{"id":63775,"date":"2010-11-16T00:00:00","date_gmt":"2010-11-16T00:00:00","guid":{"rendered":"https:\/\/www.uri.edu\/news-draft\/uncategorized\/grad-student-named-trendsetter-for-research-on-self-healing-concrete\/"},"modified":"2010-11-16T00:00:00","modified_gmt":"2010-11-16T00:00:00","slug":"grad-student-named-trendsetter-for-research-on-self-healing-concrete","status":"publish","type":"post","link":"https:\/\/www.uri.edu\/news\/2010\/11\/grad-student-named-trendsetter-for-research-on-self-healing-concrete\/","title":{"rendered":"Grad student named \u2018trendsetter\u2019 for research on self-healing concrete"},"content":{"rendered":"
\n\t\tIt\u2019s not often that a graduate student is considered a national trendsetter in their chosen field, but that\u2019s what Public Works magazine is saying about Michelle Pelletier, who earned her master\u2019s degree in chemical engineering last summer. <\/p>\n


\nThe Woonsocket native is being lauded this month as a 2010 Public Works Trendsetter for her research to develop a self-healing concrete that can extend the life of roadways, bridges, foundations and sidewalks. She has been featured in more than two dozen trade publications in the transportation, construction, engineering and chemical industries in the last five months.<\/p>\n


\nAccording to Pelletier, efforts to extend the life of structures and reduce repair costs have led engineers to develop a wide range of \u201csmart materials\u201d that have self-healing properties, but many of these new materials are difficult to commercialize. But she thinks her new concrete may prove to be cost-effective.<\/p>\n


\nPelletier embedded a microencapsulated sodium silicate healing agent directly into a concrete matrix. When tiny stress cracks begin to form in the concrete, the capsules rupture and release the healing agent into the adjacent areas.<\/p>\n


\nThe sodium silicate reacts with the calcium hydroxide naturally present in the concrete to form a calcium-silica-hydrate product to heal the cracks and block the pores in the concrete. The chemical reaction creates a gel-like material that hardens in about one week.<\/p>\n


\n\u201cSmart materials usually have an environmental trigger that causes the healing to occur,\u201d explained Pelletier, who is collaborating on the project with äçÐÄvlogÃâ·ÑBÕ¾ Chemical Engineering Professor Arijit Bose. \u201cWhat\u2019s special about our material is that it can have a localized and targeted release of the healing agent only in the areas that really need it.\u201d<\/p>\n


\nIn tests comparing a standard concrete mix to concrete containing two percent sodium silicate healing agent, Pelletier\u2019s healing mix recovered 26 percent of its original strength (after being stressed to near breaking) versus just 10 percent recovery by the standard mix. The äçÐÄvlogÃâ·ÑBÕ¾ student said that an increase in the quantity of healing agent would likely further improve the recovered strength of the concrete.<\/p>\n


\n\u201cSelf-healing concrete is a big research field right now,\u201d she said. \u201cBut many of the approaches being taken by other researchers have not ended up being economically feasible for commercial production.\u201d

\nPelletier noted that some researchers have laced the concrete with bacteria spores that secrete calcium carbonate to fill the cracks and pores, while others embedded glass capillaries with a healing agent, but the process of filling the capillaries with the agent is long and tedious.<\/p>\n


\nNext up for Pelletier is a study to see if her sodium silicate healing agent could also act as a corrosion inhibitor.<\/p>\n


\n\u201cBuilding concrete is routinely fixed with steel reinforcement bars to compensate for low tensile strength, but they are extremely susceptible to corrosion,\u201d said Pelletier, who is a process engineer for Beaver-Visitec International, which is a leading manufacturer and seller of ophthalmic and microsurgical supplies. \u201cWe are exploring if the release of the agent will result in corrosion inhibition by two mechanisms. First, the reduced water transport due to the filled pores and reduced interconnectivity within the matrix may result in less moisture reaching the metal and ultimately less corrosion. Also, silicates can deposit on the surface to form a protective film which may also help with reducing the corrosion rate of the steel rebars.\u201d <\/p>\n


\nOne additional advantage to the use of self-healing concrete is that it could reduce the significant CO2 emissions that result from concrete production. Because the production of concrete is very energy intensive \u2013 when mining, transportation and concrete plants are considered \u2013 the industry is responsible for about 10 percent of all CO2 emissions in the United States.<\/p>\n


\n\u201cIf self-healing concrete can lengthen the life of the concrete and reduce maintenance and repairs, it will ultimately reduce the production of excess amounts of concrete and result in a decrease in CO2 emissions,\u201d she said.<\/div>\n","protected":false},"excerpt":{"rendered":"

It\u2019s not often that a graduate student is considered a national trendsetter in their chosen field, but that\u2019s what Public Works magazine is saying about Michelle Pelletier, who earned her master\u2019s degree in chemical engineering last summer. The Woonsocket native is being lauded this month as a 2010 Public Works Trendsetter for her research […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[],"class_list":["post-63775","post","type-post","status-publish","format-standard","hentry","category-archives"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts\/63775","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/comments?post=63775"}],"version-history":[{"count":0,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts\/63775\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/media?parent=63775"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/categories?post=63775"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/tags?post=63775"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}