Properties and durability of coarse igneous rock aggregates and concretes

- Crushing strength is helpful at assessing frost durability of igneous rock aggregate.
- Igneous rock aggregate with weathered minerals is freeze-thaw and alkali sensitive.
- Strained quartz was the alkali reactive phase in granodiorite; chalcedony in basalt.
- Alkali nepheline basalt showed best properties and durability.

Direct tests allowed determining properties of coarse igneous rock aggregates in comparison with gravel along with freeze-thaw resistance and susceptibility to alkali-aggregate reaction. The relationship between the properties and durability of the aggregates and concretes was evaluated taking into account the results from microstructural analyses. Granodiorite, basalt and gravel were sensitive to alkali-silica reaction due to the presence of strained quartz, chalcedony and opal, respectively. The resistance of the aggregate to freezing and thawing was demonstrated to agree with the values of crushing resistance and the lowest contents of pores with diameters unsafe in terms of the freeze-thaw resistance.