A multi-scale fiber reinforced mixed mortar for protecting and reinforcing cultural relics in grottoes and a preparation method and application thereof

Abstract

The application provides application of desalted plant ash in protection of cultural relics in grotto temples. The application also provides a mixed mortar for reinforcement of the cultural relics in the grotto temples and a preparation method thereof. The multi-scale fiber reinforced mixed mortar provided by the application has mechanical properties matched with the protection requirements of the cultural relics in the grotto temples, low shrinkage, good acid resistance and salt resistance, and can cope with various adverse environmental factors such as dry-wet changes, crack water seepage, acid rain, salt crystallization damage and the like in the preservation of the cultural relics in the grotto temples. The preparation method is simple, raw materials are economical and easy to obtain, and the product is light and flexible. The application can solve the problem of insufficient anti-cracking capacity of the existing protection materials for the cultural relics in the grotto temples, improve the safety and durability of the cultural relics in the grotto temples, and has a comprehensive protection effect.

Description

Technical Field

[0001] This invention belongs to the technical field of materials for the protection and reinforcement of grotto temple cultural relics, and relates to the application of desalinated wood ash in the protection of grotto temple cultural relics, a mixed mortar for the protection and reinforcement of grotto temple cultural relics and its preparation method, and especially to a multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics, its preparation method and application. Background Technology

[0002] During the long-term preservation process, due to the influence of natural factors and human activities, grotto temple cultural relics face many problems such as weathering, damage, and loss, which seriously endanger their safety and preservation of value. The preservation status of immovable cultural relics is affected by the environmental conditions in which they are situated. Adverse environmental factors such as seepage through cracks, alternating wet and dry conditions, and acid rain can all accelerate the deterioration of the material of the cultural relics and the protective materials.

[0003] Traditional Chinese architectural materials often use lime mortar, but pure lime mortar hardens slowly and has low strength. Adding a small amount of hydraulic components creates a mixed mortar that combines air-hardening and hydraulic properties, increasing its strength and meeting the needs of stone artifact preservation. Furthermore, adding fibers can further enhance the material's toughness. Fibers of different sizes can exert their reinforcing and toughening functions at different levels, improving its crack resistance and making the material better suited for the preservation of grotto temple artifacts.

[0004] Although existing technologies use fibers to reinforce cement mortar or lime mortar, their effect is mainly to improve the strength of the material. They do not consider the compatibility of the materials used with the grotto temple relics themselves, or their weather resistance in environmental conditions such as water seepage, acid rain, and salt precipitation. Therefore, they are not suitable for the application scenarios of grotto temple relic protection and cannot meet their protection needs.

[0005] Therefore, finding a more suitable way to solve the above-mentioned problems of existing technologies and developing a series of protective and reinforcing materials that are more suitable for the protection of grotto temple cultural relics is of great significance to the safety protection and value preservation of grotto temple cultural relics. It is also one of the problems that many researchers in the field of grotto temple cultural relic protection urgently need to solve. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide the application of desalinated wood ash in the protection of grotto temple cultural relics, a mixed mortar for the protection and reinforcement of grotto temple cultural relics and its preparation method, and in particular, a multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics. The present invention specifically uses desalinated wood ash in the protection of grotto temple cultural relics and combines it with multi-scale fibers to reinforce the mixed mortar, thereby improving the strength and toughness of the protective material, greatly enhancing its weather resistance and safety in the environment where grotto temples exist, making it more suitable for the protection of grotto temple cultural relics. Moreover, the preparation method is simple, the raw materials are economical and readily available, making it more suitable for widespread promotion and practical application.

[0007] This invention provides the application of desalinated wood ash in the preservation of cultural relics in grotto temples.

[0008] Preferably, the desalinated wood ash is obtained by washing and desalinating wood ash with water;

[0009] The protection includes preparing protective materials;

[0010] The protective material includes fiber-reinforced mixed mortar.

