书城外语英国学生科学读本
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第44章 砖是怎么做出来的

1.We know that bricks are made of burned clay;but let us try to learn something more about them.Have you ever measured a brick?Ifyou do so,you will find that its length is nine inches,its breadth four and a half inches,and its thickness three inches.A good brick should weigh seven pounds.

BRICK(砖)

2.Notice what a regular shape the brick has,with its flat sides and its straight edges.It is because bricks are so regular①in shape,in size,and in weight,that they make such a good material②for building houses.

3.Let us go to a brick-field and watch the men while they are at work.Some men dig the clay,while others pick out anyBRICK-LAYERS(砖瓦匠)large stones that may be in it.

①Regular,made according to fixed rule.

②Material,that out of which a thing is made.

The clay is then moistened①with water,and ground in a kind of mill until it becomes a smooth paste.

4.It is then moulded by being pressed into wooden boxes of the right size and shape.The moulded bricks are next piled on barrows,and wheeled away to a field where they are laid in rows in the open air under low sheds.They are left here to dry for a few weeks.

5.In hot countries bricks are

BRICK-MAKING(砖的制造)

often used which have simply been dried in the sun in this way.But these sun-dried bricks will not stand much rain:the water soaks into them,and they once more become lumps of soft clay.

6.The reason of this is that there is not only water in the pores of the clay,there is also water united②with the clay itself,and this water can only be got rid of by the strong heat of a fire.So thebricks,after being dried in the air,are placed in a kiln.Fires are lighted beneath the kiln,and the bricks are baked or burned in it for some time.

7.Most bricks turn red when burnt.That is owing to the fact that the clay from which they were made contained a very little iron,and the burning changed this iron into iron-rust,which is of a red colour.

8.Bricks will stand a great heat without melting,especially③those made from a kind of clay which is called fire-clay.Such bricks are called fire-bricks,and they are used for the backs and sides of fire-places,and for building furnaces in which metals are to be melted.

①Moistened,made moist or slightly wet.

②United,combined;mixed.

③Especially,chiefly.

SUMMARY

Bricks .are made from clay,which is freed from stones,moistened with water and ground to a fine paste,and then moulded into the shape of bricks.These bricks are first dried in the open air.They are then baked in a kiln,after which they are ready to be used for building.Their red colour is due to a little iron-rust being found in the clay.Bricks are all of a regular shape,size,and weight.

【中文阅读】

1.我们知道,砖是由烧制的粘土做的。不过,我们再来学点儿关于砖的新知识吧!你量过砖的尺寸吗?量一下,就会发现长度是9英寸,宽度是4.5英寸,高度是3英寸。一块好砖的重量应该是7磅。①2.请注意,砖的形状非常规则,几个边都是平的,几个棱也都是直的。因为砖在形状、大小、重量上都非常标准,所以才成了修建房屋的好材料。②3.咱们去砖瓦厂看看工人的工作。有些工人,把粘土挖出来;另外一些工人,把里面可能有的大石头挑出来;然后把粘土用水弄湿,在一种磨粉机(mill)里面碾碎,最后粘土变成了一种细细的糊状物。③4.然后把这种糊状物,填进木匣子,木匣子的尺寸和形状,都正好是砖的尺寸和形状。④下一步,把完成了“坯体成型”的砖,堆到手推车上,运到另外的一片地方,把这些砖一排排放在露天,用低矮的棚子遮起来,放上几天,让砖干燥。⑤5.在炎热的地区,以前经常把砖直接在太阳底下晒干。但是用太阳晒干的砖经不住水,水会渗进砖里,砖就又变回了软软的粘土块儿。⑥6.这是因为,不只有粘土的孔洞里才有水,还有跟粘土融合在一起的水,这种水,只有用火焰的高热才能去掉。所以,在空气中晾干之后,砖坯就运进了砖窑,在砖窑底下烧起火来,把砖坯烤上或烧上一段时间。⑦7.大多数砖在烧过以后,都会变成红色。这种变化的原因是,砖的原料--粘土含有很少的铁,烧砖的过程,把这些铁变成了铁锈,铁锈是红色的。⑧8.砖可以承受很高的温度而不熔化,特别是那些用“耐火粘土”做的砖。这样的砖就叫做“耐火砖”,用来做壁炉的后面和两个侧面,还用来做熔化金属的熔炉。⑨译注①这个尺寸换算成公制是225×112.5×75毫米。现代英国的砖,加上砌砖用的灰缝厚度,依然是这个尺寸。单纯的砖的尺寸,是215×102.5×65毫米。现代中国的烧结普通砖,最常见的尺寸是240×115×53毫米,这样,灰缝的厚度,4块砖的长度是1米,8块砖的宽度是1米,16块砖的厚度也是1米,每一立方米要用512块砖。

②这里的“成了”原文是make,不是“制作”的意思,而是“有资格成为”的意思,是一种比较旧的用法。

③这相当于现代工艺里的第一道工序“原料制备”,也叫“坯料调制”,目的是破坏粘土的原始结构,粉碎大块原料,除去杂质,做成均匀的坯料,含水率是15%-25%。

④这相当于第二道工序“坯体成型”。用木匣子的成型办法叫做“模压法”,现代工艺用钢模代替了木匣子。此外,还有“塑性法”,用“挤泥机”把坯料挤成泥条,再切割成一块一块符合尺寸的砖形坯料。

⑤这相当于第三道工序“湿坯干燥”。现代工艺中,除了这种自然干燥法,还有人工干燥法,把湿坯放进人工干燥室中,用砖窑的余热或者热风炉干燥,目的是把湿坯的含水率降到6%以下,为烧砖做准备。

⑥这种方法制造的砖,最早可以追溯到9500年前的“泰尔·阿斯瓦德”新石器遗址(Tell Aswad,现在的叙利亚的西南部)。后来,古埃及等文明也使用过这种办法。

⑦这相当于第四道工序“成品焙烧”。“粘土孔洞里的水”就是上一课注释里提到的“自由水分”,“跟粘土融合在一起的水”,指的是粘土矿物的结晶水,在500-700摄氏度的时候才能除去。烧砖的温度大约在900-1000摄氏度。

⑧具体地说:烧砖时,砖窑里有空气流通,空气中的氧气和粘土中的铁发生反应,生成了氧化铁,也就是俗称的铁锈。氧化铁是红色的,所以砖也就是红砖了。但中国传统上还有另一种生产方式,就是向砖窑里加水,砖窑的高温会让水变成水蒸气,阻止空气流通;这时铁和氧气反应,发生不完全氧化,生成的是青灰色的氧化亚铁,于是就制造出了“青砖”。现在这种方法经过改进,制造出来的青砖叫“仿古青砖”。青砖的工艺比较麻烦,所以现在生产得比较少,但青砖在抗氧化等方面的性能比红砖好,一般用于装饰和仿古建筑。此外,砖如果发白或者发黄,是因为砖里含有石灰的缘故。

⑨进入20世纪,砖因为生产过程需要消耗大量资源,而且抗震性能不强,正在逐渐被混凝土代替。

THE FLAT FISH CALLED THE SOLE