High-strength thermal insulation mortar and preparation method thereof

Abstract

The application relates to a high-strength thermal insulation mortar and a preparation method thereof, the high-strength thermal insulation mortar comprises the following raw materials in percentage by weight: 30-50% of Portland cement, 20-30% of honeycomb stone micro powder, 16-20% of modified wollastonite mineral fiber, 1.6-2.2% of rubber powder, 0.2-0.6% of air entraining agent, 1-5% of polycarboxylate superplasticizer, and the balance is water; the modified wollastonite mineral fiber is prepared by spraying modification on the calcined wollastonite mineral fiber by using a finishing agent, the finishing agent comprises polyacrylamide and carboxymethyl starch, and the mass ratio of the polyacrylamide to the carboxymethyl starch is 2-5:1. The wollastonite mineral fiber is modified by the finishing agent, and the component ratio of the finishing agent is adjusted and designed, so that the strength of the prepared mortar is improved, the mortar has a low thermal conductivity, and the thermal insulation performance is excellent.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a high-strength thermal insulation mortar and its preparation method. Background Technology

[0002] Thermal insulation mortar is a building material used to construct the thermal insulation layer on the surface of buildings. It is a premixed dry powder mortar made by mixing various lightweight materials as aggregates, cement as binder, and some modified additives.

[0003] With the continuous increase in building energy consumption, promoting the application of thermal insulation and energy-saving wall materials with low thermal conductivity is of great practical significance for enhancing energy utilization, improving the ecological environment, reducing the excessive use and waste of resources, and leading the construction industry toward sustainable development. The most fundamental way to achieve this is to study the composition of thermal insulation mortar and introduce new materials to improve its strength and thermal insulation performance. In this regard, this invention proposes a high-strength thermal insulation mortar and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength thermal insulation mortar and its preparation method in order to solve the above-mentioned problems.

[0005] The present invention achieves the above objectives through the following technical solutions:

[0006] This invention provides a high-strength thermal insulation mortar, comprising the following raw materials by weight percentage: 30-50% silicate cement, 20-30% honeycomb micro powder, 16-20% modified wollastonite mineral fiber, 1.6-2.2% rubber powder, 0.2-0.6% air-entraining agent, 1-5% polycarboxylate superplasticizer, and the balance being water;

[0007] The modified wollastonite mineral fiber is obtained by calcining wollastonite mineral fiber and then modifying it by spraying with a finishing agent. The finishing agent includes polyacrylamide and carboxymethyl starch, and the mass ratio of polyacrylamide to carboxymethyl starch is 2-5:1.

[0008] As a further optimization of the present invention, the modification process of the modified wollastonite mineral fibers includes the following steps:

[0009] (1) Weigh out polyacrylamide and carboxymethyl starch according to the formula, add them to distilled water, heat to 40-50℃ and stir evenly to obtain finishing agent;

[0010] (2) Calcine the wollastonite mineral fiber at 200-300℃ for 40-60 minutes, and then spray the finishing agent obtained in step (1) onto the surface of the wollastonite mineral fiber to complete the modification treatment of the wollastonite mineral fiber.

[0011] As a further optimization of the present invention, the mass ratio of polyacrylamide to carboxymethyl starch is 3:1.

[0012] As a further optimization of the present invention, the rubber powder is rubber powder processed from waste tires, with a fineness of 80-100 mesh.

[0013] As a further optimization of the present invention, the air-entraining agent is one of saponin-based air-entraining agents and fatty alcohol sulfonate-based air-entraining agents, and the polycarboxylate superplasticizer has a solid content of 30-40% and a water reduction rate of ≥30%.

[0014] As a further optimization of the present invention, the particle size of the honeycomb stone powder is 20-50 μm.

[0015] This invention also provides a method for preparing high-strength thermal insulation mortar as described above, comprising the following steps:

[0016] (1) According to the composition ratio of high-strength thermal insulation mortar, accurately weigh the required amount of silicate cement, honeycomb micro powder, modified wollastonite mineral fiber, rubber powder, air-entraining agent, polycarboxylate superplasticizer and water.

[0017] (2) Add each component to the mixer in sequence and stir and mix thoroughly to obtain the high-strength thermal insulation mortar.

