In order to make the performance of all aspects of the ready-mixed mortar meet the specifications and construction requirements, the mortar admixture is an essential component. Magnesium aluminum silicate thixotropic lubricant and cellulose ether are commonly used water-retaining thickeners in mortar. Cellulose ether has better water-retaining properties, but it is expensive, and the high dosage is serious air-entrainment, which greatly reduces the strength of the mortar. and other issues; the price of magnesium aluminum silicate thixotropic lubricant is low, but when it is mixed alone, the water retention is lower than that of cellulose ether, and the dry shrinkage value of the prepared mortar is large, and the cohesiveness is reduced. The effects of compounding of magnesium aluminum silicate thixotropic lubricant and cellulose ether on the consistency, layering degree, setting time, strength and other aspects of ready-mixed (wet-mixed) mortar are as follows:
1. Although the mortar prepared without adding water-retaining thickener has high compressive strength, its water-retaining property, cohesiveness and softness are poor, bleeding is more serious, and the operation feel is poor, so it is basically unusable. Therefore, water retention and thickening materials are an essential part of ready-mixed mortar.
2. When the magnesium aluminum silicate thixotropic lubricant and cellulose ether are mixed alone, the construction performance of the mortar is obviously improved compared with the blank mortar. But there are also shortcomings. When the magnesium aluminum silicate thixotropic lubricant is single-doped, the amount of magnesium aluminum silicate thixotropic lubricant has a great influence on the single water consumption, and the water retention is lower than that of cellulose ether; when only cellulose ether is mixed, the operability of mortar It is better, but when the dosage is high, air-entrainment is serious, which leads to a great reduction in the strength of the mortar, and the price is relatively expensive, which increases the material cost to a certain extent.
3. In the case of ensuring the performance of the mortar in all aspects, the optimal dosage of magnesium aluminum silicate thixotropic lubricant is about 0.3%, the optimal dosage of cellulose is 0.1%, and the dosage of the two compounded is controlled here ratio, the overall effect is better.
4. The ready-mixed mortar prepared by compounding magnesium aluminum silicate thixotropic lubricant and cellulose ether has good workability, and its consistency and loss, delamination, compressive strength and other performance indicators can meet the specifications and construction requirements.
Mortar classification
Ordinary dry powder mortar
A. Dry powder masonry mortar: refers to the dry powder mortar used in masonry projects.
B. Dry powder plastering mortar: refers to the dry powder mortar used for plastering projects.
C. Dry powder ground mortar: refers to the dry powder mortar used for the surface layer or leveling layer of the building ground and roof.
Special dry powder mortar
Special dry powder mortar refers to thin layer dry powder mortar, decorative dry powder mortar or dry powder mortar with a series of special functions such as crack resistance, high adhesion, waterproof and impermeability and decoration. It includes inorganic thermal insulation mortar, anti-cracking mortar, plastering mortar, wall tile adhesive, interface agent, caulking agent, colored finishing mortar, grouting material, grouting agent, waterproof mortar, etc.
Basic performance characteristics of different mortars
A. Vitrified microbead inorganic thermal insulation mortar.
Vitrified microbead insulation mortar is made of hollow vitrified microbeads (mainly for heat insulation) as lightweight aggregate, cement, sand and other aggregates and various additives according to a certain proportion and then mixed evenly. A new type of inorganic thermal insulation mortar material for external and internal thermal insulation.
Vitrified microbead thermal insulation mortar has excellent thermal insulation performance, fire resistance and aging resistance, no hollowing and cracking, high strength, and can be used after adding water and stirring on site. Due to the pressure of market competition and for the purpose of reducing costs and expanding sales, there are still some companies in the market that use light aggregates such as expanded perlite particles as thermal insulation materials and call them vitrified microbeads. The quality of these products is low. Based on the real vitrified microbead insulation mortar.
B. Anti-crack mortar
Anti-cracking mortar is a mortar that is made of polymer emulsion and admixture of anti-cracking agent, cement and sand in a certain proportion, which can satisfy a certain deformation without cracking. It solves a major problem that has been plagued by the construction industry – the problem of fracture of the light-weight insulation layer. It is a high-quality environmental protection material with high tensile strength, easy construction and anti-freezing.