[0011] Preferably, the protection includes protective reinforcement;

[0012] The desalinated plant ash accounts for 26.0% to 28.0% of the mass of the fiber-reinforced mixed mortar;

[0013] The temperature range for the application environment of the fiber-reinforced mixed mortar is 0–40℃.

[0014] The relative humidity of the application environment for the fiber-reinforced mixed mortar is 30% to 80%.

[0015] Preferably, the fiber-reinforced mixed mortar is a multi-scale fiber-reinforced mixed mortar;

[0016] The multi-scale fibers include centimeter-scale fibers and micron-scale fibers;

[0017] The protection specifically refers to one or more of the following: surface repair, damage repair, and bonding and reinforcement of fragments of cultural relics in grotto temples.

[0018] Preferably, the multi-scale fiber-reinforced mixed mortar also includes calcium carbonate whiskers and hemp fibers;

[0019] The calcium carbonate whiskers account for 1.0% to 4.0% of the mass of the fiber-reinforced mixed mortar;

[0020] The mass percentage of hemp fibers in the fiber-reinforced mixed mortar is 0.1% to 1.0%.

[0021] The desalinated wood ash is used to reduce the salt content of fiber-reinforced mixed mortar.

[0022] This invention provides a mixed mortar for the protection and reinforcement of grotto temple cultural relics, comprising, by weight percentage of raw materials:

[0023] The composition consists of 26.0%–28.0% desalinated wood ash, 14.0%–16.0% lime, 17.0%–19.0% quartz sand, 6.0%–8.0% cement, 1.0%–4.0% calcium carbonate whiskers, 0.1%–1.0% hemp fiber, and the balance being water.

[0024] Preferably, the lime includes slaked lime;

[0025] The cement includes silicate cement;

[0026] The particle size of the quartz sand is 20-200 mesh;

[0027] The hemp fibers include jute fibers.

[0028] Preferably, the whisker length of the calcium carbonate whiskers is 5–15 μm;

[0029] The width of the calcium carbonate whiskers is 0.1–1 μm;

[0030] The length of the hemp fibers is 2-3 cm.

[0031] This invention provides a preparation method for the protection and reinforcement of grotto temple cultural relics as described in any of the above technical solutions, comprising the following steps:

[0032] After dry mixing desalinated wood ash, quartz sand, cement, and calcium carbonate whisker powder, water is added and the mixture is continued. Then, a paste made of lime and water is added, and the mixture is mixed again. Finally, hemp fibers are added to obtain a mixed mortar.

[0033] Preferably, the dry mixing includes low-speed stirring dry mixing;

[0034] The rotation speed of the dry mixing is 100-200 r / min;

[0035] The dry mixing time is 25-35 seconds;

[0036] The continued mixing is a high-speed stirring mixture;

[0037] The mixing speed is 200–400 r / min;

[0038] The mixing time is 1 to 2 minutes.

[0039] This invention provides the application of desalinated wood ash in the preservation of grotto temple cultural relics. Compared with existing technologies, this invention creatively applies desalinated wood ash to the preservation of grotto temple cultural relics and correspondingly provides a mixed mortar with a specific composition and ratio for the preservation and reinforcement of grotto temple cultural relics. The mixed mortar provided by this invention uses a method of compounding fibers of different scales, such as centimeter-level and micron-level fibers, to obtain a multi-scale fiber-reinforced mixed mortar for the preservation and reinforcement of grotto temple cultural relics. This method can significantly improve the material's toughness and crack resistance while increasing its compressive and flexural strength. Furthermore, the use of desalinated wood ash, without increasing the salt content of the mortar, meets the requirement of reducing the soluble salt content of cultural relic preservation materials, further enhances the material's toughness, and keeps the material density at a low level to avoid excessive self-weight of the repair layer causing damage. At the same time, the price of wood ash raw materials is extremely low, which can reduce the production cost of the mortar. This invention uses desalinated wood ash and multi-scale fibers of specific materials to enhance mixed mortar, improving the material's strength and toughness while increasing its weather resistance in the environment of grotto temples. As a protective and reinforcing material, it is more suitable for the protection of cultural relics in grotto temples and is of great significance for the safety protection and preservation of the value of cultural relics in grotto temples.