[0018] The beneficial effects of this invention are as follows:

[0019] The high-strength thermal insulation mortar provided by this invention is prepared from silicate cement, honeycomb micro powder, modified wollastonite mineral fiber, rubber powder, air-entraining agent, polycarboxylate superplasticizer, and water as the main raw materials. The wollastonite mineral fiber is modified by spraying with a finishing agent after calcination. This invention improves the strength of the mortar by modifying the wollastonite mineral fiber with a finishing agent and adjusting the component ratio of the finishing agent, while also resulting in a mortar with a low thermal conductivity and excellent thermal insulation performance. Detailed Implementation

[0020] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0021] Example 1

[0022] This embodiment provides a high-strength thermal insulation mortar composition formula, including the following raw materials by weight percentage: 30% silicate cement, 30% honeycomb micro powder, 16% modified wollastonite mineral fiber, 2.2% rubber powder, 0.2% air-entraining agent, 5% polycarboxylate superplasticizer, and the balance being water;

[0023] Among them, the rubber powder is made from waste tires and has a fineness of 80 mesh; the polycarboxylate superplasticizer has a solid content of 30% and a water reduction rate of ≥30%; and the honeycomb stone powder has a particle size of 20μm.

[0024] The modified wollastonite mineral fiber is obtained by calcining wollastonite mineral fiber and then spraying it with a finishing agent. The finishing agent includes polyacrylamide and carboxymethyl starch, and the mass ratio of polyacrylamide to carboxymethyl starch is 2:1.

[0025] The modification process of the modified wollastonite mineral fiber includes first weighing polyacrylamide and carboxymethyl starch according to the formula, adding them to distilled water, heating to 40°C and stirring evenly to obtain a finishing agent; then calcining the wollastonite mineral fiber at 300°C for 40 minutes; and then spraying the prepared finishing agent onto the surface of the wollastonite mineral fiber to complete the modification treatment of the wollastonite mineral fiber.

[0026] The preparation method of high-strength thermal insulation mortar includes the following steps:

[0027] (1) According to the composition ratio of high-strength thermal insulation mortar, accurately weigh the required amount of silicate cement, honeycomb micro powder, modified wollastonite mineral fiber, rubber powder, air-entraining agent, polycarboxylate superplasticizer and water.

[0028] (2) Add each component to the mixer in sequence and stir and mix thoroughly to obtain the high-strength thermal insulation mortar.

[0029] Example 2

[0030] This embodiment provides a component formula for a high-strength thermal insulation mortar, comprising the following raw materials by weight percentage: 50% silicate cement, 20% honeycomb micro powder, 20% modified wollastonite mineral fiber, 1.6% rubber powder, 0.6% air-entraining agent, 1% polycarboxylate superplasticizer, and the balance being water;

[0031] Among them, the rubber powder is made from waste tires and has a fineness of 100 mesh; the polycarboxylate superplasticizer has a solid content of 40% and a water reduction rate of ≥30%; and the honeycomb stone powder has a particle size of 50μm.

[0032] The modified wollastonite mineral fiber is obtained by calcining wollastonite mineral fiber and then spraying it with a finishing agent. The finishing agent includes polyacrylamide and carboxymethyl starch, and the mass ratio of polyacrylamide to carboxymethyl starch is 3:1.

[0033] The modification process of the modified wollastonite mineral fiber includes first weighing polyacrylamide and carboxymethyl starch according to the formula, adding them to distilled water, heating to 50°C and stirring evenly to obtain a finishing agent; then calcining the wollastonite mineral fiber at 200°C for 60 minutes; and then spraying the prepared finishing agent onto the surface of the wollastonite mineral fiber to complete the modification treatment of the wollastonite mineral fiber.

[0034] The preparation method of high-strength thermal insulation mortar includes the following steps:

[0035] (1) According to the composition ratio of high-strength thermal insulation mortar, accurately weigh the required amount of silicate cement, honeycomb micro powder, modified wollastonite mineral fiber, rubber powder, air-entraining agent, polycarboxylate superplasticizer and water.

[0036] (2) Add each component to the mixer in sequence and stir and mix thoroughly to obtain the high-strength thermal insulation mortar.

[0037] Example 3

[0038] This embodiment provides a component formulation for a high-strength thermal insulation mortar, comprising the following raw materials by weight percentage: 40% silicate cement, 25% honeycomb micro powder, 18% modified wollastonite mineral fiber, 1.9% rubber powder, 0.4% air-entraining agent, 3% polycarboxylate superplasticizer, and the balance being water;

[0039] Among them, the rubber powder is made from waste tires and has a fineness of 90 mesh; the polycarboxylate superplasticizer has a solid content of 35% and a water reduction rate of ≥30%; and the honeycomb stone powder has a particle size of 35μm.

