In most cases, aggregates are chemically inert in concrete. However, the issue is that certain aggregates will react negatively with alkali hydroxides found in concrete – and this causes two pressing concerns: cracking and expansion.

Indicators of an alkali reaction in concrete include random map cracking, attendant spalled concrete, and closed joints. The consequences are a decrease in durability, which is either a costly repair bill or even demolition.

Even though this degradation takes place over many years, the damage it causes can be catastrophic – and plans need to be put in place to prevent such issues from possibly occurring. One such preventative strategy is incorporating the necessary testing on construction materials.

An important test in this regard is ASTMC 1260 Potential Alkali Reactivity of Aggregates.

The ASTMC 1260 test method: an overview

The ASTMC 1260 test is performed to discover the potential alkali reactivity of aggregates. This is crucial if you incorporate aggregates with high silica content – such as glass – within your content mixture.

This could be problematic if an alkali-silica reaction were to happen in any new concrete mix. With the help of this test, the issue can be ironed out from the start.

ASTMC 1260 is a test that’s usually run alongside ASTMC 1567. The latter test covers secondary cementitious materials found within mortar bar samples in an effort to establish an effective reduction of alkali-silica reactions.

Out of the two, ASTMC 1260 is generally the initial test used. This test effectively acts as a screening assessment for aggregates, whereas ASTMC 1567 identifies the alkali-silica reaction effectiveness to moderate aggregate activity.

The scope of the test

The American Society for Testing and Materials has detailed the following scope for ASTMC 1260 (Mortar-Bar Method):

1. The test is used to detect the potential for a harmful alkali-silica reaction of aggregate in mortar bars. The test is completed within 16 days.
2. Standard values are stated in SI units. When it comes to this standard, there are no alternative units of measurement incorporated into the test. If combined-unit standards are referred to, the measurement system selections for this test method are at your discretion.
3. Other than those found in tables and figures, text found as part of this testing method shouldn’t be considered a requirement. The notes and footnotes are to be referred to as explanatory material.
4. Note that the test standard doesn’t purport to cover any possible safety concerns linked to its usage. The environmental, health, and safety practices are down to the responsibility of the user. Prior to use, they are also accountable for the applicability of regulatory limitations.

Why the right construction material testing is necessary

It is of paramount importance to use the right construction materials for projects. This is particularly the case with your concrete. A range of tests is only natural to ensure your concrete mix is right.

The problem is that testing can be complicated and difficult. That’s where we can help. With decades of experience, our experts can conduct your ASTMC 1260 test – and any other relatable test – with unsurpassed speed and accuracy.