Rheology studies how matter flows, usually in its liquid state but also as “soft solids”. The technique has been applied in the last century in fields as diverse as materials science, engineering, geophysics, physiology, human biology, and pharmaceutics. In more recent decades, it has been a key part of the rise of green technology.
Green technology, clean technology, and cleantech are used to refer to research, technology, policies, and practices being developed to reduce and counteract humanity’s negative impact on the environment.
One of the least sustainable industries must necessarily be a part of any green technology solution to environmental damage. In the construction industry, rheology has enabled significant reductions in carbon fuel consumption, and materials being wasted or unnecessarily replaced.
Making concrete more durable and long-lasting – and reducing the need to renovate or even demolish and replace buildings – is an important direction of research for green technologists. Rheology has been used to study superplasticizers, which are added to cement to make it less prone to yield to stress formation and to retain viscosity before it has set (Ferrari et al., 2011). By improving the properties of concrete in this way, rheology has contributed to longer-lasting buildings and therefore fewer finite resources used in the construction industry.
Rheology has also been used to make finished buildings greener in terms of their energy usage (Lucas et al., 2010). The green technology development of phase change materials (PCMs) introduced mortars for walls that would better retain thermal energy inside the building. This emphasis on latent heat storage results in buildings with few energy demands, especially in cooler climates. The rheological study also found that lime mortars that incorporate PCMs can be applied even in old buildings during renovation. In this way, rheology contributes to construction’s ongoing sustainability conundrum.