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Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.15,0:00:05.89,Default,,0000,0000,0000,,Concrete is the second\Nmost used substance on earth after water,
Dialogue: 0,0:00:05.91,0:00:07.06,Default,,0000,0000,0000,,and for this reason,
Dialogue: 0,0:00:07.09,0:00:09.97,Default,,0000,0000,0000,,it has a significant environmental impact.
Dialogue: 0,0:00:09.99,0:00:15.59,Default,,0000,0000,0000,,If it were a country, it would rank third\Nfor emissions after China and USA.
Dialogue: 0,0:00:15.91,0:00:20.02,Default,,0000,0000,0000,,But in fact, concrete\Nis an intrinsically low-impact material
Dialogue: 0,0:00:20.04,0:00:23.87,Default,,0000,0000,0000,,with much lower emissions\Nof CO2 and energy per ton
Dialogue: 0,0:00:23.89,0:00:28.58,Default,,0000,0000,0000,,than other materials like iron and steel,\Neven things like bricks.
Dialogue: 0,0:00:29.19,0:00:33.18,Default,,0000,0000,0000,,But because of the enormous\Nvolumes we use overall,
Dialogue: 0,0:00:33.20,0:00:38.15,Default,,0000,0000,0000,,it contributes to about eight percent\Nof man-made CO2 emissions.
Dialogue: 0,0:00:38.17,0:00:40.45,Default,,0000,0000,0000,,Concrete is an essential material.
Dialogue: 0,0:00:40.47,0:00:42.33,Default,,0000,0000,0000,,We need it to house people,
Dialogue: 0,0:00:42.36,0:00:45.60,Default,,0000,0000,0000,,to build roads, bridges and dams.
Dialogue: 0,0:00:45.62,0:00:47.65,Default,,0000,0000,0000,,So we can't do without it,
Dialogue: 0,0:00:47.67,0:00:51.51,Default,,0000,0000,0000,,but we can significantly reduce\Nits carbon footprint.
Dialogue: 0,0:00:51.53,0:00:54.26,Default,,0000,0000,0000,,Concrete is held together by cement.
Dialogue: 0,0:00:54.28,0:00:58.38,Default,,0000,0000,0000,,And cement we use today,\Ncalled Portland cement,
Dialogue: 0,0:00:58.40,0:01:03.35,Default,,0000,0000,0000,,is made by heating together a combination\Nof limestone and clay
Dialogue: 0,0:01:03.37,0:01:07.70,Default,,0000,0000,0000,,at a temperature of 1,450 degrees Celsius.
Dialogue: 0,0:01:08.18,0:01:11.17,Default,,0000,0000,0000,,But in fact, most of the CO2 emissions
Dialogue: 0,0:01:11.20,0:01:12.96,Default,,0000,0000,0000,,come not from the heating,
Dialogue: 0,0:01:12.98,0:01:17.22,Default,,0000,0000,0000,,but from the breakdown of limestone,\Nwhich is calcium carbonate,
Dialogue: 0,0:01:17.24,0:01:21.70,Default,,0000,0000,0000,,into calcium oxide\Nand carbon dioxide, or CO2.
Dialogue: 0,0:01:22.26,0:01:25.14,Default,,0000,0000,0000,,Now we can't do without\Nthis component altogether,
Dialogue: 0,0:01:25.16,0:01:29.00,Default,,0000,0000,0000,,because nothing else is so efficient\Nat holding stuff together.
Dialogue: 0,0:01:29.32,0:01:32.39,Default,,0000,0000,0000,,But we can replace\Na large proportion of it
Dialogue: 0,0:01:32.41,0:01:35.91,Default,,0000,0000,0000,,with other materials\Nwith lighter carbon footprints.
Dialogue: 0,0:01:36.27,0:01:38.98,Default,,0000,0000,0000,,Many colleagues are looking for solutions.
Dialogue: 0,0:01:39.00,0:01:40.76,Default,,0000,0000,0000,,And here in Switzerland,
Dialogue: 0,0:01:40.79,0:01:45.11,Default,,0000,0000,0000,,we have found that clays produce\Nvery reactive materials
Dialogue: 0,0:01:45.14,0:01:46.52,Default,,0000,0000,0000,,when they're calcined,
Dialogue: 0,0:01:46.55,0:01:50.32,Default,,0000,0000,0000,,that's to say heated\Nto around 800 degrees Celsius,
Dialogue: 0,0:01:50.34,0:01:55.42,Default,,0000,0000,0000,,significantly lower than the 1,450\Nneeded to produce cement.
Dialogue: 0,0:01:55.44,0:01:59.29,Default,,0000,0000,0000,,But more importantly,\Nthere's no CO2 emissions
Dialogue: 0,0:01:59.31,0:02:01.68,Default,,0000,0000,0000,,from the decomposition of limestone.
Dialogue: 0,0:02:02.34,0:02:04.70,Default,,0000,0000,0000,,We then take this calcined clay,
Dialogue: 0,0:02:04.72,0:02:06.59,Default,,0000,0000,0000,,and we add a bit of limestone --
Dialogue: 0,0:02:06.61,0:02:10.59,Default,,0000,0000,0000,,but this time not heated,\Nso no CO2 emissions --
Dialogue: 0,0:02:10.62,0:02:12.19,Default,,0000,0000,0000,,and some cement,
Dialogue: 0,0:02:12.21,0:02:19.03,Default,,0000,0000,0000,,and this combination of limestone,\Ncalcined clay and cement, we call LC3.
