Thermodynamic modified material for grotto rock mass fissure grouting and preparation method thereof

Abstract

The present application relates to the technical field of building materials, in particular to a thermodynamic modified material for grotto rock mass fissure grouting and a preparation method thereof, which comprises the following components in a mass ratio: lime-based material 100-200 parts; quartz sand 30-50 parts; metakaolin 30-70 parts; calcium aluminate expansive agent 10-20 parts.The present application has the advantages of optimized thermal conductivity, controlled thermal expansion coefficient, improved microstructure and comprehensive performance.The thermal conductivity of the lime-based grouting material is higher than that of traditional tung oil materials, reducing thermal stress concentration caused by temperature gradient;the thermal expansion coefficient can be changed from negative to positive by adjusting the water-cement ratio and the amount of expansive agent, and tends to be close to the limestone rock mass, reducing the risk of interface peeling;the optimized material has higher crystallinity and denser structure, reducing microfissures and improving heat conduction efficiency;while maintaining high mechanical strength and durability, the material realizes directional modification of thermodynamic properties, providing technical support for long-term preservation of grottoes.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a thermodynamically modified material for grouting rock fissures in grouting cave temples and its preparation method. Background Technology

[0002] As a World Cultural Heritage site, the rock mass of the grotto temple has been affected by the natural environment for a long time, and faces problems such as rock mass instability, water seepage damage, and weathering erosion. Grouting reinforcement is the main means of preventing seepage and rescuing the rock mass of the grotto temple.

[0003] However, existing grouting materials (such as traditional lime-based materials, tung oil used for historical restoration, cement, etc.) have a mismatch in thermodynamic properties with the rock mass. Under temperature cycling, due to the difference in thermal expansion coefficient and thermal conductivity between the grouting material and the rock mass, thermal stress is easily generated, leading to rock mass cracking or grout layer peeling. Summary of the Invention

[0004] The purpose of this invention is to provide a thermodynamically modified material for grouting cracks in rock masses of grouting temples and its preparation method, in order to solve the problem mentioned in the background art that the difference in thermal expansion coefficient and thermal conductivity between the grouting material and the rock mass easily generates thermal stress, leading to rock mass cracking or grout layer peeling.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a thermodynamically modified material for grouting fissures in rock masses of grouting temples, comprising the following components in the following mass ratio: 100-200 parts lime-based material, 30-50 parts quartz sand, 30-70 parts metakaolin, and 10-20 parts calcium aluminate expanding agent.

[0006] A method for preparing a thermodynamically modified material for grouting fissures in rock masses of grouting temples involves mixing LJS, fillers, and additives in a set ratio, controlling the water-cement ratio within the range of 0.5-0.7, and the amount of expanding agent between 7% and 13%. After stirring, molding, and curing, the modified grouting material is obtained.

[0007] Preferably, the stirring time is 10 minutes, the mixture is poured into the mold, and then vibrated to compact it.

[0008] Preferably, the material is cured for 28 days at 20±2°C and 95% humidity after being injected into the mold.

[0009] Compared with the prior art, the beneficial effects of the present invention are: Optimized thermal conductivity: The thermal conductivity of lime-based grouting material can be close to 1.05 W / (m·K), which is higher than that of traditional tung oil material, reducing the concentration of thermal stress caused by temperature gradient.

[0010] Thermal expansion coefficient control: By adjusting the water-cement ratio and the amount of expansion agent, the thermal expansion coefficient can be changed from a negative value to a positive value and approach the value of the limestone rock mass, thus reducing the risk of interface peeling.

[0011] Microstructure improvement: The optimized material has higher crystallinity and denser structure, reducing microcracks and improving thermal conductivity.

[0012] Overall performance: While maintaining high mechanical strength and durability, the material of this invention achieves directional modification of thermodynamic properties, providing technical support for the long-term preservation of grotto temples. Attached Figure Description

[0013] Figure 1 This is a schematic diagram illustrating the comparison of the thermodynamic properties of the historical repair materials of this invention; Figure 2 This is a schematic diagram illustrating the effect of the filler ratio on the thermal conductivity of the present invention; Figure 3 This is a schematic diagram of the thermal expansion coefficient test results of the present invention; Figure 4 This is a schematic diagram of XRD analysis according to the present invention; Figure 5 This is a schematic diagram of the XRF results of the present invention; Figure 6 This is a schematic diagram of SEM testing and microcrack parameter analysis according to the present invention. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0015] Please see Figure 1-6 One embodiment provided by the present invention: Example

[0016] A thermodynamically modified material for grouting fissures in rock masses of grout temples, comprising the following components in the following mass ratio: 100-200 parts lime-based material, 30-50 parts quartz sand, 30-70 parts metakaolin, and 10-20 parts calcium aluminate expanding agent.

