Anti-crack radiation-proof mortar and preparation method thereof

Abstract

The invention discloses anti-crack radiation-proof mortar and a preparation method thereof.The anti-crack radiation-proof mortar comprises steel fibers and 100 parts by weight of basic components, and the steel fibers account for 8%-10% of the basic components by weight; the basic components comprise 28 to 32 parts by weight of high belite sulphoaluminate cement, 3 to 7 parts by weight of Portland cement, 1 to 2 parts by weight of silica fume, 2 to 4 parts by weight of redispersible latex powder, 50 to 54 parts by weight of barite sand, 5 to 7 parts by weight of barite powder, 0.14 to 0.4 part by weight of a polycarboxylate superplasticizer, 0.05 to 0.1 part by weight of a defoaming agent, 0.01 to 0.05 part by weight of a stabilizer, 0.1 to 0.4 part by weight of a retarder, 0.04 to 0.08 part by weight of a reinforcing agent and 1.7 to 2 parts by weight of a repairing agent; 0.05 to 0.15 part by weight of polypropylene fiber; the repairing agent is a capillary crystalline material. The anti-crack radiation-proof mortar has excellent radiation shielding performance, dimensional stability and mechanical strength, and can reduce or avoid the cracking phenomenon caused by volume shrinkage of the mortar.

Description

Technical Field

[0001] This application belongs to the field of special building materials technology, specifically relating to a crack-resistant radiation-proof mortar and its preparation method. Background Technology

[0002] Radiation-shielding mortar is a special building material that can shield against ionizing radiation. It is mainly used in places requiring shielding against ionizing radiation, such as walls or floors in nuclear power plant reactor buildings, nuclear fuel processing workshops, and hospital radiology rooms. Compared to ordinary mortar, radiation-shielding mortar has a higher dry density, exceeding 20%. Therefore, it inevitably suffers from a fragile internal stress balance. When it shrinks in volume, it can easily induce cracks in the walls or floors, reducing the shielding effect and potentially causing radiation leakage. Summary of the Invention

[0003] The purpose of this application is to provide a crack-resistant radiation-proof mortar and its preparation method.

[0004] The approach of this application to solve the problem of cracking in radiation-shielding mortar is as follows: During the hardening process, the mortar undergoes volume shrinkage. When the stress caused by this volume shrinkage exceeds its tensile strength limit, cracking is induced. Therefore, on the one hand, this application reduces the stress caused by volume shrinkage by decreasing the volume shrinkage of the radiation-shielding mortar during the hardening process; on the other hand, this application enhances the mechanical strength, especially the tensile strength, of the radiation-shielding mortar to increase its resistance to stress caused by volume shrinkage. The combination of these two aspects aims to reduce or even avoid cracking.

[0005] This application provides a crack-resistant radiation-shielding mortar, comprising: steel fibers and 100 parts by weight of a base component, wherein the steel fibers constitute 8% to 10% by weight of the base component;

[0006] The basic components include: 28-32 parts by weight of high-belite sulfoaluminate cement, 3-7 parts by weight of silicate cement, 1-2 parts by weight of silica fume, 2-4 parts by weight of redispersible latex powder, 50-54 parts by weight of barite sand, 5-7 parts by weight of barite powder, 0.14-0.4 parts by weight of polycarboxylate superplasticizer, 0.05-0.1 parts by weight of defoamer, 0.01-0.05 parts by weight of stabilizer, 0.1-0.4 parts by weight of retarder, 0.04-0.08 parts by weight of reinforcing agent, 1.7-2 parts by weight of repair agent, and 0.05-0.15 parts by weight of polypropylene fiber; the repair agent is a penetrating crystallizing material.

[0007] In some embodiments, the steel fiber is stainless steel fiber, such as 304 stainless steel fiber or 316 stainless steel fiber, with a diameter of 0.18mm to 0.22mm and a length of 6mm to 12mm.

[0008] In some embodiments, the silica fume has a particle size of 0.1 micrometers to 0.3 micrometers, a specific surface area of ​​20 m² / g to 28 m² / g, and a SiO2 content of ≥90%.

[0009] In some embodiments, the redispersible latex powder is a vinyl acetate-ethylene copolymer latex powder.

[0010] In some embodiments, the particle size of barite sand is 0.08 mm to 1.15 mm; and the particle size of barite powder is 200 mesh to 300 mesh.

