CN113912343A - Building plastering mortar suitable for robot and preparation method thereof - Google Patents

Abstract

The invention discloses building plastering mortar suitable for a robot, which consists of the following materials in parts by weight: 114-132 parts of cement; 211-223 parts of dry sand; 439-465 parts of machine-made sand; 38-44 parts of fly ash; 18-22 parts of silica fume; 12-16 parts of ground slag; 6-8 parts of a steel slag admixture; 1-1.7 parts of polyhydroxy carboxylic acid type salt; 0.8-1 part of alkylbenzene sulfonate; 0.7-0.8 part of polycarboxylic acid; 0.3-0.5 part of air entraining agent; 0.5-0.7 part of dispersing agent. The components of the invention are cooperated to improve the performance of the mortar, especially the cooperation of the ground slag, the steel slag admixture and the fly ash can greatly reduce the hydration heat of the cementing material, the filling effect of the combination of the steel slag powder and the slag powder is higher than that of the single-doped fly ash, the super-superposition effect is good, the fluidity and the cohesiveness are better, and the pumping is more suitable. In addition, the synergistic cooperation of the polyhydroxy carboxylic acid salt, the alkylbenzene sulfonic acid and the polycarboxylic acid is beneficial to improving the pumping performance of the mortar mixture, thereby being suitable for long-distance conveying and improving the automatic construction efficiency.

Description

Building plastering mortar suitable for robot and preparation method thereof

Technical Field

The invention belongs to the technical field of building materials, and particularly relates to building plastering mortar suitable for a robot and a preparation method thereof.

Background

With the high-speed development of the building industry and the large application of new building material and new technology, the traditional building materials and process cannot meet the requirements of construction quality, and particularly, the traditional field configuration and construction mode of mortar not only causes extreme waste of resources and huge damage to the environment, but also cannot meet the requirements of building energy conservation, thereby hindering the pace of upgrading of the construction process. In order to protect and improve the environment, promote the comprehensive utilization of resources and ensure the quality of construction projects, according to the related laws and regulations of national regulations for promoting the development and application of bulk cement, national regulations for preventing and controlling air pollution and the like, and in combination with the development situation of domestic ready-mixed mortar, the urban and rural construction hall issues a notice of an implementation method for accelerating the development of the ready-mixed mortar, so that the ready-mixed mortar is required to be used in a construction site, and advanced construction methods such as mechanical pumping, slurry spraying and the like are encouraged to be adopted in order to improve the quality and efficiency of plastering construction.

In recent years, the production process, the product quality, the enterprise scale, the technical equipment, the modernized logistics and the like are greatly changed under the joint promotion of governments, enterprises and markets in the ready-mixed mortar industry all over the country, particularly in the aspect of the mechanical spraying technology. Although various mechanical equipment, construction operation technology and construction method have made great progress in technical research, a lot of common faults still exist, and the popularization of the mechanical spraying of the ready-mixed mortar is restricted.

The wall plastering means an engineering of plastering a cement mortar, mixed mortar and lime mortar surface layer on a wall, wherein the mortar is smeared on the surface of a base material, has the functions of protecting a base layer and improving the appearance, and provides special functions for buildings. The plastering engineering has two major functions: the wall has the advantages that firstly, the wall is protected from being eroded by wind, rain and snow, the moistureproof, weatherproof and heat insulation capabilities of the wall are improved, and the durability and thermal performance of the wall are improved; and secondly, the functions of beautifying, improving indoor sanitary conditions, purifying air, beautifying the environment and improving the living comfort level are realized.

The existing wall surface mortar scraping is mostly carried out manually, the labor intensity is high, time and labor are wasted, the flatness is not high, and certain dangerousness is realized for high-altitude operation. The problem has been solved in the appearance of plastering robot, however, the current manual plastering mortar that uses has low mobility, the bleeding rate is high and can not satisfy mechanized construction, and the pipe is blocked up very easily, increases the work load of artifical mediation, and the utilization ratio is low. Even if can adapt to the pumping, also because of long distance is influenced by pressure, the mortar mixture is inhomogeneous, when influencing thickness behind the construction and can't play the effect of making level, appear fracture, hollowing on the contrary after applying paint, peel off the scheduling problem, is difficult to adapt to present market demand.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides building plastering mortar suitable for a robot and a preparation method thereof.

