2023年01月19日 VOA慢速英语：研究人员找到罗马混凝土强度的原因

Researchers have wanted to know for years why the buildings made by the ancient Romans held up so well.
多年来，研究人员一直想知道为什么古罗马人建造的建筑如此坚固。
 
A new study finds that their concrete, a strong building material, had special characteristics.
一项新的研究发现，他们的混凝土是一种坚固的建筑材料，具有特殊的特性。
 
Researchers say the materials in the concrete worked together to make it stronger.
研究人员说，混凝土中的材料共同作用使其更坚固。
 
The three main parts were lime, volcanic ash and water. Lime is a powdery substance that comes from heating limestone.
三个主要部分是石灰、火山灰和水。石灰是一种粉状物质，来自加热石灰石。
 
Admir Masic is a civil and environmental engineering professor at Massachusetts Institute of Technology (MIT) who led the study and published the results in Science Advances. He said the way the Romans started using lime over 2000 years ago gave the concrete "self-healing" properties.
Admir Masic 是麻省理工学院 (MIT) 的土木与环境工程教授，他领导了这项研究并将结果发表在《科学进展》上。他说，罗马人在 2000 多年前开始使用石灰​​的方式赋予了混凝土“自我修复”的特性。
 
He said the discovery will help current builders improve their concrete "through a Roman-inspired strategy." Masic is working to make a new building product based on the Roman concrete and is hoping to sell it through a new business he started.
他说，这一发现将帮助当前的建筑商“通过受罗马启发的 策略”改进他们的混凝土。Masic 正在努力制造一种基于罗马混凝土的新建筑产品，并希望通过他开始的新业务来销售它。
 
Masic and his researchers wanted to know why the Roman structures lasted so long when even some modern concrete crumbles after only a few years.
Masic 和他的研究人员想知道为什么罗马建筑能持续这么久，而即使是一些现代混凝土也只用了几年就崩溃了。
 
In addition, the Roman concrete was good for use underwater. This quality helped the Romans build harbors and other structures that could hold back the ocean.
此外，罗马混凝土非常适合在水下使用。这种品质帮助罗马人建造了港口和其他可以阻挡海洋的结构。
 
The researchers said some small bits of lime that were not well mixed into the concrete were not a mistake as was thought earlier. The pieces of lime are called clasts. The new study called the clasts "instrumental."
研究人员说，一些没有很好地混合到混凝土中的小石灰并不像之前认为的那样是错误的。石灰块称为碎石。这项新研究称这些碎屑是“工具性的”。
 
Masic said the small pieces of lime keep the concrete from falling apart when it cracks. In most cases, a crack in concrete permits water to enter and the crack widens. But, in the Roman concrete, the small bits of lime would dissolve and send small pieces of calcium into the cracks. That action, Masic said, repaired the cracks. In addition, he noted, the calcium mixed with the volcanic ash to create a stronger structure.
Masic 说，小块的石灰可以防止混凝土在开裂时散开。在大多数情况下，混凝土中的裂缝允许水进入并且裂缝变宽。但是，在罗马混凝土中，小块石灰会溶解并将小块钙送入裂缝中。马西奇说，这一行动修复了裂缝。此外，他指出，钙与火山灰混合形成了更坚固的结构。
 
Both the Pantheon and the Colosseum are examples of buildings that are almost 2000 years old that used the ancient concrete and are still standing today.
万神殿和斗兽场都是具有近 2000 年历史的使用古老混凝土建造的建筑的例子，至今仍屹立不倒。
 
In the past, researchers thought the important material was volcanic ash that came from the area of Pozzuoli, near Naples.
过去，研究人员认为重要的材料是来自那不勒斯附近的波佐利地区的火山灰。
 
Linda Seymour helped write the study when she was studying at MIT. She called the ancient Romans "great engineers." She added: "The fact that we can still walk around many of their structures is a testament to that."
琳达·西摩 (Linda Seymour) 在麻省理工学院学习期间帮助撰写了这项研究。她称古罗马人为“伟大的工程师”。她补充说：“我们仍然可以绕过他们的许多建筑这一事实证明了这一点。”