Slow-release hydration heat inhibitor and preparation method thereof

Abstract

The invention discloses a slow-release hydration heat inhibitor and a preparation method thereof, and relates to the technical field of concrete admixtures, the slow-release hydration heat inhibitor comprises, by mass, 60-70 parts of a dissolution heat absorption component, 10-20 parts of a hydration reaction adjusting component, and 20-30 parts of a temperature control heat absorption component; the dissolving heat absorption component comprises one or more of calcium nitrate, ammonium nitrate or potassium nitrate, and the temperature control heat absorption component comprises the following components in percentage by mass: 70-80% of paraffin and 20-30% of barium hydroxide octahydrate. The slow-release hydration heat inhibitor is obtained by sequentially wrapping mixed particles formed by a dissolution heat absorption component and a hydration reaction adjusting component with barium hydroxide octahydrate and paraffin from inside to outside. The slow-release hydration heat inhibitor disclosed by the invention can realize step-by-step regulation and control aiming at the problem of large hydration heat release of mass concrete, the hydration heat of the mass concrete is remarkably reduced, and the risk caused by temperature difference shrinkage cracks of the concrete is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of concrete admixtures, in particular to a slow-release hydration heat inhibitor and a preparation method thereof. Background Art

[0002] During the pouring process of large-volume concrete, due to the hydration heat release of cement and other cementitious materials and the synchronous heat dissipation of the surface, the temperature of the concrete itself changes continuously in time and space, thus generating temperature stress. However, concrete itself is a poor conductor of heat, and most of the hydration heat cannot be dissipated to the surrounding environment in a short time. The temperature of the core area of ​​large-volume concrete is generally higher than 50°C, and can even reach above 80°C. During the cooling stage, large-volume concrete is constrained by the foundation or adjacent parts, and tensile stress is generated inside. Then, as the size of the concrete increases, the temperature difference between the inside and outside causes inconsistent volume deformation, which can easily lead to the surface temperature stress caused by the temperature difference between the inside and the surface exceeding the maximum allowable tensile stress of the concrete. Once the tensile stress is greater than the tensile limit of the concrete, cracks will expand from the surface to the inside, that is, cracks will occur in the constraint area, increasing the risk of cracking of large-volume concrete.

[0003] At present, it is necessary to take appropriate temperature control measures during large-volume concrete pouring construction to ensure the concrete temperature and improve the quality of concrete pouring. The traditional methods mainly include: (1) reducing the heat release of cement hydration in concrete, such as reducing the amount of adhesive, using fly ash, mineral powder and other admixtures, or using low- and medium-heat cement, etc.; (2) increasing the heat dissipation rate, such as pre-buried cooling water pipes, reducing the structural size, etc.; (3) reducing the mold entry temperature, pre-cooling raw materials, etc. These methods have the disadvantages of reducing concrete performance and greatly increasing construction difficulty and cost; and adding concrete hydration temperature rise inhibitors has become the simplest and most effective method. Adding hydration temperature rise inhibitors not only reduces the cost of cooling aggregates and pre-buried cooling water pipes, but also can more effectively reduce cement hydration heat release and reduce the temperature difference between the inside and outside of concrete compared to optimizing concrete mix ratio. It has the advantages of convenience, economy and high controllability.

[0004] Commonly used hydration heat control materials include starch dextrin polymers, inorganic salts and endothermic phase change materials. Starch and protein materials associate with water molecules through hydroxyl groups to form a stable solvated water film that wraps around the surface of cement particles, hindering the cement hydration reaction. The physical reaction of inorganic salt hydration temperature rise inhibitors dissolved in water or the chemical reaction with water are endothermic reactions, which can absorb a large amount of heat released by cement hydration and inhibit cement hydration. However, the use of dextrin has a significant adverse effect on the setting time and mechanical properties of concrete, which will cause serious slow setting of concrete and a significant decrease in strength; in addition, inorganic salts will dissolve during the mixing process of concrete. At this time, the cement has not started to hydrate and has not generated a large amount of hydration heat. The dissolution of inorganic salts cannot achieve the actual heat control effect.

