Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed

147 into the reservoir, the vacuum was interrupted, when the bricks had become covered by the water, and after being left in the re- servoir for 24 hours they were weighed. It does not appear, how- ever, from the discussions whether these experiments have been made with other stones than natural. II. Research on Methods of Testing Resistance to Frost. a. The Resistance to Frost of Sand-Lime-Bricks Tested by Various Methods. For the tests of the resistance to frost by the various methods 4 different sorts of bricks were employed, namely the factory’s own bricks and three sorts of German sand-lime-bricks, Chern. Laboratorium für Tonindustrie at Berlin assisting in the pro- curing of the latter, as our Laboratory had wanted by means of its intervention to secure, as far as possible, sand-lime-bricks from three of the most generally recognised and largest German fac- tories. In the extracts of the test-register given below the marks of A, B and C comprise the three sorts of German sand-lime-bricks, D the factory’s own bricks. Table V. Result of Compression-Tests with different Sorts of Sand-Lime-Bricks. Mark of the sort of bricks Crushing-strength kg pr. sq. cm, mean result for 10 pieces of bricks A B C D 234 243 113 238 The resistance of these sorts of bricks to c o m p r e s- s i o n appears from the above Table V, the compression-tests being excecuted as usually i. e. the bricks were cut across in the middle and the halves cemented together by means of neat ce- ment mortar into cubical or nearly cubical test specimens. a. Testing of Resistance to Frost by the Usual Method of the Laboratory. 10 pieces of bricks of each sort were first put 24 hours half, and then 24 hours entirely into water. The bricks then went