Advanced construction solutions impress by its varieties and complexity of execution. Almost all revolutionary solutions in concrete construction technologies are preceded by a vast number of researches in related fields of science and technology. Application of chemicals is an important link of many construction projects. Nowadays consumption of chemical additives to concrete is huge enough to be dedicated into own industry.
The quality of concrete depends not only of main raw materials quality, but largely on auxiliary chemical additives. Their usage allows obtaining multicomponent modified concrete with desired properties, to predict its physicochemical and operational characteristics and effectively control its structure formation at all technological stages. Modern range of chemical additives is wide and includes the following classes: plasticizers, accelerators, retarders, antifreezes, curing agents, etc. The most prevalent are plasticizers, which in turn is divided into hyperplasticizers, superplasticizers and plasticizers. The most popularity among others found hyperplasticizers based on polycarboxylate esters due to their high performance and usability. Firstly synthesized in Japan in the 1980s specifically for needs of the construction industry, they have won recognition over all economically developed countries. Currently Ukraine is on a stage of getting acquaintance with hyperplasticizers, however, trend is so that more and more construction companies are switching to advanced technologies using polycarboxylate-based plasticizers. Undoubtedly, the hyperplasticizers market share in the structure of additives in Ukraine will grow, which is explained by high modern standards requirements of the construction industry. Over the next 10 years Ukraine implements a huge state project of a full-scale construction of large infrastructure facilities and roads. In fact, it is a challenge for the Ukrainian construction industry. Plasticizers of the old generation will simply not be able to cope with such tasks.
Polycarboxylate-based hyperplasticizers are characterized by an extremely large variety of their properties due to a wide range of variations of their structure.
Variation of polymer actions spectrum is achieved by varying of length of its main and side chains, as well as number of its carboxylate groups and side chains.
There are certain advantages of additives based on polycarboxylate esters such as:
- reduction in water demand up to 40%;
- long-term preservation of concrete mixture;
- reduction of cement consumption in concrete mix up to 30%;
- obtaining self-compacting and self-levelling concrete;
- reducing the time for heat treatment of concrete or even abandonment of it.
Thus, polycarboxylate-based hyperplasticizers are universal additives and aroused of great interest for both monolithic and precast concrete construction. In monolithic construction is important to set concrete slowly, increasing its preservation time with accelerating its set of strength straight after laying. For precast production is requested to ensure good workability of the concrete mixture with maximum decreased water content to ensure its high preservation rate and significant increasing strength.
