Reinforcing concrete with fibers isn’t a new idea, Volz says. The Roman Empire used hair and straw in their concrete structures and Egyptians mixed straw in clay to make harder bricks. Today short carbon fibers – measuring no more than 1.5 inches – are found in buildings, bridges and slabs to limit the size of cracks. But in the future, Volz says the carbon fibers could be up to 6 inches in length, significantly improving a structure’s ability to withstand blasts, hurricanes and other natural disasters.
“The long fibers will absorb more energy as they pull-out during the pressure wave or impact, cutting down on the potential for failure during an explosion or earthquake,” Volz explains. “The fibers will also significantly diminish secondary fragmentation, reducing one of the leading causes of damage to surrounding personnel and materials. First responders will be able to get to the scene faster because they won’t have to clear chunks of concrete out of their way.”
Previous efforts by other researchers to incorporate longer carbon fibers have failed for two reasons. First, longer carbon fibers are more likely to ball up as the concrete is mixed. Second, it’s difficult to disperse the carbon fibers throughout the concrete.
Coating the fibers can reduce the fibers tendency to form into a ball. The team plans to study a variety of formulas to find a coating that balances between flexibility and rigidity. “A delicate balancing act is required between allowing the fibers to flow easily during mixing yet bond sufficiently with the concrete matrix in the hardened state,” Volz says.
In addition, the team plans to study how a negative electric charge, applied to a polymer coating, could force the fibers to disperse more uniformly during mixing.
Mindy Limback | Newswise Science News
Smart buildings through innovative membrane roofs and façades
31.08.2017 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP
Concrete from wood
05.07.2017 | Schweizerischer Nationalfonds SNF
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research