{"id":8889,"date":"2016-06-02T12:28:10","date_gmt":"2016-06-02T12:28:10","guid":{"rendered":"http:\/\/revoscience.com\/en\/?p=8889"},"modified":"2016-06-02T12:28:10","modified_gmt":"2016-06-02T12:28:10","slug":"finding-a-new-formula-for-concrete","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/finding-a-new-formula-for-concrete\/","title":{"rendered":"Finding a new formula for concrete"},"content":{"rendered":"

Researchers look to bones and shells as blueprints for stronger, more durable concrete.<\/strong>\u00a0<\/em><\/span><\/p>\n

\"MIT-BioInspired-1_0\"
<\/span><\/a><\/span> \u201cIf we can replace cement, partially or totally, with some other materials that may be readily and amply available in nature, we can meet our objectives for sustainability,\u201d MIT Professor Oral Buyukozturk says. Image: Christine Daniloff\/MIT<\/span><\/figcaption><\/figure>\n

CAMBRIDGE, Mass. —\u00a0Researchers at MIT are seeking to redesign concrete \u2014 the most widely used human-made material in the world \u2014 by following nature\u2019s blueprints.<\/span><\/p>\n

In a paper published online in the journal\u00a0Construction and Building Materials<\/em>, the team contrasts cement paste \u2014 concrete\u2019s binding ingredient \u2014 with the structure and properties of natural materials such as bones, shells, and deep-sea sponges. As the researchers observed, these biological materials are exceptionally strong and durable, thanks in part to their precise assembly of structures at multiple length scales, from the molecular to the macro, or visible, level.<\/span><\/p>\n

From their observations, the team, led by Oral Buyukozturk, a professor in MIT\u2019s Department of Civil and Environmental Engineering (CEE), proposed a new bioinspired, \u201cbottom-up\u201d approach for designing cement paste.<\/span><\/p>\n

\u201cThese materials are assembled in a fascinating fashion, with simple constituents arranging in complex geometric configurations that are beautiful to observe,\u201d Buyukozturk says. \u201cWe want to see what kinds of micromechanisms exist within them that provide such superior properties, and how we can adopt a similar building-block-based approach for concrete.\u201d<\/span><\/p>\n

Ultimately, the team hopes to identify materials in nature that may be used as sustainable and longer-lasting alternatives to Portland cement, which requires a huge amount of energy to manufacture.<\/span><\/p>\n

\u201cIf we can replace cement, partially or totally, with some other materials that may be readily and amply available in nature, we can meet our objectives for sustainability,\u201d Buyukozturk says.<\/span><\/p>\n

Co-authors on the paper include lead author and graduate student Steven Palkovic, graduate student Dieter Brommer, research scientist Kunal Kupwade-Patil, CEE assistant professor Admir Masic, and CEE department head Markus Buehler, the McAfee Professor of Engineering.<\/span><\/p>\n

\u201cThe merger of theory, computation, new synthesis, and characterization methods have enabled a paradigm shift that will likely change the way we produce this ubiquitous material, forever,\u201d Buehler says. \u201cIt could lead to more durable roads, bridges, structures, reduce the carbon and energy footprint, and even enable us to sequester carbon dioxide as the material is made. Implementing nanotechnology in concrete is one powerful example [of how] to scale up the power of nanoscience to solve grand engineering challenges.\u201d<\/span><\/p>\n

From molecules to bridges<\/strong><\/span><\/p>\n

Today\u2019s concrete is a random assemblage of crushed rocks and stones, bound together by a cement paste. Concrete\u2019s strength and durability depends partly on its internal structure and configuration of pores. For example, the more porous the material, the more vulnerable it is to cracking. However, there are no techniques available to precisely control concrete\u2019s internal structure and overall properties.<\/span><\/p>\n

\u201cIt\u2019s mostly guesswork,\u201d Buyukozturk says. \u201cWe want to change the culture and start controlling the material at the mesoscale.\u201d<\/span><\/p>\n

As Buyukozturk describes it, the \u201cmesoscale\u201d represents the connection between microscale structures and macroscale properties. For instance, how does cement\u2019s microscopic arrangement affect the overall strength and durability of a tall building or a long bridge? Understanding this connection would help engineers identify features at various length scales that would improve concrete\u2019s overall performance.<\/span><\/p>\n

