Early-strength high-performance sleeve grouting material as well as preparation method and application thereof

Abstract

The invention relates to an early-strength high-performance sleeve grouting material as well as a preparation method and application thereof. The early-strength high-performance sleeve grouting material is prepared from cement, silica fume, mineral powder, steel fibers, quartz sand, tailing sand, a water reducing agent, a defoaming agent, a dispersing agent and water. The invention also provides a preparation method of the early-strength high-performance sleeve grouting material, which comprises the following steps: carrying out dry mixing on the cement, the silica fume, the mineral powder, the fine aggregate, the water reducing agent and the defoaming agent to obtain sleeve grouting material dry powder; mixing a dispersing agent with water to obtain a mixture; and mixing the sleeve grouting material dry powder, the mixture and steel fibers to obtain the early-strength high-performance sleeve grouting material. The problems that an existing sleeve grouting material is complex in component and low in stability are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of grouting materials, in particular to a high-performance early-strength sleeve grouting material, a preparation method and application thereof. BACKGROUND

[0002] In the field of prefabricated buildings, effective connection between components is the key to ensuring the safety and reliability of the structure. The grouting sleeve connection technology has become the mainstream connection method in prefabricated buildings due to its simple operation, excellent mechanical properties, low cost, green environmental protection, and wide applicability. The technology connects prefabricated components through a grouting sleeve connector, which is composed of a sleeve, steel bars, and grouting material. The performance of the grouting material plays a decisive role in the overall mechanical properties of the connector. Therefore, improving the mechanical properties, operational properties, and bonding properties with steel bars of the sleeve grouting material is of great significance to the development of prefabricated buildings.

[0003] However, there are some problems in the prior art. For example, in a low-temperature environment, the hydration process of conventional sleeve grouting material is limited, making it difficult to meet the construction requirements. To solve this problem, a large amount of additives (such as early-strength agents, retarders, water-reducing agents, defoaming agents, expanding agents, and antifreeze agents) are usually added, which not only leads to complex composition and increases the instability of the system, but also makes the material need further modification (such as adding phase change materials), making the production process complex and the cost high.

[0004] In addition, another common method is to incorporate industrial waste to reduce costs. For example, an existing publicly disclosed industrial waste-containing sleeve grouting material contains cement, silica fume, fly ash, calcium carbide slag, white mud slag, composite expanding agent, mixed sand, water-reducing agent, defoaming agent, and other components. Although several industrial solid wastes are fully utilized, the formulation cost is significantly reduced compared to existing technologies. However, the addition of industrial solid waste has a significant impact on the late strength of the material, and the stability fluctuates greatly, thereby limiting its widespread application in actual engineering. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a high-performance early-strength sleeve grouting material, a preparation method and application thereof, to solve the problems of complex composition and low stability of existing sleeve grouting materials.

[0006] To achieve the above-mentioned purpose, the technical solutions adopted by the present application are as follows: A high-performance early-strength sleeve grouting material is composed of cement, silica fume, mineral powder, steel fiber, quartz sand, tailings sand, water-reducing agent, defoaming agent, dispersant, and water.

[0007] According to the above technical means, by skillfully using cement, silica fume, mineral powder, steel fiber, quartz sand, tailings sand, water reducing agent, defoaming agent, dispersant and water as raw materials, good synergies are shown between the components. Not only the traditional complex expansion agent, early strength agent and other additives are abandoned, the complex interaction between the components is greatly reduced, the uncontrollable chemical reaction risk caused by too many additives is effectively avoided, and the stability of the sleeve grouting material is significantly enhanced. At the same time, the reasonable matching and optimization of the basic components make the grouting material not only meet the key performance indicators such as early strength, but also solve the problems of complex composition and poor stability of the existing sleeve grouting material, realize the dual optimization of performance and stability, and provide more reliable and efficient grouting material for engineering application.

[0008] Preferably, the water-binder ratio of the early-strength high-performance sleeve grouting material is 0.23-0.25.

[0009] Preferably, the water-binder ratio of the early-strength high-performance sleeve grouting material is 0.23-0.25.

[0010] Preferably, the cement is selected from ordinary Portland cement and / or sulphoaluminate cement.

[0011] Preferably, the cement is selected from ordinary Portland cement and sulphoaluminate cement.

[0012] Preferably, the cement is composed of 1000-1200 parts of ordinary Portland cement and 200-300 parts of sulphoaluminate cement.

[0013] By selecting cement composed of ordinary Portland cement and sulphoaluminate cement, and combining with low water-binder ratio design, the generation of shrinkage cracks and strength reversal phenomenon is effectively inhibited, and the stability of the hydration process is significantly improved.

[0014] Preferably, the strength grade of the ordinary Portland cement is 42.5, and the strength grade of the sulphoaluminate cement is 52.5.

[0015] Preferably, the silica fume is a dark gray powder, the SiO2 content in the silica fume is 94.3%, the average particle size is 0.1-0.3um, and the specific surface area is 18-24m 2 / g.

[0016] Preferably, the mineral powder is S105 grade mineral powder, and the specific surface area of the S105 grade mineral powder is 500-520m 2 / kg, and the burning vector is 0.2%.

