Effect of HPMC on Cement based Building Materials Mortar

HPMC products for construction are widely used to improve the performance of hydraulic building materials, such as cement and gypsum. In cement-based mortar, it can improve water retention, extend correction time and opening time, and reduce sagging phenomenon.

1. Water retention

Hydroxypropyl methyl cellulose (HPMC) specially used for building shall be used to avoid water infiltration into the wall. An appropriate amount of water stays in the mortar, allowing the cement to hydrate for a longer time. The water retention is proportional to the viscosity of cellulose ether solution in the mortar. The higher the viscosity, the better the water retention. Once the water molecules increase, the water retention property decreases. For the same amount of HPMC solution specially used for construction, the increase of water content means the decrease of viscosity. The improvement of water retention will lead to the extension of the curing time of the mortar to be constructed.

2. Improve constructability

The application of HPMC can improve the workability of mortar.

3. Lubrication capacity

All air entraining agents have the function of wetting agent, because they reduce the surface tension and help the fine powder in mortar disperse when mixed with water.

4. Anti sagging

A good anti sagging mortar means that there is no danger of sagging or downward flow during thick layer construction. The sagging resistance can be improved by building specific hydroxypropyl methyl cellulose. In particular, the newly developed hydroxypropyl methyl cellulose for building can provide better anti sagging 5, 5 and bubble content of mortar

High bubble content leads to better mortar yield and workability, reducing the formation of cracks. At the same time, it also reduces the strength value, causing "liquefaction". The bubble content usually depends on the mixing time.