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Cast stone is a concrete masonry product simulating natural cut stone, it is used in architectural applications. Cast stone is used for architectural features: trim, or ornament, for facing buildings or other structures, and for garden ornaments. Cast stone can be made from white and/or grey cements, manufactured or natural sands, crushed stone or natural gravels, and colored with mineral coloring pigments. Cast stone may replace natural cut limestone, brownstone, sandstone, bluestone, granite, slate, coral rock, travertine and other natural building stones. ==History== Cast stone has been a prime building material for hundreds of years. The earliest known use of cast stone dates about to the year 1138 at Carcassonne, France, the city which contains the finest remains of medieval fortification in Europe. Cast stone was first used extensively in London in the 19th century and gained widespread acceptance in America in 1920. Some researchers have even speculated that the Egyptian pyramids were formed using a form of cast stone, rather than from cut blocks. One of the earliest developments in the industry was Coade stone, a fired ceramic, but most artificial stone consists of fine cement concrete placed to set in wooden, rubber-lined fiberglass or iron moulds. It was cheaper and more uniform than natural stone, and widely used. In engineering projects, it had the advantage that transporting the bulk materials and casting them near the place of use was cheaper than transporting very large pieces of stone. According to Rupert Gunnis〔Dictionary of British Sculptors 1660-1851, p22〕 a Dutchman named Van Spangen set up an artificial stone manufactury at Bow in London in 1800. Having later gone into partnership with a Mr. Powell the firm was broken up in 1828 and the moulds sold to a sculptor, Felix Austin who had a premises in New Road (now Euston Road), London, England. His material was not the same as the ceramic body used by Mrs. Coade, (although he is known to have copied old Coade stone designs), but made from 'Portland cement, broken natural stone, pounded marble and coarse sand' ('The Builder', 1868, now Building (magazine)). Around 1840 Austin entered into partnership with John Seeley. Seeley had trained at the Royal Academy Schools and also made an artificial stone, which he called 'artificial limestone', before entering into partnership with Austin. In 1841 Austin and Seeley published their first catalogue, 'Collection of Ornaments at Austin & Seeley's Artificial Stone Works for Gardens, Parks and Pleasure Grounds'. The firm continued in production until about 1872. Another well-known variety was Victoria stone, which is composed of finely crushed Mount Sorrel (Leicestershire) granite and Portland cement, carefully mixed by machinery in the proportions of three to one, and filled into moulds of the required shape. When the blocks are set hard the moulds are loosened and the blocks placed in a solution of silicate of soda for about two weeks for the purpose of indurating and hardening them. Many manufacturers turn out a material that is practically non-porous and is able effectually to resist the corroding influence of sea air or the impure atmosphere of large towns. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cast stone」の詳細全文を読む スポンサード リンク
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