The importance of hydroxypropyl methylcellulose (HPMC) for water retention in mortar!

Why is the requirement for water retention in mortar so high, and what are the outstanding advantages of mortar with good water retention? Let me introduce to you the importance of HPMC water retention in mortar!

The need for water retention

Water retention of mortar refers to the ability of mortar to retain water. Mortar with poor water retention is easy to bleed and segregate during transportation and storage, that is, water floats on the top, sand and cement sink below, and must be re-stirred before use.

All kinds of bases that need mortar for construction have a certain amount of water absorption. If the water retention of the mortar is poor, in the process of mortar application, as long as the ready-mixed mortar is in contact with the block or base, the ready-mixed mortar will be absorbed. At the same time, the surface of the mortar evaporates water from the atmosphere, resulting in insufficient moisture of the mortar due to water loss, affecting the further hydration of the cement, and affecting the normal development of the strength of the mortar, resulting in the strength, especially the interface strength between the hardened body of the mortar and the base layer. becomes lower, causing the mortar to crack and fall off. For mortar with good water retention, the cement hydration is relatively sufficient, the strength can be developed normally, and it can be well bonded to the base layer.

Ready-mixed mortar is usually built between water-absorbing blocks or spread on the base, forming a whole with the base. The impact of poor water retention of mortar on project quality is as follows:

 

1. Due to the excessive water loss of the mortar, the normal setting and hardening of the mortar is affected, and the adhesion between the mortar and the surface is reduced, which is not only inconvenient for construction operations, but also reduces the strength of the masonry, thereby greatly reducing the quality of the project;

2. If the mortar is not well bonded, the water will be easily absorbed by the bricks, making the mortar too dry and thick, and the application will be uneven. During the implementation of the project, it will not only affect the progress, but also make the wall easy to crack due to shrinkage.

Therefore, increasing the water retention of the mortar is not only conducive to construction, but also increases the strength.

2. Traditional water retention methods

The traditional solution is to water the base layer and water directly on the surface of the base layer, which will cause the water absorption of the base layer to be seriously scattered due to differences in temperature, watering time, and watering uniformity. The base layer has less water absorption and will continue to absorb the water in the mortar. Before the cement hydration, the water is sucked away, which affects the penetration of cement hydration and hydration products into the base; The medium migration speed is slow, and even a water-rich layer is formed between the mortar and the substrate, which also affects the bond strength. Therefore, using the common base watering method not only cannot effectively solve the problem of high water absorption of the wall base, but also affects the bonding strength of the mortar and the base, resulting in hollowing and dry cracking.

3. The role of efficient water retention

The high water retention properties of mortar have several advantages:

1. The excellent water retention performance makes the mortar open for a longer time, and has the advantages of large-scale construction, long use time in the barrel, batch mixing and batch use, etc.;

2. Good water retention can fully hydrate the cement in the mortar and effectively improve the bonding performance of the mortar;

3. The mortar has excellent water retention, which makes the mortar less prone to segregation and bleeding. Now, the workability and workability of the mortar are improved.


Post time: Apr-26-2024