According to the UN Environment Program, buildings create 40 percent of the world’s greenhouse gas emissions.
Day-to-day operational energy (lighting, heating, cooling), the way materials are manufactured and transport are all major contributors — and that’s without taking into account the actual construction process.
Cement, the primary binding material in modern concrete, is energy-intensive to produce and contributes approximately 7 percent of global human-made carbon dioxide (CO2) emissions alone.
Given Abu Dhabi’s status as a rapidly growing city, finding more sustainable construction materials and building methods is a primary area of research at New York University’s satellite campus, NYU-Abu Dhabi.
Dr Kemal Celik, a graduate of Istanbul University who also holds a PhD in civil and environmental engineering from the University of California, Berkeley, USA, now leads NYU-Abu Dhabi-based Advanced Materials and Building Efficiency Research (AMBER) Lab.
Dr. Celik, who has specialised in construction materials over the course of his career, was previously a Postdoctoral Scholar at Singapore-Berkeley Building Efficiency and Sustainability in the Tropics (SinBerBEST) program, an international collaboration led by the UC, Berkeley.
Focusing on sustainable and multi-functional construction materials, his research with AMBER Lab has developed into his current project — creating a new type of “green” concrete that actually sequesters CO2.
To do this, his team first developed a carbon-neutral, reactive-magnesium oxide cement that uses desalination brine. This is an industrial by-product common to regions with limited access to freshwater, many of which have, like Abu Dhabi, been investing in water security measures that include creating large-scale desalination facilities to process seawater.
This waste brine contains high concentrations of useful minerals, and often it is returnedto the sea, which damages sea life. It also increases the surrounding levels of salinity, further reducing the efficiency of the desalination process — particularly in the Arabian Gulf, which already has concentrated saline levels.
The minerals contained in the brine allow it to be used as an environmentally friendly alternative to traditional magnesite (MgCO3), to produce reactive magnesia cement (RMC). In addition, it has a lower carbon footprint and is widely available in the region.
Currently, AMBER Lab can use it as a paste, mortar, and concrete to 3D-print prototypes.The team is also exploring ways the cement can be mixed with desert sand — an almost boundless natural resource in the region — to make concrete blocks.
In its existing form, the RMC is equal in strength to conventional CO2-producing Portland cement, but continues to absorb and sequester CO2 during its lifespan, a chemical process that actually makes it stronger.
While the material’s applications are limited to paving or masonry blocks for now, Dr Celik foresees a time when its capabilities can be greatly expanded.
“The technical challenge is reinforcement — carbon steel bar is vulnerable to corrosion in this cement, but we are focusing on alternative reinforcement, with either synthetic fibres, or natural fibres.”
After participating in an NYU-sponsored StartAD accelerator programme in 2019, Dr Celik is confident the material is moving closer to widespread production and is already collaborating with an international architecture firm to build the UAE pavilion for the next Venice Architecture Biennale.
“We have significant support from the university, government and industrial partners,” he says. “Another advantage is the diversity we have in AMBER Lab. We are 10 people from nine countries, which has created a flourishing environment to develop research in the laboratory.”
StartAD is an accelerator based at New York University – Abu Dhabi (NYUAD), which helps seed-stage tech startups to launch, develop and grow.