[0005] Therefore, it is necessary to develop a slow-release hydration heat inhibitor and a preparation method thereof, which can achieve step-by-step regulation of the problem of large hydration heat release of large-volume concrete, significantly reduce the hydration heat of large-volume concrete, and greatly reduce the risk of temperature difference shrinkage cracks in concrete. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a slow-release hydration heat inhibitor and a preparation method thereof, which can achieve step-by-step regulation of the problem of large hydration heat release of large-volume concrete, significantly reduce the hydration heat of large-volume concrete, and greatly reduce the risk of temperature difference shrinkage cracks in concrete.

[0007] The technical solution of the present invention is: a slow-release hydration heat inhibitor, comprising 60 to 70 parts by mass of a dissolving endothermic component, 10 to 20 parts by mass of a hydration reaction regulating component, and 20 to 30 parts by mass of a temperature control endothermic component;

[0008] The dissolution endothermic component comprises one or more of calcium nitrate, ammonium nitrate or potassium nitrate; the hydration reaction regulating component is calcium complex type sulfonated dextrin; the temperature control endothermic component comprises 70-80% paraffin and 20-30% barium hydroxide octahydrate in percentage by mass, wherein the sum of the percentage by mass of paraffin and barium hydroxide octahydrate is 100%; and the slow-release hydration heat inhibitor is obtained by sequentially encapsulating mixed particles formed by the dissolution endothermic component and the hydration reaction regulating component with barium hydroxide octahydrate and paraffin from the inside to the outside.

[0009] Preferably, the mixed particles are obtained by mixing and grinding a dissolving endothermic component and a hydration reaction regulating component until the mixture passes through a sieve of 80 to 100 meshes.

[0010] Preferably, the barium hydroxide octahydrate and paraffin wax sequentially wrap the surface of the mixed particles from the inside to the outside, and the specific operation includes:

[0011] dissolving barium hydroxide octahydrate in water to form a barium hydroxide octahydrate solution, spraying the barium hydroxide octahydrate solution directly on the surface of the mixed particles or spraying the mixed particles on the surface and then drying to obtain mixed particles coated with barium hydroxide octahydrate;

[0012] The paraffin is heated in a water bath to a liquid state, mixed particles wrapped with barium hydroxide octahydrate are added, and spray granulation is performed after being stirred evenly to obtain particles wrapped with paraffin. After the particles are dried, a slow-release hydration heat inhibitor is obtained.

[0013] Furthermore, the concentration of the barium hydroxide octahydrate solution is 40-50 g / L.

[0014] Preferably, it comprises 60 parts of dissolving endothermic components, 15 parts of hydration reaction regulating components and 25 parts of temperature controlling endothermic components by mass, wherein the temperature controlling endothermic components comprise 70% paraffin and 30% barium hydroxide octahydrate by mass percentage.

[0015] Preferably, the hydration reaction regulating component is prepared by a method comprising the following steps:

[0016] a. Pyrolyze corn starch at 230-250°C for 2-3 hours and cool to room temperature;

[0017] b. The pyrolyzed corn starch is adjusted to a slurry with a mass concentration of 20-30% with water, the pH value of the sulfuric acid system is adjusted to 6-7, and the medium-temperature α-amylase is added at an amount of 50U enzyme activity per gram of corn starch. The mixture is hydrolyzed at 45-55°C for 4-5h, the pH value of the sulfuric acid system is adjusted to 2-3, the enzyme is inactivated for 30min, and then adjusted to neutral with a saturated calcium hydroxide solution;

[0018] c. Add 30% by volume ethanol aqueous solution as an extractant, stir and centrifuge to remove the solid, dry and grind it to obtain a hydration reaction regulating component.

[0019] Among them, the purpose of high-temperature pyrolysis of corn starch is to prepare starch dextrin. Starch dextrin polymers associate with water molecules through hydroxyl groups to form a layer of stable solvated water film that wraps around the surface of cement particles, which can hinder the cement hydration reaction.

[0020] Furthermore, the hydration reaction regulating component is prepared by a method comprising the following steps:

[0021] a. Pyrolyze corn starch at 240 °C for 2 h and then cool to room temperature;

[0022] b. Use water to make a slurry with a mass concentration of 30%, then use 30% sulfuric acid to adjust the system pH to 6, add medium-temperature α-amylase at a dosage of 50U enzyme activity per gram of corn starch, keep warm and hydrolyze at 50°C for 4h, then use 30% sulfuric acid to adjust the system pH to 2-3, inactivate the enzyme for 30min, and then adjust to neutral with saturated calcium hydroxide solution;

[0023] c. Add 30% by volume ethanol aqueous solution as an extractant, stir for 30 minutes, centrifuge the solid, dry and grind it to obtain the hydration reaction regulating component.

