Hydraulic lime cementing material as well as preparation method and application thereof

Abstract

The invention discloses a preparation method and application of a hydraulic lime cementing material. The hydraulic lime cementing material comprises the following raw materials in parts by weight: 12-70 parts of calcium oxide, 15-80 parts of calcium hydroxide, 10-25 parts of calcium carbonate, 1-5 parts of mineral powder and 0.2-0.5 part of an auxiliary agent. The calcium oxide, the calcium hydroxide, the calcium carbonate and the mineral powder are superfine powder and have the specific surface area of 450-500cm < 2 > / kg. The hydraulic lime cementing material is applied to restoration and reinforcement engineering of rock soil cultural relics. The bottleneck that raw materials are limited and the quality cannot be regulated and controlled in the traditional rock soil restoration material production is broken through, the related performance requirements of rock soil cultural relic protection engineering can be met, the product performance is stable, the production cost is greatly reduced, the production technological process is simplified, and large-scale mass production is completely achieved.

Description

Technical Field

[0001] The invention belongs to the field of restoration of rock and soil cultural relics and the technical field of composite materials, and specifically relates to a hydraulic lime cementitious material and a preparation method and application thereof. Background Art

[0002] Rock and soil cultural relics are one of the important types of cultural heritage. Rock and soil cultural relics are sites or relics left over from human production and life, with soil as the main building material. Due to the long-term influence of natural environment and human activities, these cultural relics have undergone quantitative or qualitative changes to varying degrees. Therefore, the protection of rock and soil cultural relics has always been the focus and difficulty of research for cultural relic protection workers.

[0003] Gel material is a kind of repair material for rock and soil cultural relics. The earliest cementitious material used by humans was natural clay, but clay has low strength and cannot resist the erosion and alkali corrosion of rainwater. Hydraulic lime has a porous structure and good air permeability, which makes it more compatible with the main material of the cultural relics to be reinforced and repaired. It can firmly combine with the main body of the cultural relics in a humid environment and absorb CO in the air. 2 In the process, it completes slow self-carbonization healing, and the strength gradually increases slowly. Therefore, hydraulic lime is widely used in rock and soil cultural relics restoration projects. At present, domestic rock and soil cultural relics restoration materials have problems such as great difficulty in raw material supply, poor uniformity, complex production process, unstable product performance, uncontrollable quality, high production cost, etc., and it is impossible to achieve large-scale mass production and market demand. In view of the above problems, the present invention provides a hydraulic lime cementitious material whose performance indicators are fully benchmarked against European standards, meet the relevant performance requirements of rock and soil cultural relics protection, and can greatly reduce the cost of cultural relics restoration projects. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a hydraulic lime gel material for the restoration and reinforcement of rock and soil cultural relics, which not only meets the expected requirements of cultural relics restoration projects for material strength, water resistance, durability, construction performance, etc., but also has both ecological and environmental adaptability. The purpose of the present invention is achieved through the following technical solutions:

[0005] A hydraulic lime cementitious material comprises the following raw materials in parts by weight: 12 to 70 parts of calcium oxide, 15 to 80 parts of calcium hydroxide, 10 to 25 parts of calcium carbonate, 1 to 5 parts of mineral powder, and 0.2 to 0.5 parts of an auxiliary agent; the calcium oxide, calcium hydroxide, calcium carbonate, and mineral powder are ultrafine powders with a specific surface area of ​​450 to 500 cm 2 / kg; the auxiliary agent is an ultrafine powder water-retaining agent.

[0006] In a further embodiment, the calcium oxide comprises 12 parts, calcium hydroxide comprises 75 parts, calcium carbonate comprises 10 parts, mineral powder comprises 2.7 parts, and an additive comprises 0.3 parts.

[0007] Furthermore, the specific surface area of ​​the ultrafine powder water retaining agent is 650-700 cm 2 / kg.

[0008] Furthermore, the ultrafine powder water retaining agent is any one of calcium formate and triethanolamine.

[0009] Furthermore, the calcium oxide, calcium hydroxide, calcium carbonate and mineral powder are ultrafine powders with a specific surface area of ​​450cm 2 / kg; the specific surface area of ​​the ultrafine powder water retaining agent is 650m 2 / kg.

[0010] Furthermore, the mineral powder is any one of the mineral powders of activity level S75, S95, and S105, or a mixed mineral powder of multiple mineral powders.