[0017] By selecting the specific surface area of the mineral powder to be 500-520m 2 / kg, S105 grade ore powder with a burning vector of 0.2%, significantly improving the performance of the grouting material. Among them, the ultra-high specific surface area can accelerate the hydration reaction process, making the reaction more complete and faster. Ultra-fine particles can effectively fill the voids between cement particles, significantly reducing porosity, thereby significantly improving the density of the slurry and enhancing the impermeability and durability of the grouting material. At the same time, the low burning vector characteristic can effectively avoid the failure of the water reducing agent, ensuring good dispersibility of the slurry, thereby ensuring the work performance and fluidity of the grouting material.

[0018] Preferably, the steel fiber is selected from copper-plated steel fiber with a diameter of 0.18-0.22 mm and a length of 10-13 mm, and a tensile strength ≥2400 MPa.

[0019] By selecting copper-plated steel fiber with a diameter of 0.18-0.22 mm and a length of 10-13 mm, and a tensile strength ≥2400 MPa, the comprehensive performance of the grouting material is significantly improved. Among them, the fine and short fiber size can effectively reduce the flow resistance of the slurry, thereby ensuring the fluidity of the grouting material. High-strength fibers can quickly provide early strength support for the grouting material within 24 hours. In addition, the copper layer on the surface of the fiber combined with its high tensile strength can significantly improve the fatigue resistance and durability of the material.

[0020] Preferably, the quartz sand is selected from machine-made quartz sand, which includes three particle sizes, 20-40 mesh, 40-70 mesh, and 70-120 mesh, and the ratio of the 20-40 mesh, 40-70 mesh, and 70-120 mesh particle sizes is 4:3:2.

[0021] Preferably, the tailings sand is a waste residue after polishing of iron ore, which is yellow gravel with a particle size of 70-120 mesh.

[0022] Preferably, the tailings sand is a waste residue of limonite beneficiation, which includes, by mass percentage, 60-70% SiO2, 6-10% TFe, 3-5% Al2O3, trace amounts of calcium and magnesium carbonates, and impurities. Among them, TFe represents total iron content, mainly in the form of FeO(OH).

[0023] Preferably, the water reducing agent is selected from polycarboxylic acid water reducing agent, which is a white powder with a water-reducing rate ≥32% and a pH value of 6-7.

[0024] Preferably, the defoaming agent is selected from polyether defoaming agent, which is a white powder with a pH value of 6-8.

[0025] Preferably, the dispersant is selected from polycarboxylic acid sodium salt dispersant, which is a colorless transparent liquid with a pH value of 6-8 and a viscosity of 500 Pa·s.

[0026] Preferably, the cement, silica fume, mineral powder, steel fiber, quartz sand, tailings sand, water reducing agent, defoaming agent and dispersant are 1250-1500 parts, 80-120 parts, 260-300 parts, 20-50 parts, 1100-1300 parts, 500-600 parts, 15-20 parts, 1-2 parts, 1-3 parts by weight percentage.

[0027] The application also provides a preparation method of the early-strength high-performance sleeve grouting material, comprising the following steps: dry-mixing cement, silica fume, mineral powder, quartz sand, tailings sand, water reducing agent and defoaming agent to obtain sleeve grouting material dry powder; mixing the dispersant with water to obtain a mixture; mixing the sleeve grouting material dry powder, the mixture and steel fiber to obtain the early-strength high-performance sleeve grouting material.

[0028] Through the step-by-step mixing and steel fiber post-doping process design, the performance and stability of the grouting material are significantly improved. First, cement, silica fume, mineral powder, quartz sand, tailings sand, water reducing agent and defoaming agent are dry-mixed to form a uniform dry powder, ensuring that the solid components are fully mixed without water interference, laying a foundation for the subsequent steps. Then, the dispersant is pre-mixed with water to ensure that the dispersant is fully dissolved and has the best dispersion effect. Finally, the dry powder, the liquid mixture and the steel fiber are mixed to obtain the grouting material. The post-doping of steel fiber effectively prevents the clustering of steel fiber during the mixing process and the resulting grout stratification problem, ensuring that the steel fiber is uniformly distributed in the grout, thereby ensuring the stability of the process and improving the uniformity, mechanical properties and durability of the grouting material, providing high-quality grouting material for engineering applications.

[0029] Preferably, the prepared early-strength high-performance sleeve grouting material has a fluidity of ≥330 mm and a 24-hour compressive strength of ≥50 MPa.

[0030] The application also provides an application of the early-strength high-performance sleeve grouting material in a grouting material for steel bar connection.

[0031] The application has the following advantages: The early-strength high-performance sleeve grouting material of the application realizes the early-strength property of grouting material with a 24-hour compressive strength of ≥50 MPa under ultra-low water consumption by compounding ordinary Portland cement and sulphoaluminate cement and precisely controlling the water-binder ratio; meanwhile, with the synergistic effect of the defoaming agent and the dispersant, the bubble defects of the low water-binder ratio system are effectively inhibited, the grout fluidity is ≥330 mm, and the problems of easy bleeding and poor fluidity of early-strength materials are solved.

[0032] The early-strength high-performance sleeve grouting material of the application innovatively uses tailings sand to replace natural aggregate, absorbs more than 30% of mining solid waste, reduces the exploitation load of natural sandstone; uses S105 grade mine powder and silica fume double industrial byproducts, the solid waste content in the cementing material is more than 25%, significantly reduces the cement consumption, reduces the carbon emission by more than 15%, and meets the core indicators of green building materials.

[0033] The early-strength high-performance sleeve grouting material of the application forms a reinforced framework through steel fibers and mechanism quartz sand, the crack resistance is improved by more than 40%; the application of tailings sand and industrial byproducts reduces the raw material cost by 18%~25%, while ensuring high performance and low cost.

