Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed

 171 about 8 weeks. The adhesion experiments were made in the Tinius Olsen machine in pressing against the projecting header- side of the middle brick, as if one would drive back the brick to be flush with the two outer bricks. The results of the experiments with the individual test-pieces agreed rather badly as is usually the case with adhesion expe- riments. For mortar C the crushing strength was found to vary from 0,2 to 1,6 kg pr. sq. cm, the mean being 0,6 kg pr. sq. cm. For mortar D the crushing strength was found to vary from 0,3 to 0,8 kg pr. sq. cm, the mean being 0,4 kg pr. sq. cm. It may be inferred from this that if half of the calcic hydrate in a mortar with 5 per cent calcic hydrate is replaced by moler-, the adhesion will at any rate be particularly diminished. The Laboratory must be of opinion that according to what is before us it would prove profitable to replace a great deal of the calcic hydrate in lime mor- tar with moler and especially in humid places. The moler has, indeed, come to be used in Frederiksholm’s Limeworks for the producing of lime mortar, and the experiments of the Laboratory have been corroborated and the lime-moler mortar is very comfortable to work with. h. Researches on Painting on Fresh, Surface-dry or Moist Cement-Plaster. These researches were occasioned by the late city-architect in Copenhagen, Prof. Fenger, and executed for the magistracy of Co- penhagen; they tended to find out how one could paint, especially paint in oil, on cement-plaster, as it is well known that oil-paint does not last in fresh cement-plaster, thus not where cement- plaster has newly been repaired, for instance on the walls in bathing establishments. The Testing Laboratory considering the chemical attack de- rived from the plaster itself to be the essential in the majority of cases the experiments were made in such a way as to be sure that this influence came to be the only one working, i. e. the expe- riments were made as laboratory experiments. As one of the by-influences that may occur during practi- cal experiments may be named the pressure to which the water may be subject in moist masonry work. To imