A hot slow-release repair material suitable for cold region repair engineering, a hot slow-release capsule and a preparation method thereof

Abstract

The application discloses a kind of hot release repair materials suitable for cold area rush-repair engineering, hot release capsule and preparation method thereof, the hot release repair material suitable for cold area rush-repair engineering of the present application includes the following weight fraction proportion of raw materials: Portland cement 40-70 parts, sulphoaluminate cement 22.5-45 parts, gypsum 7.5-15 parts, hot release capsule 1-5 parts, quartz sand 97-103 parts, water 25.5-26.5 parts, high efficiency water reducing agent 0.25-0.35 parts.The present application incorporates the heat release amount, the heat release rate controllable hot release capsule, forms artificial controllable heat source in the interior of repair material matrix, solves the problem that cement-based repair material is influenced by low temperature under cold climate and strength develops slowly even produces frost injury etc., simultaneously is favorable to reduce cold area rush-repair engineering dependence external heat source, reduce high energy consumption and high carbon emission thus generated.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a heat-slow-release repair material, heat-slow-release capsules, and their preparation method suitable for emergency repair projects in cold regions. Background Technology

[0002] Cold environments have a significant negative impact on the safety and efficiency of emergency repair projects. As the most widely used cement-based repair material, the decrease in temperature will significantly reduce its cement hydration rate, leading to slow or even stagnant strength development. On the other hand, when the water in the repair material freezes, the nearly 9% volume expansion, the water migration and water phase redistribution caused by the difference in chemical potential at different parts after the macropores freeze, and the crystallization pressure caused by the different curvatures at the pore inlets and inside all generate huge frost heave stresses, causing irreversible damage to its performance and seriously affecting the safety of emergency repair projects in cold environments.

[0003] To prevent the liquid phase in repair materials from freezing and to promote the continuous and rapid hydration of cement in low-temperature environments, ensuring the safety and efficiency of emergency repair projects, external insulation methods are often used to raise the ambient temperature of the repair materials in the early stages. However, this process not only consumes significant human, material, and financial resources, but also results in substantial energy consumption and carbon dioxide emissions, contradicting the goals of green and sustainable development. Furthermore, antifreeze methods are another commonly used approach. However, uneven mixing of antifreeze during construction can severely reduce its antifreeze effect and harm economic benefits. Additionally, the durability issues associated with inorganic salt antifreeze agents can adversely affect the quality and long-term use of building projects. Therefore, it is crucial to develop a heat-slow-release repair material suitable for emergency repair projects in cold regions by introducing a heat source within the repair material itself. Summary of the Invention

[0004] To address the problems existing in the prior art, the purpose of this invention is to provide a heat-sustaining repair material, a heat-sustaining capsule, and a method for preparing the same, suitable for emergency repair projects in cold regions.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a heat-release capsule includes the following steps:

[0007] Limestone, sodium saccharin and ethyl maltol were ground and mixed to obtain the first powder. The mass ratio of limestone, sodium saccharin and ethyl maltol was (995-1005):(0.17-0.23):(0.08-0.12).

[0008] The first powder is mixed with deionized water at a mass ratio of 100:(8-10), compacted and dried to obtain a blank.

[0009] The billet is held at 1095-1105℃ for 115-125 minutes and then air-cooled to obtain calcium oxide material.

[0010] The calcium oxide material is ground into powder to obtain a second powder.

[0011] The second powder and methacrylate silane were mixed and stirred evenly at 23-28°C in a weight ratio of 100:(5.7-6.3). The mixture was then heated to 48-52°C and stirred under a saturated steam and carbon dioxide atmosphere to obtain a heat-release capsule with calcium oxide as the core and methacrylate silane and calcium carbonate as the shell.

[0012] Preferably, the particle size of the second powder is above 200 mesh.

[0013] The present invention also provides a heat-release capsule, which is prepared by the preparation method of the present invention as described above.

[0014] This invention also provides a heat-slow-release repair material suitable for emergency repair projects in cold regions, the raw materials of which, by mass parts, include:

[0015] 40-70 parts silicate cement, 22.5-45 parts sulfoaluminate cement, 7.5-15 parts gypsum, 1-5 parts of the heat-sustaining capsules as described above, 97-103 parts quartz sand, 25.5-26.5 parts water, and 0.25-0.35 parts high-efficiency water-reducing agent.

[0016] Preferably, the silicate cement is P·O 52.5R cement.

[0017] Preferably, the sulfoaluminate cement is 72.5 cement.

[0018] Preferably, the gypsum is dihydrate gypsum.

[0019] Preferably, the water-reducing agent is a polycarboxylate water-reducing agent.

[0020] The preparation method of the heat-slow-release repair material suitable for emergency repair projects in cold regions, as described above, includes the following steps:

[0021] Silicate cement, sulfoaluminate cement, gypsum, heat-release capsules, and quartz sand are mixed to obtain uniform raw materials.

[0022] The raw material is sealed and pre-cooled to obtain pre-cooled raw material, with the pre-cooling temperature being the same as the curing temperature;

[0023] The high-efficiency water-reducing agent is mixed with water to dissolve it and obtain a homogeneous solution.

[0024] The pre-cooled raw materials and the homogeneous solution are mixed and stirred to form a homogeneous slurry, thus obtaining the heat-slow-release repair material suitable for emergency repair projects in cold regions.

[0025] Preferably, when the pre-cooled raw material and the homogeneous solution are mixed and stirred to form a homogeneous slurry:

[0026] First, stir at low speed for 3-4 minutes, then stir at high speed for 2-3 minutes to obtain the homogeneous slurry.

[0027] The stirring rate for low-speed stirring is 135-145 r / min, and the stirring rate for high-speed stirring is 280-290 r / min.

[0028] The present invention has the following beneficial effects:

[0029] The method for preparing heat-release capsules provided by this invention uses raw materials that are widely available, inexpensive, and easy to obtain, and the preparation process is simple and non-toxic.

[0030] The heat-release capsule provided by this invention has a controllable exothermic effect. This capsule significantly inhibits the temperature drop of the repair material at low temperatures and significantly delays the freezing time, providing more time and effective conditions for the early hydration of cement and the establishment of early structure in the repair material. The calcium hydroxide generated by the heat-release capsule reaction in this invention provides an additional hydration pathway for calcium sulfoaluminate in sulfoaluminate cement, greatly promoting cement hydration. The generated ettringite is beneficial for reducing early-freezing moisture and increasing strength.

[0031] This invention's heat-slow-release repair material is a composite of silicate cement, sulfoaluminate cement, and dihydrate gypsum. This composition promotes early ettringite formation, enhancing early strength, and also facilitates later CSH gel formation, ensuring sustained strength. Furthermore, the invention utilizes heat-slow-release capsules. Compared to previous repair materials, this invention requires no external heat source, uses widely available materials, is low-cost, non-toxic, and contains no inorganic salt additives, making it widely applicable, economical, environmentally friendly, and durable. It effectively solves the problems of complex insulation procedures, reliance on external heat sources, high energy consumption, and large carbon emissions in emergency repair projects in cold regions.

[0032] The method for preparing the thermally sustained-release repair material of this invention uses widely available and easily obtained raw materials, has a simple and non-toxic preparation process, low cost, and is easy to promote. Detailed Implementation

[0033] The present invention will be further described below through specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0034] This invention relates to a method for preparing heat-slow-release repair materials applicable to emergency repair projects in cold regions, comprising the following steps:

[0035] Step 1: Weigh out 40-70 parts of silicate cement, 22.5-45 parts of sulfoaluminate cement, 7.5-15 parts of gypsum, 1-5 parts of heat-release capsules, and 97-103 parts of quartz sand according to the weight ratio. Then pour them into a mixer and mix at a low speed of 135-145 r / min for 5-6 minutes until uniform raw materials are formed.

[0036] Step 2: After sealing the raw material obtained in Step 1, place it in a low temperature chamber at -8 to -12°C for 24 hours to pre-cool it and form a pre-cooled raw material. This pre-cooling temperature is the curing temperature. In the following embodiments of the present invention, a curing temperature of -10°C is used as an example for illustration. This curing temperature can be selected according to the actual situation and is not limited to the temperature exemplified in the present invention.

[0037] Step 3: Pour 0.25-0.35 parts of high-efficiency water-reducing agent into 25.5-26.5 parts of water, and stir to form a uniform solution of high-efficiency water-reducing agent and water;

[0038] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 135-145 r / min for 3-4 minutes, and then stir at a high speed of 280-290 r / min for 2-3 minutes to form a homogeneous slurry.