\u201cWe\u2019re dealing with molecules on the one hand, and building a structure that\u2019s on the order of kilometers in length on the other,\u201d Buyukozturk says. \u201cHow do we connect the information we develop at the very small scale, to the information at the large scale? This is the riddle.\u201d<\/span><\/p>\n

Building from the bottom, up<\/strong><\/span><\/p>\n

To start to understand this connection, he and his colleagues looked to biological materials such as bone, deep sea sponges, and nacre (an inner shell layer of mollusks), which have all been studied extensively for their mechanical and microscopic properties. They looked through the scientific literature for information on each biomaterial, and compared their structures and behavior, at the nano-, micro-, and macroscales, with that of cement paste.<\/span><\/p>\n

They looked for connections between a material\u2019s structure and its mechanical properties. For instance, the researchers found that a deep sea sponge\u2019s onion-like structure of silica layers provides a mechanism for preventing cracks. Nacre has a \u201cbrick-and-mortar\u201d arrangement of minerals that generates a strong bond between the mineral layers, making the material extremely tough.<\/span><\/p>\n

\u201cIn this context, there is a wide range of multiscale characterization and computational modeling techniques that are well established for studying the complexities of biological and biomimetic materials, which can be easily translated into the cement community,\u201d says Masic.<\/span><\/p>\n

Applying the information they learned from investigating biological materials, as well as knowledge they gathered on existing cement paste design tools, the team developed a general, bioinspired framework, or methodology, for engineers to design cement, \u201cfrom the bottom up.\u201d<\/span><\/p>\n

The framework is essentially a set of guidelines that engineers can follow, in order to determine how certain additives or ingredients of interest will impact cement\u2019s overall strength and durability. For instance, in a related line of research, Buyukozturk is looking into volcanic ash as a cement additive or substitute. To see whether volcanic ash would improve cement paste\u2019s properties, engineers, following the group\u2019s framework, would first use existing experimental techniques, such as nuclear magnetic resonance, scanning electron microscopy, and X-ray diffraction to characterize volcanic ash\u2019s solid and pore configurations over time.<\/span><\/p>\n

Researchers could then plug these measurements into models that simulate concrete\u2019s long-term evolution, to identify mesoscale relationships between, say, the properties of volcanic ash and the material\u2019s contribution to the strength and durability of an ash-containing concrete bridge. These simulations can then be validated with conventional compression and nanoindentation experiments, to test actual samples of volcanic ash-based concrete.<\/span><\/p>\n

Ultimately, the researchers hope the framework will help engineers identify ingredients that are structured and evolve in a way, similar to biomaterials, that may improve concrete\u2019s performance and longevity.<\/span><\/p>\n

\u201cHopefully this will lead us to some sort of recipe for more sustainable concrete,\u201d Buyukozturk says. \u201cTypically, buildings and bridges are given a certain design life. Can we extend that design life maybe twice or three times? That\u2019s what we aim for. Our framework puts it all on paper, in a very concrete way, for engineers to use.\u201d<\/span><\/p>\n

This research was supported in part by the Kuwait Foundation for the Advancement of Sciences through the Kuwait-MIT Center for Natural Resources and the Environment, the National Institute of Standards and Technology, and Argonne National Laboratory.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

CAMBRIDGE, Mass. — Researchers at MIT are seeking to redesign concrete \u2014 the most widely used human-made material in the world \u2014 by following nature\u2019s blueprints.<\/p>\n","protected":false},"author":2,"featured_media":8890,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[],"class_list":["post-8889","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",639,426,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0-300x200.jpg",300,200,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",639,426,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",639,426,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",639,426,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",639,426,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",639,426,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",639,426,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",600,400,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",600,400,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",639,426,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",540,360,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",95,63,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",639,426,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",96,64,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/06\/MIT-BioInspired-1_0.jpg",150,100,false]},"author_info":{"info":["RevoScience"]},"category_info":"Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/8889","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=8889"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/8889\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/8890"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=8889"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=8889"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=8889"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}