Preparation method of modified cave slag stone powder admixture for railway concrete

Abstract

The invention discloses a preparation method of a modified cave slag stone powder admixture for railway concrete. The modified cave slag stone powder admixture comprises a cave slag stone powder raw material and a modified material, the modified material comprises an activity improving component, a shrinkage compensating component, a workability improving component, a grinding aiding component and a surface modifying component. The method comprises the following steps: mixing and grinding a modified material grinding aid component and hole slag rock, and then spraying a surface modification component; and mixing and homogenizing the modified material activity improving component, the shrinkage compensating component, the workability improving component and the surface modified cave slag stone powder to obtain a finished product of the modified cave slag stone powder admixture. According to the invention, the urgent demand of resource utilization of the tunnel engineering hole slag can be effectively met, and a reasonable path can be provided for solving the problem of resource shortage of concrete mineral admixtures.

Description

Technical Field

[0001] This invention relates to the field of civil engineering materials technology, and more specifically to a method for preparing modified tunnel slag powder admixture for railway concrete. Background Technology

[0002] Tunnel muck, a byproduct of tunnel construction, is produced in enormous quantities. Except for a small portion used as roadbed filler, the vast majority is transported to spoil heaps for disposal. This occupies a significant amount of permanent land, alters the original surface environment, and can easily harm the environment of downstream and surrounding areas. Tunnel engineering faces a severe problem in resource utilization. Generally, in addition to being used as roadbed filler, tunnel muck can be processed into coarse and fine aggregates for concrete. This avoids the adverse environmental impact of tunnel muck during construction, provides high-quality concrete raw materials, alleviates the pressure on construction schedules caused by sand and gravel shortages, saves project investment, and creates considerable economic benefits. On the other hand, with the increasing volume of construction projects in my country, resources of mineral admixtures for concrete, such as fly ash and ground blast furnace slag powder, are scarce. Prices are rising year by year, while quality is declining, seriously affecting the quality and cost control of concrete projects, becoming a nationwide problem.

[0003] To date, stone powder mineral admixtures have established a preliminary basis for application in concrete. Existing research indicates that stone powder mineral admixtures possess certain nucleation, filling, chemical, and diluting effects in concrete materials, increasing the density of the cement matrix and interfacial transition zone, promoting the growth and precipitation of early hydration products, and adjusting the hydration heat release rate. Furthermore, by employing methods such as thermal activation, mechanical activation, and chemical activation, the activity of stone powder mineral admixtures can be enhanced to a certain extent, thereby improving their effectiveness in concrete materials.

[0004] Therefore, proposing a method for preparing modified tunnel slag powder admixture for railway concrete using tunnel slag as raw material is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention addresses the problems of resource utilization of tunnel slag and shortage of mineral admixtures for concrete by providing a method for preparing modified tunnel slag powder admixture for railway concrete.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A modified slag powder admixture for railway concrete, characterized in that it comprises slag powder raw materials and modifying materials;

[0008] The modified material includes an activity-enhancing component, a shrinkage-compensating component, a workability-improving component, a grinding-aiding component, and a surface-modifying component.

[0009] Furthermore, the raw material for the slag stone powder is selected from one or more of various lithologies such as dolomite, slate, gneiss, granite, and limestone; the particle size of the raw material for the slag stone powder is 5-20mm.

[0010] The advantages of adopting the above-mentioned further solutions are as follows: the solutions of the present invention are applicable to all common rock types and have a wide range of uses; the 5-20mm quarry stone powder raw material is more conducive to grinding and has a higher energy utilization rate.

[0011] Furthermore, the activity-enhancing components in the modified material are any one or a mixture of silica fume, sulfate, nano-silica, ultrafine mineral powder, and calcium sulfate whiskers.

[0012] The beneficial effect of adopting the above-mentioned further solution is that the active enhancing component used in this invention can be applied to all common lithological stone powders, so as to achieve the purpose of improving the strength of concrete prepared from stone powder.

[0013] Furthermore, the shrinkage compensation component in the modified material is any one or a mixture of lightly calcined magnesium oxide, heavily calcined magnesium oxide, aluminum powder, aluminum sulfate, water-absorbing resin, and calcium oxide-based expanding agents;

[0014] Furthermore, the calcium oxide-based expanding agent is a TK series calcium oxide-based expanding agent.