[0040] The modified wollastonite mineral fiber is obtained by calcining wollastonite mineral fiber and then spraying it with a finishing agent. The finishing agent includes polyacrylamide and carboxymethyl starch, and the mass ratio of polyacrylamide to carboxymethyl starch is 5:1.

[0041] The modification process of the modified wollastonite mineral fiber includes first weighing polyacrylamide and carboxymethyl starch according to the formula, adding them to distilled water, heating to 50°C and stirring evenly to obtain a finishing agent, calcining the wollastonite mineral fiber at 200°C for 60 minutes, and then spraying the prepared finishing agent onto the surface of the wollastonite mineral fiber to complete the modification treatment of the wollastonite mineral fiber.

[0042] The preparation method of high-strength thermal insulation mortar includes the following steps:

[0043] (1) According to the composition ratio of high-strength thermal insulation mortar, accurately weigh the required amount of silicate cement, honeycomb micro powder, modified wollastonite mineral fiber, rubber powder, air-entraining agent, polycarboxylate superplasticizer and water.

[0044] (2) According to the composition ratio of high-strength thermal insulation mortar, accurately weigh the required amount of silicate cement, honeycomb micro powder, modified wollastonite mineral fiber, rubber powder, air-entraining agent, polycarboxylate superplasticizer and water.

[0045] Verification test

[0046] 1. To verify the effect of modified wollastonite mineral fiber incorporation on the performance of high-strength thermal insulation mortar, using the component formulation disclosed in Example 1, and while maintaining the proportions of other components, modified wollastonite mineral fiber was incorporated at incorporation levels of 16%, 18%, and 20%, yielding samples 1-3. Additionally, control group 1 was set up with unmodified wollastonite mineral fiber incorporated at an incorporation level of 18%; control group 2 was set up with basalt fiber incorporated at an incorporation level of 18%. Performance tests were conducted on the above mortar samples.

[0047] (1) Compressive strength test: The test was conducted in accordance with JGJ70-2009.

[0048] The specimen dimensions are 70.7mm × 70.7mm × 70.7mm. After molding, the specimen should be left to stand at (20±5)℃ for (24±2)h. The specimen should be numbered, demolded, and cured under standard laboratory conditions for 28 days. Before the test, the surface of the specimen should be wiped clean and the compressive strength should be tested.

[0049] (2) Flexural strength was tested in accordance with GB / T 5486-2008.

[0050] The specimen specifications are 40mm×40mm×160mm. After the specimen is formed, it should be left to stand at a temperature of (20±5)℃ for (24±2)h. The specimen should be numbered, demolded, and cured under standard laboratory conditions for 28 days before the flexural strength is tested.

[0051] (3) The thermal conductivity of the mortar was determined according to GB / T10294-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Thermal Insulation Materials - Heat Flow Meter Method". The specimen size was 40mm×40mm×160mm. After molding, the specimens were left to stand at (20±5)℃ for (24±2)h, numbered, demolded, and cured under standard laboratory conditions for 28 days. They were then dried in an oven at (105±5)℃ until constant weight. After cooling, the thermal conductivity of the insulation mortar was determined using a Shotherm QTM thermal conductivity meter.

[0052] Table 1. Test Results

[0053]

[0054] Conclusion: As shown in Table 1, the incorporation of modified wollastonite mineral fibers helps improve the compressive and flexural strength of the mortar samples. The difference between samples 1-3 lies in the amount of modified wollastonite mineral fibers incorporated. Data comparison shows that the change in the amount of modified wollastonite mineral fibers has little effect on the thermal conductivity of the mortar, with the thermal conductivity of samples 1-3 ranging from 0.0711 to 0.0746 W / (m·K). However, the comparison of compressive and flexural strength data shows that as the amount of modified wollastonite mineral fibers increases, the compressive and flexural strength data exhibit a trend of first increasing and then decreasing. The table indicates that the optimal incorporation amount of modified wollastonite mineral fibers is 18%.

[0055] 2. To verify the effect of the composition of the finishing agent used in the modification of wollastonite mineral fibers on the performance of high-strength thermal insulation mortar, the composition of the finishing agent was adjusted using the component formulation disclosed in Example 2, while keeping the proportions of the other components constant. Samples were obtained, and the performance of the samples was tested according to the verification items shown in Verification Test 1. The results are shown in Table 2.