[0034] The preparation method of the early-strength high-performance sleeve grouting material of the application is mixed at room temperature, has the advantages of high flow state, micro-expansion, fast early strength development and high later strength, fully utilizes industrial solid waste, has good environmental and economic benefits, makes up for the defects of traditional grouting materials, continues the green and sustainable development concept in the field of building engineering, promotes the development of prefabricated buildings, and has popularization and application value in the field of grouting material technology. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is the corresponding physical picture when the flow degree initial value of the grouting material prepared in Example 2 is measured; Figure 2 It is the corresponding physical picture when the flow degree initial value of the grouting material prepared in Example 3 is measured; Figure 3 It is the flow degree initial value and flow degree 30min retention value result picture of the grouting material prepared in Example 1 to Example 5; Figure 4 It is the compressive strength determination result picture of the grouting material; Figure 5 It is the flexural strength determination result picture of the grouting material; Figure 6 It is the structure schematic view of the vertical expansion rate device; Figure 7 It is the SEM picture (1um) of the corresponding test piece of the grouting material prepared in Example 3 after curing; Figure 8 It is the SEM picture (10um) of the corresponding test piece of the grouting material prepared in Example 3 after curing; Figure 9 It is the SEM picture (100um) of the corresponding test piece of the grouting material prepared in Example 3 after curing; Among them, 1 is a steel backing plate; 2 is a micrometer stand (magnetic type); 3 is a micrometer; 4 is a glass plate; 5 is a test mold. DETAILED DESCRIPTION

[0036] The advantages and effects of the present application can be easily understood by those skilled in the art from the description disclosed herein. The present application can also be implemented or applied by other different specific embodiments, and various modifications or changes can be made to the details in the description based on different views and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, but not for limiting the protection scope of the present application.

[0037] The specific techniques or conditions not mentioned in the specific embodiments are carried out according to the techniques or conditions described in the literature in the art or according to the product instructions. The reagents or instruments not mentioned by the manufacturer are all conventional products that can be obtained by purchase.

[0038] The raw materials used in the following examples are as follows: The ordinary portland cement is P·O42.5 of Hailuo; The sulphate cement is Yunhe 52.5 grade R.SAC; The silica fume has a SiO2content of 94.3%, an average particle size of 0.1~0.3um, and a specific surface area of 18~24m 2 / g; The specific surface area of the S105 grade mineral powder is 500~520m 2 / kg, and the burning vector is 0.2%. The S105 grade mineral powder includes, in terms of mass parts, 20.28 parts of SiO2, 16.73 parts of Al2O3, 2.49 parts of Fe2O3, 39.17 parts of CaO, 7.01 parts of MgO, and inevitable impurities; The fine aggregate is machine-made quartz sand and tailings sand. The machine-made quartz sand includes three particle sizes, i.e., 20~40 mesh, 40~70 mesh and 70~120 mesh, and the ratio of the particle sizes is 4:3:2. The tailings sand is the waste residue after polishing of iron ore, and the waste residue is yellow gravel with a particle size of 70~120 mesh. The waste residue after polishing of iron ore is brown iron ore beneficiation waste residue, which includes, in terms of mass percentage, 70% of SiO2, 10% of TFe, 5% of Al2O3, trace amounts of calcium magnesium carbonate and impurities. Among them, TFe represents the total iron content, mainly in the form of FeO(OH).

[0039] The polycarboxylic acid water reducing agent and the polyether defoaming agent are commercially available in Shandong Fukui. The fiber diameter of the copper-plated steel fiber is 0.18~0.22mm, the length is 10~13mm, and the tensile strength is ≥2400MPa; The dispersant is Guangdong Zhonglian Federal DK-033 polycarboxylic acid sodium salt dispersant, colorless transparent liquid, pH value is 6-8, viscosity is 500 Pa·s.

[0040] Example 1 A preparation method of an early-strength high-performance sleeve grouting material, The early-strength high-performance sleeve grouting material is composed of 1152 parts of ordinary Portland cement, 270 parts of sulphoaluminate cement, 108 parts of silica fume, 270 parts of S105 grade mineral powder, 30 parts of copper-plated steel fiber, 1620 parts of machine-made quartz sand, 180 parts of tailings sand, 18 parts of polycarboxylic acid water reducing agent, 1.8 parts of polyether defoaming agent, 1.8 parts of polycarboxylic acid sodium salt dispersant, and water, and the water-binder ratio is 0.24. The preparation method comprises the following steps: S1, dry mixing and stirring the ordinary Portland cement, the sulphoaluminate cement, the silica fume, the mineral powder, the fine aggregate, the polycarboxylic acid water reducing agent, and the polyether defoaming agent to obtain sleeve grouting material dry powder; S2, stirring and fully mixing the polycarboxylic acid sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure conditions, slowly adding the sleeve grouting material dry powder obtained in S1 and the mixture obtained in S2 into a stirring machine, and simultaneously uniformly adding the copper-plated steel fiber into the stirring machine to stir for 3 minutes to obtain the early-strength high-performance sleeve grouting material for steel bar connection.

