CN103739241B - A kind of self-heat conserving gas concrete special mortar for dry method construction and preparation method thereof - Google Patents

Abstract

The present invention relates to a kind of self-heat conserving gas concrete special mortar for dry method construction and preparation method thereof, belong to building material technical field, it is characterized in that it is by flyash, phosphorus slag, cement clinker, phosphogypsum, carbide slag, graphite tailing sand, shale pottery, alkali lignin, polyethylene vinyl acetate fat and Vltra tears composition, and prepared by following steps: 1) prepare ecological composite gelled material: be by mass percentage: flyash 35 ~ 45%, phosphorus slag 25 ~ 50%, cement clinker 8 ~ 10%, phosphogypsum 3 ~ 8%, carbide slag 2 ~ 6%, mix and blend obtains, 2) prepare admixture: be by mass percentage: alkali lignin 35 ~ 50%, polyethylene vinyl acetate fat 15 ~ 30%, Vltra tears 20 ~ 40%, mix and blend, obtains, 3) preparation of plastering mortar: by ecological composite gelled material: graphite tailing sand: shale pottery: the mass ratio of admixture is 1: 0.7: 0.3: 0.004, chooses, mix and blend, obtains product.

Description

A special mortar for dry construction of self-insulating aerated concrete and its preparation method

technical field

The invention relates to a preparation method of special masonry mortar for dry construction of self-insulating aerated concrete, which belongs to the technical field of building materials.

Background technique

According to statistics, my country's building energy consumption has accounted for about 27% of the total energy consumption of the society, and with the improvement of people's requirements for the comfort of living environment and the vigorous promotion of urbanization, building energy consumption will further increase. According to the experience of developed countries, construction will surpass industry, transportation and other industries and eventually rank first in social energy consumption, reaching 30-40%. Therefore, building energy conservation is imperative. The country has successively promulgated a series of laws and regulations related to building energy conservation: in October 2007, the "Energy Conservation Law of the People's Republic of China" (President Order No. 77 of the People's Republic of China); Energy Conservation Regulations (Decree No. 530 of the State Council of the People's Republic of China).

Implementing building energy conservation, developing green buildings, and effectively reducing building energy consumption are long-term guidelines for the development of my country's construction industry, and are also important issues that urgently need to be resolved in the development of my country's construction technology. It is one of the important and effective ways to reduce building energy consumption by improving the thermal insulation performance of building maintenance structures. The wall is the main component of the building maintenance structure, and it is also an important place for building heat exchange. Using self-insulating walls and ensuring the effective thermal insulation function of the walls is an important measure to reduce the energy consumption of buildings.

In the wall insulation system, the wall self-insulation system has the same life span as the building, and its comprehensive cost is lower than other wall insulation systems. It is a form of wall insulation with broad application prospects. Among them, the self-insulating aerated concrete block has a good thermal insulation effect due to its low thermal conductivity. It is a single wall material that can meet the requirements of building energy-saving design. The wall self-insulation system is more and more popular.

However, when self-insulating aerated concrete is used in many places, the traditional wet construction process is still used for masonry, water is sprinkled before the wall, and ordinary mortar is used to match it. Compared with traditional wall materials, self-insulating aerated concrete is light in weight, strong in water absorption, and low in strength. It is easy to generate greater stress with ordinary mortar with high strength and elastic modulus, and it is easy to absorb the ordinary mortar. Moisture, resulting in quality problems such as hollowing and cracking of the self-insulating aerated concrete wall. In addition, the self-insulating aerated concrete wall built with ordinary mortar has large mortar joints, usually up to 20mm, which become a thermal bridge of the wall, thereby reducing the overall thermal insulation performance of the self-insulating wall.

Therefore, it is of great significance to develop and apply a new type of special mortar that is compatible with the dry construction of self-insulating aerated concrete, to solve common quality problems such as hollowing and cracking of aerated concrete walls, and to improve the thermal insulation performance of walls and the quality of masonry.

