Page:Popular Science Monthly Volume 23.djvu/632

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that, if iron is well protected by a heavy clothing of béton, its integrity can be safely depended upon in almost any emergency.

When all doubts concerning the reliability of the several combinations of materials required in the construction were removed, a building, embracing the following radical new features, was erected, for dwelling purposes, near Port Chester, New York: Not only the external and internal walls, cornices, and towers of the building were constructed of béton, but all of the beams, floors, and roofs were made exclusively of béton, re-enforced with light iron beams and rods.

Furthermore, all the closets, stairs, balconies, and porticoes, with their supporting columns, were molded from the same material; the only wood in the whole structure being window-sashes and doors, with their frames, mop-boards, and the stair-rails, thus excluding everything of a combustible nature from the main construction.

Béton can be used in any form of construction, and will serve the requirements of any architectural or decorative effects. All the exterior portions of this house, which are more or less ornamental in their functions, were made of béton in place during the progress of the work. In the interior of the house, the cornices, stiles, and panels of the ceilings are formed of béton, and covered with the hard finish usual in such work. There appears to be no limit to the reproduction in béton of any form used in stone masonry or in stucco. The proportions of material composing the béton for the work varied in strength to meet the requirements of the different parts of the structure: the heavy walls needing the least proportion of cement, while the beams, floors, and roofs required a much larger proportion. Only the best quality of Portland cement, clean beach-sand, and crushed blue-stone, were used in combination with iron for constructing the building.

The proportions used for the heavy wall-work were one part of cement to four parts of sand and fine gravel, thoroughly mixed dry, and dampened with only sufficient water to give it the consistency of well-tempered molding sand.

A finely crushed and screened, hard, blue limestone was found to be better adapted for use in combination with the béton than a coarse sized stone filling, because small-sized stones pack closer than large ones, thereby realizing a proportional saving in cement. The tests made to ascertain the comparative transverse strength of different compositions proved that the bond was stronger in béton made with small stone. In breaking test-sections made of béton in the form of bricks, the fracture of those filled with small stone was almost invariably across the stone lying in the line of fracture, while the fracture of the test-bricks made with a filling of stone three or four times larger showed a frequent tearing away from the bond between the béton and the larger stone filling, the composition of the béton being the same in both cases.