[0039] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -8 to -12℃ for continuous curing. Demold after 1 day.

[0040] In the above-described scheme of the present invention, the silicate cement is P·O 52.5R cement, the sulfoaluminate cement is 72.5 cement, the gypsum is dihydrate gypsum, and the high-efficiency water-reducing agent is polycarboxylate high-performance water-reducing agent.

[0041] This invention incorporates heat-releasing capsules with controllable heat release and rate, forming an artificially adjustable heat source inside the repair material matrix. This solves the problems of slow strength development or even frost damage in cement-based repair materials under cold climates due to low temperatures. It also helps reduce reliance on external heat sources for emergency repair projects in cold regions, thereby reducing the resulting high energy consumption and high carbon emissions.

[0042] The preparation method of the heat-release capsule includes the following steps:

[0043] Step 1: Place 995-1005 parts limestone, 0.17-0.23 parts sodium saccharin, and 0.08-0.12 parts ethyl maltol into a ball mill and grind for 85-95 minutes until uniform to obtain uniform limestone powder;

[0044] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:(8-10), compact it, and dry it in an oven at 103-107℃ for 24-36 hours to remove moisture.

[0045] Step 3: Keep the material obtained in Step 2 at a temperature of 1095-1105℃ for 115-125 minutes, then take it out and wait for it to cool to room temperature to obtain calcium oxide material with suitable activity.

[0046] Step 4: Place the material obtained in Step 3 into a ball mill and grind it for 57-63 minutes to obtain powder with a particle size of 200 mesh or more;

[0047] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:(5-7-6.3). Control the reactor temperature at 23-27℃ and stir continuously for 55-65 minutes to make the material uniform. Then, control the reactor temperature at 48-52℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 48-52 mL / min and 88-92 mL / min, respectively, while stirring the powder to obtain a heat-release capsule with calcium oxide as the core and methacrylate silane and calcium carbonate as the shell.

[0048] Example 1:

[0049] This embodiment describes a method for preparing heat-slow-release repair materials for emergency repair projects in cold regions, including the following steps:

[0050] Step 1: Weigh out 70 parts of P·O 52.5R cement, 22.5 parts of 72.5 cement, 7.5 parts of dihydrate gypsum, 1 part of heat-release capsules, and 100 parts of quartz sand according to the weight ratio. Then pour them into the mixer and stir at a low speed of 140±5r / min for 5 minutes until uniform raw materials are formed.

[0051] Step 2: Seal the raw materials obtained in Step 1 and place them in a -10℃ low-temperature chamber for 24 hours to pre-cool them, thus forming pre-cooled raw materials;

[0052] Step 3: Pour 0.3 parts of polycarboxylate superplasticizer into 26 parts of water and stir to form a uniform solution of superplasticizer and water;

[0053] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 140±5 r / min for 3 minutes, and then stir at a high speed of 285±5 r / min for 2 minutes to form a homogeneous slurry.

[0054] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -10℃ for continuous curing. Demold after 1 day.

[0055] The preparation method of the heat-release capsule includes the following steps:

[0056] Step 1: Place 1000 parts limestone, 0.2 parts sodium saccharin, and 0.1 parts ethyl maltol into a ball mill and grind for 1.5 hours until uniform to obtain a uniform powder.

[0057] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:8, compact it, and dry it in an oven at 105℃ for 24 hours to remove moisture.

[0058] Step 3: Keep the material obtained in Step 2 at 1100℃ for 2 hours, then take it out and wait for it to cool to room temperature;

[0059] Step 4: Grind the material obtained in Step 3 in a ball mill for 1 hour to obtain powder;

[0060] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:6. Control the reactor temperature at 25±2℃ and stir continuously for 1 hour to make the material uniform. Then, control the reactor temperature at 50±2℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 50±2mL / min and 90±2mL / min, respectively, while stirring the powder to obtain heat-release capsules.

