Anti-settling high-flow rate grouting material and preparation method thereof

Abstract

The present invention relates to an anti-settling high-flow rate grouting material and a preparation method thereof. The anti-settling high-flow rate grouting material comprises the following raw materials by mass fraction: 5.88% to 7.83% of slag micropowder, 2% to 5% of microsilica powder, 5% to 10% of microbeads, 0.3% to 0.5% of expansion agent, 0.02% to 0.1% of defoaming agent, 0.2% to 0.5% of water reducing agent, 0.4% to 0.8% of fumed silica, 0.3% to 0.5% of lubricant, 0.5% to 1.0% of shrinkage reducing agent, 0.02% to 0.05% of carboxyethyl hydroxyethyl cellulose ether, 0.2% to 0.4% of modified rubber powder, 0.1% to 0.2% of modified wax, and the balance is cement. The solution provided by the present invention has high fluidity, can fully fill the prestressed pipe, can prevent the corrosion of the prestressed tendons, provide good bonding between the concrete and the prestressed tendons, make the cross-section of the prestressed component complete, ensure that the entire prestressed component system has good mechanical properties, ensure that the quality of bridge construction meets the design requirements and achieves the effect of offsetting the pressure of vehicles and pedestrians on the bridge deck.

Description

Technical Field

[0001] The invention relates to the technical field of prestressed concrete, and in particular to an anti-settling high-flow rate grouting material and a preparation method thereof. Background Art

[0002] In recent years, many bridge collapse accidents have occurred due to problems with the quality of prestressed construction. During the prestressed construction, the grouting of the channels is not dense and an effective prestressed system is not established, which leads to stress concentration on the anchor head and loss of prestress over time. This will change the designed stress state of the beam, reduce the bearing capacity of the bridge, and thus affect the service life of the bridge.

[0003] The cement slurry grouting materials currently on the market generally have the problems of large fluidity loss, short operating time, and easy segregation, stratification and water seepage. After hardening, the slurry is not dense, with many bubbles and pinholes, and poor bonding with the prestressed tendons. There are even cracks in the slurry, incomplete pores, and powdery external slurry. Even with the use of vacuum cycle grouting and other grouting methods, it is difficult to ensure the density of the pore grouting, which seriously affects the safety of the prestressed structure. Summary of the invention

[0004] One of the purposes of the present invention is to overcome the problems existing in the related art and provide an anti-settling high-flow rate grouting material, which has high fluidity, can fully fill the prestressed pipe, and can effectively prevent the corrosion of the prestressed tendons, provide good bonding between the concrete and the prestressed tendons, make the cross-section of the prestressed component complete, ensure that the entire prestressed component system has good mechanical properties, ensure that the bridge construction quality meets the design requirements, give full play to the design effect, and achieve the effect of offsetting the pressure of vehicles and pedestrians on the bridge deck.

[0005] The second object of the present invention is to provide a method for preparing an anti-settling high-flow rate press slurry.

[0006] To achieve the above object, the present invention provides an anti-settling high-flow rate grouting material, comprising the following raw materials by mass fraction:

[0007] Slag powder 5.88% ~ 7.83%, microsilica powder 2% ~ 5%, microbeads 5% ~ 10%, expander 0.3% ~ 0.5%, defoamer 0.02% ~ 0.1%, water reducer 0.2% ~ 0.5%, fumed silica 0.4% ~ 0.8%, lubricant 0.3% ~ 0.5%, shrinkage reducer 0.5% ~ 1.0%, carboxyethyl hydroxyethyl cellulose ether 0.02% ~ 0.05%, modified rubber powder 0.2% ~ 0.4%, modified wax 0.1% ~ 0.2%, and the balance is cement.

[0008] In a preferred technical solution of the present invention, the modified rubber powder is prepared by the following steps:

[0009] (1) taking waste rubber powder, crushing the waste rubber powder to a fineness of 1 to 3 μm using a nano-crusher, then adding a certain amount of the waste rubber powder into a mixed solution of hydrogen peroxide and oxalic acid, soaking for 30 to 60 minutes under stirring, taking the filtered product, and then washing it to obtain pretreated rubber powder;

[0010] (2) A certain amount of pretreated rubber powder is added to a mixture of a silane coupling agent and anhydrous ethanol, and the mixture is reacted at 60° C. to 65° C. for 180 minutes. After the reaction, the mixture is washed with anhydrous ethanol and then dried in a natural environment to obtain modified rubber powder.