[0041] Example 2 A preparation method of an early-strength high-performance sleeve grouting material, The early-strength high-performance sleeve grouting material is composed of 1152 parts of ordinary Portland cement, 270 parts of sulphoaluminate cement, 108 parts of silica fume, 270 parts of S105 grade mineral powder, 30 parts of copper-plated steel fiber, 1440 parts of machine-made quartz sand, 360 parts of tailings sand, 18 parts of polycarboxylic acid water reducing agent, 1.8 parts of polyether defoaming agent, 1.8 parts of polycarboxylic acid sodium salt dispersant, and water, and the water-binder ratio is 0.24. The preparation method comprises the following steps: S1, dry mixing and stirring the ordinary Portland cement, the sulphoaluminate cement, the silica fume, the mineral powder, the fine aggregate, the polycarboxylic acid water reducing agent, and the polyether defoaming agent to obtain sleeve grouting material dry powder; S2, stirring and fully mixing the polycarboxylic acid sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure conditions, slowly adding the sleeve grouting material dry powder obtained in S1 and the mixture obtained in S2 into a stirring machine, and simultaneously uniformly adding the copper-plated steel fiber into the stirring machine to stir for 3 minutes to obtain the early-strength high-performance sleeve grouting material for steel bar connection.

[0042] Example 3 A preparation method of early-strength high-performance sleeve grouting material, The early-strength high-performance sleeve grouting material is composed of 1152 parts of ordinary Portland cement, 270 parts of sulphoaluminate cement, 108 parts of silica fume, 270 parts of S105 grade mineral powder, 30 parts of copper-plated steel fiber, 1260 parts of machine-made quartz sand, 540 parts of tailings sand, 18 parts of polycarboxylic acid water reducing agent, 1.8 parts of polyether defoaming agent, 1.8 parts of polycarboxylic acid sodium salt dispersant, and water, and the water-binder ratio is 0.24. The preparation method comprises the following steps: S1, uniformly dry mixing and stirring ordinary Portland cement, sulphoaluminate cement, silica fume, mineral powder, fine aggregate, polycarboxylic acid water reducing agent, and polyether defoaming agent to obtain sleeve grouting dry powder; S2, uniformly stirring and fully mixing polycarboxylic acid sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure, slowly adding the sleeve grouting dry powder obtained in S1 and the mixture obtained in S2 into a stirring machine, and uniformly adding copper-plated steel fiber into the stirring machine to stir for 3 minutes to obtain early-strength high-performance sleeve grouting material for steel bar connection.

[0043] Example 4 A preparation method of early-strength high-performance sleeve grouting material, The early-strength high-performance sleeve grouting material is composed of 1152 parts of ordinary Portland cement, 270 parts of sulphoaluminate cement, 108 parts of silica fume, 270 parts of S105 grade mineral powder, 30 parts of copper-plated steel fiber, 1260 parts of machine-made quartz sand, 540 parts of tailings sand, 18 parts of polycarboxylic acid water reducing agent, 1.8 parts of polyether defoaming agent, 1.8 parts of polycarboxylic acid sodium salt dispersant, and water, and the water-binder ratio is 0.24. The preparation method comprises the following steps: S1, uniformly dry mixing and stirring ordinary Portland cement, sulphoaluminate cement, silica fume, mineral powder, fine aggregate, polycarboxylic acid water reducing agent, and polyether defoaming agent to obtain sleeve grouting dry powder; S2, uniformly stirring and fully mixing polycarboxylic acid sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure, slowly adding the sleeve grouting dry powder obtained in S1 and the mixture obtained in S2 into a stirring machine, and uniformly adding copper-plated steel fiber into the stirring machine to stir for 3 minutes to obtain early-strength high-performance sleeve grouting material for steel bar connection.

[0044] Example 5 A preparation method of early-strength high-performance sleeve grouting material, The early-strength high-performance sleeve grouting material is composed of 1152 parts of ordinary Portland cement, 270 parts of sulphoaluminate cement, 108 parts of silica fume, 270 parts of S105 grade mineral powder, 30 parts of copper-plated steel fiber, 900 parts of machine-made quartz sand, 900 parts of tailing sand, 18 parts of polycarboxylic acid water reducing agent, 1.8 parts of polyether defoaming agent, 1.8 parts of polycarboxylic acid sodium salt dispersant and water, and the water-binder ratio is 0.24. The preparation method comprises the following steps: S1, uniformly dry mixing and stirring ordinary Portland cement, sulphoaluminate cement, silica fume, mineral powder, fine aggregate, polycarboxylic acid water reducing agent and polyether defoaming agent to obtain sleeve grouting dry powder; S2, uniformly stirring and fully mixing polycarboxylic acid sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure, slowly adding the sleeve grouting dry powder obtained in S1 and the mixture obtained in S2 into a stirring machine, and uniformly adding copper-plated steel fiber into the stirring machine to stir for 3 minutes to obtain the early-strength high-performance sleeve grouting material for steel bar connection.

[0045] Example 6 A preparation method of an early-strength high-performance sleeve grouting material, The early-strength high-performance sleeve grouting material is composed of 1152 parts of ordinary Portland cement, 270 parts of sulphoaluminate cement, 108 parts of silica fume, 270 parts of S105 grade mineral powder, 30 parts of copper-plated steel fiber, 1260 parts of machine-made quartz sand, 540 parts of tailing sand, 18 parts of polycarboxylic acid water reducing agent, 1.8 parts of polyether defoaming agent, 1.8 parts of polycarboxylic acid sodium salt dispersant and water, and the water-binder ratio is 0.23. The preparation method comprises the following steps: S1, uniformly dry mixing and stirring ordinary Portland cement, sulphoaluminate cement, silica fume, mineral powder, fine aggregate, polycarboxylic acid water reducing agent and polyether defoaming agent to obtain sleeve grouting dry powder; S2, uniformly stirring and fully mixing polycarboxylic acid sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure, slowly adding the sleeve grouting dry powder obtained in S1 and the mixture obtained in S2 into a stirring machine, and uniformly adding copper-plated steel fiber into the stirring machine to stir for 3 minutes to obtain the early-strength high-performance sleeve grouting material for steel bar connection.