[0011] The method for preparing the hydraulic lime cementitious material comprises the following steps:

[0012] S1. Weigh calcium oxide, calcium hydroxide, calcium carbonate and mineral powder according to the proportion, and grind and / or pneumatically homogenize calcium oxide, calcium hydroxide, calcium carbonate and mineral powder to obtain ultrafine powder;

[0013] S2, grinding and mixing the additive in a grinder to obtain additive powder;

[0014] S3, placing the ultrafine powder in S1 and the auxiliary agent powder in S2 in a mixer, and after the materials are fully homogenized, the hydraulic lime cementitious material is obtained.

[0015] The hydraulic lime cementitious material is applied to the restoration and reinforcement project of rock and soil cultural relics. The hydraulic lime cementitious material is mixed with water at a water-cement ratio of 0.2, and the mixture is evenly stirred before restoration.

[0016] Compared with the prior art, the present invention has the following characteristics and beneficial effects:

[0017] (1) The present invention uses calcium oxide, calcium hydroxide, calcium carbonate, mineral powder and additives as raw materials to prepare a hydraulic lime cementitious material. According to the characteristics of existing hydraulic lime repair materials, the bottleneck of limited raw materials and poor quality controllability in the production of rock and soil cultural relics repair materials can be broken through. It can not only meet the relevant performance requirements of rock and soil cultural relics protection, but also has stable product performance, and can reduce production costs, simplify the production process, and is conducive to large-scale mass production, and has strong industrial applicability.

[0018] (2) Hydraulic lime undergoes a hydration reaction when in contact with water and solidifies rapidly. That is, it undergoes a hydration reaction when in contact with water. At the same time, hydraulic lime can absorb CO in the air. 2 , producing a porous structure, and good air permeability becomes a major advantage of better compatibility with the repaired and reinforced materials. Based on the above characteristics, hydraulic lime maintains good water permeability and air permeability, and gradually completes self-repair during the long air hardening process, and the strength increases steadily over a long period of time. The porosity of the material of the present invention is greater than 30%, and the 28-day shrinkage rate is less than 0.1%.

[0019] (3) The main application of the hydraulic lime gel material of the present invention is the restoration and reinforcement of rock and soil cultural relics. Its 7-day compressive strength is greater than 2MPa and less than 5MPa; its 28-day compressive strength is less than 10MPa. It has good restoration bonding, affinity and compatibility with the rock and soil cultural relics. The softening coefficient can reach 0.9. The cultural relic restoration material has both water and air hardness and can be used in both dry and humid environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] Figure 1 This is a picture of the hydraulic lime cementitious material during the molding test;

[0022] Figure 2 and Figure 3 These are pictures of two groups of test specimens of hydraulic lime cementitious materials after molding; they are records of testing the flexural and compressive strength after standard curing for 28 days after molding. DETAILED DESCRIPTION

[0023] In order to make the technical means, innovative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below.

[0024] The embodiments described herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention, are illustrative and exemplary, and should not be construed as limiting the embodiments of the present invention and the scope of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the claims and the contents disclosed in the specification of this application, including technical solutions that adopt any obvious replacement and modification of the embodiments described herein.

[0025] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments.

[0026] Example 1

[0027] A hydraulic lime cementitious material comprises the following raw materials in parts by weight: 60 parts of calcium oxide, 20 parts of calcium hydroxide, 18 parts of calcium carbonate, 1.8 parts of mineral powder (single activity grade S75), and 0.3 parts of an auxiliary agent, wherein the auxiliary agent is triethanolamine, an industrial grade product.

[0028] The preparation method of the hydraulic lime cementitious material:

[0029] 1) First weigh according to the proportion, then grind the powdered calcium oxide, calcium hydroxide, calcium carbonate and mineral powder into ultrafine powder and / or pneumatically homogenize to obtain a specific surface area of ​​450cm 2 / kg of ultrafine powder;

[0030] 2) Then, the ultrafine powder water retaining agent is placed in a grinder and ground and mixed evenly to obtain a specific surface area of ​​650cm 2 / kg of auxiliary powder;

[0031] 3) Finally, the ultrafine powder and the auxiliary powder are placed in a mixer. After the materials are fully homogenized, the prepared hydraulic lime cementitious material is tested accordingly according to various components. When all components are qualified, the hydraulic lime cementitious material is sealed and packaged to obtain the rock and soil cultural relics restoration material - hydraulic lime cementitious material.

[0032] Example 2

[0033] A hydraulic lime cementitious material comprises the following raw materials in parts by weight: 12 parts of calcium oxide, 75 parts of calcium hydroxide, 10 parts of calcium carbonate, 2.7 parts of mineral powder (single activity grade S75), and 0.3 parts of an auxiliary agent, wherein the auxiliary agent is calcium formate, an industrial grade product.

