Influence of Recrystallized Silica Aggregates on Alkali-Silica Reactivity

Authors

  • Watcharagon Wongkamjan Department of Civil Engineering, Kasetsart University, Bangkok 10900, Thailand.
  • Suvimol Sujjavanich Department of Civil Engineering, Kasetsart University, Bangkok 10900, Thailand.
  • Krit Won-In Department of Earth Sciences, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.

Keywords:

alkali silica reaction (ASR), recrystallized silica, petrographic, ASR gel, accelerated test

Abstract

The potential reactivity of aggregates and the influence of recrystallized silica was studied using several test methods—namely, oxide composition analysis, accelerated mortar-bar testing (AMBT), accelerated concrete microbar testing (ACMT) and analysis of microscopic characteristics using a digital stereo microscope and a scanning electron microscope (SEM). Three different types of greywacke aggregate from the same source were investigated; greywacke aggregate (GRA), moderate quartz greywacke aggregate (MGA) and recrystallized aggregate (REA). The results indicated that all studied aggregates were quite similar in oxide composition. Thin-section analysis indicated that GRA and MGA were coarse-grained greywacke composed of quartz feldspar rock fragments. However, REA was high weathering chlorite with a matrix of re-crystallized quartz and rock fragments altered by tectonic forces. The findings indicated that the recrystallized aggregates increased the alkali silica reaction risk and may be considered as having a more deleterious effect than the other aggregates. The largest expansion was observed from both the AMBT and AMCT methods. The results from stereomicroscopy of concrete thin-section analysis and the SEM study confirmed this finding.

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Published

2014-06-30

How to Cite

Wongkamjan, Watcharagon, Suvimol Sujjavanich, and Krit Won-In. 2014. “Influence of Recrystallized Silica Aggregates on Alkali-Silica Reactivity”. Agriculture and Natural Resources 48 (3). Bangkok, Thailand:463-73. https://li01.tci-thaijo.org/index.php/anres/article/view/243371.

Issue

Section

Research Article