The building plastering mortar suitable for the robot is characterized by comprising the following materials in parts by weight:

furthermore, when the silicon ash is used for smelting ferrosilicon and industrial silicon, a large amount of SiO with strong volatility is generated in the ore-smelting electric furnace₂And Si gas, which is formed by rapid oxidation, condensation and precipitation with air after the gas is discharged; the fineness of the powder is less than 1 mu m and accounts for more than 80 percent, the average particle size is 0.1-0.3 mu m, and the specific surface area is 20-28 m²(ii) in terms of/g. The silica fume is acted by surface tension in the forming process to form the granular form of amorphous spherical particles with smooth surface, and the silica fume can replace part of fly ash to be mixed into mortar, so that tiny spheroids can play a role in lubrication. And the silica fume is a volcanic ash substance with large specific surface area and high activity, can effectively reduce the pumping resistance, simultaneously effectively prevent the alkali-aggregate reaction, avoid the subsequent cracking, hollowing and the like, and properly adjust the setting time of the mortar.

Further, the ground slag is granulated blast furnace slag in industrial slag. The fine ground slag of the invention is granulated blast furnace slag (such as a byproduct in a steel melting process) with good potential active materials in industrial waste slag, and minerals rich in silicon, calcium and iron can form a large amount of amorphous active glass body structures or network structures in the blast furnace ironmaking process, so that the mortar performance can be effectively improved. The levigated slag and the steel slag admixture are mutually blended to replace part of fly ash, and are cooperated to reduce the hydration heat of the cementing material greatly, the steel slag powder and the slag powder have higher filling effect than the single-blended fly ash, and can have good super-superposition effect, better fluidity and cohesiveness and more suitability for pumping. Preferably, the weight part ratio of the fly ash to the ground slag to the steel slag is (4-8) to (2) (1-1.5).

Further, the main components of the steel slag admixture are tricalcium carbonate, free calcium oxide, RO phase and dicalcium ferrite, and the mixing amount ratio of the steel slag admixture to the ground slag is preferably 1: 2.

Further, the polyhydroxy carboxylic acid type salt is sodium gluconate, white or light yellow crystal powder, has fresh sour taste, fixed composition and uniform structure, and the addition amount is 0.1-0.15% of the total amount. The polyhydroxy carboxylic acid type salt serving as a common retarder can play a synergistic effect after being compounded with the water reducing agent, the original working performance of the mortar is maintained, the problem that the dehydration and blockage of the mortar are influenced by pressure in the pumping process is solved, the later-stage mortar strength can be effectively improved by proper mixing amount, but the excessive addition is not suitable. The polyhydroxycarboxylic acid type salt of the present invention may also be sodium citrate, tartaric acid (potassium sodium) and other salts.

Furthermore, the branched alkylbenzene sulfonate is one or more of sodium dodecyl benzene sulfonate, polyacrylamide, alpha-olefin sulfonate, linear alkylbenzene sulfonate or alkyl glyceryl ether sulfonate, the addition amount of the branched alkylbenzene sulfonate is 0.08-0.1% of the total amount, and other types of anionic surfactants can also be selected. The branched alkylbenzene sulfonic acid is an important anionic surfactant, can well reduce the surface tension and wetting, penetrating and emulsifying properties of water, is easy to generate synergistic action with other substances, has stable chemical properties, and controls the fluidity of mortar mixing species.

Further, the polycarboxylic acid is a product obtained by addition polymerization of an unsaturated carboxylic acid monomer, such as polyacrylic acid, polymethacrylic acid. Preferably, the polycarboxylic acid is synthesized by taking Ammonium Persulfate (APS) as an initiator and Acrylic Acid (AA), cinnamic acid (CINN), isopentenol polyoxyethylene ether (TPEG) and 2-acrylamide-2-methylpropanesulfonic Acid (AMPS) as reaction monomers through free radical copolymerization, a molecular structure contains carboxyl, hydroxyl, benzene ring and other groups, cement particles are dispersed through steric hindrance, a good effect is achieved, and the addition amount is 0.7-0.8% of the total amount. The polycarboxylic acid high-performance water reducing agent is a green, environment-friendly, non-flammable and non-explosive cement dispersing agent. Compared with traditional water reducing agents such as lignosulfonate and naphthalene sulfonate formaldehyde condensate, the new-generation polycarboxylate water reducing agent has stronger molecular structure adjustability, can achieve better performance by relatively lower mixing amount, reduces mortar bleeding and effectively improves shrinkage.

