Dry-mixed mortar is a powdered building material made of cement, sand, mineral powder and other ingredients through precise proportions. When used, it only needs to be stirred by adding a certain amount of water. Dry-mixed mortar has the advantages of simple construction, stable quality and time saving, so it is widely used in construction. In order to improve the working performance, construction performance and crack resistance of dry-mixed mortar, some chemical additives are often needed. Among them, HPMC (Hydroxypropyl Methylcellulose) is an important modified material and is usually added to dry-mixed mortar.

1. Improve the construction performance of mortar
HPMC can significantly improve the construction performance of dry-mixed mortar. Construction performance includes the workability, adhesion and fluidity of mortar, which directly affects the construction quality and efficiency. HPMC has a thickening effect, which can increase the viscosity of mortar, making it easier to construct when used. Especially in the process of large-scale construction, the adhesion of mortar is enhanced, which can better adhere to the wall or ground, and prevent the mortar from flowing too much or sliding too quickly.

2. Extend the open time
The open time refers to the time window from the completion of mortar mixing to the completion of use. Extending the open time can ensure the smoothness of the construction process. The addition of HPMC helps to extend the open time of mortar. It can slow down the hydration of cement, making it difficult for the mixed mortar to harden prematurely during operation, and avoid the problem of decreased adhesion due to rapid water loss of mortar during construction. It is especially important for large-scale construction or long-term operation.

3. Improve crack resistance
Dry-mixed mortar may crack during the hardening process, especially when the external environment temperature changes greatly. HPMC can improve the rheological properties of mortar and increase its plasticity, thereby reducing stress concentration during cement hydration and slowing down the shrinkage and cracking of mortar. This has a positive effect on the long-term stability and appearance of the building.

4. Increase the water retention of mortar
HPMC has good water retention. After adding HPMC to the mortar, it can effectively reduce water evaporation and maintain the moisture in the mortar. This not only helps the cement hydration reaction of the mortar, but also ensures the strength and density of the mortar. Especially in a high temperature and dry environment, water retention is an important factor in preventing the mortar from drying and cracking early and hardening incompletely.

5. Enhance the impermeability of mortar
HPMC can improve the impermeability of mortar, make the cement paste denser, and reduce the penetration of water, gas or other substances. By improving the microstructure of the mortar and enhancing the durability of the mortar, it is particularly suitable for construction projects with special requirements such as waterproofing and moisture-proofing.

6. Improve the adhesion of mortar
HPMC can effectively increase the adhesion between the mortar and the substrate. After adding HPMC to the dry-mixed mortar, the adhesion of the mortar can be significantly improved, especially in the construction of different substrates such as walls, floors, tiles, etc. HPMC can effectively improve the adhesion of the mortar and ensure that the construction effect is long-lasting and reliable.

7. Improve anti-floating and anti-slip properties
In some special applications (such as laying tiles or marble, etc.), the anti-floating and anti-slip properties of mortar are crucial. HPMC can improve the anti-floating force of mortar, making it less likely for mortar to slip during the tiling process, and maintaining the flatness and stability of decorative materials.

8. Reduce costs
Although HPMC is an additive, it has a significant effect on improving the performance of mortar. Because it can improve the performance of mortar, especially in the construction process to extend the service life and reduce rework, it can ultimately reduce the overall construction cost. To a certain extent, HPMC can reduce dependence on other auxiliary materials and help save raw materials.

9. Environmental protection and safety
HPMC, as a material derived from natural plant fibers, has good environmental performance. Using HPMC in dry-mixed mortar can not only improve the comprehensive performance of mortar, but also has better safety, which is suitable for use in indoor environments and buildings with high environmental protection requirements. Compared with other chemical additives, HPMC has better environmental protection and biocompatibility, which meets the needs of green environmental protection in modern buildings.

The use of HPMC in dry-mix mortar not only improves the various properties of mortar, especially workability, adhesion, crack resistance, water retention, etc., but also ensures construction quality while improving work efficiency. Therefore, HPMC has become one of the indispensable and important additives in dry-mix mortar. As the construction industry continues to increase its requirements for material performance, the application prospects of HPMC will be more extensive, bringing more convenience and security to construction.