[0040] This invention provides a multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics. The hemp fiber and calcium carbonate whisker microfiber used are economical, readily available, stable, safe, durable, and highly compatible with the grotto temple relics themselves, preventing secondary damage during reinforcement. Furthermore, it possesses both air-hardening and hydraulic properties, with adjustable strength, adaptable to various grotto temple cultural relic protection needs. Through multi-scale fiber reinforcement and the application of dehydrated wood ash, the resulting material exhibits low shrinkage, volume stability, and good acid, water, and salt resistance, better addressing adverse environmental challenges such as wet-dry cycles, acid rain, and salt precipitation encountered in the preservation of grotto temple cultural relics, achieving comprehensive protective effects. In practical use, the preparation method is simple, the resulting mortar has low segregation and good water retention, exhibiting excellent workability and ease of operation in the protection of grotto temple cultural relics. It is well-suited for large-scale application and holds significant importance for the safe protection and preservation of the value of grotto temple cultural relics. Attached Figure Description

[0041] Figure 1 This is a SEM scan of the material cross-section in Embodiment 1 of the present invention;

[0042] Figure 2 The figures show a comparison of the performance of the materials in Examples 1-4 and Comparative Examples 1-3 in the salt crystallization failure experiment. Detailed Implementation

[0043] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims.

[0044] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0045] There are no particular restrictions on the purity of any of the raw materials used in this invention. However, this invention preferably uses industrial-grade pure materials or materials with the conventional purity requirements in the field of grotto temple cultural relic protection.

[0046] All raw materials of this invention are conventional in the field, and each brand name and abbreviation is clear and distinct in its relevant application. Those skilled in the art can purchase them from the market or prepare them by conventional methods based on the brand name, abbreviation and corresponding application.

[0047] This invention provides the application of desalinated wood ash in the preservation of cultural relics in grotto temples.

[0048] In this invention, the desalinated wood ash is preferably obtained by washing and desalinating wood ash with water.

[0049] In this invention, the protection preferably includes the preparation of a protective material.

[0050] In this invention, the protective material preferably comprises fiber-reinforced mixed mortar.

[0051] In this invention, the protection includes protective reinforcement;

[0052] In this invention, the mass percentage of the desalinated wood ash in the fiber-reinforced mixed mortar is preferably 26.0% to 28.0%, more preferably 26.4% to 27.6%, and even more preferably 26.8% to 27.2%.

[0053] In this invention, the temperature of the application environment of the fiber-reinforced mixed mortar is preferably 0 to 40°C, more preferably 8 to 32°C, and even more preferably 16 to 24°C.

[0054] In this invention, the relative humidity of the application environment of the fiber-reinforced mixed mortar is preferably 30% to 80%, more preferably 40% to 70%, and even more preferably 50% to 60%.

[0055] In this invention, the fiber-reinforced mixed mortar is preferably a multi-scale fiber-reinforced mixed mortar.

[0056] In this invention, the multi-scale fibers preferably include centimeter-scale fibers and micrometer-scale fibers.

[0057] In this invention, the protection is preferably one or more of the following: surface repair, damage repair, and fragment bonding and reinforcement of grotto temple cultural relics; more preferably, it is multiple of the following: surface repair, damage repair, and fragment bonding and reinforcement of grotto temple cultural relics.

[0058] In this invention, the multi-scale fiber-reinforced mixed mortar preferably also includes calcium carbonate whiskers and hemp fibers.

[0059] In this invention, the mass percentage of the calcium carbonate whiskers in the fiber-reinforced mixed mortar is preferably 1.0% to 4.0%, more preferably 1.5% to 3.5%, and even more preferably 2.0% to 3.0%.

[0060] In this invention, the mass percentage of hemp fibers in the fiber-reinforced mixed mortar is preferably 0.1% to 1.0%, more preferably 0.3% to 0.8%, and even more preferably 0.5% to 0.6%.

[0061] In this invention, the desalinated wood ash is preferably used to reduce the salt content of fiber-reinforced mixed mortar.

