The application and adaptation of a marine material system for a fresh-water, urban, architectural context. Using BioRock as a material focus, the research took on a new life featuring landscape and structural interventions.
View the full document on the Carleton University Thesis repository.
As seen in the Journal of Architectural Education (Fall 2024), Canadian Architect (Dec 2023), Urban Design Lab (Urban Landscape), Building 22 Edition 23, on Dezeen, and Carleton's Azrieli School of Architecture & Urbanism.
Presented to the Canadian Society of Landscape Architects & City of Toronto Committee on Climate Adaptation Municipal Roundtable. Recipient of the Maxwell Taylor Award, Marco Frascari Award, Azrieli Thesis Support Grant.
Abstract
This thesis explores the design potentials of BioRock, an underutilized accreting material that simulates the reef building processes of corals. BioRock is a grown limestone, alternative to concrete with design agency that has many positive benefits including its ability to act as an ecological scaffold, sequester pollutants, and being highly sustainable. This thesis proposes three speculative applications of BioRock within Toronto, including the reintroduction of Alvars as a landscape strategy extending from aggregate infills, an industrial remediation for obsolete water treatment reservoirs, and the in-situ repair of concrete bents supporting the Gardiner Expressway. As a material system, BioRock can help relieve cities from environmental and infrastructural issues, informing new design proposals for future urbanization. This design is explored through experimental models and test fragments of BioRock which form a library of artefacts that traverse biogeochemical scales of speculation, assembling a collection of work that I call a Terrestrial Reef.
Towards Toronto's Terrestrial Reefs
German-American architect, futurist and inventor Wolf Hilbertz pioneered BioRock in the 1970s as a means of growing artificial reefs to benefit coral and other forms of marine life. When a small electric current is passed between underwater metal electrodes in seawater, dissolved minerals accrete onto the cathode—a material such as rebar, for example—encrusting it with a layer of limestone. For his Master’s thesis, Carleton University Azrieli School of Architecture & Urbanism student Cameron Penney proposed that the heavily salted winter runoff from Toronto’s roads could provide a BioRock growing alternative to seawater, and that the resulting, pollution-sequestering ‘Terrestrial Reefs’ of this concrete-like substance could provide numerous benefits to the city.
Using aquariums as model growing tanks, Penney passed a low-voltage electrical current through scrap metal, along with formed metal and scrap concrete. The process prevents rusting, and the resulting limestone accretion is three times stronger than cement. It is also self-repairing, and its strength increases with age. By conducting interviews with interdisciplinary researchers, Penney learned more about BioRock’s material properties and potential applications. On the negative side, it has a slow growth rate; on the positive, it can be synthesized on an industrial scale, and it can be used to repair concrete at the nano scale.
Using aquariums as model growing tanks, Penney passed a low-voltage electrical current through scrap metal, along with formed metal and scrap concrete. The process prevents rusting, and the resulting limestone accretion is three times stronger than cement. It is also self-repairing, and its strength increases with age. By conducting interviews with interdisciplinary researchers, Penney learned more about BioRock’s material properties and potential applications. On the negative side, it has a slow growth rate; on the positive, it can be synthesized on an industrial scale, and it can be used to repair concrete at the nano scale.
The typical wet lab setup used for the research (above) and time lapse videos of conducted bioRock experiments. This setup benefitted from the guidance of chemistry professor Dr. Robert Burk (Carleton University, Ottawa) and electrical engineer Dr. Jianquin Wang (Carleton University, Ottawa).
Penney subdivided the BioRock-deploying speculative design interventions he developed into three categories:
Expansion re-introduces at-risk limestone habitats as a landscape strategy, connecting infill sites with terrestrially growing BioRock. An alvar is a type of landscape in which a thin layer of vegetation grows over outcrops of limestone or dolomite bedrock. The mouth of Toronto’s Don River is a landscape where existing alvars could be helped to flourish through the introduction of BioRock ‘landscape scaffolds’. Here, Penney proposes, BioRock could also be used to create lookouts and sheltered seating areas.
Expansion re-introduces at-risk limestone habitats as a landscape strategy, connecting infill sites with terrestrially growing BioRock. An alvar is a type of landscape in which a thin layer of vegetation grows over outcrops of limestone or dolomite bedrock. The mouth of Toronto’s Don River is a landscape where existing alvars could be helped to flourish through the introduction of BioRock ‘landscape scaffolds’. Here, Penney proposes, BioRock could also be used to create lookouts and sheltered seating areas.
Production includes a manufacturing strategy for growing BioRock scaffolds within decommissioned water treatment reservoirs to reduce urban salt and carbon pollution. The author cites existing open-air tanks at the Humber River water treatment plant as a place where high-salinity runoff could be purified by serving as a BioRock growing medium, and then released into the river.
Repair is an in-situ strategy for renewing the crumbling concrete bents supporting the Gardiner Expressway. Here, 3D-printed BioRock cells are monitored growing chambers that cover and re-cap damaged concrete on the Gardiner’s bents. When the monitor indicates that a repair is complete, the cell’s current is switched off. Penney proposes that the cells could contain a lighting component—an extension of the monitoring component—a platinum anode growing component, and gas exchange valves. Once the monitoring component has determined that the repair is complete, the lighting component can then be used a streetlight for the Bentway below. With the potential for each bent to have multiple cells attached to it, the process could supply considerable additional illumination to the underpass.
Biogeochemical Futures
This thesis has resulted in a library of material experiments that actualize a design proposal in the form of a Terrestrial Reef. I was not only able to grow BioRock under the typical aquatic conditions, but I was able to grow BioRock on concrete and on non-submerged surfaces; the first time this has been done to my knowledge. I was also the first to associate BioRock to many broader ecological issues involving in-situ repair, detoxification, and the reestablishment of historic Alvar landscapes.
Many innovative materials are brought into architecture to improve the industry. I see BioRock as one such material with a high degree of potential. Although understudied, I believe BioRock has a promising future with designers, material scientists, and ecologists to combat larger climatic related issues that we are currently facing and will continue to face for years to come. Perhaps one day BioRock could have future influence on Toronto’s urban fabric , finally granting the GTA with a Terrestrial Reef.
