Civil Engineering Reference
In-Depth Information
a
Glass particle
ASR gel
11.14
ASR affected glass particle (size range: 1.18-2.36 mm) showing
intra-particle gel formation in mortar after 14 days in ASTM C1260
test (Maraghechi et al., 2012).
to the glass content. For some reactive siliceous aggregate, there is a
pessimum proportion that causes the largest expansion of concrete, and
that the expansion decreases when the content of the reactive aggregate
in the concrete is increased or decreases from the pessimum proportion.
Ichikawa (2009) explained the pessimum effects. however, it seems that the
pessimum proportion doesn't apply to ASR of concrete with recycled glass.
According to Jin et al. (2000), the expansion due to ASR increases with the
mixed colour glass aggregate content at all tested ages. In the study of Jin
et al. (2000),
mixed colour recycled glass, which constituted 65-70% green,
25-30% clear and 5% brown by mass, was used as fine aggregate and the
expansion of mortar bar was tested according to ASTM C126.
Secondly, glass colour also has a profound influence on ASR expansion; even
the major chemistry is very similar. Figure 11.15 gives the ASR expansion of
the green, blue, amber and flint glass with the similar chemical compositions
(Zhu et al.,
2009). As shown in Fig. 11.15, the ASR expansion is strongly
dependent on the colour of the glass. Blue glass was most reactive, followed
by flint glass, amber glass and green glass. The effect of different coloured
glass on the concrete expansion can be attributed to the small amount of
additives used for colour purpose. For an example, Cr
2
O
3
in green glass
could inhibit the expansion of concrete containing glass aggregate.
However, there are conflicting results according to different investigations.