[0046] Example 7 A preparation method of an early-strength high-performance sleeve grouting material, The early-strength high-performance sleeve grouting material is composed of ordinary Portland cement 1152 parts, sulphoaluminate cement 270 parts, silica fume 108 parts, S105 grade mineral powder 270 parts, copper-plated steel fiber 30 parts, machine-made quartz sand 1260 parts, tailing sand 540 parts, polycarboxylic acid water reducing agent 18 parts, polyether defoaming agent 1.8 parts, polycarboxylic acid sodium salt dispersant 1.8 parts and water, and the water-binder ratio is 0.25. The preparation method comprises the following steps: S1, uniformly dry-mixing and stirring ordinary Portland cement, sulphoaluminate cement, silica fume, mineral powder, fine aggregate, polycarboxylic acid water reducing agent and polyether defoaming agent to obtain sleeve grouting dry powder; S2, uniformly stirring and fully mixing polycarboxylic acid sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure, slowly adding the sleeve grouting dry powder obtained in S1 and the mixture obtained in S2 into a stirrer, and uniformly adding copper-plated steel fiber into the stirrer to stir for 3 minutes to obtain the early-strength high-performance sleeve grouting material for steel bar connection.

[0047] Comparative Example 1 A preparation method of a conventional sleeve grouting material, The conventional sleeve grouting material is composed of ordinary Portland cement 1422 parts, sulphoaluminate cement 0 part, silica fume 108 parts, S105 grade mineral powder 270 parts, copper-plated steel fiber 30 parts, machine-made quartz sand 1260 parts, tailing sand 540 parts, polycarboxylic acid water reducing agent 36 parts, polyether defoaming agent 2.7 parts, polycarboxylic acid sodium salt dispersant 1.8 parts and water, and the water-binder ratio is 0.24. The preparation method comprises the following steps: S1, uniformly dry-mixing and stirring ordinary Portland cement, sulphoaluminate cement, silica fume, mineral powder, fine aggregate, polycarboxylic acid water reducing agent and polyether defoaming agent to obtain sleeve grouting dry powder; S2, uniformly stirring and fully mixing polycarboxylic acid sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure, slowly adding the sleeve grouting dry powder obtained in S1 and the mixture obtained in S2 into a stirrer, and uniformly adding copper-plated steel fiber into the stirrer to stir for 3 minutes to obtain the early-strength high-performance sleeve grouting material for steel bar connection.

[0048] Comparative Example 2 A preparation method of a conventional sleeve grouting material, The conventional sleeve grouting material is composed of ordinary Portland cement 1152 parts, sulphoaluminate cement 270 parts, silica fume 108 parts, S105 grade mineral powder 270 parts, copper-plated steel fiber 30 parts, machine-made quartz sand 1260 parts, tailing sand 540 parts, polycarboxylic acid water reducing agent 1.8 parts, polyether defoaming agent 1.8 parts, polycarboxylic acid sodium salt dispersant 0 parts and water, and the water-binder ratio is 0.24. The preparation method comprises the following steps: S1, uniformly dry mixing and stirring ordinary Portland cement, sulphoaluminate cement, silica fume, mineral powder, fine aggregate, polycarboxylate superplasticizer and polyether defoaming agent to obtain sleeve grouting material dry powder; S2, uniformly stirring and fully mixing polycarboxylate sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure conditions, slowly adding the sleeve grouting material dry powder obtained in S1 and the mixture obtained in S2 into a stirrer, and uniformly adding copper-plated steel fibers into the stirrer to stir for 3 minutes to obtain a conventional sleeve grouting material.

[0049] Comparative Example 3 A preparation method of a conventional sleeve grouting material, The conventional sleeve grouting material is composed of 1152 parts of ordinary Portland cement, 270 parts of sulphoaluminate cement, 108 parts of silica fume, 270 parts of S105 grade mineral powder, 30 parts of copper-plated steel fibers, 1800 parts of machine-made quartz sand, 0 parts of tailings sand, 1.8 parts of polycarboxylate superplasticizer, 1.8 parts of polyether defoaming agent, 3.6 parts of polycarboxylate sodium salt dispersant and water, and the water-binder ratio is 0.24. The preparation method comprises the following steps: S1, uniformly dry mixing and stirring ordinary Portland cement, sulphoaluminate cement, silica fume, mineral powder, fine aggregate, polycarboxylate superplasticizer and polyether defoaming agent to obtain sleeve grouting material dry powder; S2, uniformly stirring and fully mixing polycarboxylate sodium salt dispersant with water to obtain a mixture; S3, under normal temperature and pressure conditions, slowly adding the sleeve grouting material dry powder obtained in S1 and the mixture obtained in S2 into a stirrer, and uniformly adding copper-plated steel fibers into the stirrer to stir for 3 minutes to obtain a conventional sleeve grouting material.

[0050] Detection analysis 1) Flowability test The grouting materials prepared in Examples 1 to 7 and Comparative Examples 1 to 3 were respectively subjected to flowability test.