Furthermore, the air entraining agent is rosin resins, alkyl and alkyl aromatic hydrocarbon sulfonic acids, fatty alcohol sulfonates and saponins. Preferably, the invention adopts a saponin air entraining agent DH-4013-1, and the addition amount is 0.6-0.7% of the total amount. The air entraining agent is a hydrophobic surfactant, a large amount of micro bubbles are easily generated when the air entraining agent is stirred in a mortar mixture, the micro bubbles are uniformly distributed in the mixture, the water-cement ratio is kept unchanged, meanwhile, the air content is increased by 1 percent, and the fluidity, the water retention property and the cohesiveness of the mixture are improved. The lower mixing amount can improve the bleeding and the segregation in the pumping process and improve the volume stability of the mortar mixture.

Furthermore, the dispersing agent is sodium hexametaphosphate, is in the form of white powder crystals, is used for being matched with polycarboxylic acid, and has better effect than trisodium phosphate, and the addition amount is 0.06-0.08%. The dispersant is silicate among common inorganic dispersants. The hydroscopic property is very strong, and the hydroscopic property is that the hydroscopic property is exposed in the air, and the hydroscopic property can gradually absorb water to form a sticky substance, so that the substances of solid or liquid particle aggregation in a dispersion system are reduced, and the long-term long-distance transportation is adapted to mechanical pumping.

Furthermore, the machine-made sand is quartz particles formed by crushing and processing quartz stones, a natural high-quality quartz sand deposit is used as a raw material, and the natural structure of the quartz stones is effectively protected through a series of production processes such as mechanical crushing, rolling and rolling, washing and screening, drying and screening, vibration classification and the like. Preferably, the machine-made sand is type I sand, the particle composition is a machine-made sand 2 area, and the fineness modulus is as follows: 3.0 to 2.3.

The invention also provides a preparation method of the building plastering mortar suitable for the robot, which comprises the following steps:

s1, selecting raw materials: preparing the following materials in parts by weight: 114-132 parts of cement; 211-223 parts of dry sand; 439-465 parts of machine-made sand; 38-44 parts of fly ash; 18-22 parts of silica fume; 12-16 parts of ground slag; 6-8 parts of a steel slag admixture; 1-1.7 parts of polyhydroxy carboxylic acid type salt; 0.8-1 part of alkylbenzene sulfonate; 0.7-0.8 part of polycarboxylic acid; 0.3-0.5 part of air entraining agent; 0.5-0.7 part of a dispersing agent;

s2, screening dry sand: selecting raw materials according to the step S1, wherein the dry sand is screened, and a particle size distribution II area with the fineness of 2.3-2.6 is selected; the machine-made sand has the same grain composition and fineness, and the redundant floating powder is screened out;

s3, preparing an additive: pouring weighed polyhydroxy carboxylic acid type salt, alkylbenzene sulfonate, polycarboxylic acid, air entraining agent and dispersing agent into a special additive mixer, stirring for 3 minutes, and uniformly mixing;

s4, mortar preparation: and pouring the weighed admixture of cement, dry sand, machine-made sand, fly ash, silica fume, levigated slag and steel slag into a dry-mixed mortar stirrer, stirring for 9 minutes respectively in the middle and reverse directions, adding the admixture prepared in the S3, and stirring for 4 minutes by high-frequency pulse to complete the preparation of a dry mixture of the mortar.

The invention has the following beneficial effects:

(1) the components are cooperated to improve the performance of the mortar, particularly, the ground slag, the steel slag admixture and the fly ash are cooperated to greatly reduce the hydration heat of the cementing material, the filling effect of the combination of the steel slag powder and the slag powder is higher than that of the single-doped fly ash, the super-additive effect is good, the fluidity and the cohesiveness are better, and the pumping is more suitable.

(2) The industrial waste slag (the milled slag and the steel slag admixture) is added into the raw materials, so that the solid waste is effectively utilized, and the cost is better saved; on the other hand, the method is suitable for the aim of realizing low-carbon green development by carrying out clean production in the whole ready-mixed mortar industry at present.

(3) The synergistic cooperation of the polyhydroxy carboxylic acid salt, the alkylbenzene sulfonic acid and the polycarboxylic acid is beneficial to improving the pumping performance of the mortar mixture, thereby being suitable for long-distance conveying and improving the automatic construction efficiency.

(4) And meanwhile, the saponin air entraining agent and the sodium hexametaphosphate are selected to be matched for use, so that the water retention and the anti-sagging performance of the mortar are effectively ensured even under high-pressure pumping, and a good effect is finally achieved.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.

