The active development of the construction industry use to be stimulating the appearance on the market of progressively modern admixtures and additives for concrete. They represent a wide range of products with different structures and chemical properties. As a result, modified concrete has improved characteristics which result in greater structural and design capabilities.

Concrete chemistry – differences between additives and admixtures used in construction

According to the definition of chemical for ready mix concrete malaysia, mortar and grout. Part 2. Concrete admixtures. Definitions, Requirements, Compliance, Marking and Labeling, a concrete admixture is a material added during the process of mixing concrete in an amount not exceeding 5% by mass of the cement content of the concrete, to modify the properties of the concrete. While a concrete additive is a substance with a content of more than 5% of the mass of cement. This applies to ingredients that are not the basic raw materials for the production of concrete, namely sand or aggregates.

There are so many to choose from – what are the types of adjuvants?

Concrete admixtures can be both organic and inorganic compounds. Those which modify more than one function are called multifunctional mixtures. When using several types of adjuvants, it is important to remember their mutual influence. 

Adjuvants are classified according to their functions. There are several distinct classes of chemical adjuvants: plasticizer, liquefier, entraining air, improving viscosity, accelerating bonding and hardening reactions, retarding (retarding setting speed) and sealant.

Water reducing admixtures

This use to be a set of plasticizers which, with no changing the consistency of concrete, decrease the water amount by about 2-5%. With the use of these substances, the concrete mixture becomes plastic, and its compressive strength increases. From a chemical point of view, they are generally phosphates or polycyclic derivatives. This type of admixture is used, among others, for ready-mixed concrete, road concrete and concrete for floors.

Premium water reducing admixtures

This group includes superplasticizers that reduce the amount of water mixed by 12 to 40%. The best results might be found by making use of polymer concrete admixtures. Due to their action, the concrete mixture is liquefied, the porosity of concrete decreases, and its durability and strength increases. 

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Plasticizers for concrete and cement: types, compositions
Ajude Oziel