336 COX, REIBLING, AND REYES. 
TABLE VIII.—Pasig sand and its efficiency as a sand-lime brick material. 
° Content of silica. | 
Soluble 
Description and classification. : Solublein 
: in bydro-\" sodium Total 
chlorie Quartz. no) 
jcarbonate silica. 
(aah, | Na2C0s) 
Per cent. \ Per cent.| Per cent.\ Per cent. 
A clean, rounded, pebble sand derived principally from 
andesite and basaltic rocks. Quartz is present in 
amounts up to 12 per cent, and iron minerals are also 
more or less abundant. The prevailing color is a dark 
Slate: i. 2 252.2228 2tecs-22¢en22 2ascae es era teceee ccs! ersonis 18. 43 11.20 62. 72 
GRANULARIMETRIC COMPOSITION. 
SieveiNos we-c22 tess ase Sees 10 20 30 40 50 60 80 | 100 200 
Per cent of sand passing 
through specified sieves | a99.5) 99.0} 95.0] 71.0] 36.0] 20.5) 10.0] 2.0 | trace 
b96.0 | 64.0) 42.0) 38.0] 23.5) 10.0 5.0] 2.6 | trace 
THE SAND-LIME BRICK. 
Degree of pulverization in per cent through Compressive 
specified sieves. Daseton| Molding strength. 
Mixture of steam | Pressure 
No. ‘ treat- wae 
Pena square Per 
No. 20. | No. 40. | No. 80. | No. 100. | No. 200. , inch. Total. pquare 
inch. 
Hours. | Pounds. | Pounds. | Pounds. 
5 100.0 84.0 55.4 46.5 18.6 5.5 2,300 5, 980 1,495 
5 100.0 84.0 65.4 46.5 18.6 5.5 4, 600 10, 800 2,700 
6 89.4 67.7 23.7 16.5 11.7 8.0 7, 640 12, 720 38, 180 
6 89.4 57.7 23.7 16.5 11.7 8.0 10, 000 18, 640 8, 410 
e7 91.6 65.8 83.7 24.7 13.2 8.0 7, 640 17, 000 4, 250 
7 91.6 65.8 33.7 24.7 13.2 8.0 10, 000 21,280 5, 320 
8 99.6 72.9 40.4 37.4 20.0 8.0 7, 640 19, 040 4,760 
8 99.6 72.9 40.4 37.4 20.0 8.0 10, 000 23, 740 5, 935 
Molding pres- Density. Absorption after 24 hours in water. 
Mixture | sure in pounds 
oO. per square 
inch. Air dry. Dried at 110°. Air dry. Dried at 110°. 
vi 7, 640 2.24 2.15 6.1 10.5 
7 10, 000 2.28 2.19 4.3 oa 
©8 7, 640 2.28 2.13 5.2 10.1 
8 10, 000 2.30 2.17 3.6 9.4 
8 Dipped up in baskets. » Gravel screenings from dredges. ¢ Ground finer than No. 6. 
Strong and dense sand-lime bricks are much more readily 
obtained with Pasig than with beach sand, and this is especially 
