Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed

128 how cast-iron bars have gone through the bending tests at the Laboratory, 26 pieces having in the course of the years been tested according to the German standards specifications and 29 according to the Danish (Report XVI of the Laboratory). The named 26 experiments proved to give an average mo- dulus of rupture of 26,7 kg pr. sq. mm, 3 of {he results being below 25 kg pr. sq. mm, whilst the average number of the last 29 results was 28,8 kg pr. sq. mm of which 16 results were below 28,8 kg pr. sq. mm. As to more special tests, it may be named that the La- boratory has made Brinell tests of hardness, Heyn impact-tests on notched bars and has through a longer series of years carried on microscopical examinations of metals. II. Examinations of Cement. In the course of time the Laboratory has made a great many current examinations, for instance for The Hydraulic En- gineering Department who uses large quantities of cement, especially in working on the protection of the west coast of Jutland, for the municipality of Copenhagen for the new sewerage Table I. Results of Examinations of Cement in 1908. Time of setting Er dm en- gers high- pressure- steam- test 3 clays 7 days 28 days 3 months tensile com- press. tensile com- press. tensile com- press. tensile com- press. tensile com- press. Values obtained , . 71/ * 2 hours 26,7 339 13,6 104 19,7 194 25,7 313 31,1 383 Number of Cements 111 75 73 51 48 64 65 81 79 23 23 The five highest results were. 37,3 500 17,7 133 25,9 296 32,8 496 33,7 471 between and and and and and and and and and and 43,3 551 23,5 191 28,1 327 35,7 551 41,0 591 The five lowest results were 4,1 18 6,9 46 13,2 117 19,7 185 between 0-0 0-0 and and and and and and and and 9,2 70 10,8 104 17,8 168 28,3 283