Architectural Precast Concrete Research Articles

Restoring serenity: conservation of Minoru Yamasaki's North Shore Congregation Israel

ABSTRACT The North Shore Congregation Israel complex was designed by modernist architect Minoru Yamasaki and completed in 1964. Yamasaki's notable work includes the Pacific Science Center (1962), World Trade Center (1971), and many other significant large scale projects. North Shore Congregation Israel exemplifies his early work, which included low-rise modernist structures with decorative concrete facades. Yamasaki was very interested in the design potential of precast and cast in place concrete and the materials versatility as both a structural and decorative material, as illustrated in this complex. After several decades, spalling was observed along the edge of the architectural precast concrete panels. Previously installed concrete patch repairs were visually apparent and many were no longer serviceable. Wiss, Janney, Elstner Associates, Inc. was engaged to perform an assessment of the existing architectural precast concrete, document the extent and types of distress, and develop repair documents. The paper will describe and illustrate the process of developing concrete repairs for North Shore Congregation Israel, including an overview of the assessment process and development of repair details, concrete cleaning procedures to address soiling and biological growth present on the building, and concrete mix design and finishing procedures to blend the repairs with the existing concrete.

Methodology to evaluate variations in concrete color caused by white cement substitutions and forming materials

An experimental program was conducted to develop a methodology to quantify the gradation of the concrete color. The proposed methodology was used to evaluate the effect of the supplementary cementitious materials and the limestone filler used as partial substitution of white cement in architectural precast concrete. The effect of the formwork materials on concrete color was also investigated. Conventional concrete mixtures were prepared using different binder types, including gray-high early strength cement, white cement, limestone filler, blast-furnace slag, and metakaolin, to evaluate the compressive strength development that are suitable for the precast architectural applications. The corresponded paste mixtures were prepared to evaluate the variations in concrete color with the time under the air-curing conditions. The proposed methodology was found to provide precise classification for color gradation of concrete. The ternary powder blend of 50% high early strength cement, 25% white cement, and 25% high Blaine limestone filler, by mass, was found to be optimal to achieve reasonable white tint in compensation with the need to retain high early strength. A superworkable concrete and two self-consolidating concrete mixtures were cast in a special Z-shaped mold built up using PVC, steel, plywood, and polyester filter liner. The color of concrete surfaces cast in the plywood and polyester filter lined formwork materials were found darker than that of the concrete cast in the PVC and steel formworks.

Seismic accelerations in architectural precast concrete cladding

Architectural precast concrete (APC) cladding is a type of building facade broadly used worldwide. It is composed of an array of concrete panels attached to the building structural system with steel connections. During earthquakes, the APC system can be damaged both by excessive drifts and accelerations. While research on drift-compatibility has been performed in recent years, to the author’s knowledge there are limited studies aimed to determining the level of seismic forces in APC cladding panels and connections. However, these forces could be larger than anticipated since this system has low natural frequencies due to its large mass and low stiffness in the out-of-plane direction.This paper presents an experimental and numerical study of the seismic accelerations developed in APC cladding panels installed on a building. The design limits provided by the code for ductile and brittle elements of the cladding system indicate that the code is able to meet the desired performance criteria both in case of service and design level motions. However, the satisfactory results obtained for design level earthquakes are due to the combination of significant errors in the prediction of the component and structure amplification factors.

Effects of Fly Ash and Foundry Sand on Performance of Architectural Precast Concrete

This research was conducted to establish the effects of fly ash and used foundry sand on strength and durability of concrete. Two series (Series 1 and Series 2) of experiments were performed. All concrete mixtures were produced for and at the production plant of an architectural precast concrete products producer. Concrete mixtures produced were used in manufacture of precast concrete panels. Tests were performed with normal and air-entrained fly ash concrete. Concrete test specimens were evaluated for compressive strength, abrasion resistance, salt-scaling resistance, freezing and thawing resistance, and chloride-ion penetration resistance. On the basis of strength and durability evaluations, it was concluded that both nonair and air-entrained concrete mixtures developed in this investigation are appropriate for manufacture of high-quality, high-durability architectural precast concrete using used foundry sand and fly ash.

Project Spotlight: Precast concrete college stadium goes up quickly

When the Gustavus Adolphus College board of directors was looking to build a new football stadium, precast concrete’s speed of construction and ability to be installed in a wide range of weather led the material to be its ultimate choice. Molin Concrete Products of Lino Lakes, Minn., was the precast concrete producer. American Artstone of New Ulm, Minn., was responsible for the stadium’s architectural precast concrete.

Hearst Tower’s Precast Façade Brings Elegance to Charlotte Skyline

The latest dramatic addition to uptown Charlotte's (North Carolina) skyline is the striking architecture of the 47-story Hearst Tower. Architectural precast concrete, designed and produced with a variety of colors, textures, and forms, provides both the distinctive style and complementary architecture demanded by the owner. It was critical that the Hearst design complement its sister tower, the Interstate Johnson Lane Building, as well as nearby corporate campus structures. The precast concrete facade includes color pigments used in the exterior panels, which were sandblasted and polished to simulate the appearance of granite and natural stone. Collaboration between the project architect and precaster resulted in an innovative window panel unit that reduced production cost and erection time for the owner and general contractor. Demand for the rapid delivery and exacting design of this $ 150 million commercial building on a restrictive urban construction site made this precast concrete system the natural material of choice for this award-winning project.

Architectural and Structural Precast/Prestressed Concrete Renovates Landmark Ohio Stadium

After 75 years of service, the Horseshoe, The Ohio State University's historic landmark stadium, was badly in need of restoration, code-mandated modifications and expanded seating capacity. This high-visibility, $195 million project called for a structural system that could meet the dual challenge of preserving the original classical architecture while providing uninterrupted stadium use for three football seasons during construction. Architectural precast concrete enhanced the aesthetics of the arched motif shell, giving the stadium its powerfully arcaded form. Structural and architectural precast elements composed the new lower and upper deck levels. The renovations to the entire stadium were possible only with the production predictability and design flexibility of precast/prestressed concrete components, including raker beams, triple risers and large curved architectural precast panels. This article explains how the precast concrete construction provided a highly successful, owner pleasing renovation solution.

Design Factors Influencing the Aesthetics of Architectural Precast Concrete

Sidney Freedman Director Architectural Precast Concrete Services Precast/Prestressed Concrete Institute Chicago, Illinois Aesthetics is playing an increasingly important role in the design of building facades. In North America and Europe the concept that aesthetics (form) must follow function is well established. This article demonstrates the enormous potential of architectural precast concrete applications. The abundance of possibilities gives rise to a multitude of different forms, colors, surface finishes, and architectural designs. The era is long over when concrete was known simply as a utilitarian material. Technological innovations in concrete composition, molds, and finishes have increased the quality of this material, enabling it to compete with the most exclusive facade claddings. It is the architect’s responsibility to exploit these varied possibilities. The important aspects of sample selection for color and texture as well as the use of range samples to set production standards for color and texture, are illustrated. The myth that precasting leads to little flexibility in facade design no longer holds true. On the contrary, because of the inherent properties and varieties in shape, architectural precast concrete is at the forefront of architecture as one of the most flexible contemporary solutions for structural facades.

Curved Precast Façade Adds Elegance to IJL Financial Center and Parking Structure

Architectural precast concrete panels and exposed aggregate cladding, inlaid with granite, provided the exterior facade for a 30-story office building in downtown Charlotte, North Carolina. The lower three floors of the building were clad with architectural precast concrete. The frame of the building is structural steel with steel columns encased in concrete. Adjacent to the building is an all precast, prestressed concrete 10-story parking structure which can accommodate 1043 vehicles. The total cost of precast concrete components for both structures was about $7.25 million. This article discusses the role that precast concrete played in the design, production and erection of this prestigious project.

Restoration of a Vintage Limestone Portico with Architectural Precast Concrete

Presents a case study on the use of architectural precast concrete as a cost-effective approach to restore an historic park facility in Chicago, Illinois. The main entrance portico of the facility was originally constructed with an elaborate limestone beam or entablature, carried by massive limestone columns. The carved limestone architrave (soffit), frieze, and cornice (upper projection) pieces of the entablature were attached to backup brickwork and concealed steel lintel beams with metal anchors. After significant stone damage and movements occurred due to long-term corrosion of embedded steel components, several limestone soffit pieces were removed from the building for safety. The restoration design utilized architectural precast concrete with a formed soffit having the identical proportions, texture and color as the damaged architrave stone pieces, and had structural capacity to replace the existing steel lintel beams. The design provided a unique, cost-effective approach for replacing deteriorated and damaged components, while retaining the original, intricate limestone carvings.