[0024] The present invention also provides a method for preparing any of the above slow-release hydration heat inhibitors, comprising the following steps:

[0025] S1, mixing and grinding the dissolving endothermic component and the hydration reaction regulating component until the mixture passes through a 80-100 mesh sieve to obtain mixed particles;

[0026] S2, dissolving barium hydroxide octahydrate in water to form a barium hydroxide octahydrate solution, spraying the barium hydroxide octahydrate solution directly on the surface of the mixed particles or spraying it on the surface of the mixed particles and then drying it to obtain mixed particles coated with barium hydroxide octahydrate;

[0027] S3, heating the paraffin in a water bath until it is liquid, adding the mixed particles wrapped by barium hydroxide octahydrate, stirring evenly and then spray granulating to obtain particles wrapped by paraffin, and obtaining the slow-release hydration heat inhibitor after the particles are dried.

[0028] The present invention also provides the use of any of the above slow-release hydration heat inhibitors in concrete.

[0029] Preferably, the inhibitor is added at 1% of the mass of the cementitious material in the concrete.

[0030] The components of the slow-release hydration heat inhibitor of the present invention have the following functions:

[0031] The dissolved endothermic components absorb a large amount of heat generated by cement hydration when dissolved.

[0032] The hydration reaction regulating component is calcium complex sulfonated dextrin, which forms a wrapping structure on the surface of cement particles to prevent the cement from hydrating too quickly. As the cement hydration reaction proceeds, when a large amount of cement reacts in a concentrated manner, calcium ions react with sulfate to form needle-shaped calcium sulfonite crystals that pierce the water-soluble dextrin film, allowing the cement particles to further undergo hydration reaction, thereby preventing dextrin from causing severe slow setting of the concrete.

[0033] The temperature-controlled heat-absorbing components are paraffin and barium hydroxide octahydrate, wherein paraffin melts at 46-68°C and absorbs a large amount of heat, and barium hydroxide octahydrate melts at 78°C and absorbs a large amount of heat. Through the step-by-step melting and heat absorption of paraffin and barium hydroxide octahydrate, step-by-step regulation can be achieved within the range of 46-78°C.

[0034] The working principle of the slow-release hydration heat inhibitor of the present invention is:

[0035] First, the temperature control regulating component melts and absorbs heat step by step under different temperature gradients, which greatly reduces the hydration heat peak of cement concrete and prolongs the hydration exothermic time; then, after the temperature control regulating component is completely melted, the dissolving endothermic component begins to dissolve and absorb the hydration heat; finally, the hydration reaction regulating component forms a wrapping structure on the surface of cement particles to prevent the cement from hydrating too fast. As the cement hydration reaction proceeds, when a large amount of cement reacts concentratedly, calcium ions react with silicate and sulfonate to form needle-shaped calcium sulfonate crystals that pierce the water-soluble dextrin film, allowing the cement particles to further undergo hydration reaction, avoiding causing serious slow setting of concrete. The slow-release hydration heat inhibitor prepared by the above method can significantly reduce the hydration heat of large-volume concrete and effectively solve the problem of concrete temperature difference shrinkage cracks.

[0036] The core of the present invention is that in order to achieve the purpose of graded regulation, the slow-release hydration heat inhibitor adopts a multi-layer packaging method, wherein the first layer (outer layer) is paraffin in the temperature-controlling endothermic component, and the paraffin melts at 46-68°C and absorbs a large amount of heat; the second layer (inner layer) is barium hydroxide octahydrate in the temperature-controlling endothermic component, and the barium hydroxide octahydrate melts at 78°C and absorbs a large amount of heat; the core part is the dissolved endothermic component and the hydration reaction regulating component.

[0037] The beneficial effects of the present invention include:

[0038] 1. The temperature-controlled heat-absorbing material melts and absorbs heat step by step, and can achieve full-process step-by-step regulation within the range of 46 to 78°C; the dissolving heat-absorbing material of the present invention begins to dissolve and absorb heat when the cement reacts intensively, greatly reducing the hydration heat peak of the cement concrete; the hydration reaction regulating component of the present invention can avoid causing serious slow setting of the concrete while avoiding excessively fast hydration of the cement.