Contents of the invention

The purpose of the present invention is to provide a special mortar for dry construction of self-insulating aerated concrete wall materials and a preparation method thereof. The special mortar prepared by the method has good water retention, good deformation resistance and thermal insulation performance, and is comparable to self-heating aerated concrete wall materials. The dry construction of thermal insulation aerated concrete matches well.

In order to achieve the above object, the technical solution of the present invention is: a special mortar for dry construction of self-insulating aerated concrete and its preparation method, which is characterized in that it is composed of fly ash, phosphorus slag, cement clinker, phosphogypsum, carbide slag , graphite tailings sand, shale pottery sand, alkali lignin and hydroxypropyl methylcellulose, and is prepared through the following steps:

It includes the following steps:

1) Preparation of ecological composite cementitious material: dry and dehydrate phosphorus slag, phosphogypsum, and calcium carbide slag at a dehydration temperature of 80°C to 120°C and a constant temperature of 1.5 to 2 hours; %;

According to the mass percentage of each raw material: fly ash 35-45%, phosphorus slag 25-50%, cement clinker 8-10%, phosphogypsum 3-8%, carbide slag 2-6%, select fly ash , phosphorus slag, cement clinker, phosphogypsum and calcium carbide slag; mixing fly ash, phosphorus slag, cement clinker, phosphogypsum and calcium carbide slag to obtain an ecological composite cementitious material;

2) Preparation of additives: according to the mass percentage of each component: alkali lignin 35-50%, polyethylene-vinyl acetate 15-30%, hydroxypropyl methylcellulose 20-40%, choose alkali lignin , polyethylene-vinyl acetate and hydroxypropyl methylcellulose; mixing and stirring alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose to obtain an additive;

3) Preparation of special mortar: According to the mass ratio of ecological composite cementitious material: graphite tailings: shale pottery sand: admixture is 1:0.7:0.3:0.004, select ecological composite cementitious materials, graphite tailings sand, shale Ceramic sand and admixtures;

Put 10% of the total mass of the ecological composite gelling material and the admixture into the mixer and stir for 2 to 3 minutes, then put the remaining 90% of the composite gelling material into the mixer and stir for 5 to 8 minutes, and finally add graphite The tailings sand and shale pottery sand are stirred for 10-15 minutes to obtain a special mortar (product) for dry construction of self-insulating aerated concrete.

The performance and main principle of raw material of the present invention:

Fly ash is Class II fly ash.

Phosphorus slag is the by-product slag of phosphorus production in electric furnace. The molten phosphorus slag is obtained by water quenching and quenching. The particle size is 0.2-5mm. The main composition: w(CaO) 47%-52%, w(SiO ₂ ) 40%-43%, w(Al ₂ O ₃ ) 2%-8%, w(Fe ₂ O ₃ ) 0.4%-1.0%, w(P ₂ O ₅ ) 0.6%-3.4%, w(F) 1%-3%.

Carbide slag is the waste residue after hydrolysis of calcium carbide to produce acetylene. The main component is Ca(OH) ₂ . It is used as an alkaline activator for fly ash and phosphorus slag in this ecological cementitious material.

Phosphogypsum is the waste residue produced when sulfuric _acid is used to treat phosphate rock in the production of phosphoric acid _. Workability of mortar.

For graphite tailings sand, the fineness modulus Mx is 2.0, and the mud content is less than 5%; for shale pottery sand, the fineness modulus Mx is 2.0-2.5.

The main component of fly ash and phosphorus slag is vitreous body, which has potential activity and generates strength under the excitation of cement clinker, phosphogypsum and carbide slag. Cement clinker, continuously hydrated after adding water to form hydrated calcium silicate gel, ettringite, etc., provides early strength for products, generates Ca(OH) ₂ and continuously provides OH ^- needed to maintain fly ash and phosphorus slag excitation of alkalinity.