[0011] In a preferred technical solution of the present invention, the modified wax is a mixture of polyethylene wax, paraffin, lauric acid and stearic acid, which is modified at a temperature of 130°C to 140°C and a stirring speed of 700 to 900 r / min and is obtained after modification for 180 minutes.

[0012] In a preferred technical solution of the present invention, the ratio of the added amounts of the polyethylene wax, paraffin, lauric acid and stearic acid is (100-200):(10-20):(15-30):(15-30).

[0013] In a preferred technical solution of the present invention, the molar concentration ratio of hydrogen peroxide to oxalic acid is (1-2 Mol / L):(0.8-1.2 Mol / L); the added amount ratio of the waste rubber powder to the mixed solution of hydrogen peroxide and oxalic acid is 5g:100mL-10g:100mL.

[0014] In a preferred technical solution of the present invention, the ratio of the added amount of the silane coupling agent to anhydrous ethanol is 1:2-4; the ratio of the added amount of the pretreated rubber powder to the mixed solution of the silane coupling agent and anhydrous ethanol is 1:4-9.

[0015] In a preferred technical solution of the present invention, the activity index of the slag powder is ≥95%, the particle size of the slag powder is 1250 mesh; the particle size of the microbeads is 1250 mesh; the expansion agent is an ettringite expansion agent; and the defoaming agent is a modified polysiloxane powder defoaming agent.

[0016] In a preferred technical solution of the present invention, the water reducing agent is a polycarboxylic acid high-performance water reducing agent; and the shrinkage reducing agent is an inorganic medium ethylene glycol powder shrinkage reducing agent.

[0017] In a preferred technical solution of the present invention, the fumed silica is hydrophobic silica obtained by modification with dimethyldichlorosilane; the lubricant is modified wax, and the melting point of the modified wax is 55°C to 65°C.

[0018] The technical solution provided by the present invention may include the following beneficial effects:

[0019] (1) Ordinary rubber powder is an insoluble and infusible cross-linked body with low reactivity. When it is filled into cement mortar as a polymer material, the interface bonding between calcium silicate hydrate and calcium hydroxide after hydration reaction with cement is relatively fragile. Improving the interface bonding between rubber and cement mortar matrix is ​​an important way to improve the strength of rubber mortar and rubber concrete. The present invention adopts modified rubber powder to enhance the hydrophilicity of rubber powder, so that it can hydrate calcium silicate and calcium hydroxide to form chemical bonds, improve the bonding force between rubber powder and calcium silicate hydrate and calcium hydroxide, ensure the mechanical strength of concrete, and improve the impermeability and insulation of concrete.

[0020] (2) The present invention introduces micro-beads and modified wax to play a synergistic lubricating role, thereby improving the fluidity of the grouting material. The modified wax can not only provide an internal lubrication mechanism to reduce the friction between molecules inside the grouting material, but also play an external interface lubrication role. Micro-beads are a kind of ultra-fine solid particles with continuous particle size distribution, spherical shape, and can provide an external lubrication mechanism. They play the role of micro ball bearings in the grouting material slurry, which can improve the rheology of the grouting material, reduce viscosity, reduce the friction between the grouting material and the equipment, further increase the flow rate of the grouting material, significantly reduce the time of pouring the grouting material, and reduce the pumping pressure.

[0021] (3) The present invention introduces an expansion agent and a shrinkage reducing agent to play a synergistic compensatory role, which can avoid the shrinkage of the grouting material. The ethylene glycol in the shrinkage reducing agent can slowly release water, so that the water inside the grouting material will not evaporate too quickly, and the water required by the cement during the hydration reaction is supplemented. At the same time, ethylene glycol has antifreeze properties, which can prevent the grouting material from being damaged and cracked by freezing and thawing in low temperature weather. In the cement hydration reaction stage, the expansion agent can generate anhydrite crystals (CaSO4·2H2O) and hydrogen. The crystal filling effect of the anhydrite crystals continuously compensates for the drying shrinkage of the cement in the grouting material.

[0022] (4) The fumed silica introduced in the present invention has a small particle size, a large specific surface area, and a silicon hydroxyl group on the surface, which can interact with adjacent fumed silica particles to form hydrogen bonds, forming a three-dimensional network structure, providing a certain physical barrier, which can effectively prevent the grouting slurry from sinking, agglomerating, and lying on the bottom, thereby avoiding water seepage from the grouting material. Carboxyethyl hydroxyethyl cellulose ether has excellent water retention properties and low viscosity, avoiding the high viscosity thickening effect that increases the flow friction of the grouting material, and has good thixotropy and can give the grouting material a longer open time.

