Mixed aggregate masonry mortar is a building material with cement, sand, mineral admixtures (such as fly ash, slag, etc.), polymers, etc. as main components, and an appropriate amount of cellulose ether as a thickener and modifier. Cellulose ether, as an additive in mortar, mainly plays a role in improving the workability, water retention, adhesion, and crack resistance of mortar.

1. Basic properties of cellulose ether
Cellulose ether is a type of water-soluble polymer generated by chemical modification reaction using natural cellulose as raw material. Its molecular structure contains active groups such as hydroxyl and ether groups, which make cellulose ether have strong water solubility and good thickening effect. In mixed aggregate masonry mortar, cellulose ether mainly plays the following performance roles:

Thickening effect: The molecular structure of cellulose ether has certain hydrophilicity and hydrophobicity. By combining with water, it can increase the viscosity of mortar and improve its fluidity.

Water retention: Cellulose ether can improve the water retention of mortar, reduce the evaporation of water, and prolong the open time of mortar, thereby improving construction operability.

Improved adhesion: Cellulose ether can effectively enhance the adhesion between mortar and masonry materials, and improve the overall strength and stability of masonry.

2. The influence of cellulose ether on the performance of mixed aggregate masonry mortar
Improved construction performance
Construction performance is one of the important properties of masonry mortar, which directly affects the construction efficiency and project quality. Cellulose ether can adjust the viscosity of mortar through its thickening effect, making the mortar easier to operate. At the same time, it can maintain stable fluidity for a long time to prevent the mortar from drying and hardening too early. Especially in high temperature or air-drying environment, cellulose ether can effectively prevent the mortar from losing water too quickly, ensuring smooth operation during construction.

Enhanced water retention
Water retention is an important function of cellulose ether in masonry mortar. Cement mortar will gradually lose water after construction, which not only affects the adhesion of the mortar, but also causes cracks. Cellulose ether can absorb moisture, form a water film, delay the volatilization of moisture, keep the mortar moist, reduce the occurrence of cracks, and improve the overall quality of masonry mortar.

Improve adhesion and crack resistance
In mixed aggregate masonry mortar, cellulose ether can enhance the adhesion of mortar, especially on the contact surface between masonry materials such as bricks and stones, which helps to improve the bonding effect of mortar. In addition, cellulose ether can also improve the crack resistance of mortar. By thickening the structure of mortar and evenly distributing it in mortar, cellulose ether can reduce the occurrence of cracks, thereby improving the durability of masonry structure.

Improve anti-sagging
Sag refers to the sagging phenomenon that occurs when mortar is applied on a vertical or inclined surface. Excessive sag will affect the construction quality. Cellulose ether can enhance the anti-sagging of mortar, making the mortar more stable and avoiding sagging or falling off on the vertical construction surface. By adjusting the dosage of cellulose ether, a balance between mortar viscosity and anti-sagging can be achieved to ensure construction quality.

Enhanced antifreeze performance
In cold areas, masonry mortar needs to have good antifreeze performance. Cellulose ether can effectively improve the antifreeze performance of mortar through its water retention and improved adhesion. Its water-retaining film can protect the moisture in the mortar under low temperature conditions, reduce the damage to the mortar structure caused by water freezing and expansion, and thus improve the durability and antifreeze performance of the masonry structure.

3. Application of cellulose ether in mixed aggregate masonry mortar
Control of dosage
The dosage of cellulose ether directly affects the performance of the mortar. Excessive addition of cellulose ether may cause the mortar to be too viscous, affect the construction operability, and may even cause the compressive strength of the mortar to decrease. Therefore, in practical applications, the dosage of cellulose ether needs to be reasonably controlled according to actual needs. Usually, the dosage of cellulose ether is between 0.1% and 0.5%, and the specific dosage needs to be determined according to the specific needs of the project and the construction environment.

Synergistic effect with other additives
In mixed aggregate masonry mortar, cellulose ether is often used in combination with other polymer additives (such as polyvinyl alcohol, polypropylene alcohol, etc.) to further improve the performance of the mortar. Different additives have a certain synergistic effect, which can enhance the adhesion, water retention, crack resistance, etc. of mortar, so that the mortar can perform at its best under different construction environments.

Adapt to different construction environments
The type and dosage of cellulose ether can be adjusted according to different construction environments and needs. For example, when constructing in a humid environment, the dosage of cellulose ether can be appropriately increased to enhance the water retention of the mortar; while in a dry environment, the use of cellulose ether can be appropriately reduced to avoid construction difficulties caused by excessive water preservation.

As an important additive in mixed aggregate masonry mortar, cellulose ether plays a variety of functions such as thickening, water retention, bonding, and crack resistance. By reasonably controlling the dosage of cellulose ether, the construction performance, crack resistance, durability and other properties of the mortar can be significantly improved. With the development of building materials technology, the application of cellulose ether will be further promoted and become one of the key materials for improving the quality and performance of masonry mortar.