marine wet-dry cycle environments, is applied to impermeable and anti-corrosion concrete. The specific application method includes the following steps:
[0046] Step 1: Preparation of Materials A and B: Prepare materials A and B of the anti-corrosion additive according to the required weight proportions.
[0047] Step 2: Uniform mixing of dry powder materials: Add cement, fly ash, component A, component B, and silica sand to the mixer and mix at a speed of 100 rpm to 200 rpm for 2 to 3 minutes. The mass of each component in the mixed dry powder material is as follows: cement 200 to 250 kg, fly ash 20 to 30 kg, component A 1.76 to 4.2 kg, component B 0.66 to 1.12 kg, and silica sand 800 to 900 kg.
[0048] Step 3: Preparation of cement slurry without coarse aggregate: Add water to the mixed dry powder from Step 2 above and stir at a speed of 100-200 rpm for 1-2 minutes. After the solution has settled, continue stirring at a speed of 400-500 rpm for 3-5 minutes. The water added contains a water-reducing agent, which is added at 1.5%-2% of the mass of the cementitious material. The weight of the cementitious material refers to the total mass of cement and fly ash.
[0049] Step 4: Preparation of impermeable and corrosion-resistant concrete: Add the aggregate to the cement slurry without coarse aggregate from Step 3 and stir thoroughly for 2-3 minutes until uniformly mixed to prepare impermeable and corrosion-resistant concrete suitable for marine wet-dry cycle environments.
[0050] Therefore, the prepared anti-corrosion concrete incorporates SAP (superabsorbent polymer) resin. SAP can absorb a large amount of water, forming a hydrogel state for curing, thereby reducing the drying shrinkage of the concrete and preventing cracking and spalling, thus improving the strength and durability of the concrete. SAP can also control the rate and magnitude of temperature rise in concrete by absorbing moisture, inhibiting the rate of temperature increase during concrete heating, which helps to protect and improve the strength of the concrete.
[0051] The following is a further explanation with reference to specific embodiments.
[0052] Example 1
[0053] This embodiment discloses a concrete anti-corrosion admixture suitable for marine wet-dry cycle environments, comprising two components, A and B. Component A is obtained by uniformly dry-mixing the raw materials and includes the following raw materials in the following weight ratios: 30 parts silicate cement, 25 parts quartz sand, 5 parts silica fume, 5 parts triethanolamine, 15 parts acrylic acid, and 5 parts calcium hydroxide; Component B is superabsorbent polymer (SAP).
[0054] The concrete anti-corrosion admixture suitable for marine wet-dry cycle environments disclosed in this embodiment is applied to impermeable and anti-corrosion concrete. The specific application method includes the following steps:
[0055] Step 1: Preparation of Material A and Material B: Prepare Material A of the anti-corrosion additive according to the required weight proportions, and prepare enough Material B.
[0056] Step 2: Uniform mixing of dry powder materials: Add 200kg of cement, 20kg of fly ash, 1.76kg of component A, 0.66kg of component B, and 800kg of silica sand to the mixer and mix at a speed of 100rpm to 200rpm for 2 to 3 minutes.
[0057] Step 3: Prepare cement slurry without coarse aggregate: Add water containing water-reducing agent to the mixed dry powder in Step 2 above and stir at a speed of 100-200 rpm for 1-2 minutes. After the solution has settled, continue stirring at a speed of 400-500 rpm for 3-5 minutes.
[0058] Step 4: Preparation of impermeable and corrosion-resistant concrete: Add the aggregate to the cement slurry without coarse aggregate from Step 3 and stir thoroughly for 2-3 minutes until uniformly mixed to prepare impermeable and corrosion-resistant concrete suitable for marine wet-dry cycle environments.
[0059] Example 2
[0060] This embodiment discloses a concrete anti-corrosion admixture suitable for marine wet-dry cycle environments, comprising two components, A and B. Component A is obtained by uniformly dry-mixing the raw materials and includes the following raw materials in the following weight ratios: 50 parts silicate cement, 35 parts quartz sand, 20 parts silica fume, 8 parts triethanolamine, 30 parts acrylic acid, and 8 parts calcium hydroxide. Component B is superabsorbent polymer (SAP).
[0061] The concrete anti-corrosion admixture suitable for marine wet-dry cycle environments disclosed in this embodiment is applied to impermeable and anti-corrosion concrete. The specific application method includes the following steps:
[0062] Step 1: Preparation of Material A and Material B: Prepare Material A of the anti-corrosion additive according to the required weight proportions, and prepare enough Material B.
[0063] Step 2: Uniform mixing of dry powder materials: Add 250kg of cement, 30kg of fly ash, 4.2kg of component A, 1.12kg of component B, and 900kg of silica sand to the mixer and mix at a speed of 100rpm to 200rpm for 2 to 3 minutes.
[0064] Step 3: Prepare cement slurry without coarse aggregate: Add water containing water-reducing agent to the mixed dry powder in Step 2 above and stir at a speed of 100-200 rpm for 1-2 minutes. After the solution has settled, continue stirring at a speed of 400-500 rpm for 3-5 minutes.
[0065] Step 4: Preparation of impermeable and corrosion-resistant concrete: Add the aggregate to the cement slurry without coarse aggregate from Step 3 and stir thoroughly for 2-3 minutes until uniformly mixed to prepare impermeable and corrosion-resistant concrete suitable for marine wet-dry cycle environments.
[0066] Example 3
[0067] This embodiment discloses a concrete anti-corrosion admixture suitable for marine wet-dry cycle environments, which comprises two components, component A and component B. Component A is obtained by uniformly dry-mixing the raw materials and includes the following raw materials in the following weight ratios: 40 parts silicate cement, 30 parts quartz sand, 12.5 parts silica fume, 6.5 parts triethanolamine, 22.5 parts acrylic acid, and 6.5 parts calcium hydroxide.
[0068] The concrete anti-corrosion admixture suitable for marine wet-dry cycle environments disclosed in this embodiment is applied to impermeable and anti-corrosion concrete. The specific application method includes the following steps:
[0069] Step 1: Preparation of Material A and Material B: Prepare Material A of the anti-corrosion additive according to the required weight proportions, and prepare enough Material B.
[0070] Step 2: Uniform mixing of dry powder materials: Add 225kg cement, 25kg fly ash, 2.875kg of component A, 0.875kg of component B, and 850kg silica sand to the mixer and mix at a speed of 100rpm to 200rpm for 2 to 3 minutes.
[0071] Step 3: Prepare cement slurry without coarse aggregate: Add water containing water-reducing agent to the mixed dry powder in Step 2 above and stir at a speed of 100-200 rpm for 1-2 minutes. After the solution has settled, continue stirring at a speed of 400-500 rpm for 3-5 minutes.
[0072] Step 4: Preparation of impermeable and corrosion-resistant concrete: Add the aggregate to the cement slurry without coarse aggregate from Step 3 and stir thoroughly for 2-3 minutes until uniformly mixed to prepare impermeable and corrosion-resistant concrete suitable for marine wet-dry cycle environments.
[0073] Testing of the effectiveness of anti-corrosion additives:
[0074] Samples were selected from the impermeable and corrosion-resistant concrete prepared in Example 1. A control sample was prepared by adding only component A according to the implementation method of the example. The samples and control sample were treated under the same conditions, i.e., cured for 28 days in a standard curing chamber (relative humidity 95% ± 5%, temperature 20℃ ± 2℃). Microcracks were induced in the specimens by splitting preloading, and a permeability test was conducted under 0.2 MPa water pressure. A wet-dry cycle was performed in 12-hour increments, including 6 hours of immersion in seawater followed by 6 hours in ambient air. The degree of self-healing of the concrete was determined by the Relative Permeability Ratio (RSR). Figure 1 The image shown is a microscopic image of the repaired concrete sample. The cracks are filled with self-healing products. The specimens with a mixture of materials A and B basically completed self-repair within 20-24 cycles. Figure 2 The image shown is a microscopic image of the repaired concrete. Specimens with only component A added could complete self-repair in 32–36 cycles. The results indicate that the repair speed was increased by more than 40%, reducing the risk of structural deterioration due to untimely repair of structural damage.
[0075] The above embodiments are not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the technical solution of the present invention are also within the protection scope of the present invention.
