Fig. 1.—Quantities of cement, sand, and gravel in 1: 2: 4 concrete mixture, which means 1 part cement, 2 parts sand, 4 parts crushed stone or gravel, and the resulting quantity of concrete, which is only slightly greater in size than the gravel, the sand and cement filling the voids in the gravel.

TABLE I.

Showing the Quantities of Materials and the Resulting
Amount of Concrete for Two-bag Batch.

Kind of
Concrete
Mixture.		 Proportions by Parts. Two-bag Batch.
C
e
m
e
n
t.		 S
a
n
d.		Stone
or
Gravel. 		Materials. Size of
Measuring
Boxes.
Inside
Measurements. 		Water
in
Gallons
for
Medium
Wet
Mixture.
Cement. Sand. Stone
or
Gravel. 		Concrete Sand.Stone
or
Gravel.
Bags.Cu. ft.Cu. ft.Cu. ft. Gallons.
1:2:4 Concrete 12 42 3¾7½ 8½2′×2′ 11½″ 2′×4′ 11½″10
1:2½:5 Concrete 12½ 55 4¾9½ 10 2′×2½′ 11½″ 2′×5′ 11½″ 12½

As above explained, concrete is composed of a certain amount of cement, a larger amount of sand, and a still larger amount of stone (or gravel). To determine how much of each of these materials to use, we must first consider the type of work we wish to undertake. For ordinary work about the farm (silos, tanks, cisterns, fence posts, well curbs, etc., etc.) use twice as much stone as sand, and twice as much sand as cement. This is called a 1: 2: 4 mixture—meaning that there are in that mixture:

For sidewalks, gutters, etc., a “weaker” mixture is sometimes used, consisting of:

The proportions should always be measured by volume, and the best way to do the measuring is by the use of a home-made “measuring box,” of any kind of rough boards having straight sides, but with no top or bottom. The size of these measuring boxes is determined by the proportion desired for your mixture. For such boxes you need the following sized lumber: