Concrete has enormous resistance to compressive stress, but it is a fragile material in terms of tension, which occurs when forces are applied in opposite directions of a structure, tending to separate the parts. This is why the incorporation of steel into concrete –which provides high levels of strength when stretched– has made so-called reinforced concrete the world's most widely used construction method. In other words, reinforced concrete combines the intrinsic advantages of its two components (concrete and steel reinforcement) to produce an extremely robust, versatile, and practical material. These steel reinforcements, in addition to reinforcing concrete, can also be used in art installations, facades, and even interiors.
Researchers differ on the origins of reinforced concrete. Some credit it to the gardener Joseph Monier, while others attribute the first reinforced concrete house to industrialist François Coignet, who revolutionized the field of construction. However, there is consensus that it emerged in France around 1850, and was patented in 1867 by Joseph Louis Lambot. Subsequent years saw diverse approaches to adding iron or steel bars to the mixture of cement, gravel, and water, exploring different shapes, sizes, and joining methods. François Hennebique was a key figure, revolutionizing the material through his patented method of integrating iron bars and meshes, increasing load resistance and crack prevention.
Reinforcing bars (rebars) generally have a "ribbed" profile, characterized by highly patterned deformations that run through the piece. This texture serves to increase the effectiveness of rebar when incorporated into concrete forms, increasing its adhesion to the still-liquid mixture. In addition to their functional attributes, these bars have a peculiar character and their use for aesthetic purposes has been common in contemporary architecture.
Structuring and materializing art installations
Installations such as the one by Groves-Raines Architects in Scotland are a perfect example of the aesthetic use of steel rebars. The structure is an organic extension of the garden and functions as a shed, with vegetation growing on top. Its inspiration is derived from basket weaving and it uses rebar and Corten steel. studio:indigenous also used the material to create a replica of the First Christian Church that Eliel Saarinen and his son Eero designed in the 1940s. The Wiikiammi connects to the present due to its use of modern materials such as welded rebar and waterjet-cut metal panels.
The Cloud Pavilion by Associated Architects, on the other hand, uses welded rebar mesh in regular sizes to define the entire modulation of the system, avoiding waste and production losses. The pieces assembled on-site adopted an industrialized process, in order to allow their disassembly at the end of the event, their transport to a definitive location, and their reassembly for future reuse. Baba Beski's tomb, designed by Zav Architects, transforms a large private natural garden in Iran into a semi-public space for reflection and rest. It symbolizes the intertwined cycle of life and death and incompleteness as a perpetual state. In this sense, the monument itself, created from the rebar conventionally used in reinforced concrete, embodies this philosophy, evoking structural instability with its angled planes.
Playing with translucency in fences and facades
In Casa da Lagoa, by Brasil Arquitetura, vertical bars of rebar take the place of fences and walls, becoming apparatuses for the growth of vegetation. In Casa Feliz em Begur, by SALA FERUSIC Architects, the roof garden connects to the sloping site and creates a pleasant pathway with designed landscaping. At the edges, a guardrail molded in rebar adds safety in a light and translucent manner, and does not become a visual obstacle.
In the Fireplace Pavilion, steel reinforcement bars provide stability as well as visual permeability to the entire structure. The frame consists of 8 tons of rebar welded together by 16,000 welding points. In these voids, wooden logs are supported, making the pavilion serve as a firewood storage unit and as a place for guests to warm up. In the case of Blue Barn Theatre & Boxcar 10, rebar covers the exterior, welded in front of a corten steel cladding, accommodating the building's changes over time. While the underlying pattern was algorithmically derived and digitally optimized, the installation of parts is decidedly low-tech.
Incorporating raw structures into interiors
Rebar can also be used to structure everyday objects, such as shelves. This is the case of WeWork Yangping Lu, by Pamplona Apartment, or Ap. Cobogó, by Alan Chu. In the case of Changan Noodle Bar, by Atelier Boter, a project that sought to replicate the stripped-down look of the streets, traditional wood was replaced by thin metal elements. Steel reinforcing bars are used for their simple lines to build the display rack structure; copper rods, relatively more complicated in the manufacturing process, are used as a suspension system to create visual contrast.
In short, the incorporation of rebar into reinforced concrete has revolutionized the strength and durability of structures by allowing concrete to handle tensile forces more effectively. But the inventive use of rebar in artistic and architectural expressions reaffirms its importance as a central element of modern construction and design innovation. Though often hidden, it is a material that plays a vital role in modern construction and artistic expression. Above all, its presence is a testimony to continued innovation and the search for solutions that enhance the strength and aesthetics of built structures.
