hydroxypropyl methylcellulose HPMC in Plastering MortarFebruary 2nd 2023
The water retention property of mortar refers to the ability of mortar to retain water. Mortar with poor water retention property is easy to bleed and segregate during transportation and storage, that is, water floats above and sand and cement sink below. It must be remixed before use.
All kinds of base courses that need mortar for construction have certain water absorption. If the water retention of mortar is poor, as long as the premixed mortar contacts with the block or base course, it will absorb water from the premixed mortar during the mortar coating process. At the same time, the mortar surface will evaporate water towards the atmosphere, resulting in insufficient water for mortar due to water loss, affecting the further hydration of cement, and affecting the normal development of mortar strength, resulting in strength In particular, the interface strength between the hardened mortar and the base course becomes lower, resulting in mortar cracking and falling off. The mortar with good water retention has sufficient cement hydration, and its strength can be developed normally, and it can bond well with the base course.
The ready mixed mortar is usually laid between the water absorbing blocks or coated on the base course to form a whole with the base. The impact of poor water retention of mortar on project quality is as follows:
1. Due to excessive water loss of mortar, the normal setting and hardening of mortar are affected, and the bonding force between mortar and object surface is reduced, which is not only inconvenient for construction operation, but also reduces the strength of masonry, thus greatly reducing the project quality.
2. If the mortar bond is not good, the water is easily absorbed by the bricks, which makes the mortar too dry and thick and uneven. During the implementation of the project, it not only affects the progress, but also makes the wall easy to crack due to drying shrinkage;
Therefore, increasing the water retention of mortar is not only beneficial to construction, but also can increase the strength.
The high water retention performance of mortar has many points:
1. The different water retention performance makes the mortar open for a longer time, with large area construction, long service life in the bucket, batch mixing and batch use.
2. The good water retention property makes the cement in the mortar fully hydrated and effectively improves the bonding performance of the mortar.
3. The mortar has different water retention performance, which makes it difficult to produce segregation and bleeding, and improves the workability and workability of the mortar.