CEMENT--RETARDED SETS
498
Star 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, 30 days.
Original quantities:	'	Founds.
Cement...............................................................................94
Water.................................................................. 27.6 per cent= 25
Water added to the main batch as follows:
Water used.
Per cent, approximate.
Pounds.
Interval after mixing, hours.
27.1
28.:
21.5
.5
.12
Initial mixing
2...............
6...............
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	6.04	6.01	6.08	36.54	128,500	128,500	3,516	
0	6.01	5.98	6.05	36.18	125,300	125,300	3,463	
2	6.06	6.07	6.03.	36.60	136,800	136,800	3,737	
4	5.99	6.07	5.99	36.35	138,900	138,900	3,821	
4	6.01	6.06	6.02	36.48	134,500	134,500	3,686	
6	6.02	6.01	6.04	36.30	141,700	141,700	3,903	
8	5.97	6.02	5.60	33.71	131,100	131,100	3,889