www.concreteinternational.com | Ci | NOVEMBER 2019 25
Repair and Restoration, Second Place
Lake Peachtree Spillway Replacement, Georgia,
Nominated by: Carolinas Chapter – ACI
Owner: Peachtree City
Engineer: Schnabel Engineering
Concrete Contractor: North Georgia Concrete, Inc.
Concrete Supplier: Fairburn Ready Mix
Other: Integrated Science & Engineering, Inc.
Repair and Restoration, First Place
Palais d’Iéna (Restoration of the Façades),
Nominated by: Paris Chapter – ACI
Owner: Conseil Économique Social et
Architect: Agence Arnaud de Saint-Jouan
Engineer: Bureau Michel Bancon
General Contractor: Pierrenoël
Concrete Contractor: Freyssinet
To restore the building’s façades beyond a simple
renovation, the causes of degradations and their
consequences were analyzed. A specific protocol was
developed, phasing the work to reproduce the existing
hammered concrete finishes. Rust was removed from
the soft iron reinforcing bars and decayed concrete
eliminated beyond the reinforcement a little farther
than usual to place the newly formulated concrete,
with a few centimeters of extra thickness from the
surface. After a few weeks, the concrete was hammered.
For the raw concrete, specific formwork was used to
reproduce the building’s original board marks.
A multistaged piano key weir (PKW)—the first
PKW put into service in the United States and the first
known multistaged PKW in the world—was selected
to replace the original spillway. These nonlinear weirs
provide significant hydraulic capacity under relatively
low head, and the PKW’s unique geometry can
provide advantages over more commonly accepted
labyrinth weirs within limited structural footprints.
The PKW structure is 100% reinforced concrete.
Compressive strength of the air-entrained concrete
was specified as 4500 psi (31 MPa) to provide
long-term durability in an aggressive environment.
The deadline for submitting entries for the Excellence in Concrete Construction Awards 2020 will be April 6, 2020.
Each ACI chapter or ACI International Partner is eligible to sponsor one project in each of six possible categories. Visit
www.ACIExcellence.org for more information.