The ‘Human Sphere’ and the Figure of 8 as the Enabler of Circular Economy in Developing Countries: A Case Study

Circular Economy (CE) models offer an alternative to linear production processes that lead to resource depletion, waste management problems and environmental degradation. This is particularly true for End of Life Tires (ELTs), which at the end of their use in the automobile industry are generally burnt or dumped. The use of whole ELTs in civil engineering can be a successful, low-cost application. This is especially relevant for emerging economies, and in this context, a case study was carried out through the construction of a gravity retaining wall in Llano Chico, a low-income urban area of Quito, the capital of Ecuador. The transformation of whole ELTs into a raw construction material required nothing more than human ingenuity, making the most of the ELT’s inherent mechanical properties. In addition, the loops of the technical and biological spheres of the common CE ‘butterfly diagram’ were critically assessed. In the case study, the ELTs were cycled through the technical sphere in a collection and recycling process. The human sphere processes transformed the ELTs from being a waste product into a retaining wall. However, once constructed, the retaining wall from ELTs serves as a matrix for local flora to take root. This is in stark comparison to a traditional concrete retaining wall, which has little ecological value. The endpoint of the ELT wall is its incorporation into the environment, where its cycle ends in the biological sphere. The authors argue that the technological and biological spheres of CE do not always function as two independent cycles. The human sphere can link the two loops, drawing tires through one sphere and into the other. This is a newly defined, ‘figure of eight’ cycle.