[0056] Table 2. Test Results

[0057]

[0058] Conclusion: As shown in the table, changes in the composition ratio of the finishing agent affect the overall performance of the mortar. Comparison of samples 4-6 reveals that a mass ratio of polyacrylamide to carboxymethyl starch of 3:1 yields the best results in terms of compressive and flexural strength when using this finishing agent to modify wollastonite mineral fibers. Comparison between samples 5 and 7-8 indicates a synergistic effect between polyacrylamide and carboxymethyl starch, which can work together to improve the compressive and flexural strength of the mortar. Regarding the thermal conductivity of the mortar, samples 4-6 show a certain degree of improvement compared to samples 7-10. This suggests that changes in the composition and ratio of the finishing agent affect the modification effect of the wollastonite mineral fibers, ultimately impacting the thermal conductivity of the mortar.

[0059] 3. To verify the effect of honeycomb stone micro powder incorporation on the performance of high-strength thermal insulation mortar, modified wollastonite mineral fibers were incorporated at incorporation rates of 20%, 25%, and 30% to prepare samples 11-13. In addition, vitrified microspheres with an incorporation rate of 25% were used as control group 2. The performance of the above samples was tested according to the verification items shown in verification test 1. The results are shown in Table 3.

[0060] Table 3. Test Results

[0061]

[0062] As can be seen from the table, the incorporation of honeycomb micropowder helps to reduce the thermal conductivity of the mortar samples and improve their thermal insulation performance. Compared with the control group 3, the mortar sample with 25% incorporation of vitrified microspheres has slightly lower compressive and flexural strength than the mortar sample with 25% incorporation of honeycomb micropowder. Furthermore, the thermal conductivity of the mortar sample with 25% incorporation of honeycomb micropowder is lower than that of the control group 3, indicating that the thermal insulation performance of sample 12 is superior to that of the control group 3.

[0063] The foregoing description illustrates and describes several preferred embodiments of the invention. However, as previously stated, it should be understood that the invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the invention should be within the protection scope of the appended claims.

Claims

1. A high-strength thermal insulation mortar, characterized in that, The raw materials include the following weight percentages: silicate cement 30-50%, honeycomb powder 20-30%, modified wollastonite mineral fiber 16-20%, rubber powder 1.6-2.2%, air-entraining agent 0.2-0.6%, polycarboxylate superplasticizer 1-5%, and the balance being water; The modified wollastonite mineral fiber is obtained by calcining wollastonite mineral fiber and then modifying it by spraying with a finishing agent. The finishing agent includes polyacrylamide and carboxymethyl starch, and the mass ratio of polyacrylamide to carboxymethyl starch is 2-5:

1.

2. The high-strength thermal insulation mortar according to claim 1, characterized in that, The modification process of the modified wollastonite mineral fibers includes the following steps: (1) Weigh out polyacrylamide and carboxymethyl starch according to the formula, add them to distilled water, heat to 40-50℃ and stir evenly to obtain the finishing agent; (2) Calcine the wollastonite mineral fiber at 200-300℃ for 40-60 minutes, and then spray the finishing agent obtained in step (1) onto the surface of the wollastonite mineral fiber to complete the modification treatment of the wollastonite mineral fiber.

3. The high-strength thermal insulation mortar according to claim 1, characterized in that, The mass ratio of polyacrylamide to carboxymethyl starch is 3:

1.

4. The high-strength thermal insulation mortar according to claim 1, characterized in that, The rubber powder is made from waste tires and has a fineness of 80-100 mesh.

5. The high-strength thermal insulation mortar according to claim 1, characterized in that, The air-entraining agent is one of saponin-based air-entraining agents or fatty alcohol sulfonate-based air-entraining agents, and the polycarboxylate superplasticizer has a solid content of 30-40% and a water reduction rate of ≥30%.

6. The high-strength thermal insulation mortar according to claim 1, characterized in that, The honeycomb stone micro powder has a particle size of 20-50 μm.

7. A method for preparing high-strength thermal insulation mortar as described in any one of claims 1-6, characterized in that, Includes the following steps, (1) According to the composition ratio of high-strength thermal insulation mortar, accurately weigh the required amount of silicate cement, honeycomb micro powder, modified wollastonite mineral fiber, rubber powder, air-entraining agent, polycarboxylate superplasticizer and water. (2) Add each component to the mixer in sequence and stir and mix thoroughly to obtain the high-strength thermal insulation mortar.

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