In the admixture of the present invention, the water reducer alkali lignin is a dark brown powder extracted from papermaking waste liquid, and is a high molecular anion surface active substance with a molecular weight of 1,000-100,000. The role of water and water retention makes the water retention rate of the mortar reach more than 85%, reduces the degree of mortar stratification, and improves the workability of the mortar; polyethylene-vinyl acetate as an organic binder can increase the bonding strength of the mortar; water retention The agent hydroxypropyl methylcellulose can improve the water retention performance of the mortar, prevent the moisture in the mortar from being absorbed by the air-entrained concrete, and affect the hydration of the cementitious material in the mortar.

The composite use of light aggregate shale pottery sand in graphite tailing sand reduces the bulk density of the product and has a certain thermal insulation performance, which can improve the overall thermal insulation performance of the aerated concrete self-insulation wall.

The beneficial effects of the present invention are:

1) The dry construction special mortar prepared by the present invention has superior performance than traditional mortar, and its water retention is much better than traditional mortar. When the consistency is as high as 90mm or more, its delamination degree is obviously better than JC890-2001 standard mortar delamination degree Less than 20mm requirement. Using it together with air-entrained concrete can effectively prevent the moisture in the mortar from being absorbed by the wall, which can not only ensure the operability of the construction, but also facilitate the hydration of the cementitious material in the mortar, so that the strength of the mortar can continue to increase, and can meet the requirements of self-improvement. Requirements for thermal insulation aerated concrete block walls; add shale pottery sand to make the dry density between 750-950Kg/ ^m3 , the compressive strength between 3.6MPa-5.0MPa, and the folding ratio below 2.8. It has good anti-deformation ability; the bonding strength is greater than 0.50Mpa, which has strong bonding performance; the elastic modulus is between 1600N/mm ² and 2000N/mm ² , and the drying shrinkage value is less than 0.35mm/m, which is comparable to that of natural The material properties of thermal insulation aerated concrete are well matched; thus, quality accidents such as hollowing, cracking or even falling off of the wall can be effectively overcome. Matching with the dry construction of self-insulating aerated concrete, it can reduce the mortar joints and achieve good thermal insulation effect.

2) The method has simple process and low cost.

detailed description

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with examples, but the present invention is not limited only to the following examples.

Example 1:

A special mortar for dry construction of self-insulating aerated concrete and a preparation method thereof. Ethylene-vinyl acetate and hydroxypropyl methylcellulose are prepared through the following steps:

1) Preparation of ecological composite cementitious material: dry and dehydrate phosphorus slag, phosphogypsum, and calcium carbide slag at a temperature of 80°C and keep the temperature for 2 hours.

The ecological composite cementitious material is composed of fly ash, phosphorus slag, cement clinker, phosphogypsum and calcium carbide slag. According to the mass percentage of each raw material: fly ash 40%, phosphorus slag 40%, cement clinker 10%, Phosphogypsum 5%, carbide slag 5%, select fly ash (Class II ash), phosphorus slag, cement clinker, phosphogypsum and carbide slag; fly ash, phosphorus slag, cement clinker, phosphogypsum and carbide slag Mix and stir to obtain an ecological composite gelling material;

2) Preparation of admixture: The admixture is composed of alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose, according to the mass percentage of each component: alkali lignin 40%, polyethylene-vinyl acetate 30%, hydroxypropyl methylcellulose 30%, select alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose; alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose The cellulose is mixed and stirred to obtain the admixture (powder);

3) Preparation of special mortar: According to the mass ratio of ecological composite cementitious material: graphite tailings: shale pottery sand: admixture is 1:0.7:0.3:0.004, select ecological composite cementitious materials, graphite tailings sand, shale Ceramic sand and admixtures;

Dry mixing: put 10% of the total mass of the ecological composite gelling material and the admixture into the mixer and stir for 2 minutes, then put the remaining 90% of the composite gelling material into the mixer and stir for 6 minutes, and finally add graphite The tailings sand and shale pottery sand were stirred for 15 minutes to obtain a special mortar (product) for dry construction of self-insulating aerated concrete.

