Winners of the 2019 Excellence in Concrete Construction Awards
ACI recognized 12 winners at the 2019 Excellence in Concrete Construction Awards Gala during The ACI Concrete Convention and Exposition, October 21, 2019, in Cincinnati, OH.
Overall “Excellence” Award Winner/
First Place – Mid-Rise Buildings
King Abdulaziz Center for World Culture (ITHRA) – Eastern Province, Saudi Arabia. Also known as Ithra, the Arabic word for “enrichment,” the King Abdulaziz Center for World Culture is an 85,000 m² (914,930 ft²) building surrounded by a 220,000 m² (2,368,000 ft²) Knowledge Park that creates a space to inspire the imagination. Features of the structure include post-tensioned slabs spanning 15.9 m (52 ft), sloped concrete walls and ramps, and twisted and inclined reinforced concrete columns with decorative concrete finish. The building is 90 m (295 ft) tall and is supported on a 3 m (10 ft) thick raft foundation. Stability is provided through a reinforced concrete core acting as a propped cantilever. The columns supporting the elevated slabs are inclined and result in horizontal thrust forces at the head and base of each column lift. The post-tensioned slabs act as structural diaphragms to carry these forces back to the core. Construction was completed in the fall of 2017.
Project Team Members: Owner: Saudi Aramco; Architectural Firm: Snøhetta; Engineering Firm: BuroHappold Engineering; General and Concrete Contractor: Saudi Oger Ltd; Concrete Supplier: Saudi Readymix Concrete Co..
Nominator: Saudi Arabia Chapter – ACI
Second Place – Mid-Rise Buildings
MGM National Harbor – Maryland, United States. The MGM Resort at National Harbor is a 3.4 million ft² (315,900 m²) project that includes a 5000-space parking structure. A podium on top of the parking structure is angled and clad with white precast panels so that it looks like the monuments around the National Mall. The hotel is a 24-story, narrow structure that is meant to evoke images of the Washington Monument. The project required 2.9 million ft² (269,400 m²) of cast-in-place elevated deck supported by architecturally exposed columns and walls.
Project Team Members: Owner: MGM Resorts International; Architectural Firm: SmithGroup JJR; Engineering Firm: Cagley & Associates; General Contractor: Whiting-Turner; Concrete Contractor: DGS Construction; General Supplier: Schuster Concrete Ready Mix.
Nominator: National Capital Chapter – ACI
First Place – Low-Rise Buildings
Hamad Port Project – Design and Build of Visitors Centre – Doha, Qatar. This all-concrete building (except the roof of a pyramid exhibition area) houses a high-end aquarium that is the first of its kind in Qatar. A creative solution for the aquarium involved isolating its raft with a gap from the main building raft. The engineering merits include mitigation of the risk of cracking (as compared with a single raft with a larger thickness), isolation of the aquarium from movement (if any) in the main building structure, and provision for local repairs (if needed) to the aquarium’s raft.
Project Team Members: Owner: Hamad Port Steering Committee, Ministry of Transport and Communications; Architectural Firm: WorleyParsons and Royal HaskoningDHV; Engineering Firm: James Cubitt & Partners, Supervision Consultant AECOM; General Contractor: Al Jaber Trading & Contracting Co.; Concrete Contractor and Supplier: Rabban Readymix WLL
Nominator: Qatar Chapter – ACI
Second Place – Low-Rise Buildings
Anastasis Church – Ille-et-Vilaine, France. The Anastasis Church is a sculptural building. Its concrete had to be white and uniform, so maturity monitoring was prescribed to allow strict control of stripping times. Also, walls were cast over their full heights, without horizontal joints. The vertical joints between casting phases were carefully positioned at the level of the vertical imprints of the formwork, and they disappear into the general layout. The high pressure of self-consolidating concrete in 12 m (39 ft) high forms led to the use of stiffer forms.
Project Team Members: Owner: Association Diocésaine de Rennes; Architectural Firm: Álvaro Siza and associate architectural agency, Pranlas-Descours Architect & Associates; Engineering Firm: EVP Ingénierie; General and Concrete Contractor: Léon Grosse.
Nominator: Paris Chapter – ACI
First Place – High-Rise Buildings
Generali Tower – Milano, Italy. The Generali Tower is 186 m (610 ft) tall with a tubular core resisting vertical, horizontal, and torsional actions. A shape variation of each floor plan, and its rotation around the center, generate the form. The concrete raft foundation has 64 settlement-reducing piles. Casting was completed in 38 hours by using low-heat concrete to comply with the specification of the maximum inner allowable temperature of 70°C (158°F), which was checked with thermocouples. A special ground-floor slab is 500 mm (20 in.) deep, with 900 mm (35 in.) deep drop panel areas, designed to resist the horizontal forces created by local column shifts from vertical to inclined.
Project Team Members: Owner: CityLife SpA; Architectural Firm: Zaha Hadid Architects – London; Engineering Firm: Redesco Progetti srl; General Contractor: CMB Cooperativa Muratori e Braccianti di Carpi; Concrete Contractor: Ricca Costruzioni – Brescia; Concrete Supplier: Holcim SpA.