[0023] (5) The defoaming agent introduced in the present invention can effectively eliminate the gas generated by the expansion agent and the gas introduced into the grouting material during the stirring stage, reduce the porosity of the grouting material, and make the grouting material more compact. The water reducer can effectively reduce the water-cement ratio, play the role of adsorption, dispersion and lubrication in the grouting material, improve the fluidity of the grouting material, and improve the strength of the grouting material.

[0024] (6) The introduction of highly active slag powder and microsilica powder as fillers can achieve fine particle grading in the grouting material, which plays a role in dense stacking filling effect and can effectively fill the gaps between cement hydration products. At the same time, slag powder and microsilica powder contain rich active SiO2, which can undergo secondary hydration reaction with cement hydration product Ca(OH)2 to generate silicate gel with higher density, thereby increasing the density of the grouting material.

[0025] In order to achieve the second of the above objectives, the present invention provides the following technical solutions:

[0026] A method for preparing an anti-settling high-flow-rate press slurry comprises the following steps:

[0027] Prepare materials according to the above mass fractions, and put cement, slag powder, microsilica powder, microbeads, expansion agent, defoamer, water reducer, fumed silica, lubricant, shrinkage reducer, carboxyethyl hydroxyethyl cellulose ether, modified rubber powder and modified wax into the mixing bin in sequence. After the feeding is completed, stir at a low speed of 40-100r / min for 30 seconds, and then stir at a high speed of 800-1000r / min for 180-260 seconds to obtain the anti-sedimentation high-flow rate grouting material. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0029] In recent years, many bridge collapse accidents have occurred due to problems with the quality of prestressed construction. During the prestressed construction, the grouting of the channels is not dense and an effective prestressed system is not established, which leads to stress concentration on the anchor head and loss of prestress over time. This will change the designed stress state of the beam, reduce the bearing capacity of the bridge, and thus affect the service life of the bridge.

[0030] The cement slurry grouting materials currently on the market generally have the problems of large fluidity loss, short operating time, and easy segregation, stratification and water seepage. After hardening, the slurry is not dense, with many bubbles and pinholes, and poor bonding with the prestressed tendons. There are even cracks in the slurry, incomplete pores, and powdery external slurry. Even with the use of vacuum cycle grouting and other grouting methods, it is difficult to ensure the density of the pore grouting, which seriously affects the safety of the prestressed structure.

[0031] In response to the above problems, an embodiment of the present invention provides an anti-settling high-flow rate grouting material, which has high fluidity and can fully fill the prestressed pipe. At the same time, it can effectively prevent the corrosion of the prestressed tendons, provide good bonding between the concrete and the prestressed tendons, and make the cross-section of the prestressed component complete, ensuring that the entire prestressed component system has good mechanical properties, ensuring that the bridge construction quality meets the design requirements, giving full play to the design effect, and achieving the effect of offsetting the pressure of vehicles and pedestrians on the bridge deck.

[0032] The present invention is further described in detail below in conjunction with the examples. The components described in the present invention are all commercially available, and the components described in the specific implementation manner or examples are mass ratios or mass fractions.

[0033] To achieve the above object, in a specific embodiment provided in the present application, the anti-settling high-flow rate slurry comprises the following raw materials by mass fraction:

[0034] Slag powder 5.88% ~ 7.83%, microsilica powder 2% ~ 5%, microbeads 5% ~ 10%, expander 0.3% ~ 0.5%, defoamer 0.02% ~ 0.1%, water reducer 0.2% ~ 0.5%, fumed silica 0.4% ~ 0.8%, lubricant 0.3% ~ 0.5%, shrinkage reducer 0.5% ~ 1.0%, carboxyethyl hydroxyethyl cellulose ether 0.02% ~ 0.05%, modified rubber powder 0.2% ~ 0.4%, modified wax 0.1% ~ 0.2%, and the balance is cement.

[0035] In the present invention, the amount of slag powder is 5.88% to 7.83% of the total mass, specifically 5.88%, 5.9%, 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.75%, 6.9%, 7.0%, 7.2%, 7.5%, 7.7%, and 7.83%.

[0036] In the present invention, the amount of the microsilica powder is 2% to 5% of the total mass, specifically 2%, 2.2%, 2.5%, 2.8%, 3.1%, 3.4%, 4%, 4.5%, and 5%.

