515
CEMENT--RETARDED SETS.
Whitehall Portland Cement.
retarded set series.
Samples taken out at 2 hour intervals. Main batch of cement allowed to rest undisturbed in the mixing bed between the times of taking out samples or when regauging. Age when tested 32 to 38 days. The cement was mixed when 28 days old from the time of grinding.
Pounds.
............ 206
28.6 per cent= 59
Original quantities:
Cement.........
Water.........
Water added to the main batch as follows:
Interval after mixing.	Water used.		Interval after mixing.		Water used.	
	Succes- sive.	Total.			Succes- sive.	Total.
IIvs. mins.	Pounds.	Pounds.	Hrs.mins.		Pounds.	Pounds.
Initial			32	00	1.00	106.75
			34	00	1.00	107.75
2 00	1.75	60.75	36	00	1.00	108.75
4 00	2.50	63.25	38	00	1.00	109.75
6 00	5.00	68.25	40	00	1.00	110.75
8 00	5.50	73.75	42	00	.50	111.25
10 00	8.00	81.75	44	00	.50	111.75
12 00	6.00	87.75	46	00	.50	112.25
14 00	4.00	91.75	48	00	.25	112.50
16 00	3.00	94.75	50	00	.25	112.75
18 00	3.00	97.75	52	00	.25	113.00
20 00	2.00	99.75	54	00	.25	113.25
22 00	1.50	101.25	56	00	.25	113.50
24 00	2.00	103.25	58	00	.12	113.62
26 00	.50	103.75	60	00	.13	113.75
28 00	1.00	104.75	62	00	.12	113.87
30 00	1.00	105.75	64	00	.13	114.00
Compressive strength.		Remarks.
Total.	Per square inch.	
Pounds.	Pounds.	
112,900	7,055	Age, 32 days.
113,700	7,075	Do.
109,200	6,642	Do.
118,900	7,250	Do.
97,400	6,027	Do.
103,200	6,386	Do.
109,100	6,718	Do.
104,600	6,554	Do.
107,500	6,636	Age, 33 days.
98,300	5, 994	Do.
72,200	4,392	Do.
65,700	4,127	Do.
62,400	3,861	Do. ״
50,300	3,037	Do.
63,100	3,964	Do.
51,000	3,148	Do.
51,600	3,177	Do.
53,400	3,215	Do.
50,200	3,084	Do.
48,400	2,980	Do.
First crack.
Pounds.
92,000
85.000
81.000 104,000 104,400
96,400 58, ÓÒÒ"
59,500 47,100
30.000
35.000 49,200 48,800
Sectional
area.
Dimensions.
Compressed
surface.
Sq. inches. 16.00 16.07
16.44
16.40
16.16
16.16
16.24 15.96
16.20
16.40
16.44
15.92
16.16 16.56
15.92 16.20
16.24 16.61 16.28
16.24
Inches. 3.95 3.93 3.99
4.02
4.03
4.00
4.00
4.00
4.06
4.04
4.02
4.00
4.03
4.08
4.00
4.04
4.08
4.09
4.07
4.01
Inches.
4.05 4.09 4.12
4.08
4.01
4.04
4.06 3.99
3. 99
4.06
4.09
3.98
4.01
4.06
3.98
4.01
3.98
4.06 4.00
4.05
Height.
Inches.
4.03 4.07
4.04
4.09
4.06
4.05 3.99
4.05
4.10
4.05
3.98
3.98 4.02
3.98
3.99
3.98
3.98
3.98
10
10
12
12
14
14
16
16
18
18