William E. Ward

“ Instead of using sand and gravel, or both, in combination with cement, for floor and roof construction, the preliminary experiments that proved the superior value of broken blue-stone for massive work, led to the adoption of washed, fine screenings from the same material for the floors and roofs, because its greater angularity insured a stronger bond in the work than could be realized by using sand and gravel. ”

“ 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. ”

“ It is the opinion of the writer that for the great majority of houses required for dwelling purposes, a system of thin re-enforced double walls, with a space of from six to ten inches between them, and re-enforced cross-connections every two or three feet apart, to unite the outer and inner walls firmly together, could be built up to thirty or forty feet in height, at a cost not exceeding that of first-class brickwork. ”

“ Yet, if the remedy is only to be found in building more thoroughly, its adoption may remain doubtful so long as the hazardous method of building, and the rates for insuring hazardous property, occupy their present relations to each other. Such radical departures from conservative ideas of building as are herein described must necessarily find a slow recognition. ”

“ The proportions of cement and coarse beach-sand and gravel, used in re-enforcing iron beams for floors and roof-supports, were one part of cement to two parts of sand and gravel. The size of the iron beam, selected for an experimental test, was a four-inch I-beam of lightest pattern, twelve feet long, weighing thirty pounds to the yard, and its safety load was limited to eleven hundred and fifty pounds. A plank mold was made the length of the iron beam, twelve inches deep by five inches wide, in the bottom of which a layer of béton was first moderately tamped down to an inch in thickness ”

“ Thus, all things considered, the thin double-wall system commends itself as embodying the desirable qualities, essential to the outer and inner wall construction of dwelling-houses, furnishing as it would a sure protection against both fire and dampness, and the means for thorough ventilation. ”

“ The bulk of the material required for the work abounds in inexhaustible quantities, and is always obtainable at moderate cost. The skill needed consists in a simple knowledge of the right proportions of material, and of its proper manipulation, which can be obtained in a half-day's practice. ”

“ The reason for placing the iron beam so near the bottom of the mold was to utilize its tensile quality for resisting the strain below the neutral axis when this composite beam was exposed to heavy loads, while the béton above this line was relied on for resisting compression from load-strain. The béton became thoroughly hardened in about thirty days, when the following tests of transverse strength were made: It was placed upon suitable supports, with a bearing of three inches at each end. A lever was adjusted so as to bring the testing-load on a knife-edge bearing at the center of the beam. ”

“ The most inexperienced laborers can do all the work of the most elaborate béton construction, excepting only the surface-finishing, and this, with all the other work, can be superintended by one competent, experienced builder. ”

“ Another great advantage realized in re-enforcing béton with iron, is that the iron overcomes its tendency to check in hardening, within useful limits, however large the surface may be, if the distribution of the iron through the work is made with ordinary good judgment. ”

“ The iron beams varied in width and weight per yard in accordance with their length and the prospective load, the largest being nineteen feet long by seven inches wide. When the combination beams were completed and ready for the floors and roofs, heavy planks were firmly placed in position and securely supported between the beams, the upper surface of these plank foundations being adjusted on a level with the top surface of the molded beams. These planks served as the bottom of the floor-molds, and, after the béton forming the floor was hardened, they were removed. ”

“ Besides the special fitness of the re-enforcing system for floors, roofs, beams, and thin walls, it is an interesting question whether the same system may not be also applicable, and advantageously extended, to a more general use in many engineering requirements—especially in situations where immense weights must be sustained, and where iron construction alone is difficult of application ”

“ Incombustible materials are easily obtained, and, for every apparent reason, much better adapted to the purpose. Doubtless, the question of increased cost, both in money and in time required for more thorough construction, may be in a measure responsible for the tardiness in adopting safer methods ”

“ It is not asserted that its economic results per pound of coal are greater than those claimed for the steam or hot-water systems, but, if the latter were required to make as liberal provision for the renewal of fresh air in the interest of an equally good ventilation, the percentage of useful results per pound of coal from steam or hot water would average no higher than by this method. ”

“ They withstood this test without showing a decidedly damaging fracture, and one of the bricks was exposed to an alternate heating and cooling three times before breaking up.
These results were a surprise, and they suggest the advantage of using such a material for the walls of buildings, as a sure defense against uncontrollable conflagrations. The facts that appear to be established by the line of experiments are:
⁠1. That a system of iron beams re-enforced with béton can be made to sustain weights many times greater than the iron beams alone can bear without re-enforcing. ”

“ This comprises about the whole system of arrangements in the construction for warming the house with heat radiated from the floors and interior walls.
Its mode of operation simply consists in the body of warmed air passing from the heating-chamber upward, through the walls and under the floors, and in its passage giving up its surplus heat to the surfaces of these flues. As the air becomes reduced in temperature, it naturally descends through the pipe and trunk passage-ways provided for its return to the heating-chamber, where it is again recharged with heat. ”

“ Besides an equal economy in the construction, such double walls would be an incomparably better defense against stormy weather than the best quality of brick-work, because the absorptive capacity of béton is so much less than that of brick. ”

“ The beams for supporting the floors throughout the house were placed at such convenient distances apart as to insure perfect safety to the floors, and at the same time afford ample opportunities for producing the best effects in deep, paneled ceilings. ”

“ The writer has heretofore declined to make any public statement concerning the experiments herein described, for the reason that he considered that they ought to undergo thoroughly satisfactory tests of severe weather exposures, and varying temperatures, through a period of time long enough to determine their true and relative value. ”