INFLUENCE OF MINERAL ADDITIVES ON SULFATE STABILITY OF PORTLAND CEMENT

times comparing to the control composition. Use of fly ash is less effective from the cement grade point of view, but it provides 1.5 times better sulfate resistance comparing to Portland cement. Fly ash behavior separates on two directs – as a filler and as an aggregate. In general – as higher fly ash content, as higher sulfate resistance. The efficiency of increasing the sulfate resistance of cements with the use of active mineral additives of different types is considered. It was found that the maximum effect of increase of sulfate stability is observed with the use of combination of granular slag and fly ash in the composition of Portland cement systems, which is accompanied by an increase in sulfate stability of 2 times compared with the control composition. Portland cement systems with active mineral additives have been obtained, their sulfate stability is not inferior to traditional sulfate-resistant slag-portland cement. According to the test results it is shown possibility to obtain high sulfate corrosive resistance materials on Portland cement basis using blast furnace slag and fly ash admixtures. Service properties are meeting requirements of Ukrainian standards for common constructions.