In a context of increasingly extreme summers and overheated cities, a research team led by the University of Southeast China has created a new type of cement capable of reflecting over 95% of solar radiation and emitting heat through thermal radiation, instead of absorbing it like traditional materials.
This breakthrough could transform the way we design buildings and urban spaces, offering a passive and scalable solution to address the urban heat island effect and reduce the dependence on air conditioning, whose energy and environmental footprint is increasingly hard to justify.
How this smart cement works
Unlike conventional cement, which absorbs infrared radiation and converts it into heat, this new material was designed from scratch, modifying its basic chemical composition.
The mixture includes limestone and gypsum, which when solidified in special molds, create a surface where microcrystals of ettringite grow. These crystals act as millions of microscopic mirrors, reflecting sunlight and dissipating heat into the sky.
In real test conditions, on a roof at Purdue University (USA), the cement surface remained 5.4°C below ambient temperature at noon, a fact verified by thermal sensors and infrared cameras.
More than thermal efficiency: strength, speed, and negative carbon footprint
In addition to its ability to cool surfaces, the cement exhibits remarkable mechanical strength and ultra-fast setting: within just six minutes after hydration, it can already withstand impacts without deforming, allowing for accelerated construction and reduced waiting times.
Long-term simulations, carried out with machine learning models, suggest that this cement could achieve a negative carbon footprint over a 70-year lifecycle, absorbing more CO₂ than it emits during its production and use combined.
Urban and climate-responsible applications
This kind of innovation is particularly valuable in warm regions, where air conditioning represents a high energy cost. Countries like Spain, Mexico, or southern Italy, where summers are increasingly intense, could greatly benefit from its implementation.
Unlike other solutions such as reflective coatings or white roofs, this cement integrates thermal functionality into the structural material itself, without the need for additional layers or chemical treatments.
Its incorporation in public buildings, schools, and social housing is already being studied as a strategy to reduce energy inequalities. Its use is also planned for urban pavements, renovation of old buildings, and hybrid systems with solar panels, where the lower surface temperature improves photovoltaic performance.
Sustainable construction: a structural vision for the urban future
This cement represents a more ambitious vision of sustainable architecture, where materials not only support structures, but also enhance habitability, reduce energy consumption, and contribute to climate justice.
In a world that needs practical and scalable solutions to address climate change, innovations like this could make a difference: cooling our cities, strengthening our homes, and making access to thermal comfort more equitable.
