Title:
Effect of Aggregate Deformation on Alkali-Silica Reaction
Author(s):
Paulo J. M. Monteiro, Kome Shomglin, H. R. Wenk, and Nicole P. Hasparyk
Publication:
Materials Journal
Volume:
98
Issue:
2
Appears on pages(s):
179-183
Keywords:
alkali-silica reaction; mortar; reactive aggregate; texture.
DOI:
10.14359/10201
Date:
3/1/2001
Abstract:
Expansion of mortar specimens prepared with granodiorite, mylonite, phyllonite, and ultramylonite from the Santa Rosa mylonite zone in southern California were studied to investigate the effect of aggregate deformation on the alkali-silica reaction in concrete. While these rocks have basically the same chemical and mineralogical composition, they differ in the grain size distribution, deformation state, and structural organization of polycrystals. ASTM C 1260 expansion tests indicate that mortar expands increasingly when made with granite, mylonite, phyllonite, and ultramylonite, respectively. There is a significant correlation between expansion and the development of foliation, and the accompanying reduction in grain size. The results presented in this paper suggest that the alkali-silica reaction depends on more factors than simply the crystallinity of quartz. Deformed granitic rocks provide a good system to quantify these parameters. Texture analysis of these rocks indicate that there is a quantitative relationship between the degree of deformation and reactivity.