科学美国人60秒 新的混凝土配方可以减少道路裂缝

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There's a stretch of highway in Pennsylvania, along U.S. 422. "And like every probably 20 feet you see a big pothole¹ or cracking at the joint². Like everywhere. It was so bad." Yaghoob Farnam is a construction materials engineer at Drexel University in Philly. And this road is pretty much his worst nightmare. "Yeah and just imagine I was driving like 60 miles per hour, I could see, I could feel it, I was driving, I was so mad, like, 'what is going on with this?'"

宾夕法尼亚州有一段美国422号高速公路的延伸路段。“几乎每隔20英尺，你就会在接合处看到一个大凹坑或者裂化。它们好像无处不在。而这真是糟透了。”雅各布·法南姆是费城德雷塞尔大学的一名建筑材料工程师。这条路对他来说简直是最可怕的噩梦。“想象一下，我以时速60英里的速度在这条路上行驶，我能看到、感觉到这些凹坑，而我正在开车，而且感到非常生气，恨不得冲它吼‘这条路到底是怎么回事?’”

The culprit, he says, may be calcium³ chloride road salt, used to de-ice highways in the winter. Because calcium chloride reacts with a compound in concrete called calcium hydroxide to form something called calcium oxychloride. "It's a huge molecule⁴ that causes a lot of pressure inside concrete. And starts degradation⁵ of concrete."

法南姆说，罪魁祸首可能是用以冬季公路除冰的氯化钙路盐。由于氯化钙会与复合混凝土中一种叫做氢氧化钙的物质发生反应，从而形成一种叫做氯氧化钙的物质。“这是一种会给混凝土造成很大压力的巨大分子，并且会使混凝土开始降解。”

The solution? Novel blends of concrete that use cheap leftover⁶ materials from the coal and steel industries: fly ash, silica fume⁷ and slag⁸. In his latest work, Farnam and his team created plugs of these experimental concretes, and submerged them in salty solutions—along with plugs of conventional concrete. Then they eavesdropped⁹ on any cracking with high-sensitivity acoustic¹⁰ sensors¹¹. And they tracked heat flow through the material, to monitor chemical reactions.

解决方案？——使用来自煤炭和钢铁工业中廉价的剩余材料——粉煤灰、硅粉和矿渣的新型混凝土混合物。在其最新研究中，法南姆和他的团队发明了这些实验混凝土堵头，并将其与传统混凝土堵头一起浸入含盐的溶液中。然后，他们通过高灵敏度的声传感器对裂化声进行窃听，并通过这些材料进行热流量跟踪，以监测化学反应。

The results: concrete slugs made with ingredients like fly ash and slag held up remarkably¹² well after more than a month. Whereas normal concrete was cracked to pieces in just a week. Their recipes are in the journal Cement and Concrete Composites.

结果显示:用粉煤灰和矿渣等原料制成的混凝土块，一个多月后质地仍保持得很好，而普通混凝土仅在一周内就裂成了碎片。他们的制作配方发表在《水泥和混凝土复合材料》杂志上。

Farnam says some states have actually started using this sort of concrete—because it's already known to make the material more durable¹³ against other factors, like corrosion¹⁴ of internal steel reinforcement. As for those cracks on U.S. 422, and elsewhere? Farnam has another project in the works—to apply a bacterial¹⁵ slurry, which forms limestone¹⁶ when it interacts with salt, plugging up the gaps. But he says that work is still a ways…down the road.

法南姆表示，其实一些州已经开始使用这种混凝土了，因为相对其他因素——例如钢筋内部腐蚀，它能使材料更耐用的特性已被人们熟知。至于美国422号公路和其他公路上的裂痕？法南姆正在进行另一个项目——即填涂能与盐相互作用形成石灰石的细菌泥浆，从而封堵开裂处。不过他表示，该项目仍然……还在进行中。

1 pothole   

n.坑，穴

参考例句：

• As the car sped over a pothole she lurched forward.车子飞驶过一个坑洼时，她身子猛地向前一倾。
• The young teacher knows every pothole in the 10-minute ride to school.这位年轻的老师熟悉这条往学校的10分钟路上的每一个坑洞。

2 joint   

adj.联合的，共同的；n.关节，接合处；v.连接，贴合

参考例句：

• I had a bad fall,which put my shoulder out of joint.我重重地摔了一跤，肩膀脫臼了。
• We wrote a letter in joint names.我们联名写了封信。

3 calcium   

n.钙(化学符号Ca)

参考例句：

• We need calcium to make bones.我们需要钙来壮骨。
• Calcium is found most abundantly in milk.奶含钙最丰富。

4 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

5 degradation   

n.降级；低落；退化；陵削；降解；衰变

参考例句：

• There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。
• Gambling is always coupled with degradation.赌博总是与堕落相联系。

6 leftover   

n.剩货，残留物，剩饭；adj.残余的

参考例句：

• These narrow roads are a leftover from the days of horse-drawn carriages.这些小道是从马车时代沿用下来的。
• Wonder if that bakery lets us take leftover home.不知道那家糕饼店会不会让我们把卖剩的带回家。

7 fume   

n.(usu pl.)(浓烈或难闻的)烟，气，汽

参考例句：

• The pressure of fume in chimney increases slowly from top to bottom.烟道内压力自上而下逐渐增加，底层住户的排烟最为不利。
• Your harsh words put her in a fume.你那些难听的话使她生气了。

8 slag   

n.熔渣，铁屑，矿渣；v.使变成熔渣，变熔渣

参考例句：

• Millions of tons of slag now go into building roads each year.每年有数百万吨炉渣用于铺路。
• The slag powder had been widely used as the additive in the cement and concrete.矿渣微粉作为水泥混凝土的掺和料已得到广泛应用。

9 eavesdropped   

偷听（别人的谈话）( eavesdrop的过去式和过去分词 )

参考例句：

• He eavesdropped on our conversation. 他偷听了我们的谈话。
• He has just eavesdropped two sweethearts. 他刚刚偷听了两个情人的谈话。

10 acoustic   

adj.听觉的，声音的；(乐器)原声的

参考例句：

• The hall has a fine acoustic.这个大厅的传音效果很好。
• Animals use a whole rang of acoustic, visual,and chemical signals in their systems of communication.动物利用各种各样的听觉、视觉和化学信号来进行交流。

11 sensors   

n.传感器，灵敏元件( sensor的名词复数 )

参考例句：

• There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
• Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时，有很大变化。 来自辞典例句

12 remarkably   

ad.不同寻常地，相当地

参考例句：

• I thought she was remarkably restrained in the circumstances. 我认为她在那种情况下非常克制。
• He made a remarkably swift recovery. 他康复得相当快。

13 durable   

adj.持久的，耐久的

参考例句：

• This raincoat is made of very durable material.这件雨衣是用非常耐用的料子做的。
• They frequently require more major durable purchases.他们经常需要购买耐用消费品。

14 corrosion   

n.腐蚀，侵蚀；渐渐毁坏，渐衰

参考例句：

• Corrosion is not covered by the warranty.腐蚀不在保修范围之内。
• Zinc is used to protect other metals from corrosion.锌被用来保护其他金属不受腐蚀。

15 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。

16 limestone   

n.石灰石

参考例句：

• Limestone is often used in building construction.石灰岩常用于建筑。
• Cement is made from limestone.水泥是由石灰石制成的。