Displaying items by tag: Southeast University

China/US: A team led by Fengyin Du, then at Southeast University in Nanjing, developed a new cement formulation that reflects sunlight and emits heat more effectively than ordinary Portland cement, according to the New Scientist. The cement incorporates reflective ettringite crystals on its surface, which Du says “works like a mirror and a radiator, so it can reflect sunlight away and send heat out into the sky, so a building can stay cooler without any air conditioning or electricity.”

To make it, the researchers produce tiny pellets from limestone and gypsum, which are ground and mixed with water before being poured into a silicone mould covered in small holes. Ettringite crystals grow in slight depressions on the surface created by air bubbles, while an aluminium-rich gel allows infrared light to pass through, lowering heat retention.

Du said that tests at Purdue University, Indiana showed the cement’s surface was 5.4°C cooler than the air and 26°C cooler than conventional cement under the same conditions. The process is reportedly scalable and costs US$5/t less than ordinary Portland cement, as it can be produced at lower temperatures.

China: A team at Southeast University has developed an alternative concrete that contains 8% cement. It uses coral reef limestone fragments and biodebris with an upper particle size of 53mm as fine aggregate. The researchers concluded that the material proved suitable for use in precast concrete paving slab production.

China: Switzerland-based LafargeHolcim has announced the formation of green building solutions partnership with Southeast University (SEU) in Nanjing for research into concretes and mortars for use in 3D printing in construction. The company says that the partnership is a step towards achieving its aim of becoming a “full 3D printing solutions provider.”

Head of research and development Edelio Bermejosaid, “Our global network of academic partners is critical in helping us think outside the box. We need the brightest minds to help us lead the next frontier of building solutions.”