[0039] 2. The barium hydroxide octahydrate and paraffin in the temperature-controlled heat-absorbing component wrap the mixed particles formed by the dissolved heat-absorbing component and the hydration reaction regulating component from the inside to the outside. The paraffin is the outer layer, which melts at 46-68°C and absorbs a large amount of heat; the barium hydroxide octahydrate is the inner layer, which melts at 78°C and absorbs a large amount of heat, thereby realizing full-process step-by-step regulation within the range of 46-78°C.

[0040] 3. The barium hydroxide octahydrate in the temperature-controlled endothermic component is spray-dried or spray-coated on the surface of the mixed particles (dissolved endothermic component + hydration reaction regulating component), and the paraffin is directly coated on the surface of the particles after liquefaction, and the slow-release hydration heat inhibitor is obtained by drying. The whole preparation process is simple and efficient.

[0041] 4. After the temperature control and regulating components are completely melted, the dissolving and endothermic components begin to dissolve and absorb the hydration heat; finally, the hydration reaction regulating components form a wrapping structure on the surface of the cement particles to prevent the cement from hydrating too quickly. As the cement hydration reaction proceeds, when a large amount of cement reacts concentratedly, the calcium ions react with silicate and sulfonate to form needle-shaped calcium sulfonate crystals that pierce the water-soluble dextrin film, allowing the cement particles to further undergo hydration reactions, thereby avoiding severe slow setting of the concrete, thereby effectively solving the problem of concrete temperature difference shrinkage cracks.

[0042] 5. By adding the slow-release hydration heat inhibitor of the present invention, the 24h hydration heat reduction rate of the mortar is as high as 50%, and the compressive strength ratio of the concrete is as high as 110%. All indicators far exceed the requirements of "Concrete Hydration Temperature Rise Inhibitor" (JCT 2608-2020). DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described below in conjunction with the examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The drugs used in the following examples are all commercially available products unless otherwise specified, and the methods used are all conventional methods in the art unless otherwise specified.

[0044] Example 1

[0045] The present embodiment provides a slow-release hydration heat inhibitor, comprising a dissolving endothermic component, a temperature-controlling endothermic component and a hydration reaction regulating component, with a mass ratio of 60:25:15, the dissolving endothermic material is calcium nitrate, the temperature-controlling endothermic component contains 70% paraffin and 30% barium hydroxide octahydrate by mass percentage, and the hydration reaction regulating component is calcium complex type sulfonated dextrin.

[0046] The hydration reaction regulating component is prepared according to the following steps:

[0047] a. Pyrolyze corn starch at 240 °C for 2 h and then cool to room temperature;

[0048] b. Use water to make a slurry with a mass concentration of 30%, then use 30% sulfuric acid to adjust the system pH to 6, add medium-temperature α-amylase at a dosage of 50U enzyme activity per gram of corn starch, keep warm and hydrolyze at 50°C for 4h, then use 30% sulfuric acid to adjust the system pH to 2-3, inactivate the enzyme for 30min, and then adjust to neutral with saturated calcium hydroxide solution;

[0049] c. Add 30% by volume ethanol aqueous solution as an extractant, stir for 30 minutes, centrifuge the solid, dry and grind it to obtain the hydration reaction regulating component.

[0050] The preparation method of the slow-release hydration heat inhibitor of this embodiment is as follows:

[0051] S1. Mix and grind the dissolving endothermic component (calcium nitrate) and the hydration reaction regulating component (calcium complex type sulfonated dextrin) until they pass through a 100-mesh sieve to obtain mixed particles;

[0052] S2, dissolving barium hydroxide octahydrate in water to form a barium hydroxide octahydrate solution with a concentration of 50g / L, spraying the barium hydroxide octahydrate solution directly on the surface of the mixed particles using a spray dryer (the material processing capacity of the spray dryer is 1500-2000mL / h, the maximum air inlet temperature is 300±1°C, and the spray pressure is 0.2-0.5MPa), or spraying it on the surface of the mixed particles using a sprayer and then drying (the air inlet pressure of the sprayer is 0.3-0.6MPa, and the air consumption is 200-2000L / min), to obtain mixed particles coated with barium hydroxide octahydrate;

[0053] S3, heating the paraffin in a water bath until it is liquid, adding the mixed particles wrapped by barium hydroxide octahydrate, stirring evenly and then spray granulating to obtain particles wrapped by paraffin, and obtaining the slow-release hydration heat inhibitor after the particles are dried.

