Utilizing the impact resistance of the world's hardest concrete for disaster prevention
by Staff Writers
Kanazawa, Japan (SPX) Apr 24, 2020
Concrete is the most widely used building material in the world and consequently is being continuously developed to fulfill modern-day requirements. Efforts to improve concrete strength have led to reports of porosity-free concrete (PFC), the hardest concrete tested to date.
Some of the basic properties of PFC have already been explored, and now a team including Kanazawa University has probed the impact response of this innovative material. Their findings are published in International Journal of Civil Engineering.
Ultra-high-strength concrete offers significant advantages including reducing the weight of large structures and protecting them against natural disasters and accidental impacts. PFC is an ultra-high-strength concrete whose properties can be further enhanced by incorporating steel fibers.
The way in which PFC is prepared leads to very few voids in the final material, which gives it its high strength--400 MPa can be applied to PFC before it fails, compared with 20-30 MPa for standard concrete.
Some of the basic material properties of steel fiber-reinforced PFC have already been reported; now the researchers have evaluated the impact response of a range of PFC preparations with different steel fiber contents and section heights.
"The continued development of building materials is particularly important in areas where frequent natural disasters threaten the integrity of structures," study lead author Yusuke Kurihashi explains.
"We carried out impact tests on a variety of steel fiber-reinforced PFC samples to determine their reactions, and in so doing, accelerate the widespread application of PFC in building projects. Our testing is designed to simulate responses to events such as rock falls, blasts and flying objects."
The researchers made two key findings. Firstly, they observed that increasing the steel fiber content from 1% to 2% reduced the damage due to the impact by 30%-50%. This significant improvement in performance is expected to inform future material design decisions.
In addition, they showed that it was possible to predict the behavior of the samples with approximately 80% accuracy by comparing calculated values with those that were measured, which will help to streamline development processes.
"We hope that PFC will contribute to enhanced building safety in the future," says Dr Kurihashi.
"Although additional experimental work and statistical processing is required to fully translate PFC into widespread practical applications, our findings make a significant contribution to understanding PFC's role in improving the safety of many large structures including high-rise buildings, bridges and roads."
Cool down fast to advance quantum nanotechnology
Vienna, Austria (SPX) Apr 22, 2020
The team, led by physicists at the Technische Universitat Kaiserslautern (TUK) in Germany and University of Vienna in Austria, generated the Bose-Einstein condensate (BEC) through a sudden change in temperature: first heating up quasi-particles slowly, then rapidly cooling them down back to room temperature. They demonstrated the method using quasi-particles called magnons, which represent the quanta of magnetic excitations of a solid body. "Many researchers study different types of Bose-Einstein ... read more
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.