[0062] This invention provides a mixed mortar for the protection and reinforcement of grotto temple cultural relics, comprising, by weight percentage of raw materials:

[0063] The composition consists of 26.0%–28.0% desalinated wood ash, 14.0%–16.0% lime, 17.0%–19.0% quartz sand, 6.0%–8.0% cement, 1.0%–4.0% calcium carbonate whiskers, 0.1%–1.0% hemp fiber, and the balance being water.

[0064] In this invention, the amount of desalinated wood ash added is 26.0% to 28.0%, or 26.4% to 27.6%, or 26.8% to 27.2%.

[0065] In this invention, the amount of lime added is 16.0% to 18.0%, or 16.4% to 17.6%, or 16.8% to 17.2%.

[0066] In this invention, the amount of quartz sand added is 17.0% to 19.0%, which can be 17.4% to 18.6%, or 17.8% to 18.2%.

[0067] In this invention, the amount of cement added is 6.0% to 8.0%, or it can be 6.4% to 7.6%, or it can be 6.8% to 7.2%.

[0068] In this invention, the amount of calcium carbonate whiskers added is 1.0% to 4.0%, or 1.5% to 3.5%, or 2.0% to 3.0%.

[0069] In this invention, the amount of hemp fiber added is 0.1% to 1.0%, which can be 0.3% to 0.8%, or 0.5% to 0.6%.

[0070] In this invention, the lime preferably comprises hydrated lime;

[0071] In this invention, the cement preferably comprises silicate cement.

[0072] In this invention, the particle size of the quartz sand is preferably 20-200 mesh, more preferably 60-160 mesh, and even more preferably 100-120 mesh.

[0073] In this invention, the hemp fibers preferably include jute fibers.

[0074] In this invention, the whisker length of the calcium carbonate whiskers is preferably 5-15 μm, more preferably 7-13 μm, and even more preferably 9-11 μm.

[0075] In this invention, the whisker width of the calcium carbonate whiskers is preferably 0.1 to 1 μm, more preferably 0.3 to 0.8 μm, and even more preferably 0.5 to 0.6 μm.

[0076] In this invention, the length of the hemp fibers is preferably 2-3 cm, more preferably 2.2-2.8 cm, and even more preferably 2.4-2.6 cm.

[0077] The multi-scale fiber-reinforced mixed mortar provided by this invention has mechanical properties that match the requirements for the protection of grotto temple cultural relics. It has low shrinkage, good acid resistance and salt resistance, and can cope with various adverse environmental factors such as changes in dryness and wetness, water seepage through cracks, acid rain, and salt crystallization damage in the preservation of grotto temple cultural relics. Moreover, the preparation method is simple, the raw materials are economical and readily available, and the product is lightweight and flexible. It can solve the problem of insufficient crack resistance of existing grotto temple cultural relic protection materials, while improving their safety and durability, and has a comprehensive protection effect.

[0078] This invention provides a method for preparing mixed mortar for the protection and reinforcement of grotto temple cultural relics as described in any of the above technical solutions, comprising the following steps:

[0079] After dry mixing desalinated wood ash, quartz sand, cement, and calcium carbonate whisker powder, water is added and the mixture is continued. Then, a paste made of lime and water is added, and the mixture is mixed again. Finally, hemp fibers are added to obtain a mixed mortar.

[0080] In this invention, the desalinated wood ash is preferably prepared through the following steps:

[0081] After sieving the wood ash, it is mixed with water, allowed to stand, separated, and then dried to obtain desalinated wood ash.

[0082] In this invention, the separation specifically involves discarding the upper suspension.

[0083] In this invention, the steps prior to drying are preferably performed multiple times, specifically more than five times.

[0084] In this invention, the dry mixing preferably includes low-speed stirring dry mixing.

[0085] In this invention, the rotational speed of the dry mixing is preferably 100-200 r / min, more preferably 120-180 r / min, and even more preferably 140-160 r / min.

