1. The special thermal insulation mortar for the straw fly ash building block is characterized by comprising masonry mortar and finishing mortar:

the masonry mortar comprises the following components in parts by weight: 15-20 parts of cement, 60-65 parts of fine aggregate, 10-15 parts of vitrified micro bubbles, 0.04-0.05 part of hydroxypropyl methyl cellulose ether, 0.15-0.6 part of concrete expanding agent, 0.25-0.75 part of dispersible latex powder and 5-7 parts of fly ash;

the plastering mortar comprises the following components in parts by weight: 15-20 parts of cement, 60-65 parts of fine aggregate, 10-15 parts of vitrified micro-beads, 0.04-0.05 part of hydroxypropyl methyl cellulose ether, 0.15-0.5 part of corn straw, 0.75-2.5 parts of slaked lime and 7-9 parts of fly ash.

2. The thermal insulation mortar special for the straw fly ash building blocks as claimed in claim 1, wherein the cement is 42.5R portland cement.

3. The thermal insulation mortar special for the straw fly ash building block according to claim 1, wherein the fine aggregate is standard sand, the fineness modulus is 0.5-2.0mm, and the content of silicon dioxide is more than 96%.

4. The thermal insulation mortar special for the straw fly ash building block according to claim 1, wherein the vitrified micro bubbles have a bulk densityNot more than 120kg/m³The thermal conductivity coefficient is less than 0.048W/(m.K), the volume water absorption is less than 45%, and the surface vitrification closed-cell rate is more than 80%.

5. The thermal insulation mortar special for the straw fly ash building block according to claim 1, wherein the hydroxypropyl methyl cellulose ether is HPMC400 in type; the dispersible latex powder is SWF 05.

6. The thermal insulation mortar special for the straw fly ash building blocks as claimed in claim 1, wherein the length of the corn straw is 5-10 mm.

7. The thermal insulation mortar special for the straw fly ash building block according to claim 1, wherein the content of the calcium in the lime-eliminating mortar is 95 plus or minus 3%, and the sieving rate of a 300-mesh sieve is more than or equal to 90%.

8. The thermal insulation mortar special for the straw fly ash building block according to claim 1, wherein the fly ash is II-grade fly ash, and the balance of a 45-micron square-hole sieve is not more than 25%.

9. The preparation method of the special thermal insulation mortar for the straw fly ash building blocks as claimed in claims 1 to 8, which is characterized by comprising the following steps:

1) putting cement, fine aggregate, vitrified micro bubbles, hydroxypropyl methyl cellulose ether and fly ash into a stirrer according to the formula components of the masonry mortar, uniformly stirring for 2-4min to obtain a mixture, adding dispersible latex powder and a concrete expanding agent according to the formula components of the masonry mortar into the mixture, stirring for 5-8min, and drying to constant weight to obtain the masonry mortar;

2) putting cement, fine aggregate, vitrified micro bubbles, hydroxypropyl methyl cellulose ether and fly ash into a stirrer according to the formula components of the plastering mortar, uniformly stirring for 2-4min to obtain a mixture, adding slaked lime and corn straws according to the formula components of the plastering mortar into the mixture, stirring for 5-8min, and drying to constant weight to obtain the plastering mortar.

10. The preparation method of the special thermal insulation mortar for the straw fly ash building blocks according to claim 9, wherein the water-cement ratio of the masonry mortar to the plastering mortar is 1.2-1.4.

Background

At present, with the popularization and application of novel wall materials in China, more and more wall materials are applied to actual engineering, and the straw fly ash building block is one of the wall materials. However, in the using process, the straw fly ash wall material has the phenomena of cracking and bulging, and the phenomena are mainly caused by the fact that the common building mortar and the straw fly ash building block cannot work in a coordinated manner.

