20 BULLETIN 230, U. S. DEPARTMENT OP AGRICULTURE. 



Table 7. — Compression tests of oil-concrete 6 by 6 inch cylinders. 



Speci- 



Oil 



No. 



Pro- 

 por- 

 tions. 



Per 

 cent 

 oil. 



Air cured. 



Water cured. 



No. 



28 days. 



180 days. 



360 days. 



720 days. 



28 days. 



180 days. 



360 days. 



720 days. 



6 





1:3:6 



1:3:6 



1:3:6 



1:3:6 



1:3:6 



1:3:6 



1:3:6 



1:3:5 



1:3:5 



1:3:5 



1:3:5 



1:3:5 



1:3:5 



1:1.5:4.5 



1:1.5:4.5 



1:1.5:4.5 



1:1.5:4.5 



1:2:4 



1:2:4 



1:2:4 



1:2:4 



1:1.5:4.5 



1:1.5:4.5 



1:1.5:4.5 



1:1.5:4.5 



1:1.5:4.5 



1:1.5:4.5 



1:1.5:4.5 



1:1.5:4.5 







2* 



5 



10 

 15 

 20 

 25 







2J 



5" 

 10 

 15 

 20 







21 



5" 

 10 







2i 



5 

 10 







2J 



5 

 10 







21 



5" 

 10 



1,020 (3) 

 750 (2) 

 737 (2) 

 656 (2) 

 542 (2) 

 695 (2) 

 605 (3) 

 920 (2) 

 787 (2) 

 715 (2) 

 698 (2) 

 693(2) 

 572 (2) 

 1,880 (2) 

 1,345 (2) 

 1,250 (2) 

 9S0 (2) 



980 (2) 

 915 (2) 

 975 (2) 

 755 (2) 

 670 (2) 

 840(2) 

 678 (2) 

 998 (1) 

 945 (3) 

 822 (2) 

 965 (2) 

 828 (3) 

 639 (2) 

 2,050 (2) 

 1,490 (2) 

 1,145 (2) 

 845(2) 



1,090 (3) 



1,165 (2) 



1,015 (2) 



850 (1) 



675 2) 



900 (2) 



1,225 (2) 



1,370 (2) 



1,253 (3) 



1,142 (2) 



961 (3) 



750 (2) 



1,120 (2) 



620 (2) 



1,342 (2) 



1,222 (2) 



•1,082 (2) 



1,040 (2) 



1,040 (2) 



904 (2) 



2,185 (2) 



1,795 (2) 



1,92-5 (2) 



1,065 (2) 



1,920 (2) 



2,420 (2) 



2,750 (2) 



2,160 (3) 



2,020 



1,955 



1,815 



1,385 



1, 948 



1,710 



1,290 



. 1,057 



1,955 (3) 

 1,715 (2) 

 1,690 (2) 

 1,400 (2) 

 995 (2) 

 1,535(2) 

 1,030 (2) 

 1,705 (2) 

 1,830 (3) 

 1,626 (2) 

 1,406 (2) 

 1,380 (2) 

 1,115 (2) 

 2,670 (2) 

 2,330 (2) 

 2,355 (2) 

 1,485 (2) 

 3,280 (2) 

 3,430 (2) 

 3,270 (2) 

 2,820 (2) 



2,170 (3) 

 1,580 (3) 

 1,835 (2) 

 1,440 (3) 

 1,145 (3) 

 1,670 (3) 

 1,120 (3) 

 1,890 (2) 

 2,410 (3) 

 1,715 (3) 

 1,490 (3) 

 1,382 (3) 

 1,230 (3) 

 2,950 (2) 

 2,250 (2) 

 2,750 (2) 

 1,625 (2) 

 3,350 (2) 

 3,390 (2) 

 3,110(2) 

 3,020 (3) 



2,205 (2) 

 1,900 (2) 

 1,865 (2) 

 1,585 (2) 



7 



4923 

 4923 

 4923 

 4923 

 4923 

 4923 



8 ,. 



9 



10 



1,500(2) 

 1,230 (1) 



11 



12 



1,150 (1) 



1,005 (2) 



1,100 (2) 



1,010 (2) 



940(2) 



1,010 (3) 



888 (2) 



672 (2) 



1,975 (2) 



13 



1,010(2) 



995 (3) 



912 (3) 



975 (3) 



8S8 (3) 



772 (2) 



2,365 (2) 



1,560 (1) 



1,768 (2) 



1,170 (3) 



2,300 (2) 

 2,250 (2) 

 1,805 (2) 

 1,480 (3) 

 1,680(3) 

 1,130 (2) 

 2,850 (2) 

 2,700 (2) 

 2,800 (2) 

 1,568 (2) 

 3,370 (2) 

 3,130 (2) 

 3,160 (2) 



14.... 



15 



16.... 

 17.... 

 18.... 

 164... 



4923 

 4923 

 4923 

 4923 

 4923 



"4981 

 4981 

 4981 



168... 

 169... 

 177... 

 479... 



1,855 (2) 

 1,585 (2) 

 1,035 (2) 



480... 



4923 

 4923 

 4923 











481.., 











482... 











800... 



1,680 



1,370 



1,290 



1, 175 



990 



911 



738 



548 











801... 



7393 

 7393 

 7393 















802. . . 















803... 















796... 















797. . . 



7393 

 7393 

 7393 















798. . . 















799.. 





























Note. — Figures in parentheses indicate number of specimens tested. Gravel used as coarse aggregate 

 in Nos. 479, 480, 481, 482, 796, 797, 798, 799. Crushed gneiss used in all other tests. 



TIME OF SETTING OP PORTLAND CEMENT. 



Table 8. — Effect of oil on time of setting. 



Oil No. 4923. 



Per cent 

 of oil. 



Initial set. 



Final set. 





 2J 



5 

 10 



H.m. 

 1 18 

 1 31 



1 57 



2 27 



H.m. 



3 43 



4 56 



5 27 

 5 57 



The time of setting is delayed with tho addition of oil, as shown 

 by the above tests, which are plotted on figure 4. These results 

 were obtained with the Gillmore needles on specimens subjected to 

 identical conditions while hardening. Five per cent of oil delays 

 the initial set by 50 per cent and the final set by 47 per cent. 



TOUGHNESS OR RESISTANCE TO IMPACT. 



The toughness or resistance to impact was tested on the Page 

 impact machine under the blows of a 10-kilogram hammer falling on 

 a 5-kilogram plunger from successively increasing heights of 1 centi- 

 meter. The height of the blow causing failure corresponds to the 

 number of blows. The end of the plunger in contact with the 