[0086] In this invention, the dry mixing time is preferably 25 to 35 seconds, more preferably 27 to 33 seconds, and even more preferably 29 to 31 seconds.

[0087] In this invention, the continued mixing is preferably carried out by high-speed stirring.

[0088] In this invention, the rotational speed for continued mixing is preferably 200-400 r / min, more preferably 240-360 r / min, and even more preferably 280-320 r / min.

[0089] In this invention, the continued mixing time is preferably 1 to 2 minutes, more preferably 1.2 to 1.8 minutes, and even more preferably 1.4 to 1.6 minutes.

[0090] This invention provides a complete and detailed overall technical solution to better improve the strength and toughness of the mixed mortar during application, further reduce shrinkage, maintain volume stability, and improve acid resistance, water resistance, and salt resistance. Specifically, the aforementioned multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics and its preparation method may include the following:

[0091] One of the technical solutions of the present invention provides a multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics, characterized in that: the mixed mortar is composed of the following raw materials in the following mass percentages: 26.0% to 28.0% desalinated wood ash, 14.0% to 16.0% lime, 17.0% to 19.0% quartz sand, 6.0% to 8.0% cement, 1.0% to 4.0% calcium carbonate whiskers, 0.1% to 1.0% hemp fiber, and the balance being water.

[0092] Specifically, the desalinated wood ash is obtained through the following steps:

[0093] Step 1: After passing the wood ash through a 20-mesh square-hole sieve, add three times its volume of water and stir thoroughly.

[0094] Step 2: After standing for one hour, discard the upper suspension.

[0095] Step 3: Repeat steps 1-2 five or more times to dry the precipitate and obtain desalinated wood ash.

[0096] Specifically, the lime is industrial-grade lime containing more than 95% calcium hydroxide, and it should be mixed with water to form a paste at least 24 hours in advance before use.

[0097] Specifically, the cement is grade 42.5 ordinary Portland cement.

[0098] Specifically, the sand is quartz sand with a particle size of 20 to 200 mesh.

[0099] Specifically, the calcium carbonate whiskers are aragonite phase crystals with a length of 5-15 μm and a width of 0.1-1 μm, a tensile strength of 3-6 GPa, and an elastic modulus of 410-710 GPa.

[0100] Specifically, the hemp fibers are jute fibers 2-3 cm long, with a tensile strength of 0.3-0.7 GPa and an elastic modulus of 20-40 GPa.

[0101] The second technical solution of the present invention provides a method for preparing multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics, which is implemented according to the following steps:

[0102] Step 1: Weigh the required raw materials according to the proportions;

[0103] Step 2: Dry mix desalinated wood ash, quartz sand, cement and calcium carbonate whisker powder, stir at low speed for 30 seconds, add water and stir at high speed for 1-2 minutes, and then evenly add the prepared lime paste to the mixture.

[0104] Step 3: After the lime is completely added, continue stirring at high speed for 1 minute, and slowly incorporate the hemp fibers into the mixture to disperse the hemp fibers evenly.

[0105] The third technical solution of the present invention provides an application of multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics. This mixed mortar is used for surface repair, damage repair and bonding and reinforcement of fragments of grotto temple cultural relics.

[0106] Specifically, the third feature of the technical solution of the present invention is that the application environment temperature of the mixed mortar should be between 0-40℃ and the relative humidity should be between 30-80%.

[0107] The present invention provides the application of desalinated wood ash in the protection of grotto temple cultural relics, a multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics, its preparation method, and its application. Specifically, the present invention applies desalinated wood ash to the protection of grotto temple cultural relics and provides a mixed mortar with a specific composition and ratio for the protection and reinforcement of grotto temple cultural relics. The mixed mortar provided by the present invention uses a method of compounding fibers of different scales, such as centimeter-level and micron-level, to obtain a multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics. This method can significantly improve the compressive and flexural strength of the material while significantly enhancing its toughness and crack resistance. Furthermore, the use of desalinated wood ash, without increasing the salt content of the mortar, meets the requirement of reducing the soluble salt content of cultural relic protection materials, further enhances the toughness of the material, and keeps the material density at a low level to avoid excessive self-weight of the repair layer causing damage. At the same time, the price of wood ash raw materials is extremely low, which can reduce the production cost of the mortar. This invention uses desalinated wood ash and multi-scale fibers of specific materials to enhance mixed mortar, improving the material's strength and toughness while increasing its weather resistance in the environment of grotto temples. As a protective and reinforcing material, it is more suitable for the protection of cultural relics in grotto temples and is of great significance for the safety protection and preservation of the value of cultural relics in grotto temples.