The special mortar prepared above was subjected to a performance test, and the results are shown in Table 1:

Table 1

project Dry density/ Kg/m ³ Compressive strength/MPa Flexural strength/MPa Bond strength/MPa Elastic modulus/ N/mm ² Consistency/mm Layered degree/mm Shrinkage performance/mm/m Thermal Conductivity result 852 5.2 2.10 0.48 1735 91 5.5 0.36 0.164

Comparative experiment: the special mortar prepared in Example 1 and the existing mortar were respectively used on the aerated concrete wall under the same conditions. The special mortar prepared in Example 1 had a wall with a mortar gap width of 8 mm, and the wall did not appear after 120 days. Hollowing, cracking, falling off and other phenomena; while the width of the joints in the ordinary mortar wall is 21mm, a small amount of hollowing and cracking will appear in the plaster layer of the wall after 120 days, and it will increase over time.

Example 2:

A special mortar for dry construction of self-insulating aerated concrete and a preparation method thereof. Ethylene-vinyl acetate and hydroxypropyl methylcellulose are prepared through the following steps:

1) Preparation of ecological composite cementitious material: dry and dehydrate phosphorus slag, phosphogypsum, and calcium carbide slag at a temperature of 120°C and a constant temperature of 1.5 hours.

The ecological composite cementitious material is composed of fly ash, phosphorus slag, cement clinker, phosphogypsum and calcium carbide slag. According to the mass percentage of each raw material: fly ash 35%, phosphorus slag 50%, cement clinker 8%, Phosphogypsum 4%, carbide slag 3%, select fly ash (Ⅱ grade ash), phosphorus slag, cement clinker, phosphogypsum and carbide slag; fly ash, phosphorus slag, cement clinker, phosphogypsum and carbide slag Mix and stir to obtain an ecological composite gelling material;

2) Preparation of admixture: The admixture is composed of alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose, and the mass percentage of each component is: alkali lignin 50%, polyethylene-vinyl acetate 15%, hydroxypropyl methylcellulose 35%, select alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose; alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose The cellulose is mixed and stirred to obtain the admixture (powder);

3) Preparation of special mortar: According to the mass ratio of ecological composite cementitious material: graphite tailings: shale pottery sand: admixture is 1:0.7:0.3:0.004, select ecological composite cementitious materials, graphite tailings sand, shale Ceramic sand and admixtures;

Dry mixing: put 10% of the total mass of the ecological composite gelling material and the admixture into the mixer and stir for 3 minutes, then put the remaining 90% of the composite gelling material into the mixer and stir for 8 minutes, and finally add graphite The tailings sand and shale pottery sand were stirred for 10 minutes to obtain a special mortar (product) for dry construction of self-insulating aerated concrete.

Comparative experiment: The special mortar prepared in Example 2 and the existing mortar were respectively used on the aerated concrete wall under the same conditions. The special mortar wall prepared in Example 2 had a mortar gap width of 7.5 mm, and the wall had no cracks after 120 days. Phenomena such as hollowing, cracking, and falling off occurred; while the width of the joints in the ordinary mortar wall was 19mm, a small amount of hollowing and cracking appeared in the plaster layer of the wall after 120 days, and showed an increasing trend over time.

Example 3:

A special mortar for dry construction of self-insulating aerated concrete and a preparation method thereof. Ethylene-vinyl acetate and hydroxypropyl methylcellulose are prepared through the following steps:

1) Preparation of ecological composite cementitious material: dry and dehydrate phosphorus slag, phosphogypsum, and calcium carbide slag at a temperature of 100°C and a constant temperature of 1.8 hours.

