[abb]

http://www.cement.org/concrete-basics/paving/roller-compacted-concrete-(rcc)

Roller-compacted concrete, or RCC, takes its name from the construction method used to build it. It’s placed with conventional or high-density asphalt paving equipment,then compacted with rollers.

Roller-compacted concrete has the same basic ingredient as conventional concrete: cement, water, and aggregates, such as gravel or crushed stone.

But unlike conventional concrete, it’s a drier mix—stiff enough to be compacted by vibratory rollers. Typically, RCC is constructed without joints. It needs neither forms nor finishing, nor does it contain dowels or steel reinforcing.

[mad_as_he$$]

Here is a brief overview of what they did at Folsom.

http://sanfrancisco.cbslocal.com/2017/02/19/oroville-folsom-tale-dams-illustrates-challenge-old-infrastructure/

[meyer]

Thanks. I’m envisioning RCC as a sort of man-made “bedrock” that will be used as a base for the spillway.