Claims
1. A concrete anti-corrosion admixture suitable for marine wet-dry cycle environments, characterized in that: This corrosion inhibitor contains two components, component A and component B. Material A is obtained by uniformly dry-mixing various raw materials, including the following raw materials in the following weight ratios: 30-50 parts silicate cement, 25-35 parts quartz sand, 5-20 parts silica fume, 5-8 parts triethanolamine, 15-30 parts acrylate, and 5-8 parts calcium hydroxide; Material B is superabsorbent polymer (SAP). When this anti-corrosion admixture is added to concrete, the amount of component A is 0.8% to 1.5% of the mass of the concrete cementitious material, and the amount of component B is 0.3% to 0.4% of the mass of the concrete cementitious material.
2. The concrete anti-corrosion admixture suitable for marine wet-dry cycle environments according to claim 1, characterized in that: Material A comprises the following raw materials in the following weight ratios: 30 parts silicate cement, 25 parts quartz sand, 5 parts silica fume, 5 parts triethanolamine, 15 parts acrylate, and 5 parts calcium hydroxide.
3. The concrete anti-corrosion admixture suitable for marine wet-dry cycle environments according to claim 1, characterized in that: Material A comprises the following raw materials in the following weight ratios: Material A is obtained by uniformly dry-mixing various raw materials, including the following raw materials in the following weight ratios: 50 parts silicate cement, 35 parts quartz sand, 20 parts silica fume, 8 parts triethanolamine, 30 parts acrylate, and 8 parts calcium hydroxide.
4. The concrete anti-corrosion admixture suitable for marine wet-dry cycle environments according to claim 1, characterized in that: Material A is obtained by uniformly dry-mixing various raw materials, including the following raw materials in the following weight ratios: 40 parts silicate cement, 30 parts quartz sand, 12.5 parts silica fume, 6.5 parts triethanolamine, 22.5 parts acrylate, and 6.5 parts calcium hydroxide.
5. The concrete anti-corrosion admixture suitable for marine wet-dry cycle environments according to any one of claims 1-4, characterized in that: The particle size of the quartz sand in material A is between 70 mesh and 140 mesh.
6. The concrete anti-corrosion admixture suitable for marine wet-dry cycle environments according to claim 5, characterized in that: The superabsorbent polymer (SAP) resin used has the following properties: particle size of 30–80 mesh and density of 0.8 g / cm³. 3 The water absorption rate is 250-600g / g, and the water absorption speed is 30s.
7. The method of using the concrete anti-corrosion admixture suitable for marine wet-dry cycle environments according to any one of claims 1-4, characterized in that: The application method of corrosion inhibitors includes the following steps: Step 1: Preparation of Materials A and B: Prepare materials A and B of the anti-corrosion additive according to the required weight proportions. Step 2: Uniform mixing of dry powder materials: Add cement, fly ash, material A, material B, and silica sand to the mixer and mix at a speed of 100 rpm to 200 rpm for 2 to 3 minutes. Step 3: Prepare cement slurry without coarse aggregate: Add water to the mixed dry powder in Step 2 above and stir at a speed of 100-200 rpm for 1-2 minutes. After the solution has settled, continue stirring at a speed of 400-500 rpm for 3-5 minutes. Step 4: Preparation of impermeable and corrosion-resistant concrete: Add the aggregate to the cement slurry without coarse aggregate from Step 3 and stir thoroughly for 2-3 minutes until uniformly mixed to prepare impermeable and corrosion-resistant concrete suitable for marine wet-dry cycle environments.
8. The method of using the concrete anti-corrosion admixture suitable for marine wet-dry cycle environments according to claim 7, characterized in that: The mass of each component in the mixed dry powder is as follows: Cement 200-250kg, fly ash 20-30kg, A component 1.76-4.2kg, B component 0.66-1.12kg, silica sand 800-900kg.
9. The method of using the concrete anti-corrosion admixture suitable for marine wet-dry cycle environments according to claim 8, characterized in that: In step three, a water-reducing agent is added to the water at a rate of 1.5% to 2% of the mass of the cementitious material; the weight of the cementitious material refers to the total mass of cement and fly ash.