[0108] This invention provides a multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics. The hemp fiber and calcium carbonate whisker microfiber used are economical, readily available, stable, safe, durable, and highly compatible with the grotto temple relics themselves, preventing secondary damage during reinforcement. Furthermore, it possesses both air-hardening and hydraulic properties, with adjustable strength, adaptable to various grotto temple cultural relic protection needs. Through multi-scale fiber reinforcement and the application of dehydrated wood ash, the resulting material exhibits low shrinkage, volume stability, and good acid, water, and salt resistance, better addressing adverse environmental challenges such as wet-dry cycles, acid rain, and salt precipitation encountered in the preservation of grotto temple cultural relics, achieving comprehensive protective effects. In practical use, the preparation method is simple, the resulting mortar has low segregation and good water retention, exhibiting excellent workability and ease of operation in the protection of grotto temple cultural relics. It is well-suited for large-scale application and holds significant importance for the safe protection and preservation of the value of grotto temple cultural relics.

[0109] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, describes the application of desalinated wood ash provided by the present invention in the protection of grotto temple cultural relics, a mixed mortar for the protection and reinforcement of grotto temple cultural relics, and its preparation method. However, it should be understood that these embodiments are implemented under the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operating procedures. They are only for further illustrating the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention. The scope of protection of the present invention is not limited to the following embodiments.

[0110] Example 1

[0111] A multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics, the mixed mortar is composed of the following raw materials in the following mass percentages (kg): 25.0% desalinated wood ash, 14.7% lime, 17.6% quartz sand, 7.4% cement, 1.3% calcium carbonate whiskers, 0.16% hemp fiber, and the balance being water.

[0112] The method for preparing multi-scale fiber-reinforced mixed mortar for protection and reinforcement includes the following steps:

[0113] Step 1: Weigh the required raw materials according to the proportions;

[0114] Step 2: Dry mix desalinated wood ash, quartz sand, cement and calcium carbonate whisker powder, stir at low speed for 30 seconds, add water and stir at high speed for 2 minutes, and then evenly add the prepared lime paste to the mixture.

[0115] Step 3: After the lime is completely added, continue stirring at high speed for 1 minute, and slowly incorporate the hemp fibers into the mixture to disperse the hemp fibers evenly.

[0116] Example 2

[0117] A multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics, the mixed mortar is composed of the following raw materials in the following mass percentages (kg): 23.7% desalinated wood ash, 14.7% lime, 17.6% quartz sand, 7.4% cement, 2.6% calcium carbonate whiskers, 0.16% hemp fiber, and the balance being water.

[0118] The preparation method of the multi-scale fiber-reinforced mixed mortar used for protection and reinforcement is the same as in Example 1.

[0119] Example 3

[0120] A multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics, the mixed mortar is composed of the following raw materials in the following mass percentages (kg): 24.8% desalinated wood ash, 14.7% lime, 17.6% quartz sand, 7.4% cement, 1.3% calcium carbonate whiskers, 0.34% hemp fiber, and the balance being water.

[0121] The preparation method of the multi-scale fiber-reinforced mixed mortar used for protection and reinforcement is the same as in Example 1.

[0122] Example 4

[0123] A multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics, the mixed mortar is composed of the following raw materials in the following mass percentages (kg): 23.5% desalinated wood ash, 14.7% lime, 17.6% quartz sand, 7.4% cement, 2.6% calcium carbonate whiskers, 0.34% hemp fiber, and the balance being water.