[0034] The preparation method of the hydraulic lime cementitious material:

[0035] 1) First weigh according to the proportion, then grind the powdered calcium oxide, calcium hydroxide, calcium carbonate and mineral powder into ultrafine powder and / or pneumatically homogenize to obtain a specific surface area of ​​450m 2 / kg of ultrafine powder;

[0036] 2) Then, the ultrafine powder water retaining agent is placed in a grinder and ground and mixed evenly to obtain a specific surface area of ​​650m 2 / kg of auxiliary powder;

[0037] 3) Finally, the ultrafine powder and the auxiliary powder are placed in a mixer. After the materials are fully homogenized, the prepared hydraulic lime cementitious material is tested accordingly according to various components. When all components are qualified, the hydraulic lime cementitious material is sealed and packaged to obtain the hydraulic lime cementitious material.

[0038] Example 3

[0039] A hydraulic lime cementitious material comprises the following raw materials in parts by weight: 18 parts of calcium oxide, 60 parts of calcium hydroxide, 20 parts of calcium carbonate, 1.8 parts of mineral powder (single activity grade S75), and 0.3 parts of an auxiliary agent, wherein the auxiliary agent is calcium formate, an industrial grade product.

[0040] The preparation method of the hydraulic lime cementitious material:

[0041] 1) First weigh according to the proportion, then grind the powdered calcium oxide, calcium hydroxide, calcium carbonate and mineral powder into ultrafine powder and / or pneumatically homogenize to obtain a specific surface area of ​​450m 2 / kg of ultrafine powder;

[0042] 2) Then, the ultrafine powder water retaining agent is placed in a grinder and ground and mixed evenly to obtain a specific surface area of ​​650m 2 / kg of auxiliary powder;

[0043] 3) Finally, the ultrafine powder and the auxiliary powder are placed in a mixer. After the materials are fully homogenized, the prepared hydraulic lime cementitious material is tested accordingly according to various components. When all components are qualified, the hydraulic lime cementitious material is sealed and packaged to obtain the hydraulic lime cementitious material.

[0044] Example 4

[0045] A hydraulic lime cementitious material comprises the following raw materials in parts by weight: 66 parts of calcium oxide, 15 parts of calcium hydroxide, 15 parts of calcium carbonate, 4 parts of mineral powder (single activity grade S75), and 0.3 parts of an auxiliary agent. The auxiliary agent is calcium formate, an industrial grade product.

[0046] The preparation method of the hydraulic lime cementitious material:

[0047] 1) First weigh according to the proportion, then grind the powdered calcium oxide, calcium hydroxide, calcium carbonate and mineral powder into ultrafine powder and / or pneumatically homogenize to obtain a specific surface area of ​​450m 2 / kg of ultrafine powder;

[0048] 2) Then, the ultrafine powder water retaining agent is placed in a grinder and ground and mixed evenly to obtain a specific surface area of ​​650m 2 / kg of auxiliary powder;

[0049] 3) Finally, the ultrafine powder and the auxiliary powder are placed in a mixer. After the materials are fully homogenized, the prepared hydraulic lime cementitious material is tested accordingly according to various components. When all components are qualified, the hydraulic lime cementitious material is sealed and packaged to obtain the hydraulic lime cementitious material.

[0050] Example 5

[0051] A hydraulic lime cementitious material comprises the following raw materials in parts by weight: 12 parts of calcium oxide, 75 parts of calcium hydroxide, 10 parts of calcium carbonate, 2.7 parts of mineral powder (single activity grade S75), and 0.3 parts of an auxiliary agent. The auxiliary agent is calcium formate, an industrial grade product.

[0052] The preparation method of the hydraulic lime cementitious material:

[0053] 1) First weigh according to the proportion, then grind the powdered calcium oxide, calcium hydroxide, calcium carbonate and mineral powder into ultrafine powder and / or pneumatically homogenize to obtain a specific surface area of ​​500m 2 / kg of ultrafine powder;

[0054] 2) Then, the ultrafine powder water retaining agent is placed in a grinder and ground and mixed evenly to obtain a specific surface area of ​​700m 2 / kg of auxiliary powder;

[0055] 3) Finally, the ultrafine powder and the auxiliary powder are placed in a mixer. After the materials are fully homogenized, the prepared hydraulic lime cementitious material is tested accordingly according to various components. When all components are qualified, the hydraulic lime cementitious material is sealed and packaged to obtain the hydraulic lime cementitious material.