[0017] A method for preparing a thermodynamically modified material for grouting fissures in rock masses of grouting temples involves mixing LJS, fillers, and additives in a set ratio, controlling the water-cement ratio within the range of 0.5-0.7, and the amount of expanding agent between 7% and 13%. After stirring, molding, and curing, the modified grouting material is obtained.

[0018] Furthermore, the stirring time is 10 minutes, the mixture is poured into the mold, and then vibrated to compact it.

[0019] Furthermore, after the material is injected into the mold, it is cured for 28 days at 20±2°C and 95% humidity. Example

[0020] A thermodynamically modified material for grouting fissures in rock masses of Shikusi Temple is proposed. LJS is used as the main agent, and quartz sand, metakaolin and calcium aluminate expansion agent (AEA) are used as fillers and additives. The filler mass ratio, water-cement ratio and expansion agent dosage are the key parameters.

[0021] A method for preparing a thermodynamically modified material for grouting fissures in grouting grouting sites in grouting caves involves mixing LJS, fillers, and additives in a predetermined ratio, controlling the water-cement ratio within the range of 0.5-0.7, and the expansion agent dosage between 7% and 13%. After stirring, molding, and curing, the modified grouting material is obtained. The design gradient in Table 1 is used for optimization. Based on the grouting material design in Table 1, this invention preferably uses group D as the modification basis because group D significantly affects the thermodynamic properties through the expansion agent dosage gradient (7%-13%). Specific proportions are as follows: Table 1 Grouting Material Design

[0022] During implementation, first weigh LJS, metakaolin and quartz sand and mix them according to the above mass ratio, then add the set amount of AEA expansion agent, and finally add water according to the water-cement ratio, stir until a uniform slurry is formed, and after the sample is formed, cure it under standard conditions for 28 days for performance testing.

[0023] Combination Figure 1 It can be seen that the thermodynamic properties of historical restoration materials show that LJS-based materials have a thermal conductivity closer to that of limestone; the modified material of this invention further optimizes this property.

[0024] Combination Figure 2 It can be seen that by optimizing the proportions (such as group D), the thermal conductivity of the present invention increases with the increase of the amount of expanding agent, reaching up to 0.8-1.0 W / (m·K), which is superior to traditional materials.

[0025] Combination Figure 3 It can be seen that the present invention makes the coefficient of thermal expansion adjustable by controlling the water-cement ratio and the amount of expanding agent. For example, the coefficient of thermal expansion of the DL3 sample is positive, close to that of the limestone rock mass, thus reducing thermal mismatch.

[0026] Combination Figure 4 It can be seen that the DL3 sample has the highest crystallinity, with anorthite (CaAl2Si2O8) as the dominant crystalline phase, which is beneficial for heat conduction.

[0027] Combination Figure 5 It is known that increasing the content of trace components such as MgO can help improve thermal conductivity. This invention achieves this effect by controlling the amount of expansion agent added.

[0028] Combination Figure 6 It is evident that the material of this invention, through optimized proportioning, reduces the porosity and roundness, thereby decreasing thermal resistance. For example, the DL3 sample exhibits a porosity of 0.22, a roundness of 5.90, and a relatively high thermal conductivity.

[0029] Example 3: A method for preparing a thermodynamically modified material for grouting fissures in rock masses of grouting temples: Taking DL3 as an example, the specific implementation steps are as follows: Take 100 parts of LJS, 60 parts of metakaolin, and 40 parts of quartz sand, and mix them evenly.

[0030] Add 13 parts of AEA expanding agent, control the water-cement ratio to 0.6, and add water until the slurry has suitable fluidity.

[0031] Stir for 10 minutes, pour into the mold, and vibrate to compact.

[0032] Cured for 28 days at 20±2°C and 95% humidity.

[0033] The resulting material has a thermal conductivity of approximately 0.8 W / (m·K) and a thermal expansion coefficient close to that of limestone, resulting in a significant improvement in thermal compatibility.

[0034] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A thermodynamically modified material for grouting fissures in rock masses of grout temples, characterized in that, It includes the following mass ratios: 100-200 parts lime-based material, 30-50 parts quartz sand, 30-70 parts metakaolin, and 10-20 parts calcium aluminate expanding agent.

2. A method for preparing a thermodynamically modified material for grouting fissures in rock masses of grout temples, characterized in that: The LJS, filler, and additives are mixed in a set ratio, the water-cement ratio is controlled within the range of 0.5-0.7, and the amount of expansion agent is between 7% and 13%. After stirring, molding, and curing, the modified grouting material is obtained.

3. The method for preparing a thermodynamically modified material for grouting fissures in rock masses of grouting temples according to claim 2, characterized in that: The mixing time is 10 minutes, then the mixture is poured into a mold and vibrated to compact it.

4. The method for preparing a thermodynamically modified material for grouting fissures in rock masses of grouting temples according to claim 3, characterized in that: After the material is injected into the mold, it is cured for 28 days at 20±2°C and 95% humidity.

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