PROCESS PARAMETERS OF ARRANGING CONSTRUCTION JOINTS AND SEAMS IN REINFORCED CONCRETE STRUCTURES USING SLAG-ALKALI CONCRETE MIXTURES

Abstract

Monolithic, cast-in-place and precast reinforced concrete structures are widely used in construction practice, which inevitably necessitates a reliable concrete contact between the newly laid concrete mix (“new layer”) and the previously laid layer that has gained a certain strength (the so-called “old” concrete). The paper analyzes the requirements posed by the regulatory literature and the applicable technologies for making construction joints. It considers the results of research papers studying the influence of construction joints on the operation of monolithic reinforced concrete structures. The author’s previously developed technology for arranging construction seams and joints in reinforced concrete structures using slag-alkali concrete and the results of pilot production studies of the proposed technology using the example of hinged beams necessitated the clarification of the process parameters of the proposed technology: the type and characteristics of the newly laid concrete mix; the age of the “old” concrete at the time of laying the new layer and the condition of its contact surface; the type and material of cutting off the “old” concrete; methods of compacting the newly laid concrete mix. The paper analyzes and compares the data of the conducted studies. The process parameters of the developed technology for bonding different-age concretes are determined and justified. Recommendations are formulated to increase the contact strength of concrete in joints and seams during the construction of monolithic and precast reinforced concrete structures.