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Concrete is all around us, but most of us don't even notice that it's there.
我们身边处处是混凝土，不过多数人不会注意到它的存在。
We use concrete to build our roads, buildings, bridges, airports; it's everywhere.
我们使用混凝土来建造道路、建筑物、桥、机场；可以说，混凝土无处不在。
The only resource we use more than concrete is water.
水是唯一比混凝土更常用的资源。
And with population growth and urbanization, we're going to need concrete more than ever.
随着人口增长和城市化的发展，我们比以往更需要混凝土。
But there's a problem. Cement's the glue that holds concrete together.
但这里有一个问题：水泥是一种把混凝土粘合在一起的胶浆。
And to make cement, you burn limestone with other ingredients in a kiln at very high temperatures.
要制造水泥，需要将石灰石和其他材料放入窑炉内进行高温烧制。
One of the byproducts of that process is carbon dioxide, or CO2.
这一过程产生的副产品之一就是二氧化碳，即CO2。
For every ton of cement that's manufactured, almost a ton of CO2 is emitted into the atmosphere.
每制造一吨水泥，就有约一吨二氧化碳释放到大气中。
As a result, the cement industry is the second-largest industrial emitter of CO2,
结果就是，水泥工业成为了第二大工业二氧化碳排放源，
responsible for almost eight percent of total global emissions.
约占全球二氧化碳排放量的8%。
If we're going to solve global warming, innovation in both cement production and carbon utilization is absolutely necessary.
如果要解决全球变暖问题，我们就必须在水泥制造和碳利用方面进行创新。
Now, to make concrete, you mix cement with stone, sand, and other ingredients,
要制造混凝土，需要将水泥与石头、沙土和其他材料混合，
throw in a bunch of water, and then wait for it to harden or cure.
加入大量的水，然后等待它固化。
With precast products like pavers and blocks, you might shoot steam into the curing chamber to try to accelerate the curing process.
使用像路砖或砌块这样的预制产品，可以将蒸汽喷进凝固室里，以加快混凝土凝固。
For buildings, roads, and bridges, we pour what's called ready-mix concrete into a mold on the job site and wait for it to cure over time.
对于建筑物、道路和桥梁，我们会在施工现场将预搅拌混凝土倒入模具，然后等待它固化。
Now, for over 50 years, scientists believed that if they cured concrete with CO2 instead of water,
50多年来，科学家始终相信，如果用二氧化碳，而不是水，来固化混凝土，
it would be more durable, but they were hamstrung by Portland cement's chemistry.
混凝土就会更耐用，但这一想法受制于生产波特兰水泥时的化学反应。
You see, it likes to react with both water and CO2, and those conflicting chemistries just don't make for very good concrete.
水泥与水和二氧化碳都能产生反应，这些相互竞争的化学反应并不能制作出优质的混凝土。
So we came up with a new cement chemistry. We use the same equipment and raw materials, but we use less limestone,
于是，我们设计了一种新的水泥化学反应。我们使用相同的设备和原料，但减少了石灰石的用量，
and we fire the kiln at a lower temperature, resulting in up to a 30 percent reduction in CO2 emissions.
并降低了窑炉的烧制温度，结果，二氧化碳的排放量减少了30%。
Our cement doesn't react with water.
我们的水泥不会与水产生反应。
We cure our concrete with CO2, and we get that CO2 by capturing waste gas from industrial facilities
我们用二氧化碳固化这种混凝土，而这些二氧化碳来自工业设施，
like ammonia plants or ethanol plants that otherwise would've been released into the atmosphere.
比如合成氨厂或乙醇厂所排出的废气，从而避免了这些废气被排放到大气中。
During curing, the chemical reaction with our cement breaks apart the CO2,
在固化期间，我们的水泥所产生的化学反应会分解二氧化碳，
capturing the carbon to make limestone, and that limestone's used to bind the concrete together.
并利用捕捉到的碳制造石灰石，将混凝土粘合在一起。
Now, if a bridge made out of our concrete were ever demolished, there's no fear of the CO2 being emitted because it doesn't exist any longer.
如果使用我们的混凝土搭建的桥被摧毁了，也不用担心它会释放二氧化碳，因为二氧化碳早就不见踪影了。
When you combine the emissions reduction during cement production with the CO2 consumption during concrete curing,
如果将水泥生产过程中减少的碳排放与混凝土固化过程中消耗的二氧化碳结合起来，
we reduce cement's carbon footprint by up to 70 percent.
水泥的碳足迹最多可降低70%。
And because we don't consume water, we also save trillions of liters of water.
而且这个过程不消耗水源，所以还能节省上万亿升的水。
Now, convincing a 2,000-year-old industry that hasn't evolved much over the last 200 years, is not easy;
不过，要说服一个拥有2000年历史，但在过去的200年里没有多大发展的行业进行变革并不容易，
but there are lots of new and existing industry players that are attacking that challenge.
好在目前有许多新的和现有的业内机构正在努力应对这一挑战。
Our strategy is to ease adoption by seeking solutions that go beyond just sustainability.
我们的策略是简化方案，寻找超越可持续性的解决方案。
We use the same processes, raw material, and equipment that's used to make traditional concrete,
我们采用了传统水泥的制作过程、原料和设备，
but our new cement makes concrete cured with CO2 that is stronger, more durable, lighter in color, and it cures in 24 hours instead of 28 days.
我们的新型水泥使用二氧化碳进行固化，得到的混凝土更坚固耐用，颜色也更淡，能在24小时内凝固，而不再需要28天。
Our new technology for ready-mix is in testing and infrastructure applications,
我们用于制作预搅拌混凝土的新技术尚处于测试和基础设施应用阶段，
and we've pushed our research even further to develop a concrete that may become a carbon sink.
而且我们进一步推动了相关研究，希望能开发出一种可以用作碳汇的混凝土。
That means that we will consume more CO2 than is emitted during cement production.
这意味着，我们在制作水泥期间，消耗的二氧化碳会比排放的更多。
Since we can't use CO2 gas at a construction site, we knew we had to deliver it to our concrete in either a solid or liquid form.
鉴于我们无法在施工地使用二氧化碳，所以必须将二氧化碳以固态或液态形式注入混凝土中。
So we've been partnering with companies that are taking waste CO2 and transforming it into a useful family of chemicals
我们一直在与一些公司合作，把二氧化碳废料转化成一系列有用的化学物质，
like oxalic acid or citric acid, the same one you use in orange juice.
比如草酸或柠檬酸，跟我们在橙汁里添加的一样。
When that acid reacts with our cement, we can pack in as much as four times more carbon into the concrete, making it carbon negative.
当这种酸性物质与我们的水泥产生反应，我们能将相当于四倍的二氧化碳注入混凝土，使它变成碳负性。
That means that for a one-kilometer road section, we would consume more CO2 than almost a 100,000 trees do during one year.
这就意味着，对于一个一公里的路段，我们所消耗的二氧化碳比10万棵树在一年内消耗的还要多。
So thanks to chemistry and waste CO2, we're trying to convert the concrete industry,
利用化学反应和二氧化碳废气，我们正试图将混凝土，
the second-most-used material on the planet, into a carbon sink for the planet. Thank you.
这个地球上用量第二大的材料，转变为地球的碳汇。谢谢。
