Using Construction Grade Hydroxypropyl Methyl Cellulose As Ready Mix Masonry Mortar Additives

Using Construction Grade Hydroxypropyl Methyl Cellulose As Ready Mix Masonry Mortar Additives

Construction grade hydroxy propyl methyl cellulose is used in a wide range of building coatings as retarders, water-retaining agents and thickeners.hpmc uses construction grade hydroxy propyl methyl cellulose ready mix masonry mortar additives hpmc It is also used as a binder in tile adhesives and wall putty. It also improves the plasticity of cement mortar and self-levelling floor compounds, improves sagging resistance when spreading a thicker coat and extends the working time of the mixture.

Hydroxypropyl methylcellulose (HPMC) is a nonionic cellulosic ether, which is produced from pure cotton through a series of chemical processing. It has excellent workability, high water retention and a wide range of viscosities. It is suitable for masonry mortar, steel putty, paint glue and dry powder insulation mortar. It can significantly improve the construction performance of these materials, such as pumping and spraying. It can also increase the strength of the brick and block mortar, especially the bending tensile and shear strengths.

In addition, HPMC can reduce the amount of water required in the mortar mixture by reducing the surface area to which air can enter during hydration. It can also slow down the hydration reaction, which reduces water loss and ensures proper mixing of the ingredients. It can even protect the concrete from cracking, shrinkage and premature hardening by preventing water vapor from entering the concrete.

The effects of HPMC on the hydration of the cement paste can be assessed by means of an isothermal calorimetry test. It was found that adding 0.1-0.5% HPMC to the hydration mixture postponed the start of hydration and reduced the maximum peak temperature, which is evidence that the water absorbing properties of the HPMC are effective in slowing down the hydration process. The effect of HPMC on the hydration of cement paste can be explained by the formation of a film space structure in the interstitial solution that enhances the cohesive forces between the particles.

The microstructural characteristics of the fresh mortar samples are studied by using a frozen scanning electron microscope (FSEM). In control samples, the particles in the mortar were randomly distributed and there was a gap between them of 0-5 mm. On the other hand, in the samples with HPMC added to the hydration mixture, the particles were clustered together in a grid-like pattern with regular distribution and a gap of about 20 mm. This is due to the adsorption of HPMC on the particle surfaces. The results of the study indicate that the addition of HPMC to cement- and gypsum-based plaster can significantly improve its workability and consistency, while maintaining its final hardness. It can also help to prevent the loss of water during the hydration process, which is an important factor in achieving high bond strength. This is especially important for long-term use of the plaster, thereby making it more durable and cost-effective.

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