590 



CEMENTS, LIMES, AND PLASTERS. 



In Fig. 149 are plotted the curves, by Johnson, resulting from compari- 

 son of a large series of tests by Tetmajer on 1:3 mixtures. 



TABLE 224. 



COMPRESSIVE STRENGTH OP PORTLAND-CEMENT MORTAR AND CONCRETE CUBES, 



WATERTOWN ARSENAL. 



* Report on Tests of Metals, etc., at Watertown Arsenal, 1902, pp. 512-514. 

 t Ibid., 1900, pp. 1105-1111. 



10 





02 46 8 10 12 



AGE IN MONTHS 



;. 149. { Ratio of compressive to tensile strength. (Johnson.) 



J From Johnson's " Materials of Construction", p. 419. 



