Civil Engineering Reference
In-Depth Information
Duration of test
Measurement
Criteria
Comments
Varies: first measure-
Length change
Per ASTM C 33, maximum
Test may not produce signif-
ment at 14 days, then 1,2,
0.10% expansion at 6 months,
icant expansion, especially
3,4,6,9, and 12 months;
or if not available for a 6-
for carbonate aggregate.
every 6 months after
month period, maximum of
Long test duration.
that as necessary
0.05% at 3 months
Expansions may not be
from AAR.
24 hours
Drop in alkalinity
Point plotted on graph falls
Quick results.
and amount of
in deleterious or potentially
Some aggregates give low
silica solubilized
deleterious area
expansions even though
they have high silica content.
Not reliable.
Short duration—as long
Description of type
Not applicable
These descriptions are used
as it takes to visually
and proportion of
to characterize naturally-
examine the sample
minerals in aggregate
occurring minerals that make
up common aggregate
sources.
Short duration—visual
Particle character-
Not applicable
Usually includes optical
examination does not
istics, such as shape,
microscopy. Also may include
involve long test
size, texture, color,
XRD analysis, differential
periods
mineral composition,
thermal analysis, or infrared
and physical condition
spectroscopy—see ASTM C 294
for descriptive nomenclature.
52 weeks
Length change
Per ASTM C 33, unsatis-
Primarily used for aggregates
factory aggregate if expan-
from Oklahoma, Kansas,
sion equals or exceeds
Nebraska, and Iowa.
0.200% at 1 year
Varies: first measure-
Length change
Per ASTM C 989, minimum
Highly reactive artificial
ment at 14 days, then 1,2,
75% reduction in expansion
aggregate may not represent
3,4,5,9, and 12 months;
or 0.020% maximum expan-
real aggregate conditions.
every 6 months after
sion or per ASTM C 618, com-
Pyrex contains alkalies.
that as necessary
parison against low-alkali
control
Short duration—includes
Is the aggregate known
See measurement—this
Specimens can be examined
preparation of samples
to be reactive?
examination determines
with stereomicroscopes,
and visual and micro-
Orientation and
if ASR reactions have
polarizing microscopes,
scope examination
geometry of cracks.
taken place and their
metallographic microscopes,
Is there any gel
effects upon the concrete.
and scanning electron
present?
Used in conjunction with
microscope.
other tests.
Immediate results
Intensity of
Lack of fluorescence
Identifies small amounts of
fluorescence
ASR gel whether they cause
expansion or not.
Opal, a natural aggregate,
and carbonated paste can
Immediate results
Color of stain
Dark pink stain corresponds
glow—interpret results
to ASR gel and indicates an
accordingly.
advanced state of
Tests must be supplemented
degradation
by petrographic examination
and physical tests for deter-
mining concrete expansion.
16 days
Length change
If greater than 0.10%,
Very fast alternative to C 227.
go to supplementary test
Useful for slowly reacting
procedures; if greater than
aggregates or those that
0.20%, indicative of poten-
produce expansion late in
tial deleterious expansion
the reaction.
Varies: first measure-
Length change
Per Appendix X1, potentially
Requires long test duration
ment at 7 days, then 28
deleteriously reactive if ex-
for meaningful results.
and 56 days, then 3,6,9,
pansion equals or exceeds
Use as a supplement to C 227,
and 12 months; every
0.04% at one year
C 295, C 289, and C 1260.
6 months as after that as
Similar to CSA A23.2-14A.
necessary
3 month (91 days)
Length change
Potentially deleteriously
Fast alternative to C 227.
reactive if expansion
Good correlation to ASTM
equals or exceeds 0.04%
C 227 for carbonate and
at 91 days
sedimentary rocks.
