THURSDAY, DECEMBER 2, 2021
A team of researchers from Incheon National University, Kyung Hee University and Korea University have recently developed a cement-based composite capable of generating and storing electricity by contact electrification.
The innovation arrives as the industry pushes to build net-zero energy structures. According to reports, the building sector alone is responsible for 40% of all the world’s power consumption.
About the Material
Created with carbon fibers, the cement-based conductive composite (CBC) structural material is slated to make construction more eco-friendly and can also act as a triboelectric nanogenerator (TENG)—a type of mechanical energy harvester.
According to the research team, the material can harvest energy through various forms of external mechanical energy sources, such as human motions (footsteps), wind, rain and even waves, as a result of interactions between the two materials.
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| Tumisu / Pixabay |
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A team of researchers from Incheon National University, Kyung Hee University and Korea University have recently developed a cement-based composite capable of generating and storing electricity by contact electrification. |
“We wanted to develop a structural energy material that could be used to build net-zero energy structures (NZES) that use and produce their own electricity. Since cement is an indispensable construction material, we decided to use it with conductive fillers as the core conductive element for our CBC-TENG system,” explained INU Professor Seung-Jung Lee.
In testing the new material, the research team designed a lab-scale NZES and a CBC-based capacitor to test its energy harvesting and storage capabilities. As a result of the study, the team found that at a 1% volume of conductive carbon fibers in a cement mixture, the CBC mixture exhibits optimal electrical properties while retaining the superior mechanical properties of cement.
Further studies confirmed that the CBC-TENG could be safely used as a building material as the current generated by it was much lower than the maximum allowable current for the human body. The material could also be used to design self-sensing systems that monitor the structural health and predict the remaining service life of concrete structures without any external power.
“Our ultimate goal was to develop materials that made the lives of people better and did not need any extra energy to save the planet. And we expect that the findings from this study can be used to expand the applicability of CBC as an all-in-one energy material for net-zero energy structures,” concluded Lee.
The study has since been published in Nano Energy.
Conductive Concrete Studies
Some years ago, in 2018, an Australia-based advanced material technology company announced that testing showed high degrees of electrical conductivity in a formulation of graphene-enhanced concrete it developed, potentially opening the door to everything from advances in heated flooring to self-deicing runways and roads that could charge electric vehicles while they drive.
Talga Resources Ltd. said that initial testing of its concrete at its graphene-graphite research and development lab in the United Kingdom showed such high levels of conductivity, that it could act like the heating element of an electric stove, according to managing director Mark Thompson.
Testing of the graphene-laced cement showed about 20 million times the conductivity of a standard mortar used as a control, according to the company. Talga said the results showed that their formulation is much more efficient in its conductivity than past attempts at conductive concrete—using magnetite, graphite and other metal and carbon materials—have been.
The secret, according to the company, is a mix of graphene and other products, including graphite and what it calls a “silica-rich by-product of ore processing.”
Possible applications for the conductive graphene concrete include installation under floors as an alternative to hot-water piping used for heating, and installation under roadways and runways to heat them in winter. Talga notes that the electrically conductive concrete could be layered beneath thermally conductive concrete on roads to convey heat to the surface and melt ice and snow, eliminating the need for salts that often corrode steel structures like bridges.
Two years prior to the study, researchers in Nebraska hoped that their electrified concrete could help driver avoid the skids during winter months.
According to a statement released by the University of Nebraska-Lincoln, professor of civil engineering Chris Tuan added steel shavings and carbon particles to otherwise ordinary concrete. Although the materials add up to just 20% of the concrete slab’s total mixture, it is just enough electricity to melt snow and ice while remaining safe to the touch.
Tuan’s research team demonstrated the concrete’s de-icing performance to the Federal Aviation Administration over a one-month-long phase. To test his project, Tuan used a 200-square-foot slab of concrete outside the Peter Kiewit Institute. As flakes fell during a December Omaha squall, the snow accumulated on the grass surrounding the slab and initially clinged to the concrete, too.
But as the minutes pass, the snow began melting from only the concrete surface and the slab revealed its secret mixture.
Tagged categories: Building Envelope; Building materials; Colleges and Universities; concrete; Energy codes; Energy efficiency; Net Zero Energy ; Program/Project Management; Research and development