[0011] In some embodiments, the defoamer is a mineral oil-based powder defoamer.

[0012] In some embodiments, the stabilizer is a mixture of hydroxypropyl methylcellulose ether and polypropylene glycol monobutyl ether in a 1:1 weight ratio.

[0013] In some embodiments, the retarder is a mixture of sodium gluconate or sodium citrate and tartaric acid in a weight ratio of 1:1.

[0014] In some embodiments, the reinforcing agent is lithium sulfate or lithium carbonate.

[0015] In some embodiments, the length of the polypropylene fiber is 3mm to 9mm.

[0016] Another aspect of this application provides a method for preparing the above-mentioned crack-resistant radiation-proof mortar, which is as follows: after mixing all the components of the base component, water is added and stirred, and the amount of water added is 10% to 14% of the total weight of the base component; then steel fibers are added and stirred evenly to obtain mortar slurry.

[0017] In this crack-resistant radiation-shielding mortar, the cementitious material is a blend of high-belite sulfoaluminate cement and ordinary silicate cement. High-belite sulfoaluminate cement has low shrinkage, which helps reduce volume shrinkage during the hardening process, thus enhancing the dimensional stability of the mortar. Simultaneously, the blending with ordinary silicate cement helps ensure the stable development of the mortar's later strength. During the cement hydration stage, the active components in the penetrating crystallizing material react with cement hydration products and unhydrated cement particles. The reactants fill voids and microcracks generated during the cement plasticization stage, thereby enhancing density. Polypropylene fibers and steel fibers prevent early plastic cracking of the mortar, thus helping to improve the final tensile strength of the mortar and further enhancing its overall crack resistance.

[0018] In this application, the polypropylene fibers, characterized by their fine and randomly distributed structure, can form a dense network at the microscale, blocking the initiation of microcracks during the plastic stage and laying the foundation for the role of the steel fibers. The steel fibers, characterized by their coarseness, strength, and high elastic modulus, can bridge the ends of macroscopic cracks through mechanical interlocking forces with the cementitious material, thereby preventing further propagation of macroscopic cracks. Simultaneously, the interface between the polypropylene fibers and the cementitious material is flexible, absorbing some deformation energy; the interface between the steel fibers and the cementitious material is rigid, capable of transferring loads. The coexistence of flexible and rigid interfaces alleviates stress concentration at the interface, thus contributing to enhanced overall crack resistance of the mortar.

[0019] Barite sand and barite powder are used to increase the dry density of the mortar, thereby enhancing its shielding effect against radiation. At the same time, the compounded stabilizer is used to improve the mortar's resistance to bleeding and segregation, preventing the barite aggregate from settling due to its high density, thus enhancing the overall integrity of the radiation-shielding mortar. The reinforcing agent is used to accelerate the early strength development of the mortar, promote rapid solidification and hardening, shorten the plastic stage time, and thus improve the mortar's early resistance to stress deformation.

[0020] Compared with the prior art, this application has the following advantages and beneficial effects:

[0021] The crack-resistant radiation shielding mortar of this application has excellent radiation shielding performance, excellent dimensional stability (28-day dimensional change rate not exceeding 0.04%), and excellent mechanical strength. The excellent dimensional stability can reduce the volume shrinkage of the mortar during the hardening process, and the excellent mechanical strength, especially the tensile strength, can enhance the resistance to stress caused by volume shrinkage. Therefore, the crack-resistant radiation shielding mortar of this application can reduce or avoid cracking caused by volume shrinkage of the mortar. Detailed Implementation

[0022] The technical solutions and effects of this application will be clearly and completely described below with reference to the embodiments and comparative examples. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0023] Example 1

[0024] This embodiment of crack-resistant radiation-proof mortar includes steel fibers and 100 parts by weight of base components; wherein, the steel fibers account for 8% of the base components by weight; the base components include: 28 parts by weight of high belite sulfoaluminate cement, 7 parts by weight of silicate cement, 1.5 parts by weight of silica fume, 2 parts by weight of redispersible latex powder, 54 parts by weight of barite sand, 5 parts by weight of barite powder, 0.14 parts by weight of polycarboxylate superplasticizer, 0.08 parts by weight of defoamer, 0.05 parts by weight of stabilizer, 0.1 parts by weight of retarder, 0.08 parts by weight of reinforcing agent, 1.9 parts by weight of repair agent, and 0.15 parts by weight of polypropylene fiber.

