Keyword: «concrete»

Mineral waterproofing materials for protecting concrete and reinforced concrete structures from the destructive effects of water are analyzed. The classification of these materials based on their composition and mechanism of action is analyzed. The advantages of mineral compositions over bituminous and polymer materials are identified. The current trends in the development of materials science in this field are presented.

In this article, the authors outline the key principles of how various plasticizers function in concrete mixtures and describe the operating mechanism of polycarboxylate‑based plasticizers. The study then presents research findings on the impact of two types of polycarboxylate plasticizers – Linamix PK and Qz LS – on the plasticity kinetics of cement paste with a 15 % reduced water‑to‑cement ratio. Based on the obtained data, graphs were constructed showing the dependence of the penetration depth of the Vicat apparatus needle in the cement paste on time elapsed since the addition of mixing water. It was found that both plasticizers have a similar effect on the cement paste, but the Qz LS plasticizer demonstrates a longer‑lasting plasticizing effect on the cement paste over time.

The article discusses the factors that determine the frost resistance of concrete, as well as modern methods for assessing and improving it. It provides a classification of concrete grades based on their frost resistance (F) depending on the operating conditions. The article describes laboratory testing methods in accordance with GOST 10060-2012, including procedures for saturating samples and performing cyclic freezing and thawing. It also examines the main theories of frost damage in concrete, the role of water-cement ratio, air entrapment, and hydrophobization in shaping the material's structure. Special attention is paid to practical recommendations for selecting the type of concrete for different climatic zones and winter concreting conditions.