[0061] Example 2:

[0062] This embodiment describes a method for preparing heat-slow-release repair materials for emergency repair projects in cold regions, including the following steps:

[0063] Step 1: Weigh out 70 parts of P·O 52.5R cement, 22.5 parts of 72.5 cement, 7.5 parts of dihydrate gypsum, 3 parts of heat-release capsules, and 100 parts of quartz sand according to the weight ratio. Then pour them into the mixer and stir at a low speed of 140±5r / min for 6 minutes until uniform raw materials are formed.

[0064] Step 2: Seal the raw materials obtained in Step 1 and place them in a -10℃ low-temperature chamber for 24 hours to pre-cool them, thus forming pre-cooled raw materials;

[0065] Step 3: Pour 0.3 parts of polycarboxylate superplasticizer into 26 parts of water and stir to form a uniform solution of superplasticizer and water;

[0066] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 140±5 r / min for 3 minutes, and then stir at a high speed of 285±5 r / min for 2 minutes to form a homogeneous slurry.

[0067] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -10℃ for continuous curing. Demold after 1 day.

[0068] The preparation method of the heat-release capsule includes the following steps:

[0069] Step 1: Place 1000 parts limestone, 0.2 parts sodium saccharin, and 0.1 parts ethyl maltol into a ball mill and grind for 1.5 hours until uniform to obtain a uniform powder.

[0070] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:10, compact it, and dry it in an oven at 107℃ for 30 hours to remove moisture.

[0071] Step 3: Keep the material obtained in Step 2 at 1105℃ for 115 minutes, then take it out and wait for it to cool to room temperature.

[0072] Step 4: Place the material obtained in Step 3 into a ball mill and grind it for 57 minutes to obtain powder;

[0073] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:6. Control the reactor temperature at 25±2℃ and stir continuously for 1 hour to make the material uniform. Then, control the reactor temperature at 50±2℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 50±2mL / min and 90±2mL / min, respectively, while stirring the powder to obtain heat-release capsules.

[0074] Example 3:

[0075] This embodiment describes a method for preparing heat-slow-release repair materials for emergency repair projects in cold regions, including the following steps:

[0076] Step 1: Weigh out 70 parts of P·O 52.5R cement, 22.5 parts of 72.5 cement, 7.5 parts of dihydrate gypsum, 5 parts of heat-release capsules, and 100 parts of quartz sand according to the weight ratio. Then pour them into the mixer and stir at a low speed of 140±5r / min for 5 minutes until uniform raw materials are formed.

[0077] Step 2: Seal the raw materials obtained in Step 1 and place them in a -10℃ low-temperature chamber for 24 hours to pre-cool them, thus forming pre-cooled raw materials;

[0078] Step 3: Pour 0.35 parts of polycarboxylate superplasticizer into 26.5 parts of water and stir to form a uniform solution of superplasticizer and water;

[0079] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 140±5 r / min for 3 minutes, and then stir at a high speed of 285±5 r / min for 2.5 minutes to form a homogeneous slurry.

[0080] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -10℃ for continuous curing. Demold after 1 day.

[0081] The preparation method of the heat-release capsule includes the following steps:

[0082] Step 1: Place 995 parts limestone, 0.17 parts sodium saccharin, and 0.08 parts ethyl maltol into a ball mill and grind for 85 minutes until uniform to obtain a uniform powder.

[0083] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:8, compact it, and dry it in an oven at 105℃ for 24 hours to remove moisture.

[0084] Step 3: Keep the material obtained in Step 2 at 1100℃ for 2 hours, then take it out and wait for it to cool to room temperature;

[0085] Step 4: Grind the material obtained in Step 3 in a ball mill for 1 hour to obtain powder;

[0086] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:5.7. Control the reactor temperature at 25±2℃ and stir continuously for 65 minutes to make the material uniform. Then, control the reactor temperature at 50±2℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 50±2mL / min and 90±2mL / min, respectively, while stirring the powder to obtain heat-release capsules.

[0087] Example 4:

[0088] This embodiment describes a method for preparing heat-slow-release repair materials for emergency repair projects in cold regions, including the following steps:

[0089] Step 1: Weigh out 60 parts of P·O 52.5R cement, 30 parts of 72.5 cement, 10 parts of dihydrate gypsum, 1 part of heat-release capsules, and 100 parts of quartz sand according to the weight ratio. Then pour them into a mixer and stir at a low speed of 140±5r / min for 5 minutes until uniform raw materials are formed.

