Permeable Paver Base

[bank]

The Interlocking Concrete Paver Institute has a specification for permeable pavers that states that the stone aggregate beneath the pavers must be washed, with no more than 1% passing a No. 200 seive. The stone must be compacted to 95% of the labratory index density established for the stone.

Contractors are saying it's impossible to achieve 95% compaction with washed stone; there must be a binding agent. One contractor used the lack of binding agent as the reason for the failure of his permeable paver installation.

My questions are: Is a binding agent necessary to compact an aggregate base? Would a binding agent wash away under a permeable surface? How does the laboratory index density relate to standard/modified proctor?

Has anyone dealt with this before?

 

[concretemasonry]

The standard is probably a standard proctor and the aggregates used are genrally assumed to be a graded angular aggregate.

Since it was from the ICPI. is probably is set in a 1" clean sand setting bed, but the ICPI standards are also base on the older technology proven for years.

I would suggest contacting the ICPI engineering because they have had experience dealing with traditionaly U.S. contractors that may want to use the "lore" as the only way to do things.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[EBSEngineering]

Follow the ICPI specifications. Interlocking pavement systems fail most often due to incorrect installation including base materials. It is not a failure of the technology. There is a ton of research that has been done to show that it works. Europeans have been installing interlocking paving this way for years. If you put fines (binding agent) in it, it is no longer permeable. The other thing is, it has to be crushed (angular) and hard material.