Construction and Demolition Debris Recycling

Caltrans' Specifications for Aggregate Base and Subbase 

The California Department of Transportation (Caltrans) provides specifications for the use of recycled aggregate, usually referred to as crushed miscellaneous base (CMB), on road projects. This is a selective list of Caltrans' specifications for the use of aggregate base and subbase including recycled aggregate.

1. 2006 Standard Specifications (Adobe PDF, size unknown) 872 pages, refer to pages 229-236 in hyperlinked PDF.
2. Section 25 and 26 Updates (Word, 382 KB). In February 2007, Sections 25 and 26 of the Standard specifications were amended to allow, for Class 1, 2, 3, or 4 aggregate sub-base and Class 2 or 3 aggregate base, up to 100 percent of any combination of:
   • processed asphalt concrete,
   • Portland cement concrete,
   • lean concrete base, or
   • cement treated base
3. Standard Special Provisions, updated in February 2007, allow for the use of processed glass for some base and sub-base applications.

Last updated: November 01, 2007