Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed

160 On account of the experiments made, and reliable informa- tions as to sand-lime-bricks freezing to pieces in nature being constantly absent, the Laboratory has found it appropriate no more to maintain a test which at any rate seems to be too rigorous, as sand-lime-bricks hardly will be employed in such places where they can be exposed to frost when saturated with water1). That under such conditions they should yield the same re- sistance to frost as good well burnt bricks the Laboratory does not think. As to the carrying out of the test, the laboratory has altered the form of the straps, as showed on fig. 24, p. 67. The sand- lime-bricks are clasped here as in Berlin in a horizontal po- sition. By the shown construction of the straps is obtained, that there can be place for two straps with 5 bricks each in a freezing- case, while by the former construction there might be only 1 strap with 4 bricks in a freezing-case. d. Testing of Cement-Bricks. Of late years no slight industry for the producing of ce- ment bricks has sprung up in Denmark. This industry seems, indeed, to be rather natural for the country. The La- boratory has therefore published a Report XIV on experiments with these bricks. Up to the 1st of April 1909 the Laboratory has tested 26 sorts of bricks, both with and without mortar de- pressions. Only in 2 cases thee r u s h i n g strength (the average numbers) attained 100 kg pr. sq. cm being in most cases far below. The average crushing strength of the 17 sorts of massive bricks tested, of which have been tested at least 10 pieces of bricks, is 58 kg pr. sq. cm and for the corresponding 9 sorts of bricks with mortar depressions 55 kg pr. sq. cm. As to the tests of resistance to frost the cement bricks proved to be by no means equal to burned bricks, as each well-burnt brick can with certainty be considered able to stand the test of resistance to frost whilst none of the cement bricks tested went J) I he more lenient tests of the Laboratory for sand-lime-bricks has been criticised in Tonindustrie-Zeitung 1908, Nr. 149 a criticism which has been disproved by the director of the Laboratory in the same Nr.