[0051] A.1 The flowability test shall comply with the following provisions: a) The cement-based grouting material shall be mixed with a stirrer meeting the requirements of JC / T 681; b) The truncated cone mold shall meet the requirements of GB / T 2419, with the size of lower inner diameter 100 mm±0.5mm, upper inner diameter 70 mm±0.5mm, and height 60 mm±0.5mm; c) The glass plate shall be 500mm×500mm in size and shall be placed horizontally; d) A steel ruler shall be used for measurement, with the accuracy of 1mm.

[0052] A.2 The flowability test shall be carried out according to the following steps: a) Weigh 1800 g of cementitious grout material, accurate to 5 g; weigh the mixing water according to the water requirement of the product design (instruction), accurate to 1 g.

[0053] b) Wet the mixing pot and stirring blade, but no clear water. Pour the cementitious grout material into the mixing pot, start the mixer, and add the mixing water, which should be completed within 10 s.

[0054] c) Stir for 240 s according to the setting program of the cement mortar mixer.

[0055] d) Wet the glass plate and the inner wall of the truncated cone round mold, but no clear water; place the truncated cone round mold in the middle of the glass plate.

[0056] e) Pour the cementitious grout slurry into the truncated cone round mold until the slurry is level with the upper opening of the truncated cone round mold; slowly lift the truncated cone round mold to allow the slurry to flow freely without disturbance until it stops.

[0057] f) Measure the maximum spread diameter of the slurry and the diameter perpendicular to it, calculate the average value to 1 mm, and take it as the initial value of the flowability; the above stirring and measurement process should be completed within 6 min.

[0058] g) Put the slurry on the glass plate into the mixing pot and take measures to prevent evaporation of the slurry moisture. At 30 min after adding water, test the slurry in the mixing pot according to steps c) to f) to determine the 30 min retention value of the flowability.

[0059] The flowability test results are shown in Table 1, Figure 1 , Figure 2 and Figure 3 .

[0060] Table 1 is the flowability test results 2) Compression and flexural tests B.1 The compression strength test shall comply with the following provisions: a) The compression strength test specimen shall be a prism with dimensions of 40 mm x 40 mm x 160 mm; b) The compression strength test shall be carried out in accordance with the relevant provisions of GB / T 17671.

[0061] B.2 The compression strength test shall be carried out according to the following steps: a) Weigh 1800 g of cementitious grout material, accurate to 5 g; weigh the mixing water according to the water requirement of the product design (instruction), accurate to 1 g.

[0062] b) Mix the cementitious grout material as specified.

[0063] c) Pour the grout into the mould until the top edge of the mould is level with the top surface of the grout. Do not vibrate the mould during moulding. The mixing and moulding process should be completed within 6 minutes and the mould should be covered immediately after casting.

[0064] d) After 2 hours, remove the mould with the grout from the moulding room and place it in the curing chamber.

[0065] e) The test for compressive strength shall be carried out in accordance with the relevant provisions of GB / T 17671.

[0066] f) Calculation and presentation of results The average of the six compressive strength test values obtained on a set of three prisms is the test result. If one of the six test values is more than ±10% of the average of the six, this result is discarded and the average of the remaining five is the result. If one of the five test values is more than ±10% of the average of the five, the set of results is discarded. If two or more of the six test values are more than ±10% of the average of the six, the set of results is discarded.

[0067] The individual compressive strength result is accurate to 0.1 MPa and the arithmetic mean is accurate to 0.1 MPa.

[0068] B.2 The test for flexural strength shall comply with the following provisions: The test specimen for flexural strength shall be a prism of dimensions 40 mm x 40 mm x 160 mm;b) The test for flexural strength shall be carried out in accordance with the relevant provisions of GB / T 17671.

[0069] b) Weigh 1800 g of cementitious grout material, accurate to 5 g; weigh the water for mixing according to the water requirement of the product design (instruction), accurate to 1 g.

[0070] b) Mix the cementitious grout material as specified.

[0071] c) Pour the grout into the mould until the top edge of the mould is level with the top surface of the grout. Do not vibrate the mould during moulding. The mixing and moulding process should be completed within 6 minutes and the mould should be covered immediately after casting.

[0072] d) After 2 hours, remove the mould with the grout from the moulding room and place it in the curing chamber.

[0073] e) The test for flexural strength shall be carried out in accordance with the relevant provisions of GB / T 17671.

[0074] The specific test steps are as follows: Place one side of the test body on the support cylinder of the testing machine, with the long axis of the test body perpendicular to the support cylinder. Apply a load perpendicularly to the opposite side of the prism at a rate of 50 N / s ± 10 N / s through the loading cylinder until the prism breaks.

[0075] Keep the two half-prisms in a wet state until the compression test.

[0076] The bending strength is calculated according to Formula (I): In Formula (I), R represents the bending strength, in units of megaPascal (MPa); F represents the load applied to the middle of the prism when it breaks, in units of Newton (N); L represents the distance between the support cylinders, in units of millimeter (mm); and b represents the side length of the square cross section of the prism, in units of millimeter (mm).

[0077] Calculation and representation of results The average of a set of three prism bending results is taken as the test result. When one of the three strength values exceeds the average by +10%, it should be excluded and the average taken as the bending strength test result; when two of the three strength values exceed the average by +10%, the remaining one is taken as the bending strength result.

[0078] The individual bending strength result is accurate to 0.1 MPa, and the arithmetic mean is accurate to 0.1 MPa.

[0079] The compression and bending test results are shown in Table 2, Figure 4 and Figure 5 .