[0090] Step 2: Seal the raw materials obtained in Step 1 and place them in a -10℃ low-temperature chamber for 24 hours to pre-cool them, thus forming pre-cooled raw materials;

[0091] Step 3: Pour 0.3 parts of polycarboxylate superplasticizer into 26 parts of water and stir to form a uniform solution of superplasticizer and water;

[0092] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 140±5 r / min for 3 minutes, and then stir at a high speed of 285±5 r / min for 2 minutes to form a homogeneous slurry.

[0093] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -10℃ for continuous curing. Demold after 1 day.

[0094] The preparation method of the heat-release capsule includes the following steps:

[0095] Step 1: Place 1000 parts limestone, 0.2 parts sodium saccharin, and 0.1 parts ethyl maltol into a ball mill and grind for 1.5 hours until uniform to obtain a uniform powder.

[0096] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:8, compact it, and dry it in an oven at 105℃ for 24 hours to remove moisture.

[0097] Step 3: Keep the material obtained in Step 2 at 1100℃ for 2 hours, then take it out and wait for it to cool to room temperature;

[0098] Step 4: Grind the material obtained in Step 3 in a ball mill for 1 hour to obtain powder;

[0099] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:6. Control the reactor temperature at 25±2℃ and stir continuously for 1 hour to make the material uniform. Then, control the reactor temperature at 50±2℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 50±2mL / min and 90±2mL / min, respectively, while stirring the powder to obtain heat-release capsules.

[0100] Example 5:

[0101] This embodiment describes a method for preparing heat-slow-release repair materials for emergency repair projects in cold regions, including the following steps:

[0102] Step 1: Weigh out 60 parts of P·O 52.5R cement, 30 parts of 72.5 cement, 10 parts of dihydrate gypsum, 3 parts of heat-release capsules, and 100 parts of quartz sand according to the weight ratio. Then pour them into a mixer and stir at a low speed of 140±5r / min for 5 minutes until uniform raw materials are formed.

[0103] Step 2: Seal the raw materials obtained in Step 1 and place them in a -10℃ low-temperature chamber for 24 hours to pre-cool them, thus forming pre-cooled raw materials;

[0104] Step 3: Pour 0.3 parts of polycarboxylate superplasticizer into 26 parts of water and stir to form a uniform solution of superplasticizer and water;

[0105] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 140±5 r / min for 3 minutes, and then stir at a high speed of 285±5 r / min for 2 minutes to form a homogeneous slurry.

[0106] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -10℃ for continuous curing. Demold after 1 day.

[0107] The preparation method of the heat-release capsule includes the following steps:

[0108] Step 1: Place 1000 parts limestone, 0.2 parts sodium saccharin, and 0.1 parts ethyl maltol into a ball mill and grind for 1.5 hours until uniform to obtain a uniform powder.

[0109] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:8, compact it, and dry it in an oven at 105℃ for 24 hours to remove moisture.

[0110] Step 3: Keep the material obtained in Step 2 at 1100℃ for 2 hours, then take it out and wait for it to cool to room temperature;

[0111] Step 4: Grind the material obtained in Step 3 in a ball mill for 1 hour to obtain powder;

[0112] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:6. Control the reactor temperature at 25±2℃ and stir continuously for 1 hour to make the material uniform. Then, control the reactor temperature at 50±2℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 50±2mL / min and 90±2mL / min, respectively, while stirring the powder to obtain heat-release capsules.

[0113] Example 6:

[0114] This embodiment describes a method for preparing heat-slow-release repair materials for emergency repair projects in cold regions, including the following steps:

[0115] Step 1: Weigh out 60 parts of P·O 52.5R cement, 30 parts of 72.5 cement, 10 parts of dihydrate gypsum, 1 part of heat-release capsules, and 100 parts of quartz sand according to the weight ratio. Then pour them into the mixer and stir at a low speed of 140±5r / min for 5.5min until uniform raw materials are formed.

[0116] Step 2: Seal the raw materials obtained in Step 1 and place them in a -10℃ low-temperature chamber for 24 hours to pre-cool them, thus forming pre-cooled raw materials;

[0117] Step 3: Pour 0.3 parts of polycarboxylate superplasticizer into 26 parts of water and stir to form a uniform solution of superplasticizer and water;

[0118] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 140±5 r / min for 3 minutes, and then stir at a high speed of 285±5 r / min for 2 minutes to form a homogeneous slurry.

