期刊名称：Eastern-European Journal of Enterprise Technologies
印刷版ISSN：1729-3774
电子版ISSN：1729-4061
出版年度：2017
卷号：4
期号：6
页码：35-41
DOI：10.15587/1729-4061.2017.106803
语种：English
出版社：PC Technology Center
摘要：The problem of plasticization of alkaline cements was analyzed and the ways of its solution were offered. The problem is related to the structural instability of a number of chemical admixtures that are effective in plasticisation of clinker cements in the highly alkaline media of hardening cement. Superplasticizers based on polyesters lose their steric effect due to the hydrolysis reaction. On the other hand, selectivity of action of chemical admixtures is associated with the changes in a wide range of compositions of alkaline cements. In addition, the degree of changes in the structure of admixtures depends not only on the medium pH but also on the nature of the alkaline component, the production process and use of such cements. Generalization of the problems made it possible to proceed with the expansion of the range of substances from the class of surface active substances (SAS), their experimental verification and the application proposal for plasticization of alkaline cements. As plasticizing SAS characterized by stability of molecular structure in alkaline media, low- and high-molecular compounds from the class of acyclic (aliphatic) compounds or fatty compounds were considered. The polyester-based superplasticizers traditionally applied in plasticization of calcium cement systems were used for comparison. Variation of the nature and ratio of components in the composition of alkaline cements as well as the chemical admixture nature were taken as the main factors in the study of features of cement plasticization. Comparative evaluation of effectiveness of these admixtures indicates selectivity of use taking into account composition of alkaline cements. As a result of this research, systematization of classes of chemical compounds according to their effectiveness as plasticizers for alkaline cements was proposed. Such a systematization can be used in development of commercial products in a form of plasticizing additives for concretes and mortars.
