CEMENT---:RETARDED SETS.
518
־ Newark and Rosendale Naturae Cement.
RETARDED SET SERIES.
Samples taken out at 2-hour intervals, with one interval of 13 hours and one of 18 hours. Main batch of cement allowed fo rest undisturbed in the mixing bed after the initial gauging. Material sufficient for each lot of two 6-inch cubes was detached from the main batch, reworked, and regauged when required, just before putting into the molds. Age when tested, 35 days. The cement, when mixed, was 11 days old from the time of grinding.
Pounds.
.............295
42.7 per cent= 126
Original quantities:
Cement..........
Water.........
Water was added to the individual detached batches as follows:
Interval after mixing.	Water used.	Interval after mixing.	Water used.
	Pounds.	Hours.	Pounds.
2	3.0	25	3.5
4	2.75	43	2.0
17	3.0	45	1.75
19	2.75	47	2.25
21	3.5	49	2.50
23	3.5		
This batch of material had set sufficiently 15 minutes after initial gauging to become somewhat resonant in the mixing bed. It was necessary to scrape off the material from the main batch for cubes 17 hours retarded and thereafter.
First crack.	Compressive strength.		Remarks.
	Total.	Per square inch.	
Pounds.	Pounds.	Pounds.	
30,400	30,400	819	
27,800	27,800	750	
22,100	23,800	647	
	23,900	653	
	23,350	649	
	23,200	636	
	26,480	734	
	25,250	689	
23,300	23,900	653	
	25,500	699	
	20,300	568	
19,300	19, 500	543	
21,900	22,200	612	
	22,400	610	
	19,100	531	
	16,900	463	
	19,300	539	
18,500	19,100	527	
	19,300	532	
	19,200	536	
	20,800	572	
	20,200	561	
	17,200	476	
	15,800	441	
	Dimensions.			Sectional area.
Hours.	Height.	Compressed surface.		
0	Inches. 6.07	Inches. 5. 99	Inches. 6.20	Sq. inches. 37.14
0	6.00	6.00	6.18	37.08
2	5.94	5.98	6.15	36.78
2	5.94	6.01	6.09	36.60
4	6.02	5.91	6.09	35.99
4	5.94	5.98	6.10	36.48
17	6.00	5.96	6.05	36.06
17	6.00	5.94	6.17	36.65
19	6.01	5.97	6.13	36.60
19	6.00	5.99	6.09	36.48
21	6.02	5.97	5.99	35.76
21	5.99	5.94	6.05	35.94
23	5.96	5.95	6.10	36.30
23	5.96	C.01	6.11	36.72
25	6.00	5.97	6.02	35.94
25	6.02	5.98	6.11	36.54
43	5.99	5.93	6.04	35.82
43	5.98	5.94	6.10	36.23
45	5.99	5.91	6.14	36.29
45	5.97	5.93	6.04	35.82
47	5.98	6.00	6.06	36.36
47	5.99	5.94	6.06	36.00
49	6.00	5.93	6.10	36.17
49	5.95	5.95	6.02	35.82