Dry mortar happens to be essentially a combination of divergent kinds of lime or cement, additives, and totals with particle size not beyond 4 mm.
The variance with the mortar manufactured “in situ” happens to be that the product leaves the factory with the exact dosage of its mechanisms and in accordance with the technical prescriptions and the regulations in force. It suffices to place it on the spot in the most suitable place where the final mixture can be achieved by adding only water.
Evolution of the use of dry mortar
The greater requirements and control of construction work have led to a greater development of the materials used for this purpose, among which mortar and more particularly dry mortar.
The recent technification of dry mix mortar additives in Malaysia led, in recent decades, to the abandonment of mortars manufactured on-site in favor of industrial mortars prepared in dry conditions to then be mixed on-site.
Factory manufacturing allows greater rigor in the dosage and mixing of each of the components necessary for the preparation of the mortar, which gives the mortar a high degree of quality and guarantees for the manufacturer, difficult to obtain with manual preparation. , where the dosing process is practically non-existent or is done in a volumetric and approximate manner.
What does mortar contain?
So mortar often contains cement, but not always. In general, it can be said that the recipe always includes sand, water, and a binding agent. Depending on the area of application, other additives are added for the different product types.
The main types of additives are:
Liquid additives reduce the dynamic friction of concrete and make it more plastic. This type of additive happens to be added to the concrete mix around one liter/cubic meter of concrete and saves cement consumption by equal to 15%, in addition to facilitating the thickening and workability of the concrete by reducing the surface tension of water.
These additives reduce the hardening speed of the concrete, i.e. lengthen its setting time. It is common to use it in situations where the concrete is being made off-site and the concrete may take longer than usual to transport and place.
Its use has a number of advantages, such as B. the reduction of cracks in the concrete, a lighter density and viability, and a reduction in the permeability of the concrete.
Additives that have the opposite function of retarders: They serve to accelerate the setting of concrete and speed up the construction process. It is common to be used in works with very short lead times or with late delivery. They work by quickening the chemical procedure of cement hydration, with the intention that it sets faster, increases the preliminary strength of the concrete, and decreases the segregation of the material and exudation.
They are used to create micro air bubbles in the concrete mix. This effect is desirable, for example, when the heat resistance of the material has to be increased, for example in environments that are exposed to freezing temperatures. It also helps fight concrete aggregate segregation and fluid segregation.
These additives cause a certain controlled expansion of the concrete in cases where it is necessary to fill a vacuum or to compensate for the contraction of the cement mass
Seal for mortar
Additives for the production of waterproof concrete that reduce permeability and capillarity. In addition to the partial sealing, the workability of concrete and mortar increases. Consumption varies depending on the amount of cement to be used in the mortar or concrete.