[0015] The beneficial effect of adopting the above-mentioned further solution is that the shrinkage compensation component used in this invention can be applied to all common lithological stone powders, thereby achieving the purpose of reducing the shrinkage of stone powder in concrete preparation.

[0016] Furthermore, the workability-improving component in the modified material is any one or a mixture of cellulose ether, warm sizing agent, and glass microspheres.

[0017] The beneficial effect of adopting the above-mentioned further solution is that the workability improvement component in this invention can be applied to all common lithological stone powders, so as to achieve the purpose of improving the workability of concrete prepared from stone powder.

[0018] Furthermore, the grinding aid component in the modified material is any one or a mixture of diethylene glycol, triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, and gypsum dihydrate.

[0019] The beneficial effect of adopting the above-mentioned further solution is that the grinding aid component added by the present invention can be applied to all common lithological stone powders, so as to significantly reduce the grinding energy consumption in the stone powder preparation process.

[0020] Furthermore, the surface-modifying component in the modified material is a silane coupling agent and / or an aluminate coupling agent.

[0021] Furthermore, the silane coupling agent is a TK series silane coupling agent, and the aluminate coupling agent is a TK series aluminate coupling agent.

[0022] The beneficial effects of adopting the above-mentioned further solutions are that the surface modification components of the present invention can be applied to all common lithological stone powders, so as to improve the microscopic properties of the surface of the ground stone powder and reduce the adsorption of the stone powder.

[0023] The present invention also provides a method for preparing the above-mentioned modified slag powder admixture for railway concrete, characterized by comprising the following steps:

[0024] (1) The modified material grinding aid component is mixed with the caval rock and fed into the grinding equipment. After grinding, unmodified caval rock powder is obtained.

[0025] (2) Dilute the surface modification component of the modified material with 10-100 times the mass of water, and spray it evenly on the unmodified karst stone powder to obtain surface-modified karst stone powder.

[0026] (3) The active enhancement component, shrinkage compensation component, workability improvement component and surface modified slag powder in the modified material are put into the homogenization equipment and mixed for 10-30 minutes. Then, the mixture is transferred to the finished product silo and the material is allowed to cool naturally to room temperature to obtain the modified slag powder admixture finished product.

[0027] Furthermore, the mass ratio of the modified material grinding aid component to the cavitary rock in step (1) is 0.3 to 3:10.

[0028] Furthermore, the specific surface area of ​​the unmodified quarry stone powder after grinding in step (1) is 400-800 m². 2 / kg.

[0029] The beneficial effect of adopting the above-mentioned further solution is that the above solution can control the specific surface area of ​​the unmodified stone powder after grinding, so as to achieve the purpose of coordinating and controlling the activity and fluidity ratio of the stone powder.

[0030] Furthermore, the mass ratio of the activity-enhancing component, shrinkage-compensating component, workability-improving component and surface-modified quarry stone powder in step (3) is 5-10: 5-10: 1-5: 80-100.

[0031] The beneficial effects of adopting the above-mentioned further solutions are that the proportion range of each component of the modified material defined by the present invention comprehensively improves the workability, mechanical properties, durability and shrinkage properties of stone powder concrete.

[0032] Furthermore, the homogenization in step (3) is set to be homogenization at atmospheric pressure of 5-40℃.

[0033] Furthermore, the modified slag powder admixture for railway concrete prepared by this invention meets the following performance indicators: specific surface area ≥ 400 m². 2 / kg; 28-day activity index ≥75%; loss on ignition ≤30%; fluidity ratio ≥100%; moisture content ≤1%.

[0034] The beneficial effects of this invention are as follows: This invention is applicable to all common rocks such as dolomite, slate, gneiss, granite, and limestone. By utilizing the activity-enhancing components, shrinkage-compensating components, workability-improving components, grinding aid components, and surface-modifying components in the modified materials, the activity, fluidity ratio, shrinkage ratio, apparent structure, and grinding power of finely ground stone powder are optimized, thereby achieving the goal of comprehensively improving the workability, mechanical properties, durability, and shrinkage properties of stone powder concrete. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] A method for preparing modified dolomite slag powder admixture for railway concrete.

