SAND-LIME BRICK. 323 
and shape. These blocks are of the consistency of soft chalk 
when they leave the press, and since they are homogeneous they 
can be easily and rapidly shaped with saws and cutting tools. 
After being cut or carved to any required design, the material 
is dried at a temperature of 40° to 50° and placed in steel tanks 
from which the air is exhausted; carbon dioxide previously 
expelled from dolomite is then admitted by successive stages 
together with some steam until the carbonation of the hydrate 
of lime is complete. The stone is then ready for sale, unless 
sanding or gritting is desired. 
Any kind of sedimentary rock, whether granular or meta- 
morphic, can be reconstructed by this process which converts 
both hard and soft, perfect and imperfect, natural products into 
uniformly hard and durable stone of superior quality and ap- 
pearance. Quarry débris is preferable to ordinary rock only 
because of the difference in the state of pulverization. It would 
be too expensive to crush hard rock solely for this purpose, but 
there are many soft stones in the Philippines which crush so 
easily that the cost would not be prohibitive. 
Information regarding the durability of reconstructed stone 
is not available, but the bonding is unquestionably uniform 
and complete throughout the mass, which indicates that it should 
weather with uniformity and prove durable even under very 
severe atmospheric conditions. The resistance to crushing stress 
of 3-inch cubes of reconstructed stones is given in Table II. 
TABLE II.—Crushing strength of reconstructed Bath stone." 
Total strength in Average strength in Average strength in 
pounds. ‘pounds per square inch.| tons per square foot. 
Test 
No | stent Slightly | Slightl 
lightly ightly ‘ ightly 
cracked. | Ctushed. | cracked. | Crushed. | cracked. | Crushed. 
2424 109, 600 127, 700 11, 264 18, 124 724.4 844.0 
2422 96, 700 120, 100 9, 938 12, 348 639.1 7193.8 
2623 84, 000 98, 200 8, 571 10, 020 551.2 644.4 
ao Sera 96, 765 115, 333 9, 924 11, 829 638. 2 760.7 
8 Tests made by David Kirkaldy and Sons, London, England, and published in the manu- 
facturers’ pamphlet, ‘““About Reconstructed Building Stones and Marble.” 
The poor fire-resisting properties of this stone are detrimental 
to its efficiency as a constructive material. The binder is prin- 
cipally calcium carbonate, and a red heat will cause disinte- 
gration. 
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