Wide-temperature-range fast-bleeding quick-setting self-repairing thin-layer concrete repair material and preparation method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TIANJIN ACAD OF TRANSPORTATION SCI
- Filing Date
- 2026-03-27
- Publication Date
- 2026-06-16
Abstract
Description
Technical Field
[0001] This invention belongs to the field of concrete repair materials technology, specifically relating to a wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material and its preparation method. Background Technology
[0002] Concrete, as the most widely used building material globally, is prone to surface cracks and spalling during long-term service due to factors such as temperature changes, loads, and environmental erosion. If these damages are not repaired in time, they can become channels for the transmission of harmful substances such as moisture, chloride ions, and carbon dioxide, accelerating the deterioration of concrete structures, shortening their service life, and even causing safety hazards.
[0003] Currently, existing concrete repair materials suffer from the following technical bottlenecks: First, they have poor temperature adaptability. In low-temperature environments below -10℃, they harden slowly and their strength development is hindered. In high-temperature environments above 50℃, they are prone to water loss and cracking, making it difficult to meet the repair needs of different climate regions and extreme temperature scenarios. Second, they have poor penetration performance. Their penetration depth into the fine cracks on the concrete surface is limited, making it impossible to form a strong interface bond, and the repair layer is prone to peeling and detachment. Third, it is difficult to control the setting speed. Conventional repair materials either set too quickly, resulting in poor workability, or set too slowly, affecting repair efficiency, making it difficult to balance "fast setting" and "workability". Fourth, they lack self-healing ability. If cracks reappear after repair, they need to be repaired manually again, failing to achieve self-healing of the damage and increasing the cost of later maintenance.
[0004] To address these issues, some self-healing concrete materials have been developed, such as bacterial repair materials and microcapsule-coated repair materials. However, the former has a low bacterial survival rate in high-alkali concrete environments and poor repair timeliness; the latter mostly uses organic coating materials, which have poor compatibility with cementitious matrices, easily leading to matric strength deterioration, and it is difficult to simultaneously achieve wide temperature range adaptability and rapid penetration and setting functions.
[0005] Therefore, developing a thin-layer concrete repair material that combines wide temperature range adaptability, rapid penetration, quick setting and early strength, and self-repair function has become an urgent need in the current building materials field. Summary of the Invention
[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a wide-temperature-range fast-penetrating and quick-setting self-healing thin-layer concrete repair material and its preparation method. It can achieve rapid penetration and quick-setting early strength in a wide temperature range of -15℃ to 60℃, while also having the ability to self-repair cracks and improving the bonding strength and durability between the repair layer and the substrate.
[0007] The technical problem solved by this invention is achieved through the following technical solution:
[0008] A wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material, comprising the following components by weight:
[0009] 40-60 parts of cementitious substrate;
[0010] 8-15 portions of self-repairing microcapsules;
[0011] 5-10 parts of the penetration-modifying component;
[0012] 3-8 parts of wide-temperature-range regulator;
[0013] 1-3 parts water-reducing agent;
[0014] 15-25 parts water.
[0015] Moreover, the self-healing microcapsule is a magnesium-based inorganic coated composite capsule, with the core being a mixture of active magnesium oxide and superabsorbent polymer in a mass ratio of 4:1 to 3:2, and the shell being an active magnesium oxide cement carbonation gradient shell.
[0016] Moreover, the preparation method of the self-healing microcapsules is as follows: active magnesium oxide and superabsorbent polymer are mixed in a certain proportion, and 20% water glass solution accounting for 5-8% of the mass of the mixture is added. The mixture is stirred and granulated to form core particles with a particle size of 1-2 mm. The core particles are immersed in active magnesium oxide cement slurry for 3-5 min, and carbonated for 2-4 h in an environment of 30℃, 10% CO2, and 80% RH to form a gradient shell layer of "dense protective shell-porous active core". After drying, the self-healing microcapsules are obtained.
[0017] Moreover, the specific surface area of the active magnesium oxide is 300~400m². 2 / kg, the deionized water absorption ratio of the superabsorbent polymer is 300~350 times, and the shell thickness is 200~300μm.
