建筑石材(stone, building)
岩石切成块状及厚板状或碎成碎片。其可以跟花岗石一样坚硬也可以像石灰岩或是沙岩一样柔软。在可获得的情形下,石材通常是纪念性建筑物较喜爱使用的材料。其优点是耐久性,适合雕刻,以及可以在其自然状态下被使用。但是其取得、运输及切割也很困难,同时,其对张力的耐受性低也限制了他的用途。最简单的石料加工品是粗石,在研磨机中粗略地破碎的石头。方石加工品是由整齐地切割出具方形边缘之石块所组成。建筑石材的取得,如果是柔软的,即藉由锯及利用楔子使其裂开,或是如果很坚硬,即藉由爆破的方式。很多装置可以用来对石头进行塑型及调整,从手携式的工具到圆锯,表面处理机器,以及车床。一些石头够强壮到可以作为单独(单一块)的支持或梁,而在某些形式中(如:古代的埃及神殿),石头的厚片甚至被做为屋顶并以许多相近的圆柱支撑。在拱之前,建筑者皆受限於石头於其本身重量下有破碎倾向之现象。但是石头在压力下具有良好的强度,并且,罗马人建造了巨大的石头桥梁与沟渠。虽然石材在二十世纪的建筑上通常被放弃使用,但其被广泛使用以作为薄且不承受压力的表面包覆。亦请参阅masonry。
English version:
stone, building
Rock cut into blocks and slabs or broken into pieces. It comes as hard as granite and as soft as limestone or sandstone. Where available, stone has generally been the preferred material for monumental structures. Its advantages are durability, adaptability to sculpting, and the fact that it can be used in its natural state. But it is difficult to quarry, transport, and cut, and its weakness in tension limits its use. The simplest stonework is rubble, roughly broken stones bound in mortar. Ashlar work consists of regularly cut blocks with squared edges. Building stone is quarried by sawing if it is soft, and split apart with wedges or by blasting if hard. Many devices are used to shape and dress stone, from handheld tools to circular saws, surfacing machines, and lathes. Some stones are strong enough to act as monolithic (one-piece) supports and beams; and in some styles (e.g., ancient Egyptian temples) stone slabs are employed even for roofing, supported by many closely spaced columns. Before the arch, builders were handicapped by the tendency of stone to break under its own weight. But stone in compression has great strength, and the Romans built huge stone bridges and aqueducts. Though stone has generally been abandoned for structural use in the 20th century, it is widely used as a thin, nonbearing surface cladding. See also masonry.