The superplasticizer additive is a material that has gained a lot of space in civil engineering in general. After all, it can be used both in traditional works and in dry construction techniques, such as precast ones.
For this reason, you need to be well informed about these options, since they can significantly improve the efficiency of your works by bringing more agility and reducing waste. Are you interested? Follow the post!
What is the difference between the superplasticizer additive and the traditional options?
There are dozens of types of additives available on the market to improve the efficiency of concrete and bring new functionalities to one of the most used materials in civil construction. With them, it is possible to accelerate healing, waterproof, reduce surface tension and improve fluidity for use in mechanical applicators.
The importance of these substances is so great that there is a technical standard especially to regulate them, NBR 11768, which divides them into the following categories.
Air Incorporators
These additives increase the attraction of the concrete mix to air particles. In this way, it is possible to create a lighter and bulkier alloy for the same proportion of water and cement. It can be used during manual and mechanical kneading operations with concrete mixers.
On the other hand, concrete with embedded air impairs the surface waterproofing Wet, as it decreases resistance to water penetration. For these reasons, it is mainly used in gap-filling tasks. It rarely has any structural support function (such as columns and beams), as concrete with air embedders has a low compressive strength.
Pega accelerators
The purpose of grip accelerators is to reduce the period it takes for the concrete mixture to transform from a plastic state to a solid state. This action has several objectives, the main of which are to bring more agility to the works and to increase the mechanical strength of concrete in the early ages without, however, altering its grip.
Apart from that application, in industries of concrete artifacts prefabricated, precast industrial, Blocks, pavers, floors Cementícia, 3D coatings Cementícia and athermal floors, the handle accelerator can be used as an instrument for demoulding parts in a shorter time. In this way, reducing the production time of the parts and increasing productivity, especially in times when the temperature is lower.
Grip retardants
It is the opposite function of the previous one, seeking to leave the concrete in a plastic state for much longer. They leave the The mixture is workable for much longer and optimize concrete conditions. With this, it is possible to reduce material waste and frequent interruptions in concreting.
Water reducers
They are substances that reduce the amount of water in concrete without, however, modifying its consistency, or that change its consistency without altering the amount of water used. Its objectives are:
- maintaining the workability of the mixture even when reducing the water/cement ratio, improving its strength;
- facilitate workability without reducing the amount of water and maintaining strength;
- reduce the amount of cement used in the concrete mix without affecting workability and strength;
- improve cohesion and homogeneity;
- Reduce to permeability.
In addition, water reducers can accumulate the other functions that I mentioned above:
- acceleration of the grip;
- grip delay;
- air incorporation.
In addition, within the class of water reducers, we find three types: plasticizers, type I superplasticizers and type II plasticizers. The main difference between them is the ability to reduce the water/cement ratio:
All of these classes are polymers used in various industries and with very different mechanisms. Traditional plasticizers are based on lignosulfates, which are adsorbed in the concrete mixture, imparting a negative charge to the intermolecular spaces. In this way, there is a mutual repulsion that causes the mixture to plasticize.
In the case of type I superplasticizers, such as naphthalene and melamine, the additives encompass the cement molecules, generating a cloud of negative charge surrounding them. As a result, they repel each other.
Finally, there are polycarboxylic ethers and nitrogen compounds (type II superplasticizers), which cause steric stabilization of the mixture instead of electrostatic repulsion. With this, it is possible to increase the water reducing power, reducing the amount of air in the concrete, increasing its density and, consequently, increasing its strength.
Superplasticizers greatly increase the efficiency of traditional works and are truly essential in the precast and prefabricated concrete industry, in addition to the concrete artifacts I mentioned above.
What are the uses of superplasticizer types of additives?
In practice, superplasticizers have the following applications.
Type I superplasticizers
It is a less powerful superplasticizer, whose reduction in the amount of water in the concrete mix is between 12% and 20%. Therefore, it is more used in traditional works to improve the workability and durability of mixtures than in industrial civil construction.
It is generally presented as a normal handle additive used in concrete with a higher content of mortar. However, there are also retarding, accelerating, and air-incorporating versions.
Type II superplasticizers
In addition to providing more workability in traditional works, it is used in industrial civil construction with prefabricated and precast structures. After all, it allows for better fluidity of the plastic mixture so that it adheres evenly to the shapes without leaving bubbles or fissures. The best additives can achieve a 40% reduction in the proportion of water.
How to choose the right type for your project?
Superplasticizers are very versatile and are used in many concretes. Type II, more powerful, is widely used in modern civil construction for the manufacture of various types of concrete, such as:
- of high initial strength;
- prefabricated;
- from high performance (CAD);
- self-condensing (CAA);
- concrete Pretended;
- mortars, grouts and concrete that require a low water/cement factor and high fluidity.
What are the advantages of superplasticizers?
Superplasticizers present several benefits for civil engineering projects, as they optimize the properties of concrete in both fresh and hardened states. However, it is always important to evaluate the characteristics of each brand's additive, as the properties vary greatly. As I explained, some of them can alter the grip time, incorporate water, and others.
Regarding our superplasticizer, BlokGraute Pro+, it is included in type II superplasticizers, as it is capable of reducing water by approximately 40%. This achieves the following advantages in fresh concrete:
- increased cohesion of mortars;
- reduction of segregation;
- fluidity of mortars and grouts;
- increased workability of concrete;
- reduced healing time.
In relation to concrete hardened, it globally improves the main properties we seek in concrete:
- increased waterproofness;
- increased elastic modulus;
- increased concrete durability;
- reduction of cracks in retrenchment plastic;
- increased compressive strength;
- increased initial and final resistances;
- increased resistance to flexion;
- best finish of concrete hardened.
As you may have noticed, applying the superplasticizing additive to concrete is one of the most interesting measures to optimize the usability and functionality of this mixture. After all, it provides improvements to concrete both in its fresh and in its hardened state. To do this, choose suppliers that work with the best materials, such as Blok.
Do you need to make a budget or find the best additives on the market? So, contact us and discover our solutions!
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