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Department of Civil
and Environmental
Engineering
Spring 2017
PU Foam as Anchoring
for Small Hydro
Penstocks
Supervisor:
Leif Lia
Co-supervisor:
Tor O. Svalesen.
In cooperation with:
Statkraft AS
Nina Johnsen
MASTER THESIS
Background
The drop inNorwegian electricity prices in recent
years has reduced the potential income for new
small hydro projects, and therefore measures to
reduce the costs must be introduced. Today the
most commonly used backfill for penstocks for
small hydro are gravel and rockfill, which is time
consuming and costly due to transportation.
Penstock BV with Guy Harris developed a
method with polyurethane foam (PU foam) as
a replacement for gravel and rockfill which may
lead to lower investment costs and
reduced construction time. Statkraft AS initiated
a research project to verify this method.
In my Master Thesis I will do further work
with PU foam as replacement for gravel and
rockfill. The completed research project will
be evaluated and suggestions for the next full-
scale project will follow. Also, the mechanical
properties of the PU foam will be tested in the
laboratory with a high focus on the influence of
freeze-thaw cycles.