[0038] (1) Triethanolamine was used as a grinding aid. 0.3t of triethanolamine and 9.7t of 5-10mm dolomite slag powder were added together into an industrial ball mill. The grinding speed was 100r / min and the grinding time was 75min to obtain unmodified slag powder.

[0039] (2) Using a Blaine surface area analyzer, the specific surface area of ​​the unmodified quarry stone powder was measured to be 527 m². 2 / kg.

[0040] (3) The surface modification component uses silane coupling agent. 500 kg of silane coupling agent solution is prepared at a mass fraction of 1% and sprayed evenly onto the surface of unmodified slag powder using an industrial atomizer to obtain surface modified slag powder.

[0041] (4) The activity-enhancing component is nano-silica, the workability-improving component is cellulose ether, and the shrinkage-compensating component is internal curing agent. 2.1t of nano-silica, 0.5t of cellulose ether, 1.0t of internal curing agent, and 12t of surface-modified slag powder are added together into an industrial homogenization device and mixed at high speed for 20 minutes to obtain TK-P-1, a modified slag powder admixture for railway concrete with increased viscosity.

[0042] (5) The performance parameters of the modified slag powder admixture for thickening railway concrete were measured and are shown in Table 1.

[0043] Table 1 Performance parameters of modified caving stone powder admixture

[0044]

[0045] Example 2

[0046] A method for preparing a modified granite slag powder admixture for railway concrete:

[0047] (1) Triethanolamine and triisopropanolamine were used as grinding aids. 0.2t of triethanolamine and 0.2t of triisopropanolamine were added together with 9.6t of 5-10mm granite slag powder raw material into an industrial ball mill. The grinding speed was 105r / min and the grinding time was 60min.

[0048] (2) Using a Blaine surface area analyzer, the specific surface area of ​​the unmodified quarry stone powder was measured to be 540 m². 2 / kg.

[0049] (3) The surface modification component is an aluminate coupling agent. 500 kg of aluminate coupling agent solution is prepared at a mass fraction of 2% and sprayed evenly onto the surface of the unmodified slag powder using an industrial atomizer to obtain surface-modified slag powder.

[0050] (4) The active enhancement component is silica fume, the workability improvement component is glass microspheres, and the shrinkage compensation component is lightly calcined magnesium oxide. 3.1t of silica fume, 1.0t of glass microspheres, 1.1t of lightly calcined magnesium oxide, and 12t of surface-modified slag powder are added together into an industrial homogenization device and mixed at high speed for 20 minutes to obtain TK-P-2, a modified slag powder admixture for railway concrete with reduced viscosity.

[0051] (5) The performance parameters of the modified slag powder admixture for viscosity-reducing railway concrete were measured and are shown in Table 2.

[0052] Table 2 Performance parameters of modified caving stone powder admixture

[0053]

[0054] Example 3

[0055] A method for preparing modified gneiss slag powder admixture for railway concrete:

[0056] (1) Triisopropanolamine was used as a grinding aid. 0.4t of triisopropanolamine and 9.6t of 5-10mm gneiss slag powder were added together into an industrial ball mill. The grinding speed was 120r / min and the grinding time was 60min.

[0057] (2) Using a laser particle size analyzer, the specific surface area of ​​the unmodified quarry stone powder was measured to be 490 m². 2 / kg.

[0058] (3) The surface modification component is an aluminate coupling agent. 500 kg of aluminate coupling agent solution is prepared at a mass fraction of 2% and sprayed evenly onto the surface of the unmodified slag powder using an industrial atomizer to obtain surface-modified slag powder.

[0059] (4) The activity-enhancing component is ultrafine mineral powder, the workability-improving component is warm wheel adhesive, and the shrinkage-compensating component is internal curing agent SAP. 3.1t of ultrafine mineral powder, 1.0t of warm wheel adhesive, 1.0t of internal curing agent SAP, and 15t of surface modified slag powder are added together into an industrial homogenization device and mixed at high speed for 15 minutes to obtain the viscosity-reducing modified slag powder admixture TK-P-3 for railway concrete.