[0054] Example 2

[0055] The present embodiment provides a slow-release hydration heat inhibitor, comprising a dissolving endothermic component, a temperature-controlling endothermic component and a hydration reaction regulating component, the mass ratio of which is 65:22:13. The dissolving endothermic material is ammonium nitrate, the temperature-controlling endothermic component contains 75% paraffin and 25% barium hydroxide octahydrate in terms of mass percentage, and the hydration reaction regulating component is a calcium-complexed sulfonated dextrin (the hydration reaction regulating component is prepared according to the preparation method of the hydration reaction regulating component in Example 1).

[0056] The preparation method of the slow-release hydration heat inhibitor of this embodiment is as follows:

[0057] S1. Mix and grind the dissolving endothermic component (ammonium nitrate) and the hydration reaction regulating component (calcium complex type sulfonated dextrin) until they pass through a 100-mesh sieve to obtain mixed particles;

[0058] S2, dissolving barium hydroxide octahydrate in water to form a barium hydroxide octahydrate solution with a concentration of 50g / L, spraying the barium hydroxide octahydrate solution directly on the surface of the mixed particles using a spray dryer (the material processing capacity of the spray dryer is 1500-2000mL / h, the maximum air inlet temperature is 300±1°C, and the spray pressure is 0.2-0.5MPa), or spraying it on the surface of the mixed particles using a sprayer and then drying (the air inlet pressure of the sprayer is 0.3-0.6MPa, and the air consumption is 200-2000L / min), to obtain mixed particles coated with barium hydroxide octahydrate;

[0059] S3, heating the paraffin in a water bath until it is liquid, adding the mixed particles wrapped by barium hydroxide octahydrate, stirring evenly and then spray granulating to obtain particles wrapped by paraffin, and obtaining the slow-release hydration heat inhibitor after the particles are dried.

[0060] Example 3

[0061] The present embodiment provides a slow-release hydration heat inhibitor, comprising a dissolving endothermic component, a temperature-controlling endothermic component and a hydration reaction regulating component, the mass ratio of which is 70:20:10. The dissolving endothermic material is potassium nitrate, the temperature-controlling endothermic component contains 75% paraffin and 25% barium hydroxide octahydrate in terms of mass percentage, and the hydration reaction regulating component is a calcium-complexed sulfonated dextrin (the hydration reaction regulating component is prepared according to the preparation method of the hydration reaction regulating component in Example 1).

[0062] The preparation method of the slow-release hydration heat inhibitor of this embodiment is as follows:

[0063] S1. Mix and grind the dissolving endothermic component (potassium nitrate) and the hydration reaction regulating component (calcium complex type sulfonated dextrin) until the mixture passes through a 100-mesh sieve to obtain mixed particles;

[0064] S2, dissolving barium hydroxide octahydrate in water to form a barium hydroxide octahydrate solution with a concentration of 50g / L, spraying the barium hydroxide octahydrate solution directly on the surface of the mixed particles using a spray dryer (the material processing capacity of the spray dryer is 1500-2000mL / h, the maximum air inlet temperature is 300±1°C, and the spray pressure is 0.2-0.5MPa), or spraying it on the surface of the mixed particles using a sprayer and then drying (the air inlet pressure of the sprayer is 0.3-0.6MPa, and the air consumption is 200-2000L / min), to obtain mixed particles coated with barium hydroxide octahydrate;

[0065] S3, heating the paraffin in a water bath until it is liquid, adding the mixed particles wrapped by barium hydroxide octahydrate, stirring evenly and then spray granulating to obtain particles wrapped by paraffin, and obtaining the slow-release hydration heat inhibitor after the particles are dried.