[0119] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -10℃ for continuous curing. Demold after 1 day.

[0120] The preparation method of the heat-release capsule includes the following steps:

[0121] Step 1: Place 1000 parts limestone, 0.2 parts sodium saccharin, and 0.1 parts ethyl maltol into a ball mill and grind for 1.5 hours until uniform to obtain a uniform powder.

[0122] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:8, compact it, and dry it in an oven at 105℃ for 24 hours to remove moisture.

[0123] Step 3: Keep the material obtained in Step 2 at 1100℃ for 2 hours, then take it out and wait for it to cool to room temperature;

[0124] Step 4: Grind the material obtained in Step 3 in a ball mill for 1 hour to obtain powder;

[0125] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:6. Control the reactor temperature at 25±2℃ and stir continuously for 1 hour to make the material uniform. Then, control the reactor temperature at 50±2℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 50±2mL / min and 90±2mL / min, respectively, while stirring the powder to obtain heat-release capsules.

[0126] Example 7:

[0127] This embodiment describes a method for preparing heat-slow-release repair materials for emergency repair projects in cold regions, including the following steps:

[0128] Step 1: Weigh out 40 parts of P·O 52.5R cement, 45 parts of 72.5 cement, 15 parts of dihydrate gypsum, 1 part of heat-release capsule, and 100 parts of quartz sand according to the weight ratio. Then pour them into the mixer and stir at a low speed of 140±5r / min for 5 minutes until uniform raw materials are formed.

[0129] Step 2: Seal the raw materials obtained in Step 1 and place them in a -10℃ low-temperature chamber for 24 hours to pre-cool them, thus forming pre-cooled raw materials;

[0130] Step 3: Pour 0.25 parts of polycarboxylate superplasticizer into 25.5 parts of water and stir to form a uniform solution of superplasticizer and water;

[0131] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 140±5r / min for 3 minutes, and then stir at a high speed of 285±5r / min for 3 minutes to form a homogeneous slurry.

[0132] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -10℃ for continuous curing. Demold after 1 day.

[0133] The preparation method of the heat-release capsule includes the following steps:

[0134] Step 1: Place 1005 parts limestone, 0.23 parts sodium saccharin, and 0.12 parts ethyl maltol into a ball mill and grind for 95 minutes until uniform to obtain a uniform powder.

[0135] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:8, compact it, and dry it in an oven at 105℃ for 24 hours to remove moisture.

[0136] Step 3: Keep the material obtained in Step 2 at 1100℃ for 2 hours, then take it out and wait for it to cool to room temperature;

[0137] Step 4: Grind the material obtained in Step 3 in a ball mill for 1 hour to obtain powder;

[0138] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:6. Control the reactor temperature at 25±2℃ and stir continuously for 1 hour to make the material uniform. Then, control the reactor temperature at 50±2℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 50±2mL / min and 90±2mL / min, respectively, while stirring the powder to obtain heat-release capsules.

[0139] Example 8:

[0140] This embodiment describes a method for preparing heat-slow-release repair materials for emergency repair projects in cold regions, including the following steps:

[0141] Step 1: Weigh out 40 parts of P·O 52.5R cement, 45 parts of 72.5 cement, 15 parts of dihydrate gypsum, 3 parts of heat-release capsules, and 100 parts of quartz sand according to the weight ratio. Then pour them into the mixer and stir at a low speed of 140±5r / min for 5 minutes until uniform raw materials are formed.

[0142] Step 2: Seal the raw materials obtained in Step 1 and place them in a -10℃ low-temperature chamber for 24 hours to pre-cool them, thus forming pre-cooled raw materials;

[0143] Step 3: Pour 0.3 parts of polycarboxylate superplasticizer into 26 parts of water and stir to form a uniform solution of superplasticizer and water;

[0144] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 140±5 r / min for 3 minutes, and then stir at a high speed of 285±5 r / min for 2 minutes to form a homogeneous slurry.

[0145] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -10℃ for continuous curing. Demold after 1 day.

