Alkali-Silica Reaction Potential of Arc-related Volcanic Rocks from the Göksun Ophiolite (Kahramanmaraş-Turkey)

Authors : Tamer RIZAOĞLU

Pages : 247-256

View : 22 | Download : 9

Publication Date : 2017-04-24

Article Type : Research Paper

Abstract :The alkali-silica reactivity is one of the most important problems that can occur in concrete structures. Because of their wide spectrum of mineralogical compositions and phases, volcanic rocks are more likely to cause alkali-silica reactivity. In this study, alkali-silica reactivity potentials of the rocks representing the upper levels of the crustal section of the Late Cretaceous suprasubduction-type Göksun ophiolite in the Tauride ophiolitic belt have been investigated. The Göksun ophiolite displays and intact ophiolite pseudostratigraphy with the thick layer of volcanic section characterized by a different composition of rock units such as basalt, basaltic-andesite, andesite, dacite and rhyolite. Firstly, the petrographic determinations of the samples derived from these volcanic units were made and then geochemical analyzes carried o ut o n t he s ame s pecimens t o c ontrol t he a ccuracy o f t he petrographic analyzes and the rocks were classified according to trace elements. Finally, the accelerated mortar bar method was applied on the concrete bars produced from same rock samples to compare the variation of Alkali-Silica Reactivity (ASR) with lithology. The test results yielded that the intermediate volcanics have much Alkali Silica Reactivity (ASR) potential than basic and acidic volcanics (basalts, rhyolites and dacites). It is estimated that the glassy matrix of the intermediate volcanics is partly responsible for the alkali-silica reactivity. SiO2, TiO2, Al2O3, Na2O a nd K 2O values have show positive correlation with the amounts of expansion in the andesite and basaltic andesites, whereas the major oxide contents of acidic and basic volcanic rocks have no clear relation with the expansion ratios.
Keywords : Ophiolite, volcanic, aggregate, Alkali silica reactivity, Accelerated mortar bar method