Scientists in India have been experimenting with turning human waste into a special material that could make concrete stronger, instead of it just going to waste.
Every person produces around 400 grams of poo each day, so researchers wanted to find a useful way to reuse some of it rather than letting it all go to landfill.
To do this, engineers heat treated sewage sludge to very high temperatures, between 350 and 450 degrees Celsius, without much oxygen around. This turns it into a material called biochar.
When researchers replaced a small part of the cement in concrete with this biochar, the concrete actually became stronger. Concrete made with 10 percent biochar was 42 percent stronger after 91 days of curing, compared with normal concrete.
Lead researcher Raghuvesh Tiwari, a civil engineer at Manipal University in India, said the biochar “yields significant improvements in concrete properties.”
The biochar works a bit like volcanic ash did in ancient Roman concrete, reacting with other ingredients to form extra-strong bonds, while its tiny holes help hold water inside the concrete as it sets.
Interestingly, adding too much biochar doesn’t keep helping. Once researchers used 15 percent biochar, the concrete’s strength actually started to drop again.
It’s early days for the idea, but it could one day mean that something we usually flush away helps build stronger roads, footpaths and buildings.
Te Reo Māori
Pane: Ka Taea Pea te Hanga Raima Kaha Ake mā te Tūtae?
Kua whakamātauria e ngā kaiputaiao o Inia te huri i te para tangata hei rauemi motuhake e kaha ake ai te raima (concrete), kāore noa iho e para haere ana.
Ka puta i ia tangata te 400 karamu tūtae ia rā, nō reira i hiahia ngā kairangahau ki te kimi huarahi whaihua hei whakamahi anō i tētahi wāhanga, kaua e tukua katoatia ki ngā papa parakino.
Hei mahi i tēnei, ka whakamahana ngā mataaro i ngā para wai koretake ki ngā mahana teitei rawa atu, mai i te 350 tae atu ki te 450 nga tohu paemahana Celsius, kāore he hāora nui e āwhina ana. Ka huri tēnei hei rauemi e kīia nei ko te “biochar.”
I te wā i whakakapia ai e ngā kairangahau tētahi wāhanga iti o te raima ki tēnei biochar, kua kaha ake te raima. Ko te raima i hangaia ki te 10 ōrau biochar, 42 ōrau kaha ake i muri i te 91 rā e whakapakari ana, ki te whakataurite ki te raima māori.
Ko te kairangahau ārahi a Raghuvesh Tiwari, he mataaro hanganga i te Whare Wānanga o Manipal i Inia, i kī he “nui rawa ngā painga” e puta mai ana mā te biochar mō ngā āhuatanga o te raima.
He rite tā te biochar mahi ki te pungarehu puia i whakamahia i te raima o Roma o mua, e tūhono ana ki ētahi atu mea hei hanga here kaha rawa atu, me ōna kōhao iti e āwhina ana ki te pupuri wai i roto i te raima i a ia e whakapakari ana.
He mea whakamīharo, ki te nui rawa te biochar ka whakamahia, kāore e pai tonu ana. Ka tae ki te 15 ōrau biochar, kātahi ka tīmata anō te heke o te kaha o te raima.
He tīmatanga noa tēnei whakaaro, engari tērā pea ā tōna wā, mā tētahi mea e horoia atu ana e tātou i ia rā, ka kaha ake ngā huarahi, ngā ara hīkoi, me ngā whare.
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