[0146] The preparation method of the heat-release capsule includes the following steps:

[0147] Step 1: Place 1000 parts limestone, 0.2 parts sodium saccharin, and 0.1 parts ethyl maltol into a ball mill and grind for 1.5 hours until uniform to obtain a uniform powder.

[0148] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:9, compact it, and dry it in an oven at 103℃ for 36 hours to remove moisture.

[0149] Step 3: Keep the material obtained in Step 2 at 995℃ for 125 minutes, then take it out and wait for it to cool to room temperature;

[0150] Step 4: Place the material obtained in Step 3 into a ball mill and grind it for 63 minutes to obtain powder;

[0151] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:6. Control the reactor temperature at 25±2℃ and stir continuously for 1 hour to make the material uniform. Then, control the reactor temperature at 50±2℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 50±2mL / min and 90±2mL / min, respectively, while stirring the powder to obtain heat-release capsules.

[0152] Example 9:

[0153] This embodiment describes a method for preparing heat-slow-release repair materials for emergency repair projects in cold regions, including the following steps:

[0154] Step 1: Weigh out 40 parts of P·O 52.5R cement, 45 parts of 72.5 cement, 15 parts of dihydrate gypsum, 5 parts of heat-release capsules, and 100 parts of quartz sand according to the weight ratio. Then pour them into the mixer and stir at a low speed of 140±5r / min for 5 minutes until uniform raw materials are formed.

[0155] Step 2: Seal the raw materials obtained in Step 1 and place them in a -10℃ low-temperature chamber for 24 hours to pre-cool them, thus forming pre-cooled raw materials;

[0156] Step 3: Pour 0.3 parts of polycarboxylate superplasticizer into 26 parts of water and stir to form a uniform solution of superplasticizer and water;

[0157] Step 4: Pour the pre-cooled raw materials obtained in Step 2 and the homogeneous solution obtained in Step 3 into a mixer. First, stir at a low speed of 140±5 r / min for 3 minutes, and then stir at a high speed of 285±5 r / min for 2 minutes to form a homogeneous slurry.

[0158] Step 5: Pour the uniform slurry formed in Step 4 into a 40mm×40mm×40mm mold, vibrate for 60 seconds, cover with polyethylene film, and place in a low temperature chamber at -10℃ for continuous curing. Demold after 1 day.

[0159] The preparation method of the heat-release capsule includes the following steps:

[0160] Step 1: Place 1000 parts limestone, 0.2 parts sodium saccharin, and 0.1 parts ethyl maltol into a ball mill and grind for 1.5 hours until uniform to obtain a uniform powder.

[0161] Step 2: Mix the powder obtained in Step 1 with deionized water at a weight ratio of 100:8, compact it, and dry it in an oven at 105℃ for 24 hours to remove moisture.

[0162] Step 3: Keep the material obtained in Step 2 at 1100℃ for 2 hours, then take it out and wait for it to cool to room temperature;

[0163] Step 4: Grind the material obtained in Step 3 in a ball mill for 1 hour to obtain powder;

[0164] Step 5: Place the powder obtained in Step 4 and methacrylate silane in a reactor at a weight ratio of 100:6.3. Control the reactor temperature at 25±2℃ and stir continuously for 55 minutes to make the material uniform. Then, control the reactor temperature at 50±2℃ and simultaneously introduce saturated steam and carbon dioxide gas at rates of 50±2mL / min and 90±2mL / min, respectively, while stirring the powder to obtain heat-release capsules.

[0165] This embodiment describes a heat-release repair material suitable for emergency repair projects in cold regions, prepared according to the method described above.

[0166] The 1-day, 7-day, and 28-day compressive strength test results of the heat-release repair materials prepared in Examples 1-9 above are shown in Table 1:

[0167] Table 1

[0168]

[0169] As shown in Table 1, the compressive strength of the repair mortar increased significantly at all ages with the increase of the sustained-release heat capsule content. This indicates that the method of the present invention can effectively improve the compressive strength of the repair mortar under low-temperature conditions.

[0170] The heat-suppressed repair materials prepared in Examples 1-9 above freeze at -10℃, i.e., the time required for the temperature to drop to 0℃, as shown in Table 2:

[0171] Table 2

[0172]

[0173] As shown in Table 2, the test results indicate that with the increase of the slow-release heat capsule content, the time required for the repair mortar to enter freezing at low temperatures is prolonged. This demonstrates that the method of the present invention has a significant inhibitory effect on the temperature drop of the repair material at low temperatures, effectively delaying its freezing time and providing more time and effective conditions for the early hydration of cement and the establishment of early structure in the repair material.