[0018] Moreover, the permeation modification component is composed of nano-silica fume, ultrafine fly ash and permeation crystallization masterbatch, with a mass ratio of 2:3:1 to 3:2:1.
[0019] Furthermore, the wide temperature range regulator includes a low-temperature accelerator and a high-temperature stabilizer in a mass ratio of 1:1 to 2:1; the low-temperature accelerator is a mixture of calcium formate and calcium nitrite in a mass ratio of 2:1; and the high-temperature stabilizer is a mixture of sodium gluconate and lignin sulfonate in a mass ratio of 3:2.
[0020] Furthermore, the cementitious substrate is a mixture of sulfoaluminate cement and rapid-hardening silicate cement in a mass ratio of 3:2 to 2:3.
[0021] Moreover, the water-reducing agent is a polycarboxylate-based high-efficiency water-reducing agent with a solid content of 40%.
[0022] A method for preparing a wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material, comprising the following steps:
[0023] S1. Pretreatment: Place the gelling substrate and the penetration modification component in a dry environment and preheat to 20~30℃;
[0024] S2. Dry Mixing: Add the pretreated gelling substrate, penetration modification component and wide temperature range regulator to the mixer and stir at 100~150r / min for 3~5min until the mixture is uniform to obtain the dry mixed material.
[0025] S3. Wet mixing: Add self-healing microcapsules to the dry mixture, stir evenly, add water containing water-reducing agent, stir at 300~400 r / min for 5~8 min to form a uniform and viscous repair slurry.
[0026] S4. Finished product: After letting the repair slurry stand for 2-3 minutes to remove air bubbles, a thin layer of concrete repair material is obtained.
[0027] The advantages and beneficial effects of this invention are as follows:
[0028] 1. Wide temperature range adaptability: It can stably solidify and harden within a temperature range of -15℃ to 60℃, solving the problem of material performance degradation under extreme temperature conditions. It is suitable for concrete repair in different climate zones and special working conditions.
[0029] 2. Excellent rapid penetration and setting performance: The grout can penetrate to a depth of 5-8mm into the concrete surface, which can fully fill the fine cracks; the initial setting time is 15-25min, the final setting time is ≤45min, and the 24h compressive strength is ≥30MPa, which greatly improves the repair efficiency and reduces construction downtime.
[0030] 3. Long-lasting self-healing ability: The magnesium-based inorganic composite microcapsules have good compatibility with the matrix, no risk of strength deterioration, and can achieve self-healing of cracks. Multiple cracks can be repaired repeatedly, extending the service life of concrete structures and reducing later maintenance costs.
[0031] 4. Strong interfacial bonding: The penetrating modified components react chemically with the concrete matrix to form an integrated structure. The bonding strength of the repair layer is ≥2.5MPa, effectively preventing peeling and detachment, and improving the durability of the repair.
[0032] 5. Simple preparation process: The raw materials are readily available, the preparation process does not require complicated equipment, it can be mass-produced, and the construction is convenient. It is suitable for thin-layer repair of various concrete structures such as bridges, roads, and building walls. Detailed Implementation
[0033] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.
[0034] Example 1
[0035] A wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material, with the following raw material components by weight:
[0036] 24 parts of sulfoaluminate cement, 16 parts of rapid-hardening silicate cement, 10 parts of self-healing microcapsules, 2 parts of nano silica fume, 3 parts of ultrafine fly ash, 1 part of penetrating crystalline masterbatch, 1.2 parts of calcium formate, 0.6 parts of calcium nitrite, 0.9 parts of sodium gluconate, 0.6 parts of lignin sulfonate, 2 parts of polycarboxylate superplasticizer, and 20 parts of water.
[0037] A method for preparing a wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material:
[0038] 1) Preparation of self-healing microcapsules: Active magnesium oxide and superabsorbent polymer are mixed at a ratio of 4:1, and granulation is carried out by adding 20% water glass solution at 6% of the mass of the mixture to form core particles of 1~2 mm; the core particles are immersed in RMC slurry for 4 min, carbonized for 3 h at 30℃, 10% CO2, and 80% RH, and then dried for later use.
[0039] 2) Dry mixing: Add the cementitious substrate, nano silica fume, ultrafine fly ash, penetrating crystallizing masterbatch, and wide temperature range regulator to the mixer and mix at low speed for 4 minutes until uniform.
[0040] 3) Wet mixing: Add self-healing microcapsules and stir evenly, then add water containing water-reducing agent, stir at high speed for 6 minutes, let stand for 2.5 minutes to remove air bubbles, and obtain the repair material.
[0041] The prepared repair material was subjected to performance tests: at 25℃, the initial setting time was 20 min, the final setting time was 40 min, the 24-hour compressive strength was 32 MPa, and the bond strength was 2.8 MPa; at -15℃, the final setting time was 65 min, and the 24-hour compressive strength was 18 MPa; at 60℃, no cracking was observed, and the 24-hour compressive strength was 35 MPa; for specimens with a pre-crack width of 200~400 μm, after 5 dry and wet cycles, the crack closure rate was 92%, and the water permeability decreased by 83%.
[0042] Example 2
[0043] A wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material, with the following raw material components by weight:
[0044] 20 parts of sulfoaluminate cement, 20 parts of rapid-hardening silicate cement, 12 parts of self-healing microcapsules, 3 parts of nano silica fume, 2 parts of ultrafine fly ash, 1 part of penetrating crystalline masterbatch, 1.6 parts of calcium formate, 0.8 parts of calcium nitrite, 1.2 parts of sodium gluconate, 0.8 parts of lignin sulfonate, 2.5 parts of polycarboxylate superplasticizer, and 22 parts of water.
[0045] The preparation method is the same as in Example 1, except that the mass ratio of the core components of the self-healing microcapsule is 3:2 and the carbonation time is 4 hours.
[0046] The prepared repair material was subjected to performance tests: at 25℃, the initial setting time was 18 min, the final setting time was 38 min, the 24-hour compressive strength was 34 MPa, and the bond strength was 3.0 MPa; at -15℃, the final setting time was 62 min, and the 24-hour compressive strength was 19 MPa; at 60℃, no cracking was observed, and the 24-hour compressive strength was 36 MPa; for specimens with a pre-crack width of 200~400 μm, after 5 dry and wet cycles, the crack closure rate was 93%, and the water permeability decreased by 85%.
[0047] Comparative Example 1
[0048] A conventional concrete repair material, which does not contain self-healing microcapsules or wide temperature range regulators, and whose other raw materials and proportions are the same as in Example 1.
[0049] The performance of the prepared repair material was tested: at 25℃, the initial setting time was 45 min, the final setting time was 80 min, the 24-hour compressive strength was 20 MPa, and the bond strength was 1.8 MPa; at -15℃, it could not set normally; at 60℃, the repair layer cracked; the pre-cracked specimen had no self-healing ability, and the crack closure rate was <15%.
[0050] The core mechanism of action of this invention is:
[0051] 1. Wide temperature range adaptability mechanism: Under low temperature environment, calcium formate and calcium nitrite work together to reduce the critical temperature of cement hydration, accelerate the generation of hydration products, and ensure normal setting and hardening at -15℃; Under high temperature environment, sodium gluconate and lignin sulfonate form a composite retarding system to inhibit the excessive release of hydration heat, while locking in internal moisture to prevent the repair layer from losing water and cracking, making it suitable for high temperature scenarios up to 60℃.
[0052] 2. Rapid penetration and quick setting mechanism: Nano-silica fume and ultrafine fly ash fill the pores of cementitious materials, reduce the viscosity of the slurry, and, together with the capillary penetration effect of the penetrating crystalline masterbatch, achieve rapid penetration into the fine cracks (width 50~400μm) of concrete; the composite of sulfoaluminate cement and rapid-hardening silicate cement, under the synergistic regulation of water-reducing agent and low-temperature accelerator, the initial setting time is controlled at 15~25min, the final setting time does not exceed 45min, and the 24h compressive strength can reach more than 70% of the design strength.
[0053] 3. Self-healing mechanism: The RMC gradient shell of the self-healing microcapsules has excellent compatibility with the cement matrix, which can improve the interfacial bonding strength. When cracks occur in the concrete, the shell is stressed and fractures. The superabsorbent polymer in the porous core absorbs water and expands, releasing active magnesium oxide. The magnesium oxide hydrates to form magnesium hydroxide and produces micro-expansion, filling the crack. At the same time, the active magnesium oxide reacts with calcium hydroxide, a cement hydration product, to form calcium silicate hydrate (CSH) gel. This gel works synergistically with the expansion effect of the superabsorbent polymer to achieve self-healing of cracks. After 5 dry-wet cycles, the crack closure rate can reach more than 90%, and the water permeability is reduced by 80%.
[0054] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.
Claims
1. A wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material, characterized in that: The material comprises the following components in parts by weight: 40-60 parts of cementitious substrate; 8-15 portions of self-repairing microcapsules; 5-10 parts of the penetration-modifying component; 3-8 parts of wide-temperature-range regulator; 1-3 parts water-reducing agent; 15-25 parts water; The self-healing microcapsule is a magnesium-based inorganic coated composite capsule, with the core being a mixture of active magnesium oxide and superabsorbent polymer in a mass ratio of 4:1 to 3:2, and the shell being an active magnesium oxide cement carbonation gradient shell. The self-healing microcapsules are prepared as follows: active magnesium oxide and superabsorbent polymer are mixed in a certain proportion, and 20% water glass solution is added at 5-8% of the mass of the mixture. The mixture is stirred and granulated to form core particles with a particle size of 1-2 mm. The core particles are immersed in active magnesium oxide cement slurry for 3-5 min, and then carbonated for 2-4 h at 30℃, 10% CO2, and 80% RH to form a gradient shell of "dense protective shell-porous active core". After drying, the self-healing microcapsules are obtained. The permeation modification component is composed of nano-silica fume, ultrafine fly ash and permeation crystallization masterbatch, with a mass ratio of 2:3:1 to 3:2:1; The wide temperature range regulator includes a low-temperature accelerator and a high-temperature stabilizer in a mass ratio of 1:1 to 2:1; the low-temperature accelerator is a mixture of calcium formate and calcium nitrite in a mass ratio of 2:1; and the high-temperature stabilizer is a mixture of sodium gluconate and lignin sulfonate in a mass ratio of 3:
2.
2. The wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material according to claim 1, characterized in that: The specific surface area of the active magnesium oxide is 300~400m² / kg, the deionized water absorption ratio of the superabsorbent polymer is 300~350 times, and the shell thickness is 200~300μm.
3. The wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material according to claim 1, characterized in that: The cementitious substrate is a mixture of sulfoaluminate cement and rapid-hardening silicate cement in a mass ratio of 3:2 to 2:
3.
4. The wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material according to claim 1, characterized in that: The water-reducing agent is a polycarboxylate-based high-efficiency water-reducing agent with a solid content of 40%.
5. A method for preparing a wide-temperature-range, fast-penetrating, quick-setting, self-healing thin-layer concrete repair material, characterized in that: The method for preparing the repair material according to any one of claims 1 to 4 comprises the following steps: S1. Pretreatment: Place the gelling substrate and the penetration modification component in a dry environment and preheat to 20~30℃; S2. Dry Mixing: Add the pretreated gelling substrate, penetration modification component and wide temperature range regulator to the mixer and stir at 100~150r / min for 3~5min until the mixture is uniform to obtain the dry mixed material. S3. Wet mixing: Add self-healing microcapsules to the dry mixture, stir evenly, add water containing water-reducing agent, stir at 300~400 r / min for 5~8 min to form a uniform and viscous repair slurry. S4. Finished product: After letting the repair slurry stand for 2-3 minutes to remove air bubbles, a thin layer of concrete repair material is obtained.