Example 1

The robot plastering mortar dry powder comprises the following components:

wherein, the requirements and parameters or models of each component are as follows: the cement is 42.5 of GB175 medium silicate cement; the machine-made sand is class I machine-made sand in GB/T14684, medium sand. The dry sand is I-type natural sand and medium sand in GB/T14684; the fly ash is the fly ash for II-grade mixed mortar and concrete in GB/T1596; more than 80% of silica fume with fineness less than 1 μm, average particle diameter of 0.1-0.3 μm, and specific surface area of 20-28 m²(ii)/g; the ground slag is granulated blast furnace slag with a specific surface area of 420m²/kg～450m²Per kg; the steel slag admixture is steel-making waste slag with a specific surface area of 450m²Per kg; the polyhydroxy carboxylic acid type salt is sodium gluconate powder; the polycarboxylic acid is polyacrylic acid crystal powder; the air entraining agent is fructus Gleditsiae Abnormalis air entraining agent DH-4013-1; the dispersant is sodium hexametaphosphate crystal powder;

the preparation method of the robot plastering mortar dry powder comprises the following steps: (1) the weighed additives are prepared and poured into a special additive mixer to be stirred for 3 minutes and mixed evenly; (2) and pouring the weighed powder and aggregate into a dry-mixed mortar stirrer, stirring for 9 minutes respectively in the middle-forward and reverse directions, adding the prepared admixture, and stirring for 4 minutes by high-frequency pulse to complete the preparation of a dry mixture of the mortar.

The preparation method of the robot plastering mortar comprises the following steps: 100kg of prepared sample is poured into a small mortar stirrer, water is added for stirring for 3min, and water is added for subsequent testing when the consistency is 95 +/-5 mm according to a JGJ/T70 consistency measurement method.

Example 2

The robot plastering mortar dry powder comprises the following components:

wherein, the requirements and parameters or models of each component are as follows: the cement is 42.5 of GB175 medium silicate cement; the machine-made sand is class I machine-made sand in GB/T14684, medium sand. The dry sand is I-type natural sand and medium sand in GB/T14684; the fly ash is the fly ash for II-grade mixed mortar and concrete in GB/T1596; more than 80% of silica fume with fineness less than 1 μm, average particle diameter of 0.1-0.3 μm, and specific surface area of 20-28 m²(ii)/g; the ground slag is granulated blast furnace slag with a specific surface area of 420m²/kg～450m²Per kg; the steel slag admixture is steel-making waste slag with a specific surface area of 450m²Per kg; the polyhydroxy carboxylic acid type salt is sodium gluconate powder; the polycarboxylic acid is polyacrylic acid crystal powder; the air entraining agent is fructus Gleditsiae Abnormalis air entraining agent DH-4013-1; the dispersant is sodium hexametaphosphate crystal powder;

the preparation method of the robot plastering mortar dry powder comprises the following steps: (1) the weighed additives are prepared and poured into a special additive mixer to be stirred for 3 minutes and mixed evenly; (2) and pouring the weighed powder and aggregate into a dry-mixed mortar stirrer, stirring for 9 minutes respectively in the middle-forward and reverse directions, adding the prepared admixture, and stirring for 4 minutes by high-frequency pulse to complete the preparation of a dry mixture of the mortar.

The preparation method of the robot plastering mortar comprises the following steps: 100kg of prepared sample is poured into a small mortar stirrer, water is added for stirring for 3min, and the subsequent test can be carried out when the consistency is 95 +/-5 mm according to the JGJ/T70 consistency measurement method.

Performance test

1. The water retention performance of the plastering mortar is detected according to JGJ/T70, and the detection result is recorded in table 1; the fluidity is tested according to the specification of GBT2419-2005, wherein the cement mortar mixture is replaced by the mortar mixture; the pressure bleeding rate was measured according to the GB/T25181-2019, and the measurement results are shown in Table 1.

TABLE 1

2. Detection of sag resistance of mortar mixture

1) Test subjects: the mortar mixtures from examples 1 and 2, after being pumped through the machine, were taken as test specimens, each set of test specimens having the same initial weight: taking common plastering mortar as a comparison test; the test substrate was a normal unpainted wall surface.

2) The test method comprises the following steps: coating each group of samples on the surface of the wall surface in the same coating mode, observing the thickest scraping thickness which can be achieved under the condition of no sagging, and recording the scraping thickness;

3) the test result shows that the thicker the blade coating thickness is, the stronger the adhesion of the plastering mortar is, and the better the sag resistance is. The thickest batch thickness is recorded in table 2.

