|
Frequently Asked Questions
Water Resources Home
> RCC >
FAQs > Facing
systems for RCC dams
Q: What are the different types of facing systems
used for RCC dams?
 |
| Membrane backed precast panel from Big Haynes
Dam, Ga. |
A: A variety of upstream and downstream
facing systems have been used on RCC dams. Upstream facing systems
have consisted of conventional concrete, precast concrete with and
without membrane backing, exterior geomembrane plating and grout enriched
RCC. Downstream facing systems have also been quite varied, including
un-faced RCC, and conventional concrete placed concurrently with RCC
or following RCC placement. The exposed surface of the downstream
face is most commonly configured to have either a continuous slope
or stepped surface. Stepped configurations are often used in the overflow
section to provide the added benefit of energy dissipation for spillway
flows.
Although the type of facing system selected for a new dam is site
specific and is based on a number of criteria, all successful facing
systems for RCC dams have one feature in common – they do
not impede the potential for high RCC placement rates. This should
always be a consideration in selecting a facing system for an RCC
dam. Selection of the facing system(s) for an RCC dam must also
consider the intended purpose of the facility, operation and performance
criteria, local climatic conditions, materials availability, dam
size, owner preferences, and public perception. General selection
criteria should be based on many factors including constructibility,
watertightness, durability, appearance, and cost. The general selection
criteria will and should differ between the upstream and downstream
faces of the dam.
 For
a comprehensive look at the various types of facing systems, general
criteria for selecting a facing system, special site and structure
considerations, and current trends in facing system construction
refer to the PCA publication Facing
Systems for Roller-Compacted Concrete Dams & Spillways,
EB400.
|
 |
More on RCC:
Estimating RCC Costs for Dams
Performance
of RCC
Recent Projects
FAQs
RCC
Database
RCC/Soil Cement Contractor Directory
|