[0025] Ground construction based on the above-mentioned crack-resistant radiation-shielding mortar includes:

[0026] After mixing the components of the base material, add water and stir. The amount of water added is 14% of the total weight of the base material. Then add steel fiber and stir evenly. Use the resulting mortar to apply the mortar to the ground with a thickness of 4cm.

[0027] The specific raw materials used in this embodiment are as follows:

[0028] Steel fiber: made of 304 stainless steel, with a diameter of 0.2mm and a length of 6mm;

[0029] High belite sulfoaluminate cement: grade strength 42.5, specific surface area greater than 400m² / kg;

[0030] Silicate cement: Strength grade P•Ⅰ 52.5;

[0031] Silica fume: particle size 0.1 μm~0.3 μm, specific surface area 20 m² / g~28 m² / g, SiO₂ content ≥90%;

[0032] Redispersible latex powder: Wacker 5010N vinyl acetate-ethylene copolymer latex powder;

[0033] Barite sand: particle size 0.08mm~1.15mm;

[0034] Barite powder: particle size 200-300 mesh;

[0035] Polycarboxylate superplasticizer: Shanghai Yingshan PC-400 powder polycarboxylate superplasticizer;

[0036] Defoamer: Hansen 770 DD type mineral oil powder defoamer;

[0037] Stabilizer: Hydroxypropyl methylcellulose ether with a viscosity of 400 mPa·s and polypropylene glycol monobutyl ether with a molecular weight of 1000 g / mol are mixed in a 1:1 weight ratio. The manufacturer of hydroxypropyl methylcellulose ether is Shandong Heda, and the manufacturer of polypropylene glycol monobutyl ether is Shandong Deshang Chemical.

[0038] Retarder: Sodium gluconate and tartaric acid are mixed in a weight ratio of 1:1;

[0039] Enhancer: Lithium sulfate;

[0040] Repair agent: Sika 265WT type powder penetrating crystallizing material, which is a cement-based penetrating crystallizing material;

[0041] Polypropylene fiber: 9mm in length.

[0042] Example 2

[0043] This embodiment of the crack-resistant radiation-proof mortar includes steel fibers and 100 parts by weight of base components; wherein, the steel fibers account for 9% by weight of the base components; the base components include: 30 parts by weight of high belite sulfoaluminate cement, 5 parts by weight of silicate cement, 2 parts by weight of silica fume, 2.6 parts by weight of redispersible latex powder, 52 parts by weight of barite sand, 6 parts by weight of barite powder, 0.25 parts by weight of polycarboxylate superplasticizer, 0.05 parts by weight of defoamer, 0.04 parts by weight of stabilizer, 0.2 parts by weight of retarder, 0.06 parts by weight of reinforcing agent, 1.7 parts by weight of repair agent, and 0.1 parts by weight of polypropylene fiber.

[0044] Ground construction based on the above-mentioned crack-resistant radiation-shielding mortar includes:

[0045] After mixing the components of the base material, add water and stir. The amount of water added is 12% of the total weight of the base material. Then add steel fiber and stir evenly. Use the resulting mortar to apply the mortar to the ground, with a thickness of 3cm.

[0046] The specific raw materials used in this embodiment are as follows:

[0047] Steel fiber: made of 316 stainless steel, with a diameter of 0.2mm and a length of 10mm;

[0048] High belite sulfoaluminate cement: grade strength 42.5, specific surface area greater than 400m² / kg;

[0049] Silicate cement: Strength grade P•Ⅱ 52.5;

[0050] Silica fume: particle size 0.1 μm~0.3 μm, specific surface area 20 m² / g~28 m² / g, SiO₂ content ≥90%;

[0051] Redispersible latex powder: Wacker 5010N vinyl acetate-ethylene copolymer latex powder;

[0052] Barite sand: particle size 0.08mm~1.15mm;

[0053] Barite powder: particle size 200-300 mesh;

[0054] Polycarboxylate superplasticizer: Shanghai Yingshan PC-400 powder polycarboxylate superplasticizer;

[0055] Defoamer: Hansen 770 DD type mineral oil powder defoamer;

[0056] Stabilizer: Hydroxypropyl methylcellulose ether with a viscosity of 400 mPa·s and polypropylene glycol monobutyl ether with a molecular weight of 1000 g / mol are mixed in a 1:1 weight ratio. The manufacturer of hydroxypropyl methylcellulose ether is Shandong Heda, and the manufacturer of polypropylene glycol monobutyl ether is Shandong Deshang Chemical.