TABLE 2

Test specimen	Thickest batch scraping thickness mm
		Example 1	Batch scraping 3mm non-flowing pendant
Example 2	Batch scraping 3mm non-flowing pendant
		Comparative example 1	Batch scraping 2mm non-flowing pendant

3 analysis of test results

1. The embodiment 1 and the embodiment 2 have good performances in the aspects of overall pumpability, anti-sagging performance and water retention performance, and can be effectively matched with the use of an actual plastering robot. It can be seen that the admixture additive components are changed, and slight changes in certain properties occur. When the polyhydroxy carboxylic acid type salt and the alkylbenzene sulfonic acid with high proportion are added, the pressure bleeding rate is low, and the overall pumping performance is improved; when the addition proportion of the air entraining agent or the dispersing agent is increased, the overall water retention and the anti-sagging performance are improved. Compared with the common plastering mortar, the anti-sagging effect is more obvious in batch scraping thickness. The embodiment can finally achieve a relatively proper performance index of the mortar mixture.

2. In the embodiments 1 and 2, the blending amount of the ground slag and steel slag admixture can be slightly added, so that a good filling effect is achieved, on one hand, the overall compressive strength is obviously increased while the construction hand feeling is effectively improved, on the other hand, the cost is saved, and on the other hand, the low-carbon green development of building materials is realized.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited thereto, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (10)

1. The building plastering mortar suitable for the robot is characterized by comprising the following materials in parts by weight:

2. the building plastering mortar suitable for robot as claimed in claim 1, wherein when the silica fume is ferrosilicon and industrial silicon for smelting, a large amount of SiO with strong volatility is generated in the ore-smelting electric furnace₂And Si gas, which is formed by rapid oxidation, condensation and precipitation with air after the gas is discharged; the fineness of the powder is less than 1 μm and accounts for more than 80%, and the average particle diameter is 0.1-0.3 μmThe surface area is 20 to 28m²/g。

3. The building plastering mortar suitable for robot as claimed in claim 1, wherein the ground slag is granulated blast furnace slag among industrial slag.

4. The building plastering mortar slurry suitable for robots of claim 1, wherein the steel slag admixture comprises tricalcium carbonate, free calcium oxide, RO phase and dicalcium ferrite as main components, and the mixing ratio of the steel slag admixture to the ground slag is 1: 2.

5. The building plastering mortar suitable for robot as claimed in claim 1, wherein the polyhydroxycarboxylic acid type salt is sodium gluconate.

6. The building plastering mortar suitable for robots of claim 1, wherein the branched alkylbenzene sulfonate is one or more of sodium dodecylbenzene sulfonate, polyacrylamide, alpha-olefin sulfonate, sodium linear alkylbenzene sulfonate or alkyl glyceryl ether sulfonate.

7. A building plastering mortar suitable for use in a robot as claimed in claim 1, wherein the polycarboxylic acid is a product obtained by addition polymerization of an unsaturated carboxylic acid monomer.

8. The building plastering mortar suitable for robots of claim 1, wherein the air-entraining agent is rosin resins, alkyl and alkyl aromatic hydrocarbon sulfonic acids, fatty alcohol sulfonates, saponins.

9. The building plastering mortar suitable for robots of claim 1, wherein the dispersant is sodium hexametaphosphate in the form of white powdery crystals.

10. The method for preparing a building plastering mortar suitable for a robot according to claim 1, comprising the steps of:

s1, selecting raw materials: preparing the following materials in parts by weight: 114-132 parts of cement; 211-223 parts of dry sand; 439-465 parts of machine-made sand; 38-44 parts of fly ash; 18-22 parts of silica fume; 12-16 parts of ground slag; 6-8 parts of a steel slag admixture; 1-1.7 parts of polyhydroxy carboxylic acid type salt; 0.8-1 part of alkylbenzene sulfonate; 0.7-0.8 part of polycarboxylic acid; 0.3-0.5 part of air entraining agent; 0.5-0.7 part of a dispersing agent;

s2, screening dry sand: selecting raw materials according to the step S1, wherein the dry sand is screened, and a particle size distribution II area with the fineness of 2.3-2.6 is selected; the machine-made sand has the same grain composition and fineness, and the redundant floating powder is screened out;

s3, preparing an additive: pouring weighed polyhydroxy carboxylic acid type salt, alkylbenzene sulfonate, polycarboxylic acid, air entraining agent and dispersing agent into a special additive mixer, stirring for 3 minutes, and uniformly mixing;

s4, mortar preparation: and pouring the weighed admixture of cement, dry sand, machine-made sand, fly ash, silica fume, levigated slag and steel slag into a dry-mixed mortar stirrer, stirring for 9 minutes respectively in the middle and reverse directions, adding the admixture prepared in the S3, and stirring for 4 minutes by high-frequency pulse to complete the preparation of a dry mixture of the mortar.