503
CEMENT--RETARDED SETS.
Steel, Slag, 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, 31 days.
Original quantities:	Pounds.
Cement......................................................................80.5
Water/........................................................... 36 per cent= 29
Water added to the main batch as follows:
		Water used.	
	Interval after mixing, hours.	Pounds.	Per cent, approximate.
		29.0	36.0
2					0.5	36.9
4			0.5	38.5
6			0.5	40.0
8	 			0.25	40.5
			
Hours.	Dimensions.			Sectional area.	First crack.	Compressive strength.		Remarks.
	Height.	Compressed surface.				Total.	Per square inch.	
	Inches.	Inches.	Inches.	Sq. inches.	Pounds.	Pounds.	Pounds.	
0	5.98	6.04	6.00	36.24	42,700	42,700	1,178	
0	6.02	6.02	5.96	35.88	41,100	41,500	1,156	
2	6.06	6.07	6.03	36.60	40,600	41,400	1,131	
4	6.00	6.04	6.10	36.84	38,800	38,800	1,053	
4	6.04	6.00	6.05	36.30	36,000	36,900	1,016	
6	6.02	6.04	6.00	36.24	36,400	36,400	1,004	
8	6.03	6.00	6.08	36.48	32,300	35,100	962	
8	4.03	4.01	3.88	15.55	11,900	13,500	868