[0124] The preparation method of the multi-scale fiber-reinforced mixed mortar used for the protection and reinforcement of grotto temple cultural relics is the same as in Example 1.

[0125] Comparative Example 1

[0126] Compared to Example 1, most aspects are the same, except that calcium carbonate whiskers and hemp fibers are not added. Due to the lack of fiber reinforcement and toughening, this material has low strength, is prone to cracking, and cannot meet the needs of protecting grotto temple cultural relics.

[0127] Comparative Example 2

[0128] Compared to Example 1, most aspects are the same, with no calcium carbonate whiskers added. Due to the lack of microfibers capable of stress transmission at the microscopic level, the internal defects introduced by the hemp fibers affect the splitting tensile strength of the material, which is detrimental to improving its toughness.

[0129] Comparative Example 3

[0130] Compared to Example 1, most aspects are the same, except that no desalinated wood ash is added. Due to the absence of desalinated wood ash as an admixture, the material has poor toughness. Although the strength increases to some extent due to the increased percentage of lime and cement content, it also has a higher compression-flexural ratio, low splitting tensile strength, and poor acid resistance, making it prone to cracking during use and unable to meet the needs of grotto temple cultural relic protection.

[0131] The mixed mortars of Examples 1, 2, 3, 4 and Comparative Examples 1, 2, and 3 were poured into specimens of 40*40*160mm and 70.7*70.7*70.7mm. After curing under the same conditions, mechanical property tests were conducted on the specimens after 28 days, in accordance with the "Test Method for Strength of Cement Mortar (ISO Method)".

[0132] See Table 1, which shows the test results of the mechanical strength properties of the mixed mortars obtained in Examples 1-4 and Comparative Examples 1-3.

[0133] Table 1

[0134]

[0135]

[0136] The results are shown in Table 1. The embodiments obtained by the present invention have better mechanical properties, lower compression-to-flexural ratio, and better crack resistance.

[0137] The mixed mortars from Examples 1, 2, 3, and 4, and Comparative Examples 1, 2, and 3 were poured into specimens measuring 40*40*160mm and cured under the same conditions. After 60 days, the specimens underwent softening coefficient testing and salt crystallization damage testing. After 80 days, the specimens underwent acid treatment testing. The tests were conducted as follows:

[0138] 1. The softening coefficient test procedure is as follows: Take a prism specimen with a curing age of 60 days, dry it in an oven at 80℃ until constant weight, and measure its compressive strength; immerse the specimen of the same age completely in pure water, take it out after 48 hours, and measure its compressive strength again. The ratio of the two is the softening coefficient. During the test, always cover the specimen with a damp cloth to maintain its saturated state.

[0139] 2. The salt crystallization failure test procedure is as follows: Take a prism specimen with a curing age of 60 days, dry it in an oven at 80℃ to constant weight, and measure its compressive strength; immerse the specimen of the same age in a saturated sodium sulfate solution for 24h (±0.5h), and then place it in a test chamber at a temperature of 20℃ and a relative humidity of 70% for 24h (±0.5h) to allow salt crystals to precipitate. Immersion + crystallization constitutes one cycle, and each group of specimens undergoes 3 cycles. Take pictures to record the changes in the samples, test its compressive strength, and calculate the strength loss rate of the specimen after the salt crystallization failure cycle.

[0140] 3. The acid treatment test procedure is as follows: take a prism specimen with a curing age of 80 days, dry it in an oven at 80℃ to constant weight, soak it in a sulfuric acid solution with pH 4 for 48 hours, weigh it after drying, and calculate the mass loss rate of the specimen. At the same time, take another group of specimens of the same age and test the change in compressive strength before and after soaking, and calculate the strength loss rate of the specimens before and after acid treatment.

[0141] See Table 2, which shows the softening coefficient, salt crystallization failure, and acid treatment test results of the mixed mortars obtained in Examples 1-4 and Comparative Examples 1-3.

[0142] Table 2

[0143]

[0144]

[0145] The results are shown in Table 2. The embodiments obtained by the present invention have a higher softening coefficient, better acid resistance and salt resistance, and can better cope with environmental changes in dryness and wetness, water seepage, acid rain and salt precipitation in the protection and reinforcement of grotto temple cultural relics.

[0146] See Figure 1 , Figure 1 This is a SEM scan of the material cross-section in Embodiment 1 of the present invention.

[0147] like Figure 1 As shown, fiber breakage and pull-out marks are visible.

[0148] See Figure 2 , Figure 2 The figures show a comparison of the performance of the materials in Examples 1-4 and Comparative Examples 1-3 in the salt crystallization failure experiment.

[0149] The present invention provides a detailed description of a multi-scale fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics, its preparation method, and its application. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of the embodiments are merely to help understand the method and core ideas of the invention, including the best mode, and to enable any person skilled in the art to practice the invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the wording of the claims, or if they include equivalent structural elements that are not substantially different from the wording of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. Application of desalinated wood ash in the preservation of cultural relics in grotto temples; The desalinated wood ash is obtained by washing and desalinizing wood ash with water; The protection includes preparing protective materials; The protective material includes fiber-reinforced mixed mortar; The fiber-reinforced mixed mortar is specifically a multi-scale fiber-reinforced mixed mortar; The multi-scale fiber-reinforced mixed mortar also includes calcium carbonate whiskers and hemp fibers; The desalinated wood ash accounts for 26.0% to 28.0% of the mass of the fiber-reinforced mixed mortar.

2. The application according to claim 1, characterized in that, The protection includes reinforcement.

3. The application according to claim 1, characterized in that, The temperature range for the application environment of the fiber-reinforced mixed mortar is 0~40℃; The relative humidity of the application environment for the fiber-reinforced mixed mortar is 30%~80%.

4. The application according to claim 1, characterized in that, The multi-scale fibers include centimeter-scale fibers and micron-scale fibers; The protection specifically refers to one or more of the following: surface repair, damage repair, and bonding and reinforcement of fragments of cultural relics in grotto temples.

5. The application according to claim 1, characterized in that, The calcium carbonate whiskers constitute 1.0% to 4.0% of the mass of the fiber-reinforced mixed mortar. The mass percentage of hemp fibers in the fiber-reinforced mixed mortar is 0.1% to 1.0%; The desalinated wood ash is used to reduce the salt content of fiber-reinforced mixed mortar.

6. A fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics as described in any one of claims 1 to 5, characterized in that, By percentage of raw material mass, including: The composition consists of 26.0%~28.0% desalinated wood ash, 14.0%~16.0% lime, 17.0%~19.0% quartz sand, 6.0%~8.0% cement, 1.0%~4.0% calcium carbonate whiskers, 0.1%~1.0% hemp fiber, and the balance being water.

7. The fiber-reinforced mixed mortar according to claim 6, characterized in that, The lime includes slaked lime; The cement includes silicate cement; The particle size of the quartz sand is 20~200 mesh; The hemp fibers include jute fibers.

8. The fiber-reinforced mixed mortar according to claim 6, characterized in that, The whisker length of the calcium carbonate whiskers is 5~15 μm; The width of the calcium carbonate whiskers is 0.1~1 μm; The length of the hemp fibers is 2-3 cm.

9. A method for preparing fiber-reinforced mixed mortar for the protection and reinforcement of grotto temple cultural relics as described in any one of claims 6 to 8, characterized in that, Includes the following steps: After dry mixing desalinated wood ash, quartz sand, cement and calcium carbonate whisker powder, water is added and the mixture is continued to mix. Then, a paste made of lime and water is added, and the mixture is mixed again. Finally, hemp fibers are added to obtain fiber-reinforced mixed mortar.

10. The preparation method according to claim 9, characterized in that, The dry mixing includes low-speed stirring dry mixing; The rotation speed of the dry mixer is 100~200 r / min; The dry mixing time is 25-35 seconds; The continued mixing is a high-speed stirring mixture; The mixing speed is 200~400 r / min; The mixing time is 1 to 2 minutes.

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