[0057] Retarder: Sodium citrate and tartaric acid are mixed in a weight ratio of 1:1;

[0058] Enhancer: Lithium sulfate;

[0059] Repair agent: Sika 265WT type powder penetrating crystallizing material, which is a cement-based penetrating crystallizing material;

[0060] Polypropylene fiber: 6mm in length.

[0061] Example 3

[0062] This embodiment of crack-resistant radiation-proof mortar includes steel fibers and 100 parts by weight of base components; wherein, the steel fibers account for 10% of the base components by weight; the base components include: 32 parts by weight of high belite sulfoaluminate cement, 3 parts by weight of silicate cement, 1 part by weight of silica fume, 4 parts by weight of redispersible latex powder, 50 parts by weight of barite sand, 7 parts by weight of barite powder, 0.4 parts by weight of polycarboxylate superplasticizer, 0.1 parts by weight of defoamer, 0.01 parts by weight of stabilizer, 0.4 parts by weight of retarder, 0.04 parts by weight of reinforcing agent, 2 parts by weight of repair agent, and 0.05 parts by weight of polypropylene fiber.

[0063] Ground construction based on the above-mentioned crack-resistant radiation-shielding mortar includes:

[0064] After mixing the components of the base material, add water at a rate of 10% of the total weight of the base material. Then add steel fibers and mix thoroughly. Use the resulting mortar for ground construction with a thickness of 2cm.

[0065] The specific raw materials used in this embodiment are as follows:

[0066] Steel fiber: made of 304 stainless steel, with a diameter of 0.2mm and a length of 12mm;

[0067] High belite sulfoaluminate cement: grade strength 42.5, specific surface area greater than 400m² / kg;

[0068] Silicate cement: Strength grade P•Ⅰ 52.5;

[0069] Silica fume: particle size 0.1 μm~0.3 μm, specific surface area 20 m² / g~28 m² / g, SiO₂ content ≥90%;

[0070] Redispersible latex powder: Wacker 5010N vinyl acetate-ethylene copolymer latex powder;

[0071] Barite sand: particle size 0.08mm~1.15mm;

[0072] Barite powder: particle size 200-300 mesh;

[0073] Polycarboxylate superplasticizer: Shanghai Yingshan PC-400 powder polycarboxylate superplasticizer;

[0074] Defoamer: Hansen 770 DD type mineral oil powder defoamer;

[0075] Stabilizer: Hydroxypropyl methylcellulose ether with a viscosity of 400 mPa·s and polypropylene glycol monobutyl ether with a molecular weight of 1000 g / mol are mixed in a 1:1 weight ratio. The manufacturer of hydroxypropyl methylcellulose ether is Shandong Heda, and the manufacturer of polypropylene glycol monobutyl ether is Shandong Deshang Chemical.

[0076] Retarder: Sodium gluconate and tartaric acid are mixed in a weight ratio of 1:1;

[0077] Enhancer: Lithium sulfate;

[0078] Repair agent: Sika 265WT type powder penetrating crystallizing material, which is a cement-based penetrating crystallizing material;

[0079] Polypropylene fiber: 3mm in length.

[0080] Comparative Example 1

[0081] This comparative example of crack-resistant radiation-proof mortar includes steel fibers and 100 parts by weight of base components; wherein, the steel fibers account for 8% of the base components by weight; the base components include: 35 parts by weight of high-belite sulfoaluminate cement, 7 parts by weight of silicate cement, 1.5 parts by weight of silica fume, 2 parts by weight of redispersible latex powder, 47 parts by weight of barite sand, 5 parts by weight of barite powder, 0.14 parts by weight of polycarboxylate superplasticizer, 0.08 parts by weight of defoamer, 0.05 parts by weight of stabilizer, 0.1 parts by weight of retarder, 0.08 parts by weight of reinforcing agent, 1.9 parts by weight of repair agent, and 0.15 parts by weight of polypropylene fiber.

