STRENGTH OF BRICK MASONRY The strength of brick is some indication of the strength of the masonry made from it, but the mortar and the svorkmanship must also be taken into account in making comparisons.
Table XTTT gives results of some recent tests of brick columns made of brick similar to those referred to in Tables XI and XTT. The columns were inches square, and were from 40 to 43 courses of brick high. The letters at the left refer to groups of several tests. Group H is of under-burned clay brick. The load in C was applied one inch from the center.
of sand, lime, or cement depends on the rich ness of the mortar and the thickness of the joints.
Table XIV gives the necessary amount of sand and cement to lay 1,000 bricks with joints about inch thick.
Stated otherwise, a cubic yard of brick masonry with joints requires rather more than of a cubic yard of mortar. If the joints are inch thick, cubic yard of mortar will be sufficient to lay a cubic yard of brick work. When joints are only inch thick, cubic yard of mortar will be required to a cubic yard of brickwork.
Data Concerning Brickwork. The weight of brick walls, at 112 pounds per cubic foot, is: A load of sand or mortar is a cubic yard. Sand weighs from 80 to 115 pounds per cubic foot, or 1 to tons per cubic yard.
A cubic yard of mortar requires a cubic yard of sand, and equals 30 hodfuls.
A bricklayer's hod holds 20 bricks.
Masonry with %-inch joints contains 500 bricks per cubic yard. With joints the number will be 575.
No eight-inch brick wall should be over 14 feet in height.
A mason and his helper should lay 1,000 bricks in seven hours on plain work.
Flemish bond costs more to lay than plain or English bond.
The waste of brick in good material is about 2 per cent for ordinary work; in soft or salmon, as much as 5 per cent.
Walls that are a brick-length thick are often called 9-inch walls.
A 13-inch wall is a brick-length, plus its width, plus the thickness of a mortar joint.
A 17-inch wall has a thickness equal to the length of two bricks, with the mortar joint.
A barrel of Portland cement, nominally 400 pounds, weighs about 380 pounds net.
A barrel of natural cement, nominally 300 pounds, weighs about 265 pounds net.
A barrel of lime weighs about 200 pounds. Two and a-half bushels equals a barrel.