The method of mixing concrete is immaterial, if a homogeneous mass is secured of a uniform consistency, containing the cement, sand, and stone in the correct proportions. The value of the concrete depends greatly upon the thoroughness of the mixing. The color of the mass must be uniform, every grain of sand and piece of the stone should have cement adhering to every point of its surface.

Table VI. Barrels Of Portland Cement Per Cubic Yard Of Mortar

(Voids in Sand Being 35 per cent and 1 Bbl. Cement Yielding 3.65 Cubic Feet of Cement Paste.)

Proportion of Cement to Sand

1:1

1:1.5

1:2

1:2.5

l:3

1:4

Bbls.

Bbls.

Bbls.

Bbls.

Bbls.

Bbls.

Bbl. specified to be 3.5 cu. ft.

4.22

3.49

2.97

2.57

2.28

1.76

,,

,,

,,

3.8

,, ...

4.09

3.33

2.81

2.45

2.16

1.62

,,

,,

,,

4.0

,, ..

4.00

3.24

2.73

2.36

2.08

1.54

,,

,,

,,

4.4

,, ...

3.81

3.07

2.57

2.27

2.00

140

Cu. yds. sand per cu. yd. mortar. .

0.6

0.7

0.8

0.9

1.0

1.0

Table VII. Barrels Of Portland Cement Per Cubic Yard Of Mortar

(Voids in Sand Being 45 per cent and 1 Bbl. Cement Yielding 3.4 Cubic Feet of Cement P ste.)

Proportion of ement to Sand

1:1

1:1.5

1:2

1:2.5

1:3

1:4

Bbls.

Bbls.

Bbls.

Bbls.

Bbls.

Bbls.

Bbl. specified to b 3.5 cu.ft..

4.62

3.80

3.25

2.84

2.35

1.76

,,

,,

,,

3.8

,, ...

4.32

3.61

3.10

2.72

2.16

1.62

,,

,,

,,

40

,, ...

4.19

3.46

3.00

2.64

2.05

1.54

,,

,,

,,

4.4

,, ...

3.94

3.34

2.90

2.57

1.86

1.40

Cu. yds. sand per cu. yds. mortar.

0.6

0.8

0.9

1.0

1.0

1.0

Table VIII. Ingredients In 1 Cubic Yard Of Concrete

(Sand Voids, 40 per cent; Stone Voids, 45 per cent; Portland Cement Barrel Yi lding 3.65 cu. ft. Paste. Barrel specified to be 3.8 cu. ft.)

Proportions by Volum

1:2:4

1:2:5

1:2:6

1: 2.5:5

1:2.5:6

1:3:4

Bbls. cement per. cu. vd. concrete.

1.46

1.30

1.18

1.13

1.00

1.25

Cu. yds. sand

,,

,,

0.41

0.36

0.33

0.40

0.35

0.53

" stone

,,

,,

0.82

0.90

1.00

0.80

0.84

0.71

Proportions by volum.. ..

1:3:5

1:3:6

1:3:7

1:4:7

1:4:8

1:4:9

Bbls. cement per u. vd. con rete.

1.13

1.05

0.96

0.82

0.77

0.73

Cu. yds. sand

,,

,,

0.48

0.44

0.40

0.46

0.43

0.41

" stone

,,

,,

0.80

0.88

0.93

0.80

0.86

0.92

This table is to be used when cement is measured packed in the barrel, for the ordinary barrel holds 3.8 cu. ft.

Table IX. Ingredients In 1 Cubic Yard Of Concrete

(Sand Voids, 40 per cent; Stone Voids, 45 per cent; Portland Cement Barrel Yielding 3.65 cu. ft. of Paste. Barrel specified to be 4.4 cu. ft.)

Proportions by Volume

1:2:4

1:2:5

1:2:6

1:2.5:5

1:2.5:6

1:3:4

Bbls. cement per cu. yd. concrete. . .

1.30

1.16

1.00

1.07

0.96

1.08

Cu. yds. sand

,,

,,

0.42

0.38

0.33

0.44

0.40

0.53

,,

stone

,,

,,

0.84

0.95

1.00

0.88

0.95

0.71

Proportions by volume..

1:3:5

1:3:6

1:3:7

1:4:7

1:4:8

1:4:9

Bbls. cement per cu. yd. concrete. .

0.96

0.90

0.82

0.75

0.68

0.64

Cu. yds. sand

,,

,, .

0.47

0.44

0.40

0.49

0.44

0.42

,,

stone

,,

,, ..

0.78

0.88

0.93

0.86

0.88

0.95

This table is to be used when the cement is measured loose, after dumping it into a box, for under such conditions a barrel of cement yields 4.4 cu. ft. of loose cement.

[Tables V to IX have been taken from Gillette's "Handbook of Cost Data."]