Selection and classification of various additives for monolithic concrete depending on the working conditions

Abstract

Abstract The article presents the results of research on the choice of chemical additives for monolithic concrete depending on their types, main properties and applications. The working conditions are analyzed under which various monolithic concrete or monolithic reinforced concrete objects are constructed. The influence of additives on the properties of concrete and its performance characteristics is considered. The recommended calculation of the strength of concrete with additives is presented. It is shown that in the case of additives, the strength calculation should be performed using refined coefficients, mainly for the water-cement ratio. The calculation of the dosage of the additive in concrete, depending on the volume of the prepared mixture, is given. The results of an experiment with the addition of calcium nitrate to the concrete structure are presented, which confirmed an increase in the strength of the product by 20% compared to normal hardening conditions. An approximate method of selecting the most rational additives for concrete, depending on the working conditions, is given. The basis for classification of recommended additives is defined in order to ensure the required properties of concrete, taking into account the conditions of production and operation of objects using elements made of monolithic concrete.