Crushed concrete fill

[dtsk]

Hi all,

Does anyone have any experience with using crushed-concrete as a substitute to hardfil?

Is there any disadvantages to it, provided that the fines percentages are kept low, and grain sizes mimic conventional hardfill?

It is for compaction beneath floor slabs.

Thank you.

 

[geomane]

We use it in the Florida panhandle on commercial parking lots. Local availability and municipal standards typically govern the use of crushed concrete as a base material.

It's advanatages include high strength and resistance to groundwater related distress. A strict quality control program should be enforced however. Run sieve gradation tests and CBR/LBR tests at a minimum frequency.

 

[fattdad]

We (Virginia Department of Transportation) are currently working with George Mason University (Dr. Tanyu) to evaluate the use of RCP (reinforced concrete pavement) as subbase materials. Leaching of aklaki and flow towards edge drains is an area of concern as such activity "could" clog filter materials in proximity to the edge drain. We are looking for long-term performance in our roadway design.

Not sure all the research findings are available, however.

f-d

ípapß gordo ainÆt no madre flaca!

 

[JMackNH]

I've worked with it as a slab base and as foundation backfill on a number of projects. I'm not sure about the alkali impact, but in structural terms, I've never had an issue with it. It compacts well in both wet and dry states. The common issue I see is low compaction tests with a nuclear gauge. The area will look and feel thoroughly compacted, but the density tests come up low. If this becomes an issue, have the testing agency use the specific gravity of the concrete instead of the specific gravity of rock when calculating their Proctor value.

 

[dtsk]

That is good to hear.

Thanks guys.

 

[Ron]

dtsk...have used it as a graded aggregate base course. Works well.