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In a few hours, this sloppy wet concrete will harden into a solid, which, after a few days will be strong enough to hold many tons of weight.
在几个小时内，这种潮湿的混凝土会变硬成固体，几天后，它将足够坚固，可以承受许多吨的重量。
Pasta also starts in a moist amorphous state, hardens after a few hours, and it can also hold a lot of weight.
意大利面也是在潮湿的无定形状态下开始的，几小时后变硬，它也能承载重量。
But there's an important difference between capellini and concrete – noodles dry out
但是天使细面和混凝土之间有一个重要的区别——面条会干
(which you can tell because when you add water, they re-absorb it and become soft again),
（这个你能够看出来，因为当你加入水的时候，它们会重新吸收，再次变得柔软），
while concrete sets (you can pour as much water on it as you want, and it won't become soggy -
而混凝土会凝结（无论你往上浇多少水，它都不会被浸湿——
which is good because you don't want buildings and bridges to get soggy when it rains).
这一点很好，因为你也不希望在下雨时，建筑物和桥梁被浸湿）。
The distinction is that when pasta is made, water simply evaporates out of the dough,
不同之处在于，在做意大利面时，水会从面团中蒸发出来，
leaving behind a desiccated, starchy scaffolding with plenty of holes and gaps ready to re-absorb water in the future and re-soften the dough.
留下一个干燥的、淀粉质的支架，上边有很多小孔和缝隙，为了在将来重新吸收水分和重新软化面团而做准备。
When concrete sets, on the other hand, calcium oxide, silicon dioxide and other molecules in the cement
另一方面，混凝土凝结时，水泥中的氧化钙、二氧化硅和其他分子
chemically combine with water molecules to create new compounds like calcium silicate hydrate.
与水分子发生化学反应，生成像水化硅酸钙这样的新化合物。
These molecules grow into crystalline fibers that bond with each other and literally cement together rock, sand, metal or whatever else you put into the mix.
这些分子成长为相互结合的晶体纤维，并将岩石、沙子、金属或其他任何你放入混合物中的东西粘合在一起。
So when concrete hardens, it's not drying out, because water isn't leaving it – water is reacting with and becoming PART of the cement.
所以当混凝土变硬时，它并没有变干，因为水没有离开它——水与水泥发生反应，并成为了水泥的一部分。
In fact, concrete continues to set for months and even years after it's poured,
实际上，在浇筑几个月甚至几年之后，混凝土还会继续凝结，
increasing in strength over time and enabling the construction of miraculously strong and durable structures,
随着时间的推移，混凝土的强度会不断增加，从而能够建成异常坚固耐用的结构，
like the 2000 foot tall CN Tower in Toronto or the 2000 year old Pantheon in Rome.
比如多伦多的2000英尺高的加拿大国家电视塔，或者拥有2000年历史的罗马万神殿。
