Aggregate Alkali-Silica Reactivity (ASR) testing represents an integral part of ongoing laboratory testing services at American Engineering Testing, Inc. (AET). AET can test for this important parameter using any of seven accepted methods.
The following table details our scope of services for ASR testing:
Test method
|
Name of test
|
Completion time
|
Sample size (lbs.)
|
ASTM:C1260
|
Potential alkali reactivity of aggregates (Rapid Mortar Bar Method)
|
3 - 4 weeks |
10# Aggregate
3# Cementitious
(of each size & source)
|
ASTM:C1293
|
Length change of concrete due to
alkali-silica reaction
|
12 months minimum |
125# Aggregate
50# Cementitious
|
ASTM:C227
|
Potential alkali reactivity of cement-aggregates combinations (Original Mortar Bar Method)
|
6 months |
15# Aggregate
5# Cementitious
(of each size & source)
|
ASTM:C289
|
Potential alkali-silica reactivity of aggregates (Chemical Method)
|
3 - 4 weeks |
5# Aggregate |
ASTM:C295
|
Petrographic examination of aggregates for
concrete
|
2 - 4 weeks |
5# Fine aggregate
30# Coarse aggregate
(of each size & source)
|
ASTM:C856
|
Petrographic examination of hardened concrete
|
2 - 3 weeks
Rush: add 20% |
Cylinder or chunk
(full depth)
|
ASTM:C441
|
Effectiveness of
mineral admixture in controlling alkali-silica reactivity
|
6 months |
10# Aggregate
5# Cementitious
|
ASTM: C1567
|
Determining the potential cementitious materials and
aggregate
|
3-4 weeks |
10# Aggregate
3# Cementitious
(of each size & source) |
ASR is the reaction between unstable silica in aggregates and the alkali in the cement paste, which produces an expansive gel. This reaction causes extensive cracking and expansion within the aggregate particles and ultimately damages the concrete itself. Common reactive aggregates include chert and shale as well as igneous and metamorphic rocks containing strained quartz. As these reactions are driven by moisture, reactive aggregates used in exterior construction are typically the most susceptible. The reaction continues as long as reactive silica and moisture are available.
To avoid ASR issues, fine and coarse aggregates are tested in concert with a high alkali cement. For specific projects, testing may be performed with the actual materials proposed for the new construction. Representative testing in early stages can minimize problems in the future.
Additional lab and field services are available. Please call for additional information, pricing information or to request a proposal. Prices may vary to specific project requirements or local specifications. |