[0056] Example 6

[0057] A hydraulic lime cementitious material includes the following raw materials by weight: 12 parts of calcium oxide, 75 parts of calcium hydroxide, 10 parts of calcium carbonate, 2.7 parts of mineral powder (a mixture of activity grade S75 and activity grade S105, with a mixing ratio of 2:1), and 0.3 parts of an auxiliary agent. The auxiliary agent is triethanolamine, an industrial grade product.

[0058] The preparation method of the hydraulic lime cementitious material:

[0059] 1) First weigh according to the proportion, then grind the powdered calcium oxide, calcium hydroxide, calcium carbonate and mineral powder into ultrafine powder and / or pneumatically homogenize to obtain a specific surface area of ​​450m 2 / kg of ultrafine powder;

[0060] 2) Then, the ultrafine powder water retaining agent is placed in a grinder and ground and mixed evenly to obtain a specific surface area of ​​650m 2 / kg of auxiliary powder;

[0061] 3) Finally, the ultrafine powder and the auxiliary powder are placed in a mixer. After the materials are fully homogenized, the prepared hydraulic lime cementitious material is tested accordingly according to various components. When all components are qualified, the hydraulic lime cementitious material is sealed and packaged to obtain the hydraulic lime cementitious material.

[0062] Preparation and curing of specimens: The specimens were made by mixing hydraulic lime cementitious materials with water, with a water-cement ratio of 0.2. The specimens were prepared in accordance with the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar (ISO Method)"; they were left to stand at a relative humidity of 50% to 60% and an ambient temperature of 18°C ​​to 22°C until final setting, demoulded after final setting and cured in a natural environment, and then subjected to flexural strength and compressive strength tests in accordance with the standard GB / T 17671-1999 "Test Method for Strength of Cement Mortar (ISO Method)".

[0063] The standard consistency water consumption and setting time are determined in accordance with JGJ / T70-2009 "Standard for Test Methods for Basic Properties of Building Mortar".

[0064] The porosity is determined in accordance with GB / T 23561.4-2009 “Determination of physical and mechanical properties of coal and rock Part 4: Calculation method of porosity of coal and rock”.

[0065] The softening coefficient was determined with reference to GB / T 4111-2009 “Test methods for concrete blocks and bricks”.

[0066] The shrinkage rate was determined with reference to JGJ / T70-2009 "Standard for Test Methods for Basic Properties of Building Mortar".

[0067] In addition, the prepared specimens were immersed in water for 24 hours to test their strength and water resistance. The immersed specimens and the dried specimens were also tested to evaluate the performance of the specimens in the dry and wet states at different dosages. Table 1 shows the performance test results of each embodiment:

[0068] Table 1 Performance test results of various embodiments

[0069]

[0070] According to the test results, the flexural strength of Example 1 at 28 days was 1.896 MPa, the compressive strength was 5.738 MPa, and the softening coefficient was 0.65; the flexural strength of Example 2 at 28 days was 2.327 MPa, the compressive strength at 28 days was 7.263 MPa, and the softening coefficient was 0.90; the flexural strength of Example 3 at 28 days was 1.726 MPa, the compressive strength was 6.172 MPa, and the softening coefficient was 0.73; the flexural strength of Example 4 at 28 days was 1.948 MPa, the compressive strength was 6.915 MPa, and the softening coefficient was 0.76.

[0071] It can be seen that compared with Examples 1, 3, and 4, Example 2 has significantly improved flexural and compressive strengths, significantly improved softening coefficient, the largest porosity, and a shrinkage rate similar to that of Example 3 but better than that of Examples 1 and 4; Examples 5 and 6 have the same main components as Example 2, with only some parameters changed, and the measurement results are slightly worse than those of Example 2, and the optimal solution is Example 2.

[0072] Based on Example 2, the performance of the hydraulic lime cementitious material was compared with that of European natural hydraulic lime.

[0073] Comparative Example 1

[0074] This comparative example is natural hydraulic cement NHL5 imported from Europe. The test results are shown in Table 2.

[0075] Table 2

[0076]

[0077] As can be seen from Table 2, all properties of Example 2 are improved over those of Comparative Example 1. The 28-day flexural strength of Example 2 is 2.327 MPa, the compressive strength is 7.263 MPa, and the softening coefficient is 0.90, while the 28-day flexural strength of Comparative Example 1 is 2.029 MPa, the compressive strength is 6.048 MPa, and the softening coefficient is 0.52. The 28-day flexural strength, compressive strength, and softening coefficient of Example 2 are significantly higher than those of Comparative Example 1, and the porosity is significantly increased, and the shrinkage rate is better.

