A cement mortar dry mix essentially comprises of cement, aggregates, resin and a hardener in a single mixture. The hardener is generally present as the reaction product of the hardener with either an organic acid or a functional derivative of it. Dry mix mortar technology is gaining predominant recognition in Europe due to its efficiency and ability to yield high performance. In contrast to job site mortars, these dry mix mortars are produced in special factories with dedicated batching and blending facilities of all the necessary ingredients in a highly controlled fashion. Such controlled processing enables the production of different types of dry mix products with specific properties for specific applications. In addition to significantly enhancing the product performance, these pre-mixed dry mortars enable a high degree of application reliability and consistency.
Dry Mix Mortar Additives
Job site mortars are generally composed of simple ingredients in varying proportions whereas dry mix mortars require numerous varieties of ingredients in complicated mix proportions. The raw materials used for the production of dry mix mortars can be broadly classified as:
Binders are available in different forms and types. The commonly preferred varieties are ordinary portland cement, high alumina cement, micro silica, hydrated lime, gypsum, polymer, anhydrite and pulverized fuel ash.
Fillers are widely used to provide support to other ingredients while minimize unwanted gaps in dry mix mortar formulation. The key filler agents are silica sand, limestone powder, cellulose fibre and expansion clay
Dry mix mortars contain other chemical additives as well. Cellulose ethers, starch ethers, plasticizers, air-entrainers, defoamers, hydrophobising agents and redispersible powders are the major additives in addition to other marginally used chemistries.
Pigments, both organic and inorganic varieties find application in dry mix mortars. Depending on the need of the end application, either one of the category is chosen.
Dry mix mortar products are also be referred to as Pre-mixed Polymer Modified as they contain both mineral (ordinary portland cement) and cementitious binders (redispersible powders).