Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cement design should take into account the water confined in the smallest pores

10.08.2016

A researcher at the UPV/EHU-University of the Basque Country is participating in the study of the stresses of confined water in the micropores of cement at extreme temperatures

As it is a basic building material used across the world, cement is subjected to a vast range of conditions, both physiological and meteorological, no matter whether they are caused by extreme temperatures and humidity, pressure, etc. It is possible to find conditions ranging from -80 ºC, in places such as the scientific bases in the Antarctic, to several hundreds of degrees in infrastructures close to heat sources or in the case of fires, for example.


At low temperatures, from inside towards the outside, exerted by the water molecules, and at high temperatures from outside towards the inside caused by the absence of the molecules.

Credit: Hegoi Manzano - UPV/EHU

These variations in humidity and temperature are translated into physical processes involving evaporation or freezing of the water contained in the cement paste, which often cause stresses and even micro-cracking inside the cement.

Characterizing the response to these phenomena affecting the confined water in the smallest pores of the cement "is hugely important as a large proportion of the water, about 30 %, is located in these small spaces, so to a great extent it contributes towards the final properties of the material," explained Hegoi Manzano, a researcher in the UPV/EHU's department of Condensed Matter Physics, and author of the study in collaboration with a research group of the University of Tohoku in Japan.

Given the complexity involved in studying the behaviour of the water located in such tiny pores of approximately 1 nanometre in size by means of experimental channels, the researchers resorted to molecular simulation methods that "imitate" the interactions among the atoms that make up the cement in order to determine how they behave as a whole and the properties that these interactions are translated into," he explained. The temperature range they studied was from -170 ºC to 300 ºC.

Stresses at both extremes

In the results obtained in the simulations they were able to observe that at both extremes of temperature "significant volume changes owing to water physics take place. Through totally opposite effects we arrived at the same consequences", he remarked. At high temperatures the water evaporates and disappears from the pores. In these conditions the pressure brought to bear by the material itself may cause the empty pores to collapse and micro cracking to be created which, in particularly serious cases, could cause the material to collapse.

At the other extreme, at extremely low temperatures, what happens is that the water freezes and therefore expands. "In these conditions it should be highlighted that the frozen water does not manage to form ice because of the small space in which it is located; the water molecules cannot order themselves to form a crystalline ice structure," he stressed. But the expansion it undergoes is enough to create stresses in the cement and likewise cause micro cracking.

The information extracted from this study can be used to "modify the formulation of the cement for infrastructures that are going to be located in environments with extreme temperatures. Let us take for example an oil company: knowing the stresses and forces that may be created in the cement, they would have the chance to change certain design factors, such as the additives added to the cement to compensate for the expansion or collapsing of the material in oil wells. That would be the ideal application of the work," concluded Manzano.

###

Additional information

Hegoi Manzano-Moro has a PhD in Chemistry and works as a Temporary Contractual Lecturer in the UPV/EHU's department of Condensed Matter Physics. This work is the result of the collaboration he has with Patrick A. Bonnaud, a researcher at the University of Tohoku in Japan.

Bibliographical reference

P. A. Bonnaud, H. Manzano, R. Miura, A. Suzuki, N. Miyamoto, N. Hatakeyama, A. Miyamoto. Temperature Dependence of Nanoconfined Water Properties: Application to Cementitious Materials. J. Phys. Chem. C, 2016, 120 (21), pp 11465-11480. DOI: 10.1021/acs.jpcc.6b00944. Publication Date (Web): May 10, 2016

Media Contact

Naiara Billalabeitia
bizkaiakomunikazioa@ehu.eus
0034-601-3453

 @upvehu

http://www.ehu.es 

Naiara Billalabeitia | EurekAlert!

Further reports about: Cement building material frozen water high temperatures pores tiny pores

More articles from Materials Sciences:

nachricht Move over, Superman! NIST method sees through concrete to detect early-stage corrosion
27.04.2017 | National Institute of Standards and Technology (NIST)

nachricht Control of molecular motion by metal-plated 3-D printed plastic pieces
27.04.2017 | Ecole Polytechnique Fédérale de Lausanne

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>