Preventing ASR

ATXheat

New member
Mar 10, 2024
4
Lakeway, TX
Hi folks, we are under construction with the dig done and forms being built and just learned about the nightmare of ASR happening to many pools in the Austin area. We are using a pool builder out of Round Rock. They said their gunite is mixed with ash to prevent ASR and the pool shell is warrantied for the life of the pool or until we sell the house.

I've read several of the ASR threads and am trying to understand what exactly we should / can do before concrete and gunite to minimize our risk.

Feel free to redirect me, if this is already written up in an existing thread.
 
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Hi folks, we are under construction with the dig done and forms being built and just learned about the nightmare of ASR happening to many pools in the Austin area. We are using a pool builder out of Round Rock. They said their gunite is mixed with ash to prevent ASR and the pool shell is warrantied for the life of the pool or until we sell the house.

I've read several of the ASR threads and am trying to understand what exactly we should / can do before concrete and gunite to minimize our risk.

Feel free to redirect me, if this is already written up in an existing thread.
Here is one thread. Just type in ASR in search on TFP.
 
Thanks. I've read that thread. It's mostly about people who think they have ASR, how to test it, and how to deal with it. It doesn't explain what to do if you haven't built yet and want to minimize your risk. That thread does have a podcast linked that I'm currently listening to and may touch on what I'm looking for. Will report back.
 
The podcast gets into it about 13 minutes in. To summarize:
  1. Ensure the concrete supplier is providing engineered aquatic concrete. This should mean that fly ash is included.
    1. 25% grade T fly ash in needed in a shot Crete application
    2. 10% grade T fly ash in needed in a gunite application
  2. Collect the batch sheet from the actual truck that comes to the job site and document it (take a picture). If it doesn’t have fly ash, reject the batch.
  3. Use water damming / water proofing membranes in the construction
 
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FHWA Launches Online ASR Reference Center.

The Federal Highway Administration (FHWA) has gone live with an online Alkali-Silica Reactivity (ASR) Reference Center.

It was developed to provide users with access to pertinent information related to ASR.

It was organized for quick, easy access and will be updated regularly.

The Reference Center includes research reports, guidance documents, specifications related to ASR, field trials reports, and helpful links.

The ASR Reference Center can be found at www.fhwa.dot.gov/pavement/concrete/asr/reference.cfm
 
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Aggregate is usually inert, meaning it is unreactive and ideal to use in concrete.

However, some aggregates can react with the alkali hydroxides in concrete, causing expansion and cracking over a period of many years.

This alkali aggregate reaction has two forms: alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR).

That is why it is very important to test the aggregates for ASR and ACR reactivity before the aggregates are used in concrete.

 

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  • Can Shotcrete be Affected by ASR.pdf
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  • ASAPositionPaper_PoolRec_1.pdf
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