Context for Conserving Concrete Heritage

Concrete met postwar needs for faster and more economical construction methods. The consequent large number of extraordinary concrete buildings, particularly from the mid-twentieth century, defined a new architecture. Although there are many well-constructed, carefully crafted concrete buildings of this time, there are also many buildings suffering rapid deterioration.

Some of the issues currently observed can be linked to the novelty of the material and construction techniques at the time of construction, for example there was often limited understanding of its durability, a dearth of experience working with reinforced concrete, and lack of industry standards and regulations. In addition, architects and engineers were experimenting with reinforced concrete pushing the limits of the material structurally and aesthetically.

Other conditions at the time of construction that sometimes resulted in poor durability are scarcity of building materials, pressure for accelerated construction, and little quality control. Moreover, these buildings often suffer from the mistaken belief that reinforced concrete was a maintenance-free material. The result is a large stock of culturally significant reinforced concrete buildings in need of repair.

Despite the development of a multibillion-dollar concrete repair industry, the conservation of reinforced concrete has seen little advancement in terms of materials or methods developed specifically to meet the typical conservation principles of minimum intervention and retention of original fabric. That is not to say that existing repair and treatment methods developed to meet the needs of the concrete repair industry cannot be successfully applied in the conservation of culturally significant concrete.

The concrete repair industry has developed a significant amount of knowledge, repair and treatment techniques, skills and experience that are applicable in the conservation field. The challenge is determining how to properly select and apply these resources at a level that satisfies conservation criteria. This is particularly difficult in sites where concrete is integral to the aesthetic value of the place, such as the use of exposed concrete in brutalist structures, where color and texture were carefully specified.

The Conservation Institute’s work starts from a recognition that the heritage of the modern era should be conserved according to established conservation principles. Reinforced concrete is the most ubiquitous building material of the twentieth century, and as such its conservation is challenging practitioners all over the world. With the pioneering concrete structures of the early modern period now nearing 100 years old and the second wave of architectural concrete exemplars, particularly the brutalist buildings of the 1960s, now needing repair, addressing their conservation is currently critical for the preservation of their cultural significance.