经济学人下载:治愈混凝土癌症(2)

To get around this the team have worked out how to minimise cost by using carbon-fibre rebars only where strictly necessary.
为了解决这个问题，该团队研究出了如何通过只在必要的地方使使用碳纤维钢筋的方式来降低成本。

In other places they use glass fibre, which is cheaper.
他们在其他的地方会使用更便宜的玻璃纤维。

The result is a frame that acts as a skeleton for precast concrete sections which can then be assembled into a bridge.
结果是一个框架作为预制混凝土部分的骨架，然后可以组装成一座桥。

According to Mahbube Subhani, one of the researchers at Deakin,
根据迪肯大学的一位研究人员Mahbube Subhani，

a three-metre long version of such a section has just been tested and has passed local building codes.
这样一个三米长的版本刚刚经过测试，并通过了当地的建筑法规。

The group is now pressing ahead with the first of the ten-metre sections needed to construct the bridges themselves.
该团队现在正在抓紧建造桥梁所需的10米长截面的第一部分工程。

The new castings are, as was hoped, both stronger and lighter than steel-reinforced concrete.
正如所希望的那样，新铸件比钢筋混凝土更坚固，也更轻。

Tests showed that the prototype's load-carrying capacity was 20% better, even though its cross-section was 15% smaller.
测试表明原型的承载能力提高了20%，尽管横断面小了15%。

Production costs are "a little bit higher", Dr Subhani admits. But in the long run, he says,
Subhani博士承认建造成本要“稍微高一点。”在从长远来看，他表示，

the bridges will work out cheaper because they should last for at least 100 years without any maintenance being required.
这些桥梁会更加便宜，因为在无需养护的情况下，它们至少可以使用100年。

They will also be more environmentally friendly, for the concrete surrounding the skeleton is unconventional, too.
它们也会更加环保，因为骨架周围的混凝土也不是传统的混凝土。

Normal concrete is bound with Portland cement, which is made by roasting a mixture that includes limestone (calcium carbonate).
普通的混凝土与硅酸盐水泥结合在一起，硅酸盐水泥是通过焙烧含有石灰石的（碳酸钙）混合物制成。

This process drives off carbon dioxide, a greenhouse gas, and cement-making is a big source of such emissions.
这一过程会排出一种温室气体—二氧化碳，而水泥制造是这种排放的一大来源。

Geelong's bridges, by contrast, will be made with geopolymer concrete.
相比之下，吉朗的桥梁将采用无机矿物聚合物混凝土。

This uses cement made from a different mixture of ingredients, including furnace fly-ash, which do not release carbon dioxide when being processed.
这种方法使用的是由不同成分混合而成的水泥，包括在加工过程中不会释放二氧化碳的炉灰。

Further down the line Deakin's researchers are looking into making rebars out of basalt, an abundant volcanic rock,
再往下，Deakin的研究团队正在研究如何从玄武岩中（一种储量丰富的火山岩）提取钢筋，

by melting it and extruding it into fibres.
方法是将其融化并压制成纤维。

That could provide a cheaper and greener alternative to carbon fibres, which are usually made from oil-based polymers.
这可能为碳纤维提供一种更便宜、更环保的替代品，而碳纤维通常是由石油聚合物制成的。

Some commercial basalt-fibre composites are already available,
一些商业化的玄武岩纤维复合材料已经有了，

but the team think they can improve the performance of such fibres further, by adding other materials.
但是研究团队认为他们可以通过添加其他材料来进一步提高这种纤维的性能。

Coincidentally, one of the ingredients of the Pantheon's concrete dome is pumice, another volcanic rock.
巧合的是，万神殿混凝土圆顶的成分之一是浮石，另一种火山岩。

Whether basalt-fibre concrete will similarly stand the test of time only future architects will know.
玄武岩纤维混凝土能否经受住时间的考验，只有未来的建筑师才能知道。