[0037] In the present invention, the amount of the microbeads is 5% to 10% of the total mass, specifically 5%, 6%, 7%, 8%, 9%, 10%.

[0038] In the present invention, the amount of the expander is 0.3% to 0.5% of the total mass, specifically 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%.

[0039] In the present invention, the amount of the defoaming agent is 0.02% to 0.1% of the total mass, specifically 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%.

[0040] In the present invention, the amount of the water reducer is 0.2% to 0.5% of the total mass, specifically 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%.

[0041] In the present invention, the amount of the fumed silica is 0.4% to 0.8% of the total mass, specifically 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, or 0.8%.

[0042] In the present invention, the amount of the lubricant is 0.3% to 0.5% of the total mass, specifically 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%.

[0043] In the present invention, the amount of the reducing agent is 0.5% to 1.0% of the total mass, specifically 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, and 1.0%.

[0044] In the present invention, the amount of the carboxyethyl hydroxyethyl cellulose ether is 0.02% to 0.05% of the total mass, specifically 0.02%, 0.03%, 0.04%, 0.045%, 0.05%.

[0045] In the present invention, the amount of the modified rubber powder is 0.2% to 0.4% of the total mass, specifically 0.2%, 0.22%, 0.25%, 0.275%, 0.3%, 0.325%, 0.35%, 0.375%, 0.4%.

[0046] In the present invention, the amount of the modified wax is 0.1% to 0.2% of the total mass, specifically 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%.

[0047] In the present invention, when the above-mentioned anti-settling high-flow rate grouting material is stirred, mixed and dispersed with water, the hydroxyethyl cellulose ether maintains a certain viscosity before the cement undergoes hydration heat, reduces the fluidity of each component, and thus ensures the concentration balance of the grouting material. At the same time, it has good thixotropy and can give the grouting material a longer open time. When the cement undergoes hydration reaction, the produced hydroxide destroys the molecular chain of the hydroxyethyl cellulose ether, so that the viscosity of the slurry system is reduced and the thermal motion of the system is increased, which can accelerate the speed of the hydration reaction and increase the setting speed of the cement, thereby ensuring that the components with lower density will not be stratified or segregated due to long-term hydration reaction.

[0048] In a preferred embodiment of the present invention, the modified rubber powder of the anti-settling high-flow rate press slurry is prepared by the following steps:

[0049] (1) taking waste rubber powder, crushing the waste rubber powder to a fineness of 1 to 3 μm using a nano-crusher, then adding a certain amount of the waste rubber powder into a mixed solution of hydrogen peroxide and oxalic acid, soaking for 30 to 60 minutes under stirring, taking the filtered product, and then washing it to obtain pretreated rubber powder;

[0050] (2) A certain amount of pretreated rubber powder is added to a mixture of a silane coupling agent and anhydrous ethanol, and the mixture is reacted at 60° C. to 65° C. for 180 minutes. After the reaction, the mixture is washed with anhydrous ethanol and then dried in a natural environment to obtain modified rubber powder.

[0051] Specifically, the preparation method of modified rubber powder mainly includes three steps, mainly:

[0052] In the first step, the waste rubber powder is crushed to a fineness of 1 to 3 microns, which can increase the specific surface area of ​​the waste rubber powder, increase the number of grafted silanols in the subsequent steps, and improve the chemical bonding between the rubber powder and the hydrated calcium silicate and calcium hydroxide. The mixed solution of oxalic acid and hydrogen peroxide can remove impurities such as oil and dust on the surface of the rubber powder. Oxalic acid and hydrogen peroxide can corrode the rubber powder, thereby forming an uneven microstructure on the surface of the rubber powder, further increasing the specific surface area of ​​the rubber powder.

[0053] In the second step, the rubber treated with hydrogen peroxide and oxalic acid is added to a mixture of a silane coupling agent and anhydrous ethanol. The silane coupling agent is hydrolyzed under heating conditions, and the hydrolyzed silanol is combined with molecules on the surface of the rubber, thereby grafting silanol on the rubber powder, increasing the hydrophilicity of the rubber powder, and improving the wettability and dispersibility of the rubber powder in the grouting material. When the grouting material and water are mixed, it can ensure that the rubber powder is evenly dispersed in the slurry, and when the cement undergoes a hydration reaction, it can form a chemical bond with hydrated calcium silicate and calcium hydroxide, thereby improving the bonding strength of the cement system and improving the application effect of the grouting material on the prestressed pipe.