[0174] The ettringite crystal content of the heat-suppressed remediation materials prepared in Examples 1-9 above at -7 days is shown in Table 3:

[0175] Table 3

[0176]

[0177] As shown in Table 3, the test results indicate that the content of early-formed ettringite crystals in the repair mortar increases significantly with the increase of the sustained-release heat capsule content. The calcium hydroxide generated by the heat-suppressed capsule reaction provides an additional hydration pathway for calcium sulfoaluminate in sulfoaluminate cement, which is beneficial to the promotion of cement hydration and thus enables rapid strength development at low temperatures.

[0178] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a heat-release capsule, characterized in that, The process includes the following: Limestone, sodium saccharin, and ethyl maltol were ground and mixed to obtain the first powder. The mass ratio of limestone, sodium saccharin, and ethyl maltol was (995-1005):(0.17-0.23):(0.08-0.12). The first powder is mixed with deionized water at a mass ratio of 100:(8-10), compacted and dried to obtain a blank. The billet is held at 1095-1105℃ for 115-125 minutes and then air-cooled to obtain calcium oxide material. The calcium oxide material is ground into powder to obtain a second powder. The second powder and methacrylate silane were mixed and stirred evenly at 23~28°C in a weight ratio of 100:(5.7-6.3). Then the temperature was raised to 48~52°C, and the material was stirred under a saturated steam and carbon dioxide atmosphere to obtain a heat-release capsule with calcium oxide as the core and methacrylate silane and calcium carbonate as the shell.

2. The method for preparing a heat-release capsule according to claim 1, characterized in that, The particle size of the second powder is above 200 mesh.

3. A heat-sustaining capsule, characterized in that, The heat-release capsule is prepared by the preparation method described in claim 1 or 2.

4. A heat-slow-release repair material suitable for emergency repair projects in cold regions, characterized in that, The raw materials, by mass parts, include: 40-70 parts silicate cement, 22.5-45 parts sulfoaluminate cement, 7.5-15 parts gypsum, 1-5 parts of the heat-sustaining capsules as described in claim 3, 97-103 parts quartz sand, 25.5-26.5 parts water, and 0.25-0.35 parts high-efficiency water-reducing agent.

5. A heat-slow-release repair material suitable for emergency repair projects in cold regions according to claim 4, characterized in that, The silicate cement used is P·O 52.5R cement.

6. A heat-slow-release repair material suitable for emergency repair projects in cold regions according to claim 4, characterized in that, The sulfoaluminate cement used is 72.5 cement.

7. A heat-slow-release repair material suitable for emergency repair projects in cold regions according to claim 4, characterized in that, The gypsum used is dihydrate gypsum.

8. A heat-slow-release repair material suitable for emergency repair projects in cold regions according to claim 5, characterized in that, The high-efficiency water-reducing agent is a polycarboxylate water-reducing agent.

9. The method for preparing the heat-slow-release repair material suitable for emergency repair projects in cold regions according to any one of claims 4-8, characterized in that, The process includes the following: Silicate cement, sulfoaluminate cement, gypsum, heat-release capsules, and quartz sand are mixed to obtain uniform raw materials. The raw material is sealed and pre-cooled to obtain pre-cooled raw material, with the pre-cooling temperature being the same as the curing temperature; The high-efficiency water-reducing agent is mixed with water to dissolve it and obtain a homogeneous solution. The pre-cooled raw materials and the homogeneous solution are mixed and stirred to form a homogeneous slurry, thus obtaining the heat-slow-release repair material suitable for emergency repair projects in cold regions.

10. The method for preparing the heat-slow-release repair material suitable for emergency repair projects in cold regions according to claim 9, characterized in that, When the pre-cooled raw material and the homogeneous solution are mixed and stirred to form a homogeneous slurry: First, stir at low speed for 3-4 minutes, then stir at high speed for 2-3 minutes to obtain the homogeneous slurry. The stirring rate for low-speed stirring is 135-145 r / min, and the stirring rate for high-speed stirring is 280-290 r / min.

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