THE INFLUENCE OF A COMPLEX ADDITIVE ON THE STRENGTH CHARACTERISTICS OF CONCRETE FOR ROAD CONSTRUCTION
Keywords:Road concrete, Metakaolin, Wollastonite, Compressive strength of concrete
Intensive traffic and the rapid growth of the use of motor vehicles necessitate the construction of the most durable roads possible. In this regard, roads made of cement concrete have a number of advantages in comparison with asphalt roads. In the Republic of Kazakhstan, at the moment, it is urgently required to improve the quality of roads. Road concrete works in difficult operating conditions may lead to significant deterioration of its properties (characteristics). To increase the durability of cement concrete coatings and obtain high-strength concrete, there are chemical additives and special-purpose fillers. It is also possible to apply surface treatments to the exposed concrete surfaces. In turn, fillers and additives improve the grain composition, microstructure and reduce the porosity of concrete. In this article, modern additives such as metakaolin, wollastonite and superplasticizer were used to improve the strength of concrete. As a result of the research, it was determined that the use of metakaolin (15% of the cement weight) in combination with a superplasticizer increases the compressive strength of concrete from 40.45 MPa to 54.7 MPa. We also studied the addition of a dispersed filler - wollastonite, which allowed us to achieve an increase in strength up to 40% of the original value. The use of pre-treated water in the electrolyzer was investigated and found to achieve up to 1.5 times increase in strength. Thus, the claimed modified concrete mixture with metakaolin has high strength indicators and has an additional dispersed filler in its composition.