[0054] In a preferred embodiment, the waste rubber powder is waste tire rubber powder.

[0055] In a preferred embodiment of the present invention, the modified wax of the above-mentioned anti-settling high-flow rate press slurry is a mixture of polyethylene wax, paraffin wax, lauric acid and stearic acid, which is modified at a temperature of 130°C to 140°C and a stirring speed of 700 to 900 r / min and is obtained after modification for 180 minutes.

[0056] The polyethylene wax is mainly used, and paraffin, lauric acid and stearic acid are used as modifiers. The polyethylene wax is modified at a temperature of 130°C to 140°C, thereby changing the needle penetration of the polyethylene wax and reducing the melting point of the polyethylene wax.

[0057] During the hydration reaction of cement, the temperature can reach 70°C. At this temperature, polyethylene wax melts in water. During the hydration process, polyethylene wax can be evenly distributed in the slurry system, reducing the friction between molecules inside the slurry, and may be adsorbed on the surface of the steel bars. After the system temperature drops to the melting point, polyethylene wax can coat the steel bars, providing early anti-corrosion protection for the steel bars, and avoiding continuous corrosion of the steel bar surface by water molecules after the hydration reaction.

[0058] In a preferred embodiment of the present invention, the ratio of the added amounts of polyethylene wax, paraffin wax, lauric acid and stearic acid in the above-mentioned anti-settling high-flow rate slurry is (100-20): (10-2): (15-3): (15-30).

[0059] In a preferred embodiment, the ratio of polyethylene wax, paraffin wax, lauric acid and stearic acid added is 100:10:15:15.

[0060] In a preferred embodiment of the present invention, the molar concentration ratio of hydrogen peroxide and oxalic acid in the above-mentioned anti-settling high-flow rate slurry is (1-2 Mol / L): (0.8-1.2 Mol / L); the ratio of the added amount of the waste rubber powder and the mixed solution of hydrogen peroxide and oxalic acid is 5g:100mL~L~10g:100mL.

[0061] In a preferred embodiment, the concentration of hydrogen peroxide is 1 Mol / L and the concentration of oxalic acid is 1 Mol / L; the amount of waste rubber powder and the mixed solution of hydrogen peroxide and oxalic acid added is 5g:100mL.

[0062] In a preferred embodiment of the present invention, the ratio of the added amount of the silane coupling agent and anhydrous ethanol in the above-mentioned anti-settling high-flow rate slurry is 1:2-4; the ratio of the added amount of the pretreated rubber powder and the mixed solution of the silane coupling agent and anhydrous ethanol is 1:4-9.

[0063] In a preferred embodiment of the present invention, the slag powder activity index of the above-mentioned anti-settling high-flow rate grouting material is ≥95%, the particle size of the slag powder is 1-3 μm; the particle size of the microbeads is 1250 mesh; the expansion agent is an ettringite-based expansion agent; and the defoaming agent is a modified polysiloxane powder defoaming agent.

[0064] In a preferred embodiment of the present invention, the water reducing agent of the anti-settling high-flow rate press slurry is a polycarboxylic acid high-performance water reducing agent; and the shrinkage reducing agent is an inorganic medium ethylene glycol powder shrinkage reducing agent.

[0065] In a preferred embodiment of the present invention, the fumed silica of the anti-settling high-flow rate press slurry is hydrophobic silica modified with dimethyldichlorosilane; the lubricant is modified wax, and the melting point of the modified wax is 55°C to 65°C.

[0066] The beneficial effects of the present invention will be further described below in conjunction with embodiments.

[0067] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0068] Each embodiment and each comparative example in the present invention can be tested accordingly according to the relevant technical requirements of the standard JT / T946-2014 "Prestressed Duct Grouting Material for Highway Engineering";

[0069] The corrosion effect on steel bars in each embodiment of the present invention and each comparative example can be tested according to the provisions of JC / T986-2018 "Cement-based Grouting Materials" standard.

[0070] Examples 1 to 4 and Comparative Examples 1 to 6

[0071] Example 1

[0072] In parts by weight, the raw materials for its preparation include: 74.65 parts of cement, 7.83 parts of slag powder, 5 parts of microsilica powder, 10 parts of microspheres, 0.3 parts of expander, 0.02 parts of defoamer, 0.2 parts of water reducer, 0.8 parts of fumed silica, 0.3 parts of lubricant, 0.5 parts of shrinkage reducer, 0.05 parts of hydroxyethyl cellulose ether, 0.2 parts of modified rubber powder, and 0.1 parts of modified wax.