[0060] (5) The performance parameters of the modified tunnel slag powder admixture for general railway concrete were measured and are shown in Table 3.

[0061] Table 3 Performance parameters of modified caving stone powder admixture

[0062]

[0063] Comparative Example

[0064] A method for preparing unmodified granite slag powder admixture for railway concrete:

[0065] (1) The granite slag powder raw material was ground for 5 hours without the use of any grinding aids, surface modifiers and activity enhancers.

[0066] (2) Using a Blaine surface area analyzer, the specific surface area of ​​the unmodified quarry stone powder was measured to be 350 m². 2 / kg.

[0067] (3) Measure the performance parameters of the unmodified slag powder admixture, as shown in Table 4.

[0068] Table 4 Performance parameters of unmodified cavitary stone powder admixture

[0069]

[0070] Comparing the above embodiments and comparative examples, it was found that the specific surface area, 28-day activity index, and flowability ratio of the stone powder in the comparative example were all significantly reduced.

[0071] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A modified slag powder admixture for railway concrete, characterized in that, Including quarry stone powder raw materials and modified materials; The modified material includes an activity-enhancing component, a shrinkage-compensating component, a workability-improving component, a grinding-aiding component, and a surface-modifying component.

2. The modified slag powder admixture for railway concrete according to claim 1, characterized in that, The raw material for the slag stone powder is selected from any one of dolomite, slate, gneiss, granite, and limestone; the particle size of the raw material for the slag stone powder is 5-20mm.

3. The modified slag powder admixture for railway concrete according to claim 1, characterized in that, The activity-enhancing components in the modified material are any one or more of silica fume, sulfate, nano-silica, ultrafine mineral powder, and calcium sulfate whiskers.

4. The modified slag powder admixture for railway concrete according to claim 1, characterized in that, The shrinkage compensation component in the modified material is any one or a mixture of light-burned magnesium oxide, dark-burned magnesium oxide, aluminum powder, aluminum sulfate, water-absorbing resin, and calcium oxide expanding agent; The workability-improving component is any one or a mixture of cellulose ether, warm sizing agent, and glass microspheres.

5. The modified slag powder admixture for railway concrete according to claim 1, characterized in that, The grinding aid component in the modified material is any one or a mixture of diethylene glycol, triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, and gypsum dihydrate. The surface-modifying components are silane coupling agents and / or aluminate coupling agents.

6. A method for preparing modified slag powder admixture for railway concrete according to any one of claims 1-5, characterized in that, Includes the following steps: (1) The modified material grinding aid component is mixed with the caval rock and fed into the grinding equipment. After grinding, unmodified caval rock powder is obtained. (2) Dilute the surface modification component of the modified material with 10-100 times the mass of water, and spray it evenly on the unmodified karst stone powder to obtain surface-modified karst stone powder. (3) The active enhancement component, shrinkage compensation component, workability improvement component and surface modified slag powder in the modified material are put into the homogenization equipment and mixed for 10-30 minutes. Then, the mixture is transferred to the finished product silo and the material is allowed to cool naturally to room temperature to obtain the modified slag powder admixture finished product.

7. The preparation method of modified tunnel slag powder admixture for railway concrete according to claim 6, characterized in that, The mass ratio of the modified material grinding aid component to the cavitary rock in step (1) is 0.3 to 3:

10.

8. The preparation method of modified tunnel slag powder admixture for railway concrete according to claim 6, characterized in that, The specific surface area of ​​the unmodified quarry stone powder after grinding in step (1) is 400-800 m². 2 / kg.

9. The preparation method of modified tunnel slag powder admixture for railway concrete according to claim 6, characterized in that, The mass ratio of the activity-enhancing component, shrinkage-compensating component, workability-improving component and surface-modified quarry stone powder in step (3) is 5-10: 5-10: 1-5: 80-100.

10. The preparation method of modified tunnel slag powder admixture for railway concrete according to claim 6, characterized in that, The homogenization in step (3) is set to be homogenization at atmospheric pressure of 5-40℃.

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