标题：A comparative study on the influence of metakaolin and kaolin additives on properties and structure of the alkali-activated slag cement and concrete
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：2018
卷号：1
期号：6
页码：33-39
DOI：10.15587/1729-4061.2018.119624
语种：English
出版社：PC Technology Center
摘要：The influence of the metakaolin and kaolin additives on the formation and properties of the alkali-activated slag cements and concretes was studied.The influence of the metakaolin and kaolin additives on macro- and microstructure formation of the cements and concretes was studied.A conclusion was drawn that the processes of microstructure formation of the cement stone with the additive flow in a similar sequence but with different intensity. A conclusion was drawn that the addition of the kaolin instead of metakaolin affected as follows: 2.5–10 % by mass reduced the value of NCP by 9.5–8.7 %, respectively; 2.5–5 % by mass did not affect setting times, but with increase up to 10 % by mass the initial setting time was shorter (from 48 min to 40 min); 2.5–5 % by mass did not affect compressive strength at all stages of hardening, but with increase up to 10 % by mass reduced strength characteristics of the cement-sand specimens (from 57.0 MPa to 49.0 MPa).In case of the addition of 5 % kaolin by mass, an optimal macrostructure of the concrete is formed in which the quantities of the ''conditionally'' closed pores are by 17.7 % higher compared to those of the concretes with the same quantities of the metakaolin. This resulted in the higher freeze/thaw resistance of the concrete (from F400 up to F500). Based on the comparison of properties and structure of the cement and concrete containing the kaolin and metakaolin additives, a possibility to substitute metakaolin by kaolin as a correcting additive was established.