[0073] The preparation method of the above-mentioned anti-settling high-flow rate grouting material is as follows: prepare the materials according to the above-mentioned weight distribution ratio, and add cement, slag powder, microsilica powder, microbeads, expander, defoamer, water reducer, fumed silica, lubricant, shrinkage reducer, and hydroxyethyl cellulose ether into the mixing bin in sequence. After the feeding is completed, stir at a low speed of 40 to 100 r / min for 30 seconds, and then stir at a high speed of 800 to 1000 r / min for 180 to 260 seconds. After stirring is completed, discharge the materials and package them.

[0074] The application of the above-mentioned anti-settling high-flow rate press slurry is as follows: water: anti-settling high-flow rate press slurry = 0.28:1 (weight ratio) are added into the pulping machine in sequence, and the rotation speed of the pulping machine is controlled to be not less than 1000r / min; the blade linear speed is 10-20m / s, high-speed stirring is performed for 5 minutes, then stop for 30 seconds, and then stir for 1-2 minutes to obtain an anti-settling high-flow rate press slurry; after the stirring and pulping is completed, the slurry is immediately pressed, and the obtained slurry is used up within 1 hour, and no additional water or powder can be added in the middle.

[0075] Example 2

[0076] In parts by weight, the raw materials for its preparation include: 78.5 parts of cement, 7.28 parts of slag powder, 4 parts of microsilica powder, 8 parts of microbeads, 0.35 parts of expander, 0.03 parts of defoamer, 0.25 parts of water reducer, 0.6 parts of fumed silica, 0.35 parts of lubricant, 0.6 parts of shrinkage reducer, 0.04 parts of hydroxyethyl cellulose ether, 0.25 parts of modified rubber powder, and 0.15 parts of modified wax.

[0077] The preparation method of the above-mentioned anti-settling high-flow rate grouting material is as follows: prepare the materials according to the above-mentioned weight distribution ratio, and add cement, slag powder, microsilica powder, microbeads, expander, defoamer, water reducer, fumed silica, lubricant, shrinkage reducer, and hydroxyethyl cellulose ether into the mixing bin in sequence. After the feeding is completed, stir at a low speed of 40 to 100 r / min for 30 seconds, and then stir at a high speed of 800 to 1000 r / min for 180 to 260 seconds. After stirring is completed, discharge the materials and package them.

[0078] The application of the above-mentioned anti-settling high-flow rate press slurry is as follows: water: anti-settling high-flow rate press slurry = 0.28:1 (weight ratio) are added into the pulping machine in sequence, and the rotation speed of the pulping machine is controlled to be not less than 1000r / min; the blade linear speed is 10-20m / s, high-speed stirring is performed for 5 minutes, then stop for 30 seconds, and then stir for 1-2 minutes to obtain an anti-settling high-flow rate press slurry; after the stirring and pulping is completed, the slurry is immediately pressed, and the obtained slurry is used up within 1 hour, and no additional water or powder can be added in the middle.

[0079] Example 3

[0080] In parts by weight, the raw materials for its preparation include: 82 parts of cement, 6.53 parts of slag powder, 3 parts of microsilica powder, 6 parts of microspheres, 0.4 parts of expander, 0.04 parts of defoamer, 0.3 parts of water reducer, 0.5 parts of fumed silica, 0.4 parts of lubricant, 0.8 parts of shrinkage reducer, 0.03 parts of hydroxyethyl cellulose ether, 0.25 parts of modified rubber powder, and 0.15 parts of modified wax.

[0081] The preparation method of the above-mentioned anti-settling high-flow rate grouting material is as follows: prepare the materials according to the above-mentioned weight distribution ratio, and add cement, slag powder, microsilica powder, microbeads, expander, defoamer, water reducer, fumed silica, lubricant, shrinkage reducer, and hydroxyethyl cellulose ether into the mixing bin in sequence. After the feeding is completed, stir at a low speed of 40 to 100 r / min for 30 seconds, and then stir at a high speed of 800 to 1000 r / min for 180 to 260 seconds. After stirring is completed, discharge the materials and package them.