Dialogue: 0,0:02:19.87,0:02:21.98,Default,,0000,0000,0000,,Now this LC3 here
Dialogue: 0,0:02:22.01,0:02:25.73,Default,,0000,0000,0000,,has the same properties\Nas Portland cement.
Dialogue: 0,0:02:26.06,0:02:29.65,Default,,0000,0000,0000,,It can be produced\Nwith the same equipment and processes
Dialogue: 0,0:02:29.68,0:02:31.65,Default,,0000,0000,0000,,and used in the same way,
Dialogue: 0,0:02:31.67,0:02:35.88,Default,,0000,0000,0000,,but has up to 40 percent\Nlower CO2 emissions.
Dialogue: 0,0:02:36.27,0:02:42.03,Default,,0000,0000,0000,,And this was demonstrated in this house\Nwe built near Jhansi in India,
Dialogue: 0,0:02:42.05,0:02:45.77,Default,,0000,0000,0000,,where we could save\Nmore than 15 tons of CO2,
Dialogue: 0,0:02:45.80,0:02:50.23,Default,,0000,0000,0000,,which was 30 to 40 percent\Ncompared to existing materials.
Dialogue: 0,0:02:50.59,0:02:54.27,Default,,0000,0000,0000,,So why isn't everybody already using LC3?
Dialogue: 0,0:02:54.82,0:02:57.42,Default,,0000,0000,0000,,Well, cement is a local material.
Dialogue: 0,0:02:57.44,0:03:00.66,Default,,0000,0000,0000,,The reason Portland cement is so pervasive
Dialogue: 0,0:03:00.69,0:03:04.66,Default,,0000,0000,0000,,is that it's produced\Nfrom the most abundant materials on Earth
Dialogue: 0,0:03:04.68,0:03:06.85,Default,,0000,0000,0000,,and can be produced in India,
Dialogue: 0,0:03:06.87,0:03:11.53,Default,,0000,0000,0000,,in the United States,\Nin Ethiopia, almost anywhere.
Dialogue: 0,0:03:12.06,0:03:14.52,Default,,0000,0000,0000,,And we have to work with people locally
Dialogue: 0,0:03:14.54,0:03:18.75,Default,,0000,0000,0000,,to find the best combination\Nof materials to make LC3.
Dialogue: 0,0:03:19.52,0:03:24.52,Default,,0000,0000,0000,,We have already done\Nfull-scale trials in India and Cuba.
Dialogue: 0,0:03:24.54,0:03:27.60,Default,,0000,0000,0000,,In Colombia, a product\Nbased on this technology
Dialogue: 0,0:03:27.62,0:03:30.05,Default,,0000,0000,0000,,was commercialized a few months ago,
Dialogue: 0,0:03:30.07,0:03:31.53,Default,,0000,0000,0000,,and in the Ivory Coast,
Dialogue: 0,0:03:31.56,0:03:35.85,Default,,0000,0000,0000,,the full-scale plant\Nis being commissioned to calcine clays.
Dialogue: 0,0:03:36.22,0:03:39.19,Default,,0000,0000,0000,,And many of the world's\Nlargest cement companies
Dialogue: 0,0:03:39.21,0:03:43.06,Default,,0000,0000,0000,,are looking to introduce this\Nin some of their plants soon.
Dialogue: 0,0:03:43.51,0:03:47.27,Default,,0000,0000,0000,,So the possibility to replace\NPortland cement
Dialogue: 0,0:03:47.29,0:03:49.22,Default,,0000,0000,0000,,with a different material --
Dialogue: 0,0:03:49.25,0:03:53.63,Default,,0000,0000,0000,,but with the same properties,\Nproduced in the same processes
Dialogue: 0,0:03:53.66,0:03:55.62,Default,,0000,0000,0000,,and used in the same way,
Dialogue: 0,0:03:55.64,0:03:58.38,Default,,0000,0000,0000,,but with much lighter carbon footprint --
Dialogue: 0,0:03:58.40,0:04:01.78,Default,,0000,0000,0000,,is really crucial\Nto confront climate change
Dialogue: 0,0:04:01.80,0:04:06.66,Default,,0000,0000,0000,,because it can be done fast\Nand it can be done on a very large scale
Dialogue: 0,0:04:06.68,0:04:09.03,Default,,0000,0000,0000,,with the possibility to eliminate
Dialogue: 0,0:04:09.05,0:04:14.13,Default,,0000,0000,0000,,more than 400 million tons\Nof CO2 every year.
Dialogue: 0,0:04:15.13,0:04:17.54,Default,,0000,0000,0000,,So we can't do without concrete,
Dialogue: 0,0:04:17.56,0:04:22.20,Default,,0000,0000,0000,,but we can do without a significant amount\Nof the emissions it produces.
Dialogue: 0,0:04:22.75,0:04:23.96,Default,,0000,0000,0000,,Thank you.