The ecological composite cementitious material is composed of fly ash, phosphorus slag, cement clinker, phosphogypsum and calcium carbide slag. According to the mass percentage of each raw material: fly ash 45%, phosphorus slag 32%, cement clinker 9%, Phosphogypsum 8%, carbide slag 6%, select fly ash (Ⅱ grade ash), phosphorus slag, cement clinker, phosphogypsum and carbide slag; fly ash, phosphorus slag, cement clinker, phosphogypsum and carbide slag Mix and stir to obtain an ecological composite gelling material;

2) Preparation of admixture: The admixture is composed of alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose, and the mass percentage of each component is: alkali lignin 35%, polyethylene-vinyl acetate 25%, hydroxypropyl methylcellulose 40%, select alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose; alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose The cellulose is mixed and stirred to obtain the admixture (powder);

3) Preparation of special mortar: According to the mass ratio of ecological composite cementitious material: graphite tailings: shale pottery sand: admixture is 1:0.7:0.3:0.004, select ecological composite cementitious materials, graphite tailings sand, shale Ceramic sand and admixtures;

Dry mixing: put 10% of the total mass of the ecological composite gelling material and the admixture into the mixer and stir for 2.5 minutes, then put the remaining 90% of the composite gelling material into the mixer and stir for 5 minutes, and finally add Graphite tailings sand and shale pottery sand were stirred for 13 minutes to obtain a special mortar (product) for dry construction of self-insulating aerated concrete.

Comparative experiment: The special mortar prepared in Example 3 and the existing mortar were respectively used on the aerated concrete wall under the same conditions. The special mortar wall prepared in Example 3 had a mortar gap width of 8.5 mm, and the wall had no cracks after 120 days. Phenomena such as hollowing, cracking, and falling off appear; while the width of the joints in the ordinary mortar wall is 20mm, a small amount of hollowing and cracking appear in the plaster layer of the wall after 120 days, and it shows a trend of increasing over time.

The upper and lower limits and interval values of each raw material in the present invention, as well as the upper and lower limits and interval values of process parameters (such as temperature, time, etc.) can realize the present invention, and the embodiments are not listed one by one here.

Claims (1)

1. A self-insulating aerated concrete dry construction special mortar is characterized in that it consists of fly ash, phosphorus slag, cement clinker, phosphogypsum, carbide slag, graphite tailings sand, shale pottery sand, alkali lignin, Polyethylene-vinyl acetate and hydroxypropyl methylcellulose, and prepared by the following steps: 1) Preparation of ecological composite cementitious material: dry and dehydrate phosphorus slag, phosphogypsum, and calcium carbide slag at a dehydration temperature of 80°C to 120°C and a constant temperature of 1.5 to 2 hours; %; According to the mass percentage of each raw material: fly ash 35-45%, phosphorus slag 25-50%, cement clinker 8-10%, phosphogypsum 3-8%, carbide slag 2-6%, the content of each raw material The sum is 100%, and fly ash, phosphorus slag, cement clinker, phosphogypsum and carbide slag are selected; fly ash, phosphorus slag, cement clinker, phosphogypsum and carbide slag are mixed and stirred to obtain an ecological composite cementitious material; 2) Preparation of additives: according to the mass percentage of each component: alkali lignin 35-50%, polyethylene-vinyl acetate 15-30%, hydroxypropyl methylcellulose 20-40%, choose alkali lignin , polyethylene-vinyl acetate and hydroxypropyl methylcellulose; alkali lignin, polyethylene-vinyl acetate and hydroxypropyl methylcellulose are mixed and stirred to obtain an additive; 3) Preparation of special mortar: according to the mass ratio of ecological composite cementitious material: graphite tailing sand: shale ceramic sand: admixture is 1:0.7:0.3:0.004, select ecological composite cementitious material, graphite tailing sand, shale Ceramic sand and admixtures; Put 10% of the total mass of the ecological composite gelling material and the admixture into the mixer and stir for 2 to 3 minutes, then put the remaining 90% of the composite gelling material into the mixer and stir for 5 to 8 minutes, and finally add graphite The tailings sand and shale pottery sand are stirred for 10 to 15 minutes to obtain a special mortar for dry construction of self-insulating aerated concrete.