Investigation of the Use of Micronized Dunite Additive for Fine-Grained Concrete

Abstract

Securing dense concrete structure and the intensification of cement hydration processes plays an important role in ensuring high concrete strength. The results of the applicability of dunite magnesian rocks of Central Aldan (Yakutia) for concrete production are presented. Petrographic and thermographic studies are conducted for the preliminary preparation of the charge. Pre-firing, fine intergrinding, and additional mechanical activation of the charge were applied. It is found that finely ground and pre-fired magnesium silicates act as both a micro-filler contributing to increased stone density and an active agent in forming robust crystallization structure. It is established that the use of pre-fired dunite powder with specific surface area of 8000 ± 200 cm2/kg in combination with the SP-1 superplasticizer allows obtaining autoclaved reactive powder concrete with a strength grade of up to B45.