[0082] The application of the above-mentioned anti-settling high-flow rate press slurry is as follows: water: anti-settling high-flow rate press slurry = 0.28:1 (weight ratio) are added into the pulping machine in sequence, and the rotation speed of the pulping machine is controlled to be not less than 1000r / min; the blade linear speed is 10-20m / s, high-speed stirring is performed for 5 minutes, then stop for 30 seconds, and then stir for 1-2 minutes to obtain an anti-settling high-flow rate press slurry; after the stirring and pulping is completed, the slurry is immediately pressed, and the obtained slurry is used up within 1 hour, and no additional water or powder can be added in the middle.

[0083] Embodiment 4:

[0084] In parts by weight, the raw materials for its preparation include: 85 parts of cement, 5.18 parts of slag powder, 2 parts of microsilica powder, 5 parts of microspheres, 0.5 parts of expansion agent, 0.05 parts of defoaming agent, 0.35 parts of high-efficiency water reducing agent, 0.4 parts of fumed silica, 0.5 parts of lubricant, 1.0 parts of shrinkage reducing agent, 0.02 parts of hydroxyethyl cellulose ether, 0.4 parts of modified rubber powder, and 0.2 parts of modified wax.

[0085] The preparation method of the above-mentioned anti-settling high-flow rate grouting material is as follows: prepare the materials according to the above-mentioned weight distribution ratio, and add cement, slag powder, microsilica powder, microbeads, expansion agent, defoaming agent, high-efficiency water reducer, fumed silica, lubricant, shrinkage reducer, and hydroxyethyl cellulose ether in the mixing bin in sequence. After the feeding is completed, stir at a low speed of 40 to 100 r / min for 30 seconds, and then stir at a high speed of 800 to 1000 r / min for 180 to 260 seconds. After stirring is completed, discharge the materials and package them.

[0086] The application of the above-mentioned anti-settling high-flow rate press slurry is as follows: water: anti-settling high-flow rate press slurry = 0.28:1 (weight ratio) are added into the pulping machine in sequence, and the rotation speed of the pulping machine is controlled to be not less than 1000r / min; the blade linear speed is 10-20m / s, high-speed stirring is performed for 5 minutes, then stop for 30 seconds, and then stir for 1-2 minutes to obtain an anti-settling high-flow rate press slurry; after the stirring and pulping is completed, the slurry is immediately pressed, and the obtained slurry is used up within 1 hour, and no additional water or powder can be added in the middle.

[0087] Comparative Example 1

[0088] The difference from Example 1 is that Comparative Example 1 uses microsilica powder to replace the fumed silica in Example 1.

[0089] Comparative Example 2

[0090] The difference from Example 2 is that Comparative Example 2 uses slag powder to replace the microbeads and lubricant in Example 2.

[0091] Comparative Example 3

[0092] The difference from Example 3 is that, in Comparative Example 3, slag powder is used to replace the expansion agent and the reduction agent in Example 3.

[0093] Comparative Example 4

[0094] The difference from Example 4 is that Comparative Example 4 does not use modified rubber powder.

[0095] Comparative Example 5

[0096] The difference from Example 4 is that Comparative Example 5 does not use modified wax.

[0097] Comparative Example 6

[0098] The difference from Example 4 is that Comparative Example 6 does not use modified rubber powder and modified wax.

[0099] The test parameters of Examples 1 to 4 and Comparative Examples 1 to 6 are shown in Table 1:

[0100] Table 1: Test parameters of various embodiments and comparative examples

[0101]

[0102]

[0103] According to the test results of the embodiments and comparative examples, it can be seen from Table 1 that, compared with comparative example 1, the grouting materials added with fumed silica in embodiments 1 to 4 showed no water seepage phenomenon, and the free water seepage rate, the water seepage rate between steel wires, and the pressure water seepage rate test items all met the standard requirements. In the formula of comparative example 1, no fumed silica was added, and a more serious water seepage situation occurred, and the free water seepage rate, the water seepage rate between steel wires, and the pressure water seepage rate test items were all unqualified. At the same time, due to the serious water seepage, the grouting material showed a bottoming phenomenon, resulting in the failure of the 7d and 28d compressive flexural strength and fullness test items. Compared with comparative example 2, the formulas added with microspheres and lubricants in embodiments 1 to 4 all had high fluidity, and the initial, 30mim, and 60min fluidity test items all met the standard requirements; in the formula of comparative example 2, no microspheres and lubricants were added, and the fluidity of the grouting material was poor, and the initial, 30mim, and 60min fluidity were all unqualified. Compared with Comparative Example 3, the free expansion rate and the restricted expansion rate of the formulas added with the expansion agent and the shrinkage reducer in Examples 1 to 4 were slightly expanded and met the requirements; in Comparative Example 3, no expansion agent and shrinkage reducer were added, and the free expansion rate and the restricted expansion rate test items were severely shrunk, which did not meet the standard requirements. Compared with Comparative Examples 4 to 6, the grouting materials without the addition of modified rubber powder and / or modified wax in Examples 1 to 4 were weaker than those in Examples 1 to 4 in terms of comprehensive performance. Among them, in the test item of the corrosion effect on steel bars, it can be seen that Comparative Examples 5 and Comparative Examples 6 have slight corrosion. Therefore, the use of the modified wax in the present invention can reduce the corrosion effect of the pressure drop material on the steel bars.