Nominator: Italy Chapter – ACI and Spain – Asociación Científico-Técnica del Hormigón Estructural (ACHE)
Second Place – High-Rise Buildings
Statue of Unity – Gujarat, India. The Statue of Unity is 182 m (597 ft) high, the tallest statue built worldwide to date. Its structural system consists of two reinforced concrete cores, a reinforced concrete podium, and a foundation on solid rock in the middle of a river. Approximately 210,000 m3 (275,000 yd3) of concrete of all types was produced by onsite batching plants. The total concrete produced primarily comprised 13,500 m3 (17,700 yd3) of controlled low-strength material concrete and 180,000 m3 (235,400 yd3) of self-consolidating concrete. To compensate for hot weather, ice flakes were used to replace part of the mixing water.
Project Team Members: Owner: Sardar Vallabhbhai Patel Rashtriya Ekta Trust (SVPRET); Architectural Firm: Michael Graves and Associates; Engineering Firm, General/Concrete Contractor and Supplier: L&T Construction – Buildings & Factories.
Nominator: India Chapter – ACI
First Place – Decorative Concrete
Qatar National Library – Doha, Qatar. The Qatar National Library is one of the first buildings in Qatar with cast-in-place white concrete, so the challenges faced on this project were workability, placing methodology/sequence, and finishing. To provide an unobstructed view and vast plaza space within the building, the entire roof is supported by 1.2 m (4 ft) diameter columns. To transfer loading, multiple columns required a structural steel cruciform to be cast embedded for the structural connection. With some columns 18 m (59 ft) high, multiple placements were required.
Project Team Members: Owner: Qatar Foundation; Architectural Firm: Office for Metropolitan Architecture (OMA); Engineering Firm: Arup; General Contractor: Multiplex Construction W.L.L; Concrete Contractor: Readymix Qatar LLC.
Nominator: Qatar Chapter – ACI
Second Place – Decorative Concrete
Metro State University of Denver – Aerospace and Engineering Building – Colorado, United States. Ten different mixture proportions were used for this project, including a polished concrete mixture that could not be placed by pumping. The high-end polished mixture consisted of a 1/2 in. (13 mm) chip black aggregate with 62% coarse aggregate that had to be ground down 1/4 in. (6 mm) deep to simulate terrazzo stone. The mixture was placed by buggy, which also ensured that the surface was finished slowly and consistently so the floor flatness remained high and the aggregate was not pushed down due to overfinishing.
Project Team Members: Owner: Metro State University of Denver; Architectural Firm: Anderson Mason Dale Architects; Engineering Firm: KL&A Structural Engineers, Inc.; Concrete Contractor: GH Phipps Construction Companies; Concrete Supplier: Ready Mixed Concrete.
Nominator: Rocky Mountain Chapter – ACI
First Place – Infrastructure
I-91 Brattleboro Bridge – Concrete Bridges to Nature – Vermont, United States. Designed for an enhanced service life of 150 years, Vermont’s first concrete segmental bridge used 18,882 yd3 (14,436 m3) of concrete. The 4000 psi (28 MPa) footings were constructed with 700 yd3 (535 m3) mass concrete placements completed without the use of cooling tubes. A main aesthetic feature, the bridge’s signature quad wall piers were cast-in-place using 6000 psi (41 MPa) self-consolidating concrete. The quad wall piers provided stability and allowed for the balanced cantilever segmental construction of the bridge superstructure to be constructed from above using 8000 psi (55 MPa) high-performance concrete.
Project Team Members: Owner: Vermont Agency of Transportation (VTrans); Engineering Firm: Figg Bridge Engineers, Inc.; General Contractor: PCL Civil Constructors; Concrete Supplier: Carroll Concrete.
Nominator: New England Chapter – ACI
Second Place – Infrastructure
Goethals Bridge Replacement Project – New Jersey, United States. Design life for the new Goethals Bridge is 150 years, achieved through a combination of means. Portions of the bridge were designed with stainless-steel reinforcement while others included ternary cements. Mixture designs using ternary blends with larger aggregate sizes and aggregate volumes lowered the hydration heat, minimized shrinkage, and also achieved low permeability. Thermal control plans and curing protocols were further measures used to control cracking. State-of-the-art smart bridge technology was also incorporated.
Project Team Members: Owner: The Port Authority of NY & NJ; Architectural and Engineering Firm: Parsons Transportation Group; General Contractor: Kiewit-Weeks-Massman, AJV; Concrete Contractor: Berto Construction, Inc. (barrier concrete subcontractor); Concrete Supplier: US Concrete NY and Atlantic; Other: Unistress (precast full-depth panels), Northeast Prestressed Products, LLC (precast girders).
Nominator: CIB, a New York City Chapter – ACI
First Place – Repair and Restoration
Palais d’Iéna (Restoration of the Façades) – Paris, France. 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.
Project Team Members: Owner: Conseil Économique Social et Environnemental (CESE); Architectural Firm: Agence Arnaud de Saint-Jouan; Engineering Firm: Bureau Michel Bancon; General Contractor: Pierrenoël; Concrete Contractor: Freyssinet.
Nominator: Paris Chapter – ACI
Second Place – Repair and Restoration
Lake Peachtree Spillway Replacement – Georgia, United States 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.
Project Team Members: Owner: Peachtree City; Engineering Firm: Schnabel Engineering; Concrete Contractor: North Georgia Concrete, Inc.; Concrete Supplier: Fairburn Ready Mix; Other: Integrated Science & Engineering, Inc..
Nominator: Carolinas Chapter – ACI