MENU
MENU

ASR – The Hidden Threat

What is ASR? And why is it such a threat?

ASR – The Hidden Threat
19 July 2016 Posted in , ,

Over recent years, discussion on the maintenance and repair of concrete structures in Australasia and elsewhere have increasingly featured the condition ‘ASR’ (Alkali Silicate Reactivity), sometimes known as ‘AAR’ (Alkali Aggregate Reactivity).

 

As is well known, ASR/AAR is an expansive reaction within the concrete; and its severity can be driven by localised factors such as environment or the content of the aggregates used.

 

The impact of ASR has increased in recent decades, partly as a result of changes in concrete construction methods arising from the demands of the economy.

 

How is the extent of ASR assessed in the field?

Critically, ASR is commonly identified in the field by the extent and appearance of its cracking.
(See, for example, the US FDA Field Identification Handbook)

ASR in concrete - alkali silicate reactivity
Photo courtesy US FDA Field Identification Handbook

 

You may be aware of the discussions about ASR’s effect of increasing concrete density; and the fact that this may theoretically, under certain circumstances, actually boost the concrete’s durability.

 

More urgently, there is evidence emerging that this same effect of increasing density may actually mask the cracking occurring in the matrix of the concrete. This means that deterioration may exist and advance considerably before being evident to the naked eye.

 

As discussed elsewhere, once the process of deterioration has taken hold, it is self-accelerating.

High-St-Bridge-Aquron-Concrete-Treatment

It is critical that ASR is identified and remediated at the earliest possible point.

Markham recommends the application of penetrating catalytic silicates for the arrest and prevention of ASR development.
Better still – consider applying this treatment when the concrete is new, for maximised service life and protection!

 

Download the Concrete remediation treatment for ASR project example below:

 

Solution Brief - Concrete remediation treatment for ASR alkali silica reactivity




Contact

Let’s talk
about it

We understand that choosing the correct solution and type of product is essential for the success of any project. Markham has a technical support team with many years of concrete industry experience and successful project applications and we are ready to help you find the right solution for your application.

Ask an expert

0800 693 694

Monday to Friday.

9am to 5pm.