340 COX, REIBLING, AND REYES. 
TABLE XI.—Sand-lime brick made with a mixture of equal parts of Tarlac 
and beach sand. 
1 
| 
Degree of fineness in per cent Per- Compressive 
through the specified sieves. cent- strength. 
| os Molding 
Mix- | water |Pressure 
ture added| _ P& Remarks. 
No. to the| Sauare Per 
No. 20.|No. 40.|No. 80./No. 100.| No. 200.) yay inch. | Total. | square 
| mate- inch. 
| rials | 
Pounds. | Pounds. | Pounds Ri NED one 
a14| 95.7] 62.1] 49.4 33.7 8.4 8.0 7, 640 7,920 | 1,980 | mresnedtontntnes 
14] 95.7] 62.1) 49.4 83.7 8.4] 8.0} 10,000} 18,360) 3,340 ing the molding: 
| | About 10 per cent 
b15| 95.7] 62.1} 49.4 33.7 8.4 15.0 7,640 | 14,040 | 3,510 of the water was 
15 | 95.7} 62.1) 49.4 33.7 8.4) 15.0} 10,000} 16,620) 4,155 pressed out dur- 
| |- ing the molding. 
Molding pres- Density. | Absorption after 24 hours in water. 
Mixture | sure in pounds e 
No. per square 
inch. Air dry. Dried at 110°. Air dry. Dried at 110°. 
15 7, 640 2.11 2.09 6.5 7.7 
15 10, 000 2.19 2.14 4.9 7.5 
[ees 
8 A comparatively dry mixture. bA comparatively wet mixture. 
Fig. 5, Plate VII, is a photograph of a brick made from mixture 
15, after it had been subjected to the fire test. It remained 
perfectly sound. 
Orani sand.—At the mouth of the Orani River, about 55 
kilometers northwest of Manila and directly across Manila Bay, 
there is an abundance of good sand which can be secured with- 
out dredging. The river can be entered by launches, and at 
low tide the sand can be loaded directly into barges and, with- 
out rehandling, towed to Manila. Orani sand is very similar 
to that from Tarlac except that it is less clean and its color is 
less attractive. Otherwise, it is as good as Tarlac sand for the 
manufacture of sand-lime bricks. We obtained a strength of 
3,238 pounds per square inch with Orani sand when the molding 
pressure employed was only 4,600 pounds per square inch. 
Volcanic tuff, unusually abundant in Bulacan and along 
the Pasig River, especially near Guadalupe, is another avail- 
able source of siliceous material in the vicinity of Manila. It 
is a fragmental material which contains pieces of scoria, basaltic 
pebbles, and voleaniec ash in varying and nonuniform propor- 
tions, and it is easily crushed. When mined, it is so soft that 
it can be quarried with an ax, but it hardens rapidly on ex- 
posure to the air. There are two grades of this water-laid 
