523
CEMENT—RETARDED SETS.
Mankato Natural Cement.
RETARDED SET SERIES, GROUTS.
Original quantities: Cement, 72 pounds; water, 49.5 pounds = 68.8 per cent.
Mixed and allowed to remain over night, 16 hours, in the mixing bed. Worked over in the morning and put into molds. No water needed. -Age when tested, 31 days.
Num- ber.	Dimensions.			Sectional area.	First crack.	Compressive strength.		Remarks.
	Height.	Compressed surface.				Total.	Per square inch.	
	Inches.	Inches.	Inches.	Sq. inches.	Pounds.	Pounds.		
1	5.98	5.91	5.83	34.45	9,400	10,700	311	
2	5.90	5.96	5.82	34.69	10,950	10,950	316	
3	6.02	5.96	5.70	33.98	5,800	9,02Q	265	
4	5.97	5.96	5.93	35.34	9,500	10,100	286	
5	6.05	6.01	5.73	34.43				Split into halves in
6	6.00	6.01	5.75	34.55	8,050	8,800	255	setting. Corners gone.
7	5.92	5.95	5.80	34.51	8,300	10,900	316	
8	5. 96	5.91	5.85	34.58	9,950	10,800	312	
1	3.99	4.00	3.86	15.44	3,800	4,480	290	
2	4.01	3.98	3.87	15.40	4,400	4,900	318	
3	3.98	3.99	3.91	15.60	5,300	5,570	357	
Norton Natural Cement.
RETARDED SET SERIES, GROUTS.
Original quantities: Cement, 73 pounds; water, 43 pounds = 59 per cent.
Mixed and allowed to remain over night, 15 hours, in the mixing bed; 4 pounds of water added in the morning, making 47 pounds = 64.5 per cent in the mixture. Worked over and put into molds.
Age, when tested, 31 days.
Num- ber.	Dimensions.			Sectional area.	First crack.	Compressive strength.		Remarks.
	Height.	Compressed surface.				Total.	Per square inch.	
	Inches.	Inches.	Inches.	Sq. inches.	Pounds.	Pounds.		
1	5.98	5.91	5.90	34.87	9,400	11,900	341	
2	5.97	5.91	5.83	34.45	8,900	10,500	305	
3	5.97	5.90	5.90	34.81	10,400	11,600	333	
4	5.98	5.91	5.93	35.04	10,400	12,400	354	
5	5.97	5.90	5.93	34.99	9,500	11.200	320	
6	5.99	5.90	5.95	35.10	11.000	12,200	348	
7	5.98	5.91	5.96	35.22	12,080	12,900	366	
8	5.99	5.90	5. 98	35.29	12,200	13,300	377	
1	3.99	3.97	3.84	15.24	3,300	4,600	302	
2	3.99	3.98	3.89	15.49	4,100	5,300	342