Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spheres can make concrete leaner, greener

27.09.2018

Rice University's microscopic particles promise stronger building materials and more

Rice University scientists have developed micron-sized calcium silicate spheres that could lead to stronger and greener concrete, the world's most-used synthetic material.


Packed, micron-scale calcium silicate spheres developed at Rice University are a promising material that could lead to stronger and more environmentally friendly concrete.

Credit: Multiscale Materials Laboratory/Rice University

Usage Restrictions: For news reporting purposes only.


Calcium silicate spheres synthesized at Rice University and packed into a pellet hold together under compression. The spheres are building blocks that can be made at low cost and promise to mitigate the energy-intensive techniques now used to make cement, the most common binder in concrete.

Credit: Multiscale Materials Laboratory/Rice University

Usage Restrictions: For news reporting purposes only.

To Rice materials scientist Rouzbeh Shahsavari and graduate student Sung Hoon Hwang, the spheres represent building blocks that can be made at low cost and promise to mitigate the energy-intensive techniques now used to make cement, the most common binder in concrete.

The researchers formed the spheres in a solution around nanoscale seeds of a common detergent-like surfactant. The spheres can be prompted to self-assemble into solids that are stronger, harder, more elastic and more durable than ubiquitous Portland cement.

"Cement doesn't have the nicest structure," said Shahsavari, an assistant professor of materials science and nanoengineering. "Cement particles are amorphous and disorganized, which makes it a bit vulnerable to cracks. But with this material, we know what our limits are and we can channel polymers or other materials in between the spheres to control the structure from bottom to top and predict more accurately how it could fracture."

He said the spheres are suitable for bone-tissue engineering, insulation, ceramic and composite applications as well as cement.

The research appears in the American Chemical Society journal Langmuir.

The work builds on a 2017 project by Shahsavari and Hwang to develop self-healing materials with porous, microscopic calcium silicate spheres. The new material is not porous, as a solid calcium silicate shell surrounds the surfactant seed.

But like the earlier project, it was inspired by how nature coordinates interfaces between dissimilar materials, particularly in nacre (aka mother of pearl), the material of seashells. Nacre's strength is a result of alternating stiff inorganic and soft organic platelets. Because the spheres imitate that structure, they are considered biomimetic.

The researchers discovered they could control the size of the spheres that range from 100 to 500 nanometers in diameter by manipulating surfactants, solutions, concentrations and temperatures during manufacture. That allows them to be tuned for applications, Shahsavari said.

"These are very simple but universal building blocks, two key traits of many biomaterials," Shahsavari said. "They enable advanced functionalities in synthetic materials. Previously, there were attempts to make platelet or fiber building blocks for composites, but this works uses spheres to create strong, tough and adaptable biomimetic materials.

"Sphere shapes are important because they are far easier to synthesize, self-assemble and scale up from chemistry and large-scale manufacturing standpoints."

In tests, the researchers used two common surfactants to make spheres and compressed their products into pellets for testing. They learned that DTAB-based pellets compacted best and were tougher, with a higher elastic modulus, than either CTAB pellets or common cement. They also showed high electrical resistance.

Shahsavari said the size and shape of particles in general have a significant effect on the mechanical properties and durability of bulk materials like concrete. "It is very beneficial to have something you can control as opposed to a material that is random by nature," he said. "Further, one can mix spheres with different diameters to fill the gaps between the self-assembled structures, leading to higher packing densities and thus mechanical and durability properties."

He said increasing the strength of cement allows manufacturers to use less concrete, decreasing not only weight but also the energy required to make it and the carbon emissions associated with cement's manufacture. Because spheres pack more efficiently than the ragged particles found in common cement, the resulting material will be more resistant to damaging ions from water and other contaminants and should require less maintenance and less-frequent replacement.

###

The National Science Foundation and C-Crete Technologies LLC supported the research.

Read the abstract at https://pubs.acs.org/doi/10.1021/acs.langmuir.8b00917

This news release can be found online at http://news.rice.edu/2018/09/26/spheres-can-make-concrete-leaner-greener/

Follow Rice News and Media Relations via Twitter @RiceUNews.

Related materials:

Multiscale Materials Laboratory (Shahsavari Lab): http://rouzbeh.rice.edu/

George R. Brown School of Engineering: http://engineering.rice.edu

Rice Department of Civil and Environmental Engineering: http://www.ceve.rice.edu

Rice Department of Materials Science and NanoEngineering: https://msne.rice.edu

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,970 undergraduates and 2,934 graduate students, Rice's undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 2 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to http://tinyurl.com/RiceUniversityoverview.

Media Contact

David Ruth
david@rice.edu
713-348-6327

 @RiceUNews

http://news.rice.edu 

 

David Ruth | EurekAlert!
Further information:
http://dx.doi.org/10.1021/acs.langmuir.8b00917

Further reports about: Cement Spheres building blocks elastic manufacture surfactants synthetic

More articles from Materials Sciences:

nachricht From foam to bone: Plant cellulose can pave the way for healthy bone implants
19.03.2019 | University of British Columbia

nachricht Additive printing processes for flexible touchscreens: increased materials and cost efficiency
19.03.2019 | INM - Leibniz-Institut für Neue Materialien gGmbH

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>