C. Plastering mortar
All mortar applied on the surface of buildings or building components is collectively referred to as plastering mortar. According to the different functions of plastering mortar, plastering mortar can be divided into ordinary plastering mortar, decorative sand and plastering mortar with some special functions (such as waterproof mortar, thermal insulation mortar, sound-absorbing mortar and acid-resistant mortar, etc.). The plastering mortar is required to have good workability, and it is easy to plaster into a uniform and flat layer, which is convenient for construction. It should also have high cohesion, and the mortar layer should be able to bond firmly with the bottom surface without cracking or falling off for a long time. It should also have high water resistance and strength when it is in a humid environment or vulnerable to external forces (such as the ground and dado, etc.).
D. caulk
Tile grout is made of fine quartz sand, high-quality cement, filler pigments, additives, etc., which are precisely compounded by advanced production technology, so that the color is more vivid and durable, and it is harmonious and unified with the wall tiles. The perfect combination of mildew and anti-alkali.
E. Grouting material
The grouting material is made of high-strength materials as aggregate, cement as binder, supplemented by high fluidity, micro-expansion, anti-segregation and other substances. A certain amount of water is added to the grouting material at the construction site, and it can be used after stirring evenly. The grouting material has the characteristics of good self-flowing property, rapid hardening, early strength, high strength, no shrinkage, and slight expansion; non-toxic, harmless, non-aging, no pollution to water quality and surrounding environment, good self-tightness, and anti-rust. In terms of construction, it has the advantages of reliable quality, reduced cost, shortened construction period and convenient use.
F. Grouting agent
The grouting agent is a grouting agent refined from high-performance plasticizers, surfactants, silicon-calcium micro-expansion agents, heat of hydration inhibitors, migratory rust inhibitors, nano-scale mineral silicon-aluminum-calcium-iron powder, and stabilizers Or refined and compounded with low-alkali and low-heat Portland cement. It has micro-expansion, no shrinkage, large flow, self-compacting, extremely low bleeding rate, high filling degree, thin airbag foam layer, small diameter, high strength, anti-rust and anti-rust, low alkali and chlorine-free, high adhesion, green and environmental protection excellent performance.
G. Decorative mortar – colored finishing mortar
Colored decorative mortar is a new type of inorganic powdered decorative material, which has been widely used in the interior and exterior wall decoration of buildings instead of paint and ceramic tiles in developed countries. Colored decorative mortar is refined with polymer material as the main additive, together with high-quality mineral aggregates, fillers and natural mineral pigments. The thickness of the coating is generally between 1.5 and 2.5 mm, while the thickness of ordinary latex paint is only 0.1 mm, so it can obtain excellent texture and three-dimensional decorative effect.
H. Waterproof mortar
Waterproof mortar is made of cement and fine aggregate as the main material, and high molecular polymer as the modified material, which is made by mixing according to the appropriate mixing ratio and has certain impermeability. Guangdong is now forcing promotion, and the national market will gradually grow bigger.
J. Ordinary Mortar
It is made by mixing inorganic cementitious material with fine aggregate and water in proportion, also known as mortar. For masonry and plastering projects, it can be divided into masonry mortar, plastering mortar and ground mortar. The former is used for masonry and component installation of bricks, stones, blocks, etc.; the latter is used for walls, floors, etc. , Roof and beam-column structures and other surface plastering, in order to meet protection and decoration requirements.
The performance and function of magnesium aluminum silicate in dry powder mortar
Magnesium aluminum silicate is added to the mortar mainly to lubricate, thixotropy, anti-sagging, and improve workability, so its trade name in this field is called thixotropic lubricant. Magnesium aluminum silicate thixotropic lubricant will produce the following benefits when added to putty:
(1) This product is an environment-friendly pure inorganic material, which has better characteristics than starch ether organic materials.
(2) It can improve the workability of the mortar and make the appearance of the prepared mortar round and full.
(3) It can prolong the opening time and operability time of the mortar, improve the lubricity of the mortar, reduce the resistance during scraping, save time and effort when scraping, improve construction efficiency and labor productivity, and thus reduce labor costs.
(4) It can make the surface of the mortar after batch scraping more plump and smooth, and can carry out one-time thick slurry construction for the thermal insulation mortar, and reduce the loss of mortar.
(5) It can make the mortar and grouting material homogeneous and stable, prevent the mortar and grouting material from bleeding, and improve the storage stability of the mortar.
(6) It can reduce the flow viscosity and resistance of mortar and grouting material, make pumping and machine spraying more convenient and smooth, improve the delivery efficiency of mortar and grouting material, and reduce the wear of mortar and grouting material on pumps and pipelines , Prolong the life of the equipment, thereby reducing the overall cost.
(7) Depending on the formula and the use of raw materials, the amount of cellulose and rubber powder in the mortar can be appropriately reduced, and the mortar formula can be optimized