Alkali–silica reactivity of alkali volcanic rocks

Abstract

The purpose of this study is to determine the alkali silica reactivity (ASR) of alkali volcanic rocks (from basalt to rhyolite) that have different mineralogical, chemical compositions and textures. For this purpose, nine different alkali volcanic samples, located in seismically active Lake Van region, were collected from five different volcanic area named as Etrüsk volcano, Girekol volcano, Timar, Yüksektepe and Bendimahi. Petrographical analysis, chemical method and accelerated mortar bar test results showed that intermediate and acidic alkali volcanic rocks are deleterious but basic alkali volcanic rocks are innocuous in terms of ASR. It is concluded that the products resulted from alteration processes, amount of volcanic glass in the aggregate and magma-mixing processes of the magma chamber in which rocks are formed may be effective in ASR of aggregates.

Keywords:

• alkali–silica reactivity
• alkali volcanic rocks
• petrographic examination
• SEM
• chemical analysis