1. Recycled Concrete in Alaska
Availability and Uses
Shane Durand
Kauai Alpha

2. Recent study by the CMRA construction material recycling association shows AK lagging behind other states in the acceptance of RCA

3. Recycling concrete relatively new in AK traditionally been buried on site or near by property.
New operations allow this material to be recycled at fixed site recyclers or on site

4. Source of Concrete and type of material important to final product

6. Source typically determines
Size, quality

7. Curb and gutter, sidewalk etc. makes up the gravy of recycled concrete
Very consistent, sized well

8. Another overlooked portion of the recycled concrete waste stream is brick and material recovered from C&D Facilities.
5% by weight or more of a roll off is brick, rock, mortar etc.

9. Brick in a straight demo is often found to be painted or coated and thrown away. Try not to crush full loads of brick.

10. More than half of concrete recycled is structural from demolition such as buildings bridges and

11. Airport hard stands

12. Typical Recycle Facility accepts 2 categories of rubble
Typical Recycle Facility accepts 2 categories of rubble. Everyone seems to have some what different requirements but generally it is what will fit directly into crusher and materials that require further processing.

13. Nonconforming, vaults, pole bases, lots of embedded metals

14. Nonconforming, vaults, pole bases, Bollards are the bane of the recycler

15. These require further processing on site or at the recycle facility prior to crushing These are the same large nonconforming materials being on site pulverized. This material could be used as fill on site or crushed into a spec product.

16. Coatings on concrete
Paint, waterproofing, fireproofing, insulation, vapor barrier.
Besides the debris and contamination health and environmental issues.
Lead paint and Asbestos containing materials
Lead paint studies by the USACE indicate this may not be of concern in final product but issues during processing.
ACM can not be processed and has to be removed or landfilled
Recycle facilities require paperwork on demolition debris.

17. Lead coating
USACE Pubs

18. Debris such as vapor barrier, insulation pex tubing

19. Here at fixed plant picker on the screen removing debris

20. Need picture of air lift separator
Air density separation started using in 2012
Works at fixed plant not so well on site
Is deleterious material overblown?

21. Here are results from Kulis 20 different structures demolished
Here are results from Kulis 20 different structures demolished. Average of results and outliers. Hi Deleterious .6% on 6” minus average .1% all in the field

22. 3” minus hi .2% average .1%

23. So we have discussed sources, considerations and requirements so lets talk about more hows and tools of the trade.
Prior to crushing most all concrete requires some sort of demolition.
Saw cutting both structural and flat work

24. Hydraulic Hammers are main tool for demolition and size reduction.
Does not efficiently liberate all of the steel or size well under 24”

25. Good for primary reduction

26. Example of concrete demolition with hammer
Lots of steel but sized well for crusher

27. Pulverizes many different kinds but used for demolition and well suited for secondary size reduction and making a 6” minus product
Can make a spec subbase on site with a pulverizer. Liberates a lot of the metal. Some pulverizers use magnet

28. Does the material need to be sized further 3” minus subbase, 1” minus base course etc.
On site a portable crusher can be used or an excavator mounted crusher jaw or horizontal impactor
Jaws make 1” minus impactors 3” minus

30. Mobile on site crushers same feed requirements as fixed facility

32. Fixed facilities use multiple types of crusher and screen combinations can make different products in Anchorage the typical material is a 1” minus RCA that meets the gradations specifications etc. for Base Course.

33. Whichever method of processing you end up with a lot of rebar.

34. Processing on site this can become troublesome to handle

35. Fixed site process rebar down or bale it for recycling

36. What are uses of RCA. Before recent development of specs by ADOT private use.

38. Besides use as base or subbase RCA can be used for Gabbion fill material
On the left is basket with crushed concrete and the right is alluvial virgin rock

40. Questions? Shane Durand (907)748-7400 CRS@CRS-Alaska.com
A lot of different uses. Depends on source, location, qnty value