[0080] Table 2 shows the compression and bending strength test results 3) Vertical expansion rate test C.1 Basic requirements for contact measurement of vertical expansion rate C.1.1 The testing instrument tools should meet the following requirements: a) dial gauge: range 10 mm; b) dial gauge stand: magnetic stand; c) glass plate: length 140 mm x width 80 mm x thickness 5 mm; d) test mold: the assembly joint of the 100 mm x 100 mm x 100 mm cubic test mold should be filled with butter and should not leak water; e) spatula: width 60 mm, length 160 mm; f) tamping plate: can be replaced by a steel saw blade; g) steel backing plate: length 250 mm x width 250 mm x thickness 15 mm, ordinary steel plate.

[0081] C.1.2 The schematic diagram of the vertical expansion rate device is shown in Figure 6 The instrument installation should meet the following requirements: a) Steel base plate: surface is flat, and is placed horizontally on the workbench, the level should not exceed 0.02; b) Test mold: placed on the steel base plate, and should not be shaken; c) Glass plate: placed in the middle of the test mold, and the left and right sides are left with a 10 mm gap with the inner side of the test mold; d) Micrometer stand is fixed on the steel base plate, and is as close to the test mold as possible to shorten the length of the horizontal rod cantilever; e) Micrometer: the micrometer is fixed firmly with the micrometer stand clamping head, but the table rod can be freely raised and lowered. When installing the micrometer, the table head is pressed down, and the needle is pointed to about 1 / 2 of the scale. The micrometer should not be inclined forward, backward, left or right.

[0082] C.1.3 Vertical expansion rate contact measurement method test procedure The vertical expansion rate test procedure shall comply with the following provisions: a) The cement-based grouting material is mixed according to the relevant provisions of Appendix A.

[0083] b) The glass plate is placed flat in the middle of the test mold, and the glass plate is gently pressed. The mixed material is poured into the test mold from one side at one time, and the other side overflows and is about 2 mm higher than the edge of the test mold.

[0084] c) The slurry on both sides of the glass plate is covered with wet cotton yarn.

[0085] d) The micrometer measuring head is placed vertically in the center of the glass plate and is firmly installed. The initial reading h0 of the micrometer is read within 30 s; the molding process should be completed within 5 min after the mixing is completed.

[0086] e) The reading h of the micrometer is read at 3 h ± 5 min and 24 h ± 15 min, respectively, from the beginning of the water mixing. t The cotton yarn should be kept wet during the entire measurement process, and the device should not be shaken. The molding and curing temperature is 20℃ ± 2℃.

[0087] C.1.4 Vertical expansion rate contact measurement method calculation formula The vertical expansion rate contact measurement method of sleeve grouting material shall be calculated according to formula (II): In formula (II), ε t represents the vertical expansion rate; h0 represents the initial reading of the height of the test piece, in millimeters (mm); h t represents the height reading of the test piece at age t, in millimeters (mm); h represents the reference height of the test piece, 100, in millimeters (mm).

[0088] Note: The test results are taken as the arithmetic mean of 3 test pieces, and the calculation is accurate to 10 -2 . The results are shown in Table 3.

[0089] Table 3 is the test results of vertical expansion rate From Table 1 to Table 3, and Figures 1 to 5 It can be known from the comparative analysis that, in the comparative example 1, the early strength loss of the grouting material is serious without using sulphoaluminate cement, which cannot meet the use requirement of sleeve grouting material; in the comparative example 2, the steel fibers are not uniformly dispersed without using dispersant, and the bending strength is obviously decreased; in the comparative example 3, tailings sand is not mixed, but the strength is similar to that of the examples, which can be seen that the use of tailings sand to replace quartz sand meets the use requirement. The sleeve grouting material provided by the application has good performance, and each performance index meets or is far superior to the standard regulation of JG / T408-2019 "sleeve grouting material for steel bar connection", which is a high-performance sleeve grouting material with high flow state, micro-expansion, fast early strength development and high late strength.

[0090] 4) SEM analysis The corresponding test piece of the early high-performance sleeve grouting material for steel bar connection prepared in the example 3 after curing was subjected to SEM test, and the result is shown in Figures 7 to 9 .

[0091] Among them, the curing method is: the early high-performance sleeve grouting material for steel bar connection prepared in the example 3 is made into a test block, after the test block is formed in a test mold, the surface is immediately covered with a plastic film to prevent water evaporation. The test block with the mold is placed in a standard curing room or a curing box with a temperature of 20℃±2℃ and a relative humidity of ≥95% for 24 hours. After 24 hours of standing, the test block is immediately carefully removed from the test mold. The demolding operation should be rapid and gentle to avoid damaging the corners of the test block. After demolding, the test block must be immediately moved into the standard curing room or the curing box for continuous curing. The test blocks should be kept at a certain distance during curing to ensure that the curing environment can uniformly act on each surface of each test block.

[0092] From Figures 7 to 9 It can be known from the comparative analysis that, in the comparative example 1, the early strength loss of the grouting material is serious without using sulphoaluminate cement, which cannot meet the use requirement of sleeve grouting material; in the comparative example 2, the steel fibers are not uniformly dispersed without using dispersant, and the bending strength is obviously decreased; in the comparative example 3, tailings sand is not mixed, but the strength is similar to that of the examples, which can be seen that the use of tailings sand to replace quartz sand meets the use requirement. The sleeve grouting material provided by the application has good performance, and each performance index meets or is far superior to the standard regulation of JG / T408-2019 "sleeve grouting material for steel bar connection", which is a high-performance sleeve grouting material with high flow state, micro-expansion, fast early strength development and high late strength.

