{"id":124216,"date":"2024-04-16t11:55:37","date_gmt":"2024-04-16t15:55:37","guid":{"rendered":"\/\/www.g005e.com\/?p=124216"},"modified":"2024-08-29t23:53:28","modified_gmt":"2024-08-30t03:53:28","slug":"new-phase-change-concrete-melts-snow-and-ice-without-salt-or-shovels","status":"publish","type":"post","link":"\/\/www.g005e.com\/2024\/04\/16\/new-phase-change-concrete-melts-snow-and-ice-without-salt-or-shovels\/","title":{"rendered":"new phase-change concrete melts snow and ice without salt or shovels"},"content":{"rendered":"
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new self-heating concrete mixes could eliminate the need for snowplows, salt trucks and shovels.<\/strong><\/p>\n by rick richardson researchers have devised a self-heating substance that can melt snow and ice for up to 10 hours without the need for shovels or salt by incorporating a phase-change compound into concrete. the new substance may lessen the requirement for salting and plowing while helping maintain road surface integrity.<\/p>\n more:<\/b> ai generates revolutionary new battery design<\/a> | chatgpt is getting humanlike memory<\/a> | one state is now america\u2019s clean energy paradise<\/a> | did ancient romans find a solution for climate change?<\/a> | telehealth advances with ai-powered clinics<\/a> | fcc approves superfast wi-fi tethering<\/a> | major websites blocking content from ai crawlers<\/a> | printer ink: not just expensive, but a blatant scam?<\/a> | generative ai coming to microsoft 365<\/a> | electronic skin that can sense touch will transform robotics<\/a> the u.s. department of transportation<\/a> (dot) reports that over 70 percent of roadways are in areas with snowfall. accumulation of snow and ice decreases vehicle mobility and road friction, slowing down traffic and raising the possibility of collisions. besides the millions of dollars spent restoring infrastructure damage caused by snow and ice, the dot reports that local and state governments spend more than $2.3 billion a year on snow and ice control activities. before a snowfall, salt is frequently applied to prevent icing, yet the highly concentrated salt solution can damage<\/a> asphalt or concrete. water penetrating the pavement freezes and expands, creating internal pressure and deteriorating the pavement.<\/p>\n researchers from drexel university, in the well-known \u201ccold state\u201d of pennsylvania, recently described their self-heating concrete in a study as a potential solution to snow-covered roads and the expenses related to cleaning and maintaining them.<\/p>\n \u201cone way to extend the service life of concrete surfaces, like roadways, is to help them maintain a surface temperature above freezing during the winter,\u201d said amir farnam, principal investigator at drexel\u2019s advanced infrastructure materials (aim) lab and one of the study\u2019s corresponding authors. \u201cpreventing freezing and thawing and cutting back on the need for plowing and salting are good ways to keep the surface from deteriorating. so, our work is looking at how we can incorporate special materials in the concrete that help it maintain a higher surface temperature when the ambient temperature around it drops.\u201d<\/p>\n paraffin, a substance known as a phase-change material because it produces heat when it transitions from a liquid form at ambient temperature to a solid one when temperatures drop, is the \u201cspecial material\u201d used by the researchers. in a prior study, phase-change concrete was tested in a thermally controlled lab environment,<\/a> but in this one, real-world circumstances and real-time testing were used.<\/p>\n paraffin was incorporated into concrete slabs using two different techniques. the first method involved soaking and absorbing porous lightweight aggregate \u2013 the tiny stones and pebbles added to concrete to give it strength \u2013 in liquid paraffin before mixing it into the concrete. in the second method, the concrete was mixed immediately with paraffin microcapsules.<\/p>\n the researchers poured three slabs; two had paraffin included in different ways, while the third had no phase-change substance. since december 2021, all three have been outside, close to a parking lot on the drexel university campus. over the first two years, they experienced five snowfalls of one inch or more and 32 freeze-thaw occurrences, which were defined as periods when the temperature fell below freezing regardless of precipitation (rain, drizzle, snow, sleet or hail).<\/p>\n thermal sensors and cameras were used to track the snow- and ice-melting capabilities of the 30- by 30-inch slabs. when air temperatures dropped below freezing, the researchers discovered that the phase-change concrete maintained its surface temperature between 42\u00b0f and 55\u00b0f (5.6\u00b0c and 12.8\u00b0c) for as long as 10 hours. because of the heat generated, about a quarter of an inch of snow might be melted every hour at a rate of a few inches.<\/p>\n \u201cwe have demonstrated that our self-heating concrete is capable of melting snow on its own, using only the environmental daytime thermal energy \u2013 and doing it without the help of salt, shoveling or heating systems,\u201d farnam said. \u201cthis self-heating concrete is suitable for mountainous and northern regions in the u.s., such as northeast pennsylvania and philadelphia, where there are suitable heating and cooling cycles in winter.\u201d<\/p>\n the microcapsule paraffin heated up faster but only held heat for half the duration of the lightweight aggregate slab\u2019s heating, which allowed it to stay above freezing for up to 10 hours. according to the researchers, the porosity of the aggregate probably helps the paraffin stay liquid below its typical freezing temperature of 42\u00b0f. this means that instead of releasing its heat energy immediately when the temperature dropped, the slab held off until the material reached 39\u00b0f\/3.9\u00b0c. in comparison, the paraffin slab that was microencapsulated started to release heat energy as soon as it reached 42\u00b0f.<\/p>\n \u201cour findings suggest that the phase-change material treated lightweight aggregate concrete was more suited for deicing applications at subzero temperatures because of its gradual heat release within a wider range of temperature,\u201d said farnam.<\/p>\n according to the experts, concrete deterioration can be avoided if the concrete can be kept from falling below freezing.<\/p>\n
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