Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Crush those clinkers while they're hot


Rice University study suggests changes to cement manufacturing will save energy

Making cement is a centuries-old art that has yet to be perfected, according to researchers at Rice University who believe it can be still more efficient.

A cutaway illustration of a clinker, a pellet manufactured in a kiln and then ground to make cement, shows a defect called a screw dislocation. Rice University scientists studied the effect of such defects on the quality of cement used in concrete and how much energy could be saved by modifying the manufacturing process.

Credit: Shahsavari Group/Rice University

Former Rice graduate student Lu Chen and materials scientist Rouzbeh Shahsavari calculated that fine-tuning the process by which round lumps of calcium silicate called clinkers are turned into cement can save a lot of energy. Their new findings are detailed in the American Chemical Society journal Applied Materials and Interfaces.

Manufacturers of Portland cement, the most common type in use around the world, make clinkers by heating raw elements in a rotary kiln and grinding them into the fine powder that becomes cement. Mixed with water, cement becomes the glue that holds concrete together. An earlier study by Shahsavari and his colleagues that viewed the molecular structure of cement noted that worldwide, concrete manufacturing is responsible for 5 to 10 percent of the carbon dioxide, a greenhouse gas, released into the atmosphere.

The researchers analyzed the crystal and atomic structures of five phases of clinkers representing stages of cooling after they leave the kiln. They focused on the internal stresses that make some more brittle (and easier to grind) than others. They also looked at the unavoidable defects called screw dislocations, shear offsets in the raw materials that, even when ground, influence how well the powders mix with water. That reactivity determines the cement's ultimate strength.

They found that clinkers were not only most brittle when hottest, but also the most reactive. In ranking the five samples' qualities, they suggested their research could lead manufacturers to consolidate processes and cut grinding energy that now absorbs around 10-12 percent of the energy required to make cement. Equally important, for each ton of produced cement, the grinding energy accounts for roughly 50 kilograms of carbon dioxide emissions into the atmosphere, they determined.

"Defects form naturally, and you cannot do anything about them," Shahsavari said. "But the more brittle the clinkers are, the better they are for grinding. We found that the initial phase out of the kiln is the most brittle and that defects carry through to the powder. These are places where water molecules want to react."


The National Science Foundation supported the research. Shahsavari is an assistant professor of civil and environmental engineering and of materials science and nanoengineering and a member of the Richard E. Smalley Institute for Nanoscale Science and Technology at Rice. Chen is now a structural engineer at Arup.

Read the abstract at

This news release can be found online at

Follow Rice News and Media Relations via Twitter @RiceUNews

Related Materials

Shahsavari Group:

George R. Brown School of Engineering:

Images for download:

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 3,920 undergraduates and 2,567 graduate students, Rice's undergraduate student-to-faculty ratio is just over 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is highly ranked for best quality of life by the Princeton Review and for best value among private universities by Kiplinger's Personal Finance.

Media Contact

David Ruth


David Ruth | EurekAlert!

More articles from Materials Sciences:

nachricht 3-D-printed structures shrink when heated
26.10.2016 | Massachusetts Institute of Technology

nachricht From ancient fossils to future cars
21.10.2016 | University of California - Riverside

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>