Foundation Preparations Prior to Grouting

[jdogg05]

Hi,

I have had to do a few inspections of concrete foundation pads that are to have pump skids (rotating equipment) grouted to them. The preparation has been done via bush hammering. I have looked in API 686 with regards to proper foundation preparation and I understand the general idea: remove laitence to expose aggregate rock. It also says to cover and protect the foundation if this prep work is completed months before the actual equipment is to be set.

However, I am interested in the details of foundation preparation and I was wondering if anyone knows of any spec or standard that addresses this in more detail.

I have attached a picture that shows preparation of a pad. From a quality perspective it is obvious that the left side was properly chipped and the aggregate is sufficiently exposed. The right side has been roughened with the bush hammer but is not as well done as the right side. Would you still consider this right side laitence? If so, I would think it is unacceptable.

I am interested in these details from a long-term quality perspective. I have heard from guys that have been in the business a long time that these foundational details can make the difference between say 15 and 30 years of life.

Any input would be greatly appreciated.

 

[hokie66]

Either side looks perfectly fine to me. I prefer the right side, but even then, I think the preparation has been too robust. There is no laitance left, that is long gone. All that is really required is for the surface to be clean.