[0104] In summary, the parameters of the grouting material can be significantly improved by adding modified rubber powder and modified wax to the grouting material.

[0105] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An anti-settling high-flow rate slurry press, characterized in that: In terms of mass fraction, it includes the following raw materials: Slag powder 5.88%~7.83%, microsilica powder 2%~5%, microspheres 5%~10%, expander 0.3%~0.5%, defoamer 0.02%~0.1%, water reducer 0.2%~0.5%, fumed silica 0.4%~0.8%, lubricant 0.3%~0.5%, shrinkage reducer 0.5%~1.0%, carboxyethyl hydroxyethyl cellulose ether 0.02%~0.05%, modified rubber powder 0.2%~0.4%, modified wax 0.1%~0.2%, and the balance is cement; The modified rubber powder is prepared by the following steps: (1) taking waste rubber powder, crushing the waste rubber powder to a fineness of 1 to 3 μm using a nano-crusher, then adding a certain amount of the waste rubber powder into a mixed solution of hydrogen peroxide and oxalic acid, soaking for 30 to 60 minutes under stirring, taking the filtered product, and then washing it to obtain pretreated rubber powder; (2) adding a certain amount of pretreated rubber powder to a mixture of a silane coupling agent and anhydrous ethanol, reacting at 60° C. to 65° C. for 180 minutes, washing with anhydrous ethanol after the reaction, and then drying in a natural environment to obtain modified rubber powder; The modified wax is a mixture of polyethylene wax, paraffin wax, lauric acid and stearic acid, which is modified at a temperature of 130°C to 140°C and a stirring speed of 700 to 900 r / min, and is obtained after modification for 180 minutes; The ratio of the polyethylene wax, paraffin wax, lauric acid and stearic acid added is (100-200): (10-20): (15-30): (15-30); The melting point of the modified wax is 55°C to 65°C; The molar concentration ratio of the hydrogen peroxide and oxalic acid is (1-2 mol / L): (0.8-1.2 mol / L); the added amount ratio of the waste rubber powder to the mixed solution is 5g:100mL-10g:100mL.

2. The anti-settling high-flow rate grouting material according to claim 1, characterized in that: The ratio of the added amount of the silane coupling agent to the anhydrous ethanol is 1:2-4; the ratio of the added amount of the pretreated rubber powder to the mixed solution of the silane coupling agent and the anhydrous ethanol is 1:4-9.

3. The anti-settling high-flow rate grouting material according to claim 1, characterized in that: The activity index of the slag powder is ≥95%, the particle size of the slag powder is 1250 meshes; the particle size of the microbeads is 1250 meshes; the expansion agent is an ettringite expansion agent; and the defoaming agent is a modified polysiloxane powder defoaming agent.

4. The anti-settling high-flow-rate grouting material according to claim 1, characterized in that: The water reducing agent is a polycarboxylic acid high-performance water reducing agent; and the shrinkage reducing agent is an inorganic medium ethylene glycol powder shrinkage reducing agent.

5. The anti-settling high-flow-rate grouting material according to claim 1, characterized in that: Fumed silica is hydrophobic silica modified with dimethyldichlorosilane.

6. The anti-settling high-flow-rate grouting material according to claim 1, characterized in that: The lubricant is modified wax.

7. A method for preparing the anti-settling high-flow rate press slurry according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: Prepare materials according to the above mass fractions, and put cement, slag powder, microsilica powder, microbeads, expansion agent, defoamer, water reducer, fumed silica, lubricant, shrinkage reducer, carboxyethyl hydroxyethyl cellulose ether, modified rubber powder and modified wax into the mixing bin in sequence. After the feeding is completed, stir at a low speed of 40-100r / min for 30 seconds, and then stir at a high speed of 800-1000r / min for 180-260 seconds to obtain the anti-sedimentation high-flow rate grouting material.

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