|
Test Name |
Purpose |
Type
of Test |
Duration
of Test |
Comments |
| ASTM C 227,
Potential alkali-reactivity
of cement-aggregate combinations (mortar-bar method) |
To
test the susceptibility of
cement-aggregate combinations
to expansive reactions involving alkalies |
Mortar
bars stored over water at 37.8°C (100°F) and high relative
humidity |
Varies:
first measurement at 14 days, then 1, 2, 3, 4, 6, 9, and 12
months; every 6 months afterthat
as necessary |
Test may not
produce significant expansion, especially for carbonate aggregate.
Long test duration. Expansions may not be from AAR. |
| ASTM C 289,
Potential
alkali-silica reactivity of aggregates |
To determine
potential reactivity of siliceous aggregates |
Sample reacted
with alkaline solution at 80°C (176°F). |
24 hours |
Quick results. Some aggregates
give low expansions even though they have high silica content.
Not reliable. |
| ASTM C 294,
Constituents of
natural mineral aggregates |
To give descriptive
nomenclature for themore common or
important natural minerals—an aid in determining their performance |
Visual
identification |
Short
duration—as long as it takes to visually examine the sample |
These descriptions are
used to characterize naturally-occurring minerals that makeup
common aggregate sources. |
|
ASTM C 295,
Petrographic examination of aggregates for concrete |
To outline
petrographic
examination procedures for aggregates—an aid indetermining
their performance |
Visual and
microscopic examination of prepared samples—sieve analysis,
microscopy, scratch or acid tests |
Short duration—visual
examination does not involve long test periods |
Usually includes opticalmicroscopy.
Also may include XRD analysis, differential thermal analysis,
or infrared spectroscopy—see ASTM C 294 for descriptive nomenclature. |
|
ASTM C 342,
Potential volume
change of cement-aggregate combinations |
To determine
the potential ASR expansion of cement-aggregate
combinations |
Mortar bars
stored in water at 23°C (73.4°F) |
52 weeks |
Primarily used for aggregates
from Oklahoma,
Kansas, Nebraska, and Iowa. |
ASTM C 441,
Effectiveness of
mineral admixtures or GBFS inpreventing
excessive expansion of concrete due to alkali-silica reaction |
To determine effectiveness
of supplementary cementing materials in controlling expansion
from ASR |
Mortar bars—using Pyrex
glass as aggregate—stored over water at 37.8°C (100°F) and high
relative humidity |
Varies: first measurement
at 14 days, then 1, 2, 3, 4, 5, 9, and 12 months; every 6 months
after that as necessary |
Highly reactive artificial
aggregate may not represent real aggregate conditions. Pyrex contains alkalies. |
ASTM C 856,
Petrographic examination of hardened concrete |
To outline petrographic
examination procedures for hardened concrete—useful in determining
condition or performance |
Visual (unmagnified) and
microscopic examination of prepared samples |
Short duration — includes
preparation of samples and visual and microscope examination |
Specimens can be examined
with stereomicroscopes,polarizing microscopes, metallographic microscopes,
and scanning electron microscope. |
ASTM C 856 (AASHTO T 299),
Annex uranyl-
acetate treatment procedure |
To identify products of
ASR in hardened concrete |
Staining of a freshly-exposed
concrete surface and viewing under UV light |
Immediate results |
Identifies
small amounts of ASR gel whether they cause expansion or not.Opal,
a natural aggregate, and carbonated paste can glow—interpret
results accordingly.Tests must be supplemented by petrographic examination and physical
tests for determining concrete expansion |
| Los Alamos staining method (Powers
1999) |
To identify products of
ASR in hardened concrete. |
Staining of a freshly-exposedconcrete
surface with two different reagents. |
Immediate results |
ASTM C 1260 (AASHTO T303),
Potential alkali
reactivity of aggregates (mortar-bar method)
|
To test the potential for
deleterious alkali-silica reaction of aggregate in mortar bars |
Immersion of mortar bars
in alkaline solution at 80°C (176°F) |
16 days |
Very fast alternative to
C 227. Useful for slowly reacting aggregates or those that produce expansion late in the
reaction. |
ASTM C 1293,
Determination of
length change of concrete due to alkali-silica reaction (concrete
prism test)
|
To determine the potential
ASR expansion of cement-aggregate combinations. |
Concrete prisms stored
over water at 38°C (100.4°F) |
Varies: first measurement
at 7 days, then 28and 56 days, then 3,6,9,and 12 months; every
6 months as after that as necessary |
Preferred method of assessment.
Best represents the field. Requires long test duration for meaningful
results. Use as a supplement to C 227,C 295, C 289, and C 1260.
Similar to CSA A23.2-14A. |
ASTM C 1567, Potential
alkali-silica reactivity of combinations of cementitious materials
and aggregate (accelerated mortar-bar method)
|
To test the potential
for deleterious alkali-silica reaction of cementitious materials
and aggregate combinations in mortar bars
|
Immersion of mortar
bars in alkaline solution at 80°C (176°F)
|
16 days
|
Very
fast alternative to C 1293. Allows for evaluation of effectiveness
of supplementary cementitious materials.
|