Comparison of the Alkali-Silica Reactivity of North Cyprus and South Cyprus aggregates; preliminary studies using RILEM method

Abstract

Alkali-silica reaction (ASR) is regarded as one of the most deleterious concrete durability problems, known to cause severe deteriorations in reinforced concrete structures all around the world. ASR involves the reaction of alkaline concrete pore solution with silica minerals in the aggregates and as a result, hydrous alkali-silica gel is produced. Expansion caused by this gel upon absorbing moisture results in serious deterioration in concrete. Although the susceptibility of South Cyprus aggregates to ASR has been previously studied to a very limited extent in the past, no scientific information on the ASR susceptibility of North Cyprus aggregates are available in the related literature. Beşparmak (Pentadaktylos) Mountains (North Cyprus) and from Troodos Mountains (South Cyprus) are positioned close to each other; however, aggregates obtained from both mountains are known to differ in composition. This difference in composition has the potential to yield ASR performances varying significantly. The aim of this study was to carry out preliminary investigations on the alkali-silica reactivity performance of both North and South Cyprus aggregates under same conditions, in a systematic and comparative manner. Aggregates obtained from both mountains are tested in combination with CEM I and CEM II (with supplementary cemenetitious materials) under the exposure conditions of RILEM method AAR-2. Preliminary results showed that North Cyprus aggregates are potentially reactive when used with CEM II, where South Cyprus aggregates tested under same conditions are detected to have much higher levels of reactivity.