CEMENT---־RETARDED SETS
504
Austin, Natural 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:	Pounds.
Cement....................................................................82-5
Water......................................................... 39.4 per cent= 32.5
Water added to the main batch as follows:
								Water used.		
		Interval after mixing, hours.								Per cent,
								Pounds.		approxi-
										mate.
								32.5		39.4
								3.5		45.1
								2		49
								.5		50.2
								.25		51
										
	Dimensions.					Compressive strength.				
				Sectional area.	First crack.					
Hours.									Remarks.	
	Height.	Compressed surface.				Total.	square inch.			
		Inches.	Inches.	So. inches.	Pounds.	Pounds.	Pounds.			
0	6.04	6.01	6.09	36.60	26,600	26,600		727		
0	6.03	6.02	6.10	36.72	25,000	26,100		711		
2	6.05	6.00	6.13	36.78	15,600	15,600		־ 724		
4	6.02	5.98	6.11	36.53	10,300	12,800		350		
4	5.99	6.02	6.08	36.60	10,700	12,100		331		
6	6.02	6.00	6.10	36.60	9,800	10,100		276		
8	5.96	6.00	6.12	36.72	9,600	10,900		297		
8	4.01	4.02	4.03	16.20	3,810	3,810		235		
8	4.01	4.03	3.99	16.08	3,900	4,300		267		
8	1.95	2.02	2.05	4.14	710	710		171		
8	2.01	1.96	2.04	4.00	640	640		160		
8	2.02	1.96	2.06	4.03	590	620		153		
8	2.02	1.96	2.05	4.01	630	630		157