Architectural Precast Concrete Beautifies Shriners Hospital for Children in Sacramento

The new multi-million dollar Shriners Hospital for Children at the University of California-Davis in Sacramento, California, serves as the gateway to a multi-functional redeveloping medical center. Situated in an old neighborhood replete with brick residences, the nine-story hospital and its adjacent three-level above grade and three-level below grade parking structure had to reflect the existing heritage while also projecting a contemporary image. To achieve this goal, the designers created a facade using architectural precast concrete featuring spandrel panels with two sandblast finishes incorporating a variety of reveals, a band of red granite and green terra cotta medallions that protrude attractively from the wall. The adjoining parking structure also is clad with architectural precast panels that reflect the style of the hospital facade. This was all accomplished while satisfying fire safety regulations and Seismic Zone 3 code requirements. This article presents the conceptual design, architectural features of the precast facade, and seismic considerations together with the production and erection highlights of the precast components.

Corrosion Resistance of Reinforcement in Architectural Precast Concrete

Presents the mechanism of corrosion of reinforcement and the conditions under which corrosion can occur in reinforced concrete. Chloride ingress and carbonation are discussed together with the importance of concrete cover and an impervious surface. Criteria for evaluating crack widths are given. Methods of protecting reinforcement, such as galvanized and epoxy-coated reinforcement, are discussed but not generally advocated. It is concluded that corrosion of reinforcement is usually not a problem in architectural precast concrete. High quality concrete with strengths between 5000 and 6000 psi (34.5 and 41.4 MPa) and a water-cement ratio of 0.40 or less is adequate in preventing corrosion.

Thin-Brick Panels Add Distinctive Accent to All-Precast Concrete Office Building

Precast and prestressed concrete, together with architectural precast concrete, were used innovatively to build the new $13 million, five-story 333 West Eleventh Street office building in Kansas City, Missouri. Adjacent and beneath the building are two below-grade and three above-grade levels for parking vehicles. The precast/ prestressed structural system provided an economical way for the designers to match the 60 ft (18.3 m) parking bays below to the overhead office spaces. The exterior of the building features curves, overhangs and roof details that are created imaginatively from a combination of wide glass expanses, curtain wall and thin-brick-set architectural precast panels. This article presents the design and construction challenges, architectural and structural features, design considerations as well as the production and erection highlights of the project.

Multiple Precast Concrete Arches Replace Old Garfield Park Bridge in Chicago

The new $1.2 million Jackson Boulevard replacement bridge in historic Garfield Park, Chicago, Illinois, is an excellent example of the blending of architectural precast concrete with structural precast concrete. This article discusses the design considerations that led to the selection of a precast concrete system together with the production and erection highlights of the project. The bridge was built on schedule and within budget.

Interstitial Precast Prestressed Concrete Trusses for Ciba-Geigy Life Science Building

Architectural precast concrete and structural precast, prestressed concrete combine effectively to frame the new $126 million, three-story, Ciba-Geigy Life Science Building in Summit, New Jersey. A major feature of the building is the use of interstitial pretensioned Vierendeel trusses which permit large column-free spaces and thus much needed flexibility in the layout of floors. The result is a cost-effective, totally prefabricated building which is functional and attractive. The purpose of this article is to present the design concept and structural features of the system, and to describe the production, handling and erection highlights of the precast concrete elements.

Overview of Canadian Practices in Architectural Precast Concrete for Building Facades

T he buildings we construct reflect strongly the values, needs and aspirations of the culture that we live in. All our notable new works are built upon a firm base of past experience using current science and technology. In the Canadian construction market, cladding materials (masonry, glass, metal, stone, stucco, tile and precast concrete) compete vigorously for a share of the $35 billion (Canadian) being spent annually on building construction. Architectural precast concrete encompasses all precast concrete units employed as elements of architectural design. Such units can be structural, loadbearing by themselves, act as permanent formwork for cast-in-place concrete or be mainly decorative, The ability of concrete to flow and assume the contours of its mold, combined with the enormous number of finishes and textures which can be produced on the face of architectural precast concrete panels, gives a designer tremendous freedom to select the color, texture and shape he/she wishes to impart to his/her building. High quality precast concrete produced in a plant under controlled conditions is extremely durable and resistant to weathering and abrasion. The effects of weathering, dirt accumulation and air pollution can he minimized by careful consideration of how rainwater will flow down the face of a building. The provision of drips, channels and scuppers can be used to direct this flow. Penetrating sealers are often used to repel water from absorbent surfaces, particularly where soft aggregates and a light colored matrix is used.

Production and Design of Architectural Precast Concrete

Production and Design of Architectural Precast Concrete