The straw fly ash wall material mainly has the characteristics of good heat insulation performance and effective utilization of waste straw resources, so that good social benefits can be achieved after popularization and use. However, when the straw fly ash wall material is used in combination with common building mortar, shrinkage cracks and hollowing phenomena occur, and the key point for effectively solving the problems is to research special mortar which is coordinated with the straw fly ash wall material in terms of shrinkage deformation and heat preservation performance.

Disclosure of Invention

The invention aims to solve the technical problems that under the condition of meeting the requirements of compressive strength, bending strength and bonding strength of building mortar, drying shrinkage is reduced, the thermal insulation performance of mortar is improved, cracks and hollowing of a wall body are avoided, and meanwhile, waste straw resources are effectively utilized, and the thermal insulation mortar special for the straw fly ash building block and the preparation method thereof are provided.

The invention is realized by the following technical scheme:

the invention provides a special thermal insulation mortar for a straw fly ash building block, which comprises masonry mortar and finishing mortar:

the masonry mortar comprises the following components in parts by weight: 15-20 parts of cement, 60-65 parts of fine aggregate, 10-15 parts of vitrified micro bubbles, 0.04-0.05 part of hydroxypropyl methyl cellulose ether, 0.15-0.6 part of concrete expanding agent, 0.25-0.75 part of dispersible latex powder and 5-7 parts of fly ash;

the plastering mortar comprises the following components in parts by weight: 15-20 parts of cement, 60-65 parts of fine aggregate, 10-15 parts of vitrified micro-beads, 0.04-0.05 part of hydroxypropyl methyl cellulose ether, 0.15-0.5 part of corn straw, 0.75-2.5 parts of slaked lime and 7-9 parts of fly ash.

Further, the cement is 42.5R portland cement.

Furthermore, the fine aggregate is standard sand, the fineness modulus is 0.5-2.0mm, and the content of silicon dioxide is more than 96%.

Further, the bulk density of the vitrified micro bubbles is not more than 120kg/m³The thermal conductivity coefficient is less than 0.048W/(m.K), the volume water absorption is less than 45%, and the surface vitrification closed-cell rate is more than 80%.

Further, the hydroxypropyl methylcellulose ether model is HPMC 400; the dispersible latex powder is SWF 05.

Further, the length of the corn straws is 5-10 mm.

Furthermore, the content of the calcium in the lime stone is 95 +/-3%, and the sieving rate of a 300-mesh sieve is more than or equal to 90%.

Further, the fly ash is II-grade fly ash, and the balance of a 45-micrometer square-hole sieve is not more than 25%.

The invention also provides a preparation method of the special thermal insulation mortar for the straw fly ash building block, which comprises the following steps:

1) putting cement, fine aggregate, vitrified micro bubbles, hydroxypropyl methyl cellulose ether and fly ash into a stirrer according to the formula components of the masonry mortar, uniformly stirring for 2-4min to obtain a mixture, adding dispersible latex powder and a concrete expanding agent according to the formula components of the masonry mortar into the mixture, stirring for 5-8min, and drying to constant weight to obtain the masonry mortar;

2) putting cement, fine aggregate, vitrified micro bubbles, hydroxypropyl methyl cellulose ether and fly ash into a stirrer according to the formula components of the plastering mortar, uniformly stirring for 2-4min to obtain a mixture, adding slaked lime and corn straws according to the formula components of the plastering mortar into the mixture, stirring for 5-8min, and drying to constant weight to obtain the plastering mortar.

Furthermore, the water cement ratio of the masonry mortar to the plastering mortar is 1.2-1.4.

Compared with the prior art, the invention has the beneficial effects that:

the invention effectively utilizes the straws and the vitrified micro bubbles, avoids the damage of the burning of the straws to the environment, has simple preparation process and low production cost, and produces the building mortar with excellent performances. The invention has important significance for effective utilization of waste resources, environmental protection and building energy conservation.

