ACTIVATION HARDENING OF PORTLAND CEMENT WITH ADDITION OF GRANULATED BLAST FURNACE SLAG

The cement industry has accumulated a great positive experience in the use of metallurgical slags in the production of binding materials. The volume of slag utilization in the construction industry is 5...8% of their annual output. This predetermines the necessity of effective utilization of slags in construction. It is necessary to develop new methods and techniques to improve the quality of Portland blast furnace slag cement and concrete on their basis. The researches on increase of activity of blast furnace granulated slags and Portland blast furnace slag cement by their separate and joint activation in aqueous medium have been carried out. The activation was carried out immediately before the preparation of concrete at the construction site. The activation was carried out in apparatuses under hydrodynamic and cavitation impact. The activation of Portland blast furnace slag cement, as well as the joint activation of cement and granulated blast furnace slag significantly increases the strength of concrete samples. The specimens obtained on the basis of activated Portland blast furnace slag cement have in-creased early strength. This is due to increased pozzolanic activity of slag and intensive hydration of clinker minerals. The increased late strength of the samples is due to the active participation of blast furnace granulated slag in the formation of the structure of the hardened cement matrix. The obtained results allow more efficient use of metallurgical industry wastes in the production of cements and concretes.