Since their appearance, high – activity superplasticizer/reducer additives have set themselves apart from previous technologies thanks to their greater fluidizing and water-reducing capacity. From then on, all efforts to evolve this technology have focused on further enhancing its fluidizing capacity. (We provide best services for Civil Works Contractors.)
Both by designing molecules that are more efficient in themselves. And by optimizing their compatibility with the cement to obtain the maximum performance of the additive.
Introduction
However, the latest developments in the chemistry of superplasticizers have focused more on specialization than on the progressive increase in their water-reducing capacity, with the aim of solving those new limitations that appeared when we overcame the previous barriers.
This specialization is becoming more selective, from the first level, differentiating between superplasticizers for prepared and precast concrete, to current technologies aimed at controlling the viscosity of concrete, maintaining consistency in low a/co ratio conditions for work with contentious arenas.
Undoubtedly, superplasticizer additives are no longer just simple fluidizers that allow and to reduce the w/c ratio. Its range of benefits is becoming wider, to the point that with the same additive it is possible to control other properties beyond the consistency and development of concrete resistance.
Development Of Concrete Resistance Superplasticizer
New generation superplasticizer additives:
The current regulation for additives for concrete requires a minimum water reduction capacity of 12% to be able to consider a product as a superplasticizer additive (in addition to other requirements), while for plasticizer additives this minimum requirement is 5%.
Water Reductions from Plasticizing Additives
For practical purposes, and considering the usual dosages, the plasticizing additives achieve effective water reductions of up to 10%. Similarly, the water reduction capacity of conventional superplasticizer additives based on naphthalene polymers or sulfonated melamine’s (BNS and MNS) reaches up to 20%. This differential property allowed the development of new concretes with greater resistance capacity and high fluidity for optimal placement on site. They were the first high-strength and long-lasting concrete.
With the development of the chemistry of branched polycarboxylate polymers (PCE), the so-called new generation superplasticizer additives appear, around the year 2000, with an effective water reduction capacity that can reach up to 40%.
Self- Compacting Concrete (SCC) And Ultra-High-Performance Concrete (UHPC),
These new super plasticizing additives allowed the technological development of concrete to experience great advances. New types of concrete design that are based exclusively on the high water-reducing capacity of the new generation superplasticizer additives, and that have revolutionized the concept of design and execution of concrete structures. These are the cases of self- compacting concrete (SCC), widely used in the prefabricated sector, high-performance concrete (present in many large projects) and UHPC (ultra-high-performance concrete), with enormous potential to revolutionize the sector of the entire construction.
Polymer Engineering: The Origin of Specialization and Additives
Since their appearance, the new generation superplasticizer additives have been gaining space in the market, until they became the most widely used superplasticizer technology. However, this chemistry was found to be much more sensitive to compatibility effects with the composition of the cement and sands (i.e. they did not always work as expected) (i.e. they did not always work as expected). But in order to overcome this limitation in the robustness of the new generation superplasticizer admixtures, it was necessary to understand in detail the interaction between the PCE polymer and the cement, and in turn, to know the links between the polymer structure and its behavior.
PCE Polymer Compatibility with Cement
The following years of research devote almost exclusively to this purpose, and a good part of achieve the objectives. With this new knowledge, polymer engineering was born. Whereby the structure of the PCE polymer can modify in order to optimize compatibility with cement. And thus maximize its performance. It could now serve as a la carte additives, customized for each particular situation.
Polymer engineering was the springboard for the first clear and obvious specialization of new generation superplasticizer additives to appear. Unlike all the previous advances, now it no longer intended to further increase its fluidizing capacity. The objective was different: to design superplasticizer additives adapted to the particular requirements of each application.
Superplasticizer Admixtures for The Precast Concrete
At this time the market specialized. New generation of superplasticizer admixtures specifically for prepared concrete and those specific for the precast sector appeared. The former, combining a high fluidizing capacity with a prolonged maintenance of consistency. And the latter, with a rapid development of initial resistance.
This specialization of additives has provided great benefits to both sectors, both economically and in terms of sustainability (optimization of cement content, increased durability), and they are the technologies most widely used in the ready-mix and precast concrete sectors, respectively (each one is your branch of specialization).
For further information contact Construction companies in Lahore.
