Impact of the Portland Cement Activation Method on the Properties of Cement Stone and Fine-Grained Concrete

Abstract

Statement of the problem. In the article the experience of scientific research in the field of cement activation is summarized. It is noted that concretes modified with activated binder are characterized by increased chemical contracture, which leads to cracking in the contact zone of cement stone and coarse aggregate. To obtain high-quality structure of such concretes requires the use of additives, compensating for the contracting. Results. In the experimental part of the work two ways of cement activation are considered: mechanical one in the disintegrator and hydro-mechanical one in the rotary-pulsation apparatus. Cement activation has been performed both without additives and in combination with the expanding additive which was introduced into a composition of fine-grained concrete with the purpose of compensation of contractility deformations. Conclusions. Based on the analysis of the influence of cement activation and extending additive on strength properties, water absorption and contracture of fine-grained concrete preliminary conclusions about the possibility of the production of concretes with increased indices of durability by means of using of mechanically and hydromechanically activated cement have been made.