[0082] Ground construction based on the above-mentioned crack-resistant radiation-shielding mortar includes:

[0083] After mixing the components of the base material, add water and stir. The amount of water added is 14% of the total weight of the base material. Then add steel fiber and stir evenly. Use the resulting mortar to apply the mortar to the ground with a thickness of 2cm.

[0084] The specific raw materials used in this embodiment are as follows:

[0085] Steel fiber: made of 304 stainless steel, with a diameter of 0.2mm and a length of 6mm;

[0086] High belite sulfoaluminate cement: grade strength 42.5, specific surface area greater than 400m² / kg;

[0087] Silicate cement: Strength grade P•Ⅰ 52.5;

[0088] Silica fume: particle size 0.1 μm~0.3 μm, specific surface area 20 m² / g~28 m² / g, SiO₂ content ≥90%;

[0089] Redispersible latex powder: Wacker 5010N vinyl acetate-ethylene copolymer latex powder;

[0090] Barite sand: particle size 0.08mm~1.15mm;

[0091] Barite powder: particle size 200-300 mesh;

[0092] Polycarboxylate superplasticizer: Shanghai Yingshan PC-400 powder polycarboxylate superplasticizer;

[0093] Defoamer: Hansen 770 DD type mineral oil powder defoamer;

[0094] Stabilizer: Hydroxypropyl methylcellulose ether with a viscosity of 400 mPa·s and polypropylene glycol monobutyl ether with a molecular weight of 1000 g / mol are mixed in a 1:1 weight ratio. The manufacturer of hydroxypropyl methylcellulose ether is Shandong Heda, and the manufacturer of polypropylene glycol monobutyl ether is Shandong Deshang Chemical.

[0095] Retarder: Sodium gluconate and tartaric acid are mixed in a weight ratio of 1:1;

[0096] Enhancer: Lithium sulfate;

[0097] Repair agent: Sika 265WT type powder penetrating crystallizing material, which is a cement-based penetrating crystallizing material;

[0098] Polypropylene fiber: 9mm in length.

[0099] Comparative Example 2

[0100] This comparative example of crack-resistant radiation-proof mortar includes steel fibers and 100 parts by weight of base components; wherein, the steel fibers account for 5% of the base components by weight; the base components include: 30 parts by weight of high-belite sulfoaluminate cement, 5 parts by weight of silicate cement, 2 parts by weight of silica fume, 2.6 parts by weight of redispersible latex powder, 52 parts by weight of barite sand, 6 parts by weight of barite powder, 0.25 parts by weight of polycarboxylate superplasticizer, 0.05 parts by weight of defoamer, 0.04 parts by weight of stabilizer, 0.2 parts by weight of retarder, 0.06 parts by weight of reinforcing agent, 1.7 parts by weight of repair agent, and 0.1 parts by weight of polypropylene fiber.

[0101] Ground construction based on the above-mentioned crack-resistant radiation-shielding mortar includes:

[0102] After mixing the components of the base material, add water and stir. The amount of water added is 12% of the total weight of the base material. Then add steel fiber and stir evenly. Use the resulting mortar to apply the mortar to the ground, with a thickness of 3cm.

[0103] The specific raw materials used in this embodiment are as follows:

[0104] Steel fiber: made of 316 stainless steel, with a diameter of 0.2mm and a length of 10mm;

[0105] High belite sulfoaluminate cement: grade strength 42.5, specific surface area greater than 400m² / kg;

[0106] Silicate cement: Strength grade P•Ⅱ 52.5;

[0107] Silica fume: particle size 0.1 μm~0.3 μm, specific surface area 20 m² / g~28 m² / g, SiO₂ content ≥90%;

[0108] Redispersible latex powder: Wacker 5010N vinyl acetate-ethylene copolymer latex powder;

[0109] Barite sand: particle size 0.08mm~1.15mm;

[0110] Barite powder: particle size 200-300 mesh;

[0111] Polycarboxylate superplasticizer: Shanghai Yingshan PC-400 powder polycarboxylate superplasticizer;

[0112] Defoamer: Hansen 770 DD type mineral oil powder defoamer;

[0113] Stabilizer: Hydroxypropyl methylcellulose ether with a viscosity of 400 mPa·s and polypropylene glycol monobutyl ether with a molecular weight of 1000 g / mol are mixed in a 1:1 weight ratio. The manufacturer of hydroxypropyl methylcellulose ether is Shandong Heda, and the manufacturer of polypropylene glycol monobutyl ether is Shandong Deshang Chemical.