[0093] In summary, the early-strength high-performance sleeve grouting material of the application realizes the early-strength characteristic of 24-hour compressive strength ≥ 50 MPa of the grouting material under ultra-low water consumption by compounding ordinary Portland cement and sulphoaluminate cement and precisely controlling the water-binder ratio; meanwhile, with the synergistic effect of the defoaming agent and the dispersing agent, the bubble defects of the low water-binder ratio system are effectively inhibited, the slurry flowability ≥ 330 mm is ensured, and the problems of easy bleeding and poor flowability of the early-strength material are solved. Meanwhile, the tailing sand is innovatively used to replace the natural aggregate, more than 30% of mining solid waste is absorbed, and the exploitation load of natural sand and stone is reduced; the S105 grade mine powder and silica fume double industrial by-products are used, the solid waste content in the cementing material is more than 25%, the cement consumption is significantly reduced, the carbon emission is reduced by more than 15%, and the core index of green building materials is met. And through the reinforced skeleton formed by the steel fiber and the mechanism quartz sand, the crack resistance is increased by more than 40%; the application of the tailing sand and the industrial by-products reduces the raw material cost by 18%~25%, while ensuring high performance and low cost.

[0094] The preparation method of the early-strength high-performance sleeve grouting material of the application is mixed at room temperature, has the advantages of high flow state, micro-expansion, fast early strength development and high later strength, fully utilizes industrial solid waste, has good environmental and economic benefits, makes up for the defects of traditional grouting materials, can continue the green and sustainable development concept in the field of building engineering, promotes the development of prefabricated buildings, and has popularization and application value in the field of grouting material technology.

[0095] The above examples are only preferred embodiments for fully illustrating the application, and the protection scope of the application is not limited thereto. Any equivalent replacement or transformation of the application made by those skilled in the art based on the application is within the protection scope of the application.

Claims

1. An early-strength high-performance sleeve grouting material, characterized in that: It consists of cement, silica fume, mineral powder, steel fiber, quartz sand, tailings sand, water reducer, defoamer, dispersant and water.

2. The early-strength high-performance sleeve grouting material according to claim 1, characterized in that: The water-to-cement ratio of the early-strength high-performance sleeve grouting material is 0.23-0.

25.

3. The early-strength high-performance sleeve grouting material according to claim 1, characterized in that: The cement is selected from ordinary Portland cement and / or sulphoaluminate cement; And / or, the silica ash is a dark grey powder, wherein the SiO2 content in the silica ash is 94.3%, the average particle size is 0.1-0.3 μm, and the specific surface area is 18-24 m 2 / g.

4. The early-strength high-performance sleeve grouting material according to claim 1, characterized in that: The mineral powder is S105 grade mineral powder; the specific surface area of ​​the S105 grade mineral powder is 500~520m 2 / kg, the burning vector is 0.2%; And / or, the steel fiber is selected from copper-plated steel fiber, the copper-plated steel fiber has a diameter of 0.18-0.22 mm, a length of 10-13 mm, and a tensile strength of ≥2400 MPa.

5. The early-strength high-performance sleeve grouting material according to claim 1, characterized in that: The quartz sand is selected from machine-made quartz sand, which includes three particle sizes, namely 20-40 mesh, 40-70 mesh and 70-120 mesh, and the ratio of the particle sizes of 20-40 mesh, 40-70 mesh and 70-120 mesh is 4:3:2; And / or, the tailings sand is waste residue after grinding iron ore, and the waste residue is yellow gravel with a particle size of 70-120 mesh.

6. The early-strength high-performance sleeve grouting material according to claim 1, characterized in that: The water reducer is selected from polycarboxylic acid water reducer, which is a white powder with a water reduction rate of ≥32% and a pH value of 6-7; And / or, the defoaming agent is selected from a polyether defoaming agent, the polyether defoaming agent is a white powder with a pH value of 6 to 8; And / or, the dispersant is selected from a polycarboxylate sodium salt dispersant, and the polycarboxylate sodium salt dispersant is a colorless transparent liquid with a pH value of 6-8 and a viscosity of 500 Pa·s.

7. The early-strength high-performance sleeve grouting material according to claim 1, characterized in that: The cement, silica fume, mineral powder, steel fiber, quartz sand, tailings sand, water reducer, defoamer and dispersant are calculated in percentage by weight as follows: 1250-1500 parts: 80-120 parts: 260-300 parts: 20-50 parts: 1100-1300 parts: 500-600 parts: 15-20 parts: 1-2 parts: 1-3 parts.

8. A method for preparing the early-strength high-performance sleeve grouting material according to any one of claims 1 to 7, characterized in that: The following steps are involved: Dry-mix cement, silica fume, mineral powder, quartz sand, tailings sand, water reducer and defoamer to obtain sleeve grouting material dry powder; mixing the dispersant with water to obtain a mixture; The sleeve grouting material dry powder, the mixture and the steel fiber are mixed to obtain an early strength and high performance sleeve grouting material.

9. The preparation method according to claim 8, characterized in that The prepared early-strength high-performance sleeve grouting material has a fluidity of ≥330 mm and a 24-hour compressive strength of ≥50 MPa.

10. Use of the early-strength high-performance sleeve grouting material according to any one of claims 1 to 7 as a grouting material for steel bar connection.

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