18 



BULLETIN 230, U. S. DEPARTMENT OF AGRICULTURE. 



The foregoing results are plotted on figure 1. It will be noticed 

 that, in general, the specimens containing oil have a higher tensile 

 strength than those without oil. 



CRUSHING STRENGTH. 



Specimens of mortar and concrete containing different percentages 

 of various kinds of oils were molded 6 inches in diameter and 6 inches 

 high. They were bedded in plaster of Paris and blotting paper, and 

 crushed at a speed of 0.152 inch per minute. Table 6 gives the 

 crushing strength of 1:3 oil-mortar specimens for periods of 28, 180, 

 and 360 days; and Table 7, the crushing strength of oil-concrete 

 cylinders tested at various periods up to two years. The results are 

 plotted on figures 2 and 3. It will be noted that the crushing strength 

 is decreased by the addition of oil, but that the decrease is not serious 

 when the amount of oil does not exceed 10 per cent. It will also be 

 noted that oil-mixed cement concrete gains in strength with time 

 in about the same ratio as untreated concrete. This fact indicates 

 that the addition of oil to the mixture in small amounts has no 

 disintegrating effect on the cement. This statement holds true for 

 periods up to and including two years. 



Table 6. — Compression test of oil-mortar 6 by 6 inch cylinders, proportions 1:3 by weight. 



Specimen 



Per 

 cent 

 of oil. 



Oil No. 



Air cured. 



Water cured. 



No. 



28 days. 



ISO days. 



360 days. 



28 days. 



180 days. 



360 days. 



1 







5 

 10 

 15 

 20 



5 

 10 

 15 

 20 



5 

 10 

 15 

 20 



5 

 10 

 15 

 20 



5 

 10 

 15 

 20 





1,170(5) 



1,050(2) 



790(1) 



S95 (2) 



775 (2) 



915(2) 



S30(l) 



1,215(2) 



935 (2) 



1,405(2) 



1,070(1) 



975 (2) 



795 (2) 



1,305(2) 



1,170(1) 



1,440(2) 



925 (2) 



1,010(2) 



9S0(2) 



1,055(2) 



S90(2) 



1,350(2) 

 830(2) 



1,597(2) 

 1,220(2) 



2, 135 (6) 

 1,715(2) 

 1,320(1) 

 1,290(2) 

 1,020(2) 

 1,770(2) 

 2,400(2) 

 1,775(2) 

 1,345(2) 

 1,995(2) 

 1,720(1) 

 1,670(2) 

 1,400(2) 

 2,220(2) 

 1,750(1) 

 1,895(2) 

 1,230(2) 

 1,760(2) 

 1,680(2) 

 1,265(2) 

 1, 175 (2) 



2, 275 (2) 

 2, 160 (2) 



2,308(2) 

 2,240(2) 



17 



4145 

 4145 

 4145 

 4145 

 4146 

 4146 

 4146 

 4146 

 4147 

 4147 

 4147 

 4147 

 4149 

 4149 

 4149 

 4149 

 4170 

 4170 

 4170 

 4170 



2 



22 . 



7S0 (2) 

 910 (2) 



880 (2) 

 1, 125 (2) 

 1,110(2) 



1,615(2) 

 1,420(2) 



1,700(2) 

 1,425(2) 



27 



18 



2,560(2) 



3. 







23 



1,275(2) 

 1,295(2) 

 1, 155 (2) 



1,670(2) 

 1,3S0(2) 

 1,715(2) 



2,410(2) 

 1,640(2) 

 2,475(2) 



2.475(2) 

 1,780(2) 



28 



19 



2, 700 (2) 



4. 



24 



1,0S5(2) 

 1,055(2) 

 1, 105 (2) 



1,435(1) 

 1,310(2) 

 1,395(2) 



2,350(2) 

 2,010(2) 

 2,655(2) 



2,250(1) 

 1,895(2) 

 2,450(1) 



29 



21 



6 



26... 



1,395(2) 

 1,085(2) 

 940(2) 

 1,005(2) 

 1,170(2) 

 1, 220 (2) 



1,330(2) 

 1,135(2) 

 1,315(2) 

 1,510(2) 

 1,555(2) 

 1,325(2) 



2,215(2) 

 1.475(2) 

 2,065(2) 

 1,S25(2) 

 1,365(2) 

 1,340(2) 



2,320(2) 

 1,530(2) 



31 



7 



2,345(1) 



8 



2, 200(1) 



9 



1,685(1) 



10 



1,375(1) 







Note. — Numbers in parentheses indicate number of specimens tested. 