[0114] Retarder: Sodium citrate and tartaric acid are mixed in a weight ratio of 1:1;

[0115] Enhancer: Lithium sulfate;

[0116] Repair agent: Sika 265WT type powder penetrating crystallizing material, which is a cement-based penetrating crystallizing material;

[0117] Polypropylene fiber: 6mm in length.

[0118] Comparative Example 3

[0119] This comparative example of crack-resistant radiation-proof mortar includes steel fibers and 100 parts by weight of base components; wherein, the steel fibers account for 10% of the base components; the base components include: 32 parts by weight of high-belite sulfoaluminate cement, 3 parts by weight of silicate cement, 1 part by weight of silica fume, 4 parts by weight of redispersible latex powder, 50 parts by weight of barite sand, 7 parts by weight of barite powder, 0.4 parts by weight of polycarboxylate superplasticizer, 0.1 parts by weight of defoamer, 0.01 parts by weight of stabilizer, 0.4 parts by weight of retarder, 0.04 parts by weight of reinforcing agent, 2 parts by weight of repair agent, and 0.05 parts by weight of polypropylene fiber.

[0120] Ground construction based on the above-mentioned crack-resistant radiation-shielding mortar includes:

[0121] After mixing the components of the base material, add water and stir. The amount of water added is 16% of the total weight of the base material. Then add steel fiber and stir evenly. Use the resulting mortar to apply the mortar to the ground with a thickness of 2cm.

[0122] The specific raw materials used in this embodiment are as follows:

[0123] Steel fiber: made of 304 stainless steel, with a diameter of 0.2mm and a length of 12mm;

[0124] High belite sulfoaluminate cement: grade strength 42.5, specific surface area greater than 400m² / kg;

[0125] Silicate cement: Strength grade P•Ⅰ 52.5;

[0126] Silica fume: particle size 0.1 μm~0.3 μm, specific surface area 20 m² / g~28 m² / g, SiO₂ content ≥90%;

[0127] Redispersible latex powder: Wacker 5010N vinyl acetate-ethylene copolymer latex powder;

[0128] Barite sand: particle size 0.08mm~1.15mm;

[0129] Barite powder: particle size 200-300 mesh;

[0130] Polycarboxylate superplasticizer: Shanghai Yingshan PC-400 powder polycarboxylate superplasticizer;

[0131] Defoamer: Hansen 770 DD type mineral oil powder defoamer;

[0132] Stabilizer: Hydroxypropyl methylcellulose ether with a viscosity of 400 mPa·s and polypropylene glycol monobutyl ether with a molecular weight of 1000 g / mol are mixed in a 1:1 weight ratio. The manufacturer of hydroxypropyl methylcellulose ether is Shandong Heda, and the manufacturer of polypropylene glycol monobutyl ether is Shandong Deshang Chemical.

[0133] Retarder: Sodium gluconate and tartaric acid are mixed in a weight ratio of 1:1;

[0134] Enhancer: Lithium sulfate;

[0135] Repair agent: Sika 265WT type powder penetrating crystallizing material, which is a cement-based penetrating crystallizing material;

[0136] Polypropylene fiber: 3mm in length.

[0137] The mortars of Examples 1-3 and Comparative Examples 1-3 underwent performance tests, including flowability, lead equivalent, dry density, mechanical strength, and dimensional change rate. Flowability was tested according to GB / T 50448-2015 "Technical Specification for Application of Cement-Based Grouting Materials"; lead equivalent and dry density were tested according to JC / T 2676-2022 "Barium Sulfate Radiation-Shielding Mortar," where lead equivalent characterizes the radiation shielding performance of the mortar; a higher lead equivalent value indicates stronger radiation shielding performance. Mechanical strength and dimensional change rate were tested according to JC / T 985-2017 "Cement-Based Self-Leveling Mortar for Floors." The performance test data are listed in Table 1 below.