[0066] Comparative Example 1

[0067] The raw materials and proportions used in Comparative Example 1 are basically the same as those in Example 1, except that the method for preparing the sustained-release hydration heat inhibitor does not adopt a multi-layer film wrapping method, but directly mixes the dissolving endothermic component, the temperature-controlling endothermic component and the hydration reaction regulating component to obtain a comparative sustained-release hydration heat inhibitor.

[0068] Comparative Example 2

[0069] The raw materials and the proportions used in Comparative Example 2 are substantially the same as those in Example 1, except that the hydration reaction regulating component is dextrin (a commercially available product). The comparative slow-release hydration heat inhibitor is obtained by the preparation method of Example 1.

[0070] Comparative Example 3

[0071] The raw materials and the proportions used in Comparative Example 3 are basically the same as those in Example 1, except that the slow-release hydration heat inhibitor does not contain a temperature-controlling endothermic component, and the slow-release hydration heat inhibitor is composed of a dissolving endothermic component and a hydration reaction regulating component in a mass ratio of 75:25. During the preparation, the dissolving endothermic component and the hydration reaction regulating component are evenly mixed to obtain a comparative slow-release hydration heat inhibitor.

[0072] Performance Testing

[0073] The concretes of the embodiments and comparative examples were prepared according to the dosage in Table 1 below. P.O52.5 ordinary Portland cement was used as cement, and commercially available products that met the requirements were used for quartz sand, crushed stone, and water reducing agent. The water reducing rate of the water reducing agent was 18%, and the dosage of the slow-release hydration heat inhibitor was 1% of the mass of the cementitious material (cement).

[0074] Table 1 Concrete mix ratio (kg / m 3 )

[0075] Material cement sand gravel water Water reducing agent Slow-release hydration heat inhibitor Dosage 360 790 1080 170 4 3.6

[0076] The test was carried out in accordance with the relevant provisions of "Concrete Hydration Temperature Rise Inhibitor" (JCT 2608-2020), and the test results of relevant performance are shown in Table 2.

[0077] Table 2 Performance test results

[0078]

[0079] From the test results in Table 2, it can be seen that by adding the slow-release hydration heat inhibitor of the present invention, the 24h hydration heat reduction rate of the mortar is as high as 50%, and the compressive strength ratio of the concrete is as high as 110%. All indicators far exceed the requirements of "Concrete Hydration Temperature Rise Inhibitor" (JCT 2608-2020), indicating that the slow-release hydration heat inhibitor of the present invention can effectively reduce the hydration heat of cement, improve the mechanical properties of concrete, and greatly reduce the risk of temperature difference shrinkage cracks in concrete.

[0080] Compared with Example 1, the slow-release hydration heat inhibitor of Comparative Example 1 does not adopt a multi-layer film wrapping method, but directly mixes the dissolving endothermic component, the temperature control endothermic component and the hydration reaction regulating component for uniform use, resulting in a 24h hydration heat depression rate reduced to 24%, a 28d compressive strength ratio reduced to 103%, and a final setting time extended to 15.0h; the hydration reaction regulating component of Comparative Example 2 is dextrin, resulting in a 24h hydration heat depression rate reduced to 29%, a 28d compressive strength ratio reduced to 95%, and a final setting time extended to 19.3h; the slow-release hydration heat inhibitor of Comparative Example 3 does not contain a temperature control endothermic component, resulting in a 24h hydration heat depression rate reduced to 26%, a 28d compressive strength ratio reduced to 99%, and a final setting time extended to 17.2h.

Claims

1. A slow-release hydration heat inhibitor, characterized in that: The invention comprises 60 to 70 parts by mass of a dissolving endothermic component, 10 to 20 parts by mass of a hydration reaction regulating component, and 20 to 30 parts by mass of a temperature controlling endothermic component; The dissolution endothermic component comprises one or more of calcium nitrate, ammonium nitrate or potassium nitrate; the hydration reaction regulating component is calcium complex type sulfonated dextrin; the temperature control endothermic component comprises 70-80% paraffin and 20-30% barium hydroxide octahydrate in percentage by mass, wherein the sum of the percentage by mass of paraffin and barium hydroxide octahydrate is 100%; and the slow-release hydration heat inhibitor is obtained by sequentially encapsulating mixed particles formed by the dissolution endothermic component and the hydration reaction regulating component with barium hydroxide octahydrate and paraffin from the inside to the outside.

2. The slow-release hydration heat inhibitor according to claim 1, characterized in that: The mixed particles are obtained by mixing and grinding the dissolved endothermic component and the hydration reaction regulating component until the mixed particles pass through a sieve of 80 to 100 meshes.

3. The slow-release hydration heat inhibitor according to claim 1, characterized in that: The barium hydroxide octahydrate and paraffin wax sequentially wrap the surface of the mixed particles from the inside to the outside, and the specific operation includes: dissolving barium hydroxide octahydrate in water to form a barium hydroxide octahydrate solution, spraying the barium hydroxide octahydrate solution directly on the surface of the mixed particles or spraying the mixed particles on the surface and then drying to obtain mixed particles coated with barium hydroxide octahydrate; The paraffin is heated in a water bath to a liquid state, mixed particles wrapped with barium hydroxide octahydrate are added, and spray granulation is performed after being stirred evenly to obtain particles wrapped with paraffin. After the particles are dried, a slow-release hydration heat inhibitor is obtained.

4. The slow-release hydration heat inhibitor according to claim 3, characterized in that: The concentration of the barium hydroxide octahydrate solution is 40-50 g / L.

5. The slow-release hydration heat inhibitor according to claim 1, characterized in that: The invention comprises 60 parts of dissolving heat absorbing components, 15 parts of hydration reaction regulating components and 25 parts of temperature controlling heat absorbing components by weight, wherein the temperature controlling heat absorbing components comprise 70% of paraffin wax and 30% of barium hydroxide octahydrate by weight.

6. The slow-release hydration heat inhibitor according to claim 1, characterized in that: The hydration reaction regulating component is prepared by a method comprising the following steps: a. Pyrolyze corn starch at 230-250°C for 2-3 hours and cool to room temperature; b. The pyrolyzed corn starch is adjusted to a slurry with a mass concentration of 20-30% with water, the pH value of the sulfuric acid system is adjusted to 6-7, and the medium-temperature α-amylase is added at an amount of 50U enzyme activity per gram of corn starch. The mixture is hydrolyzed at 45-55°C for 4-5h, the pH value of the sulfuric acid system is adjusted to 2-3, the enzyme is inactivated for 30min, and then adjusted to neutral with a saturated calcium hydroxide solution; c. Add 30% by volume ethanol aqueous solution as an extractant, stir and centrifuge to remove the solid, dry and grind it to obtain a hydration reaction regulating component.

7. The slow-release hydration heat inhibitor according to claim 6, characterized in that: The hydration reaction regulating component is prepared by a method comprising the following steps: a. Pyrolyze corn starch at 240 °C for 2 h and then cool to room temperature; b. Use water to make a slurry with a mass concentration of 30%, then use 30% sulfuric acid to adjust the system pH to 6, add medium-temperature α-amylase at a dosage of 50U enzyme activity per gram of corn starch, keep warm and hydrolyze at 50°C for 4h, then use 30% sulfuric acid to adjust the system pH to 2-3, inactivate the enzyme for 30min, and then adjust to neutral with saturated calcium hydroxide solution; c. Add 30% by volume ethanol aqueous solution as an extractant, stir for 30 minutes, centrifuge the solid, dry and grind it to obtain the hydration reaction regulating component.

8. A method for preparing a slow-release hydration heat inhibitor according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, mixing and grinding the dissolving endothermic component and the hydration reaction regulating component until the mixture passes through a 80-100 mesh sieve to obtain mixed particles; S2, dissolving barium hydroxide octahydrate in water to form a barium hydroxide octahydrate solution, spraying the barium hydroxide octahydrate solution directly on the surface of the mixed particles or spraying it on the surface of the mixed particles and then drying it to obtain mixed particles coated with barium hydroxide octahydrate; S3, heating the paraffin in a water bath until it is liquid, adding the mixed particles wrapped by barium hydroxide octahydrate, stirring evenly and then spray granulating to obtain particles wrapped by paraffin, and obtaining the slow-release hydration heat inhibitor after the particles are dried.

9. A use of any one of claims 1 to 7 as a slow-release hydration heat inhibitor, characterized in that: Used in concrete.

10. The use of the slow-release hydration heat inhibitor according to claim 9, characterized in that: The inhibitor is added at 1% of the mass of cementitious materials in concrete.

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