Detailed Description

In order to facilitate the understanding of the invention, the invention is further described below with reference to specific examples, but the scope of the invention is not limited thereto. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Example 1

A special thermal insulation mortar for straw fly ash building blocks:

1) putting 225g of cement, 162g of vitrified micro bubbles, 738g of fine aggregate, 75g of fly ash and 0.45g of hydroxypropyl methyl cellulose ether into a stirrer, uniformly stirring for 3min, adding 3g of dispersible emulsion powder and 3.6g of concrete expanding agent, continuously stirring for 6min, drying to constant weight, metering and packaging to obtain masonry mortar;

2) putting 195g of cement, 162g of vitrified micro bubbles, 738g of fine aggregate, 90g of fly ash and 0.6g of hydroxypropyl methyl cellulose ether into a stirrer, uniformly stirring for 3min, adding 15g of slaked lime and 3g of corn straw, continuously stirring for 6min, drying to constant weight, metering and packaging to obtain the plastering mortar.

And (3) pulping the masonry mortar according to the water cement ratio of 1.2, pulping the plastering mortar according to the water cement ratio of 1.3, carrying out standard oxidation on the mortar for 28 days, and carrying out performance detection. Table 1 shows the consistency, compressive and flexural strength, bond strength, thermal conductivity and shrinkage of the mortar obtained in this example.

Example 2

The method of example 1 is repeated, but the usage amount of the concrete expanding agent in the masonry mortar formula is changed to 4.5g, and the other components and the usage amount are not changed; the components and the dosage of the formula of the plastering mortar are unchanged. The mortar obtained in this example is shown in Table 1 for consistency, compressive and flexural strength, bond strength, thermal conductivity and shrinkage.

Example 3

The method of the embodiment 1 is repeated, but the usage amount of the dispersible latex powder in the masonry mortar formula is changed to 4.5g, the usage amount of the concrete expanding agent is changed to 4.5g, and the other components and the usage amount are not changed; the usage amount of lime in the plastering mortar formula is changed to 18g, the usage amount of corn straws is changed to 3.6g, and the other components and usage amounts are unchanged. The mortar obtained in this example is shown in Table 1 for consistency, compressive and flexural strength, bond strength, thermal conductivity and shrinkage.

Example 4

The method of the embodiment 1 is repeated, but the usage amount of the dispersible latex powder in the masonry mortar formula is changed to 4.5g, the usage amount of the concrete expanding agent is changed to 5.4g, and the other components and the usage amount are not changed; the consumption of lime in the plastering mortar formula is changed to 18g, the consumption of corn straws is changed to 4.6g, and the other components and the consumption are not changed. The mortar obtained in this example is shown in Table 1 for consistency, compressive and flexural strength, bond strength, thermal conductivity and shrinkage.

Example 5

The method of the embodiment 1 is repeated, but the usage amount of the dispersible latex powder in the masonry mortar formula is changed to 6g, and the other components and usage amount are not changed; the usage amount of lime in the plastering mortar formula is changed to 21g, and the other components and usage amount are unchanged. The mortar obtained in this example is shown in Table 1 for consistency, compressive and flexural strength, bond strength, thermal conductivity and shrinkage.

Example 6

The method of the embodiment 1 is repeated, but the usage amount of the dispersible latex powder in the masonry mortar formula is changed to 6g, the usage amount of the concrete expanding agent is changed to 4.5g, and the other components and the usage amount are not changed; the usage amount of lime in the plastering mortar formula is changed to 21g, the usage amount of corn straws is changed to 3.6g, and the other components and usage amounts are not changed. The mortar obtained in this example is shown in Table 1 for consistency, compressive and flexural strength, bond strength, thermal conductivity and shrinkage.

Table 1: performance test of special thermal insulation mortar for straw fly ash building block

From the data analysis of table 1, it can be seen that: the masonry mortar prepared by the invention has the advantages of small heat conductivity coefficient and shrinkage rate, high compressive and flexural strength and bonding strength and moderate consistency.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. The present invention is not to be limited by the specific embodiments disclosed herein, and other embodiments that fall within the scope of the claims of the present application are intended to be within the scope of the present invention.