[0138] Table 1 Performance test data of mortars from Examples 1-3 and Comparative Examples 1-3

[0139] Performance indicators Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Initial flowability, mm 300 320 315 310 300 330 Lead equivalent, mmPb / mm 0.10 0.13 0.12 0.06 0.09 0.08 <![CDATA[Dry density, g / cm 3 > 2800 2900 2850 2650 2600 2700 24h flexural strength, MPa 6.1 6.8 7.3 6.1 4.8 5.4 24-hour compressive strength, MPa 44.4 41.5 45.3 37.6 28.6 30.1 28-day flexural strength, MPa 10.9 11.2 12.5 11.7 6.5 8.4 28-day compressive strength, MPa 65.4 66.8 68.5 68.1 50.3 51.6 28-day tensile strength, MPa 6.5 7.4 6.8 7.4 3.8 4.9 28-day bond strength, MPa 2.1 2.0 2.2 1.6 1.5 1.4 28d dimensional change rate, % 0.04 0.03 0.04 0.08 0.05 0.10

[0140] As shown in Table 1, the radiation-shielding mortars of Examples 1-3 meet the requirements for Type II radiation-shielding mortar in JC / T 2676-2022 "Barium Sulfate Radiation-Shielding Mortar," particularly exhibiting excellent dimensional stability with a 28-day dimensional change rate far below the required 0.15%. Furthermore, the radiation-shielding mortars of Examples 1-3 also demonstrate good workability. Although the 28-day dimensional change rate of the radiation-shielding mortars of Comparative Examples 1-3 is also far below the required 0.15%, their radiation shielding performance is lower than the aforementioned standard requirements.

[0141] In addition, the radiation-shielding mortars of Examples 1-3 have superior mechanical strength, especially excellent tensile strength, which helps to enhance the mortar's ability to resist deformation during the hardening process, thereby reducing or avoiding cracking during the hardening process.

[0142] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A crack-resistant radiation-shielding mortar, characterized in that: It includes steel fibers and 100 parts by weight of a base component, wherein the steel fibers constitute 8% to 10% by weight of the base component; The basic components include: 28-32 parts by weight of high-belite sulfoaluminate cement, 3-7 parts by weight of silicate cement, 1-2 parts by weight of silica fume, 2-4 parts by weight of redispersible latex powder, 50-54 parts by weight of barite sand, 5-7 parts by weight of barite powder, 0.14-0.4 parts by weight of polycarboxylate superplasticizer, 0.05-0.1 parts by weight of defoamer, 0.01-0.05 parts by weight of stabilizer, 0.1-0.4 parts by weight of retarder, 0.04-0.08 parts by weight of reinforcing agent, 1.7-2 parts by weight of repair agent, and 0.05-0.15 parts by weight of polypropylene fiber; the repair agent is a penetrating crystallizing material.

2. The crack-resistant radiation-shielding mortar as described in claim 1, characterized in that: The steel fiber is stainless steel fiber with a diameter of 0.18mm to 0.22mm and a length of 6mm to 12mm.

3. The crack-resistant radiation-shielding mortar as described in claim 1, characterized in that: The silica fume has a particle size of 0.1 micrometers to 0.3 micrometers, a specific surface area of ​​20 m² / g to 28 m² / g, and a SiO2 content of ≥90%.

4. The crack-resistant radiation-shielding mortar as described in claim 1, characterized in that: The redispersible latex powder is a vinyl acetate-ethylene copolymer latex powder.

5. The crack-resistant radiation-shielding mortar as described in claim 1, characterized in that: The barite sand has a particle size of 0.08 mm to 1.15 mm; and the barite powder has a particle size of 200 mesh to 300 mesh.

6. The crack-resistant radiation-shielding mortar as described in claim 1, characterized in that: The stabilizer is a mixture of hydroxypropyl methylcellulose ether and polypropylene glycol monobutyl ether in a 1:1 weight ratio.

7. The crack-resistant radiation-shielding mortar as described in claim 1, characterized in that: The retarder is a mixture of sodium gluconate or sodium citrate and tartaric acid in a weight ratio of 1:

1.

8. The crack-resistant radiation-shielding mortar as described in claim 1, characterized in that: The reinforcing agent is lithium sulfate or lithium carbonate.

9. The crack-resistant radiation-shielding mortar as described in claim 1, characterized in that: The polypropylene fiber has a length of 3mm to 9mm.

10. The method for preparing crack-resistant radiation-shielding mortar as described in any one of claims 1 to 9, characterized in that: Mix all the components of the base component and add water, the amount of water being 10% to 14% of the total weight of the base component; then add steel fiber and stir evenly.