MODERN TYPES OF INJECTION MATERIALS AND THE TECHNOLOGY OF THEIR APPLICATION FOR REPAIRING BUILDING STRUCTURES AND SOIL REINFORCEMENT

Abstract

Defects in the form of cracks, voids, and cavities that arise in concrete, brick, and masonry structures during their long‑term operation significantly reduce the load‑bearing capacity, operational reliability, and durability of the structures. Damage to structures can also lead to moisture penetration, the development of corrosion processes, and further material degradation. One of the most effective methods for restoring the integrity of damaged structures, filling internal defects, and strengthening soil foundations is injection technology using special repair materials. The aim of the work is to provide an analytical review of modern injection materials, as well as to develop and substantiate the use of fast‑setting microcement for repairing building structures and strengthening soils. The study examines the main types of injection materials, the areas and conditions of their application, classifies them according to their chemical nature and functional purpose, and analyses their main advantages and disadvantages. The material’s frost resistance is at least F1800, and its water resistance is at least W16. W16. Particular attention is paid to the technological features of preparing, supplying, and injecting materials into damaged structures and soil foundations. Based on the research results, a fast‑setting microcement has been developed with a water‑to‑solid ratio of 0.4–0.6 and a flowability cone mobility of more than 30 cm. The grade compressive strength is at least 60 MPa, and a strength of 20 MPa is achieved within 1 day. A significant advantage of the developed microcement is the ability to quickly repair structures within a short timeframe, including at sub‑zero ambient temperatures down to –15 C. The material underwent pilot‑industrial tests at a dry building mix plant and was approved for production and practical use.