TABLE No. 16.

EFFECT OF SEA WATER ON STRENGTH OF CEMENT.


Neat cement 1 cement to 3 sand
set in set in
Sea Water Fresh Water Sea Water Fresh Water

7 days 682 548 214 224
28 days 836 643 293 319
2 months 913 668 313 359
3 months 861 667 301 387
6 months 634 654 309 428
9 months 542 687 317 417
12 months 372 706 325 432


Some tests were also made by Messrs. Westinghouse, Church,
Kerr, and Co., of New York, to ascertain the effect of sea-
water on the tensile strength of cement mortar. Three sets of
briquettes were made, having a minimum section of one square
inch. The first were mixed with fresh water and kept in fresh
water; the second were mixed with fresh water, but kept
immersed in pans containing salt water; while the third were
mixed with sea-water and kept in sea-water. In the experiments
the proportion of cement and sand varied from 1 to 1 to 1 to 6.
The results of the tests on the stronger mixtures are shown in
Fig. 32.