[0078] Comparative Example 2

[0079] This comparative example is a comparative example of Example 2. During the preparation process, powdered calcium oxide, calcium hydroxide, calcium carbonate, and mineral powder are ultrafinely ground and / or pneumatically homogenized to obtain a specific surface area of ​​650 m 2 / kg of ultrafine powder. The test results are shown in Table 3.

[0080] Table 3

[0081]

[0082] Comparative Example 3

[0083] This comparative example is a comparative example of Example 2. During the preparation process, powdered calcium oxide, calcium hydroxide, calcium carbonate, and mineral powder are ultrafinely ground and / or pneumatically homogenized to obtain a specific surface area of ​​350 m 2 / kg of ultrafine powder. The test results are shown in Table 4.

[0084] Table 4

[0085]

[0086] The specific surface area of ​​the ultrafine powders in Comparative Examples 2 and 3 is different from that in Example 2, which affects the performance of the products.

[0087] Example 7

[0088] The hydraulic lime cementitious material prepared by any one of Examples 1 to 6 is applied to the restoration and reinforcement of rock and soil cultural relics.

[0089] The usage steps include the following:

[0090] 1) While ensuring that rock and soil cultural relics are not damaged, clean the surface transition zone of the cultural relics to be restored;

[0091] 2) Mix the hydraulic lime cementitious material with water at a water-cement ratio of 0.2 and stir thoroughly;

[0092] 3) The evenly mixed hydraulic lime cementitious material is applied to the cleaned rock and soil cultural relics, and professional cultural relics restoration personnel carry out the construction and restoration;

[0093] 4) Carry out natural curing after construction to ensure that the cultural relic restoration materials are fully hardened and their strength increases steadily.

[0094] The above embodiments are only used to explain the present invention and do not constitute a limitation on the scope of the claims. Other alternative means that can be thought of by those skilled in the art based on the contents of the present specification should be within the protection scope of the claims of the present invention.

Claims

1. A hydraulic lime cementitious material, characterized in that: The invention comprises the following raw materials in parts by weight: 12 to 70 parts of calcium oxide, 15 to 80 parts of calcium hydroxide, 10 to 25 parts of calcium carbonate, 1 to 5 parts of mineral powder, and 0.2 to 0.5 parts of additives; the calcium oxide, calcium hydroxide, calcium carbonate, and mineral powder are ultrafine powders with a specific surface area of ​​450 to 500 cm 2 / kg; the auxiliary agent is an ultrafine powder water-retaining agent.

2. The hydraulic lime cementitious material according to claim 1, characterized in that: The calcium oxide is 12 parts, the calcium hydroxide is 75 parts, the calcium carbonate is 10 parts, the mineral powder is 2.7 parts, and the auxiliary agent is 0.3 parts.

3. The hydraulic lime cementitious material according to claim 1, characterized in that: The ultrafine powder water retaining agent is any one of calcium formate and triethanolamine.

4. The hydraulic lime cementitious material according to claim 1, characterized in that: The specific surface area of ​​the ultrafine powder water retaining agent is 650-700cm 2 / kg.

5. The hydraulic lime cementitious material according to claim 1, characterized in that: The calcium oxide, calcium hydroxide, calcium carbonate and mineral powder are ultrafine powders with a specific surface area of ​​450cm 2 / kg; the specific surface area of ​​the ultrafine powder water retaining agent is 650cm 2 / kg.

6. The hydraulic lime cementitious material according to claim 1, characterized in that: The mineral powder is any one of the mineral powders of activity level S75, S95 and S105, or a mixed mineral powder obtained by mixing multiple mineral powders.

7. A method for preparing a hydraulic lime cementitious material according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Weigh calcium oxide, calcium hydroxide, calcium carbonate and mineral powder according to the proportion, and grind and / or pneumatically homogenize calcium oxide, calcium hydroxide, calcium carbonate and mineral powder to obtain ultrafine powder; S2, grinding and mixing the additive in a grinder to obtain additive powder; S3, placing the ultrafine powder in S1 and the auxiliary agent powder in S2 in a mixer, and after the materials are fully homogenized, the hydraulic lime cementitious material is obtained.

8. The use of the hydraulic lime cementitious material according to any one of claims 1 to 6, characterized in that: Applied to the restoration and reinforcement projects of rock and soil cultural relics.

9. The use according to claim 8, characterized in that: The usage steps include the following: Step 1: Clean the surface of the cultural relics to be restored; Step 2: Mix the hydraulic lime cementitious material with water at a water-cement ratio of 0.2 and stir evenly; Step 3: Use the evenly mixed hydraulic lime cementitious material for the restoration of the cleaned rock and soil cultural relics; Step 4: Carry out natural maintenance after construction.

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