Help needed regarding Shrinkage & Expansion Tester for cement slurries

**akvtech** · 10-21-2016, 07:15 PM

We have supplied a Shrinkage & Expansion Tester (Annular Ring Test)

[link Point to another website Only the registered members can access] failed to observe significant shrinkage – in fact, in some of the tests the measurements actually showed a bit of expansion.

The Shrinkage & Expansion Tester has been made in compliance with the API Recommended Practices RP10B-5 for the purpose of measuring shrinkage or expansion in cement slurry designs under condition of free access to water (the Shrinkage & Expansion Tester is filled with cement slurry and placed in a controlled temperature water bath and left to cure for a few days. There is a fairly large hole in the top of the apparatus, so the cement is in direct contact with the water in the water bath).

The customer is now asserting that the Shrinkage & Expansion Tester that has been supplied is defective, and is insisting that we replace it. Their stand is that a neat cement slurry should show significant shrinkage, and have referred us to a line in API Recommended Practices RP10B-5 that says:

Attempts have been made to find additives that decrease cement shrinkage (shrinkage being a fundamental characteristic of Portland cement)

We have tried telling them that a neat cement slurry with free access to water will not necessarily show shrinkage, and have referred them to API Technical Report 10TR2 which clearly says:

Once the slurry is poured, the mold is placed into a thermostated water bath. Slurry is in contact with water during the entire test. Water entry will compensate for any inner shrinkage as long as the cement matrix is permeable. If the cement expands during the hydration period, the outside diameter of the annulus will expand.

The customer, however, rejects this document, saying that they purchased the equipment to comply with RP10B-5, and not 10TR2 or any other document.

Could anyone please suggest a way out for us? The Shrinkage & Expansion Tester is a very simple apparatus – the annular ring mold is comprised of a top plate, a bottom plate, a split steel ring, a hex bolt, and a small spacer to keep the ring expanded during the curing period for shrinkage measurements. There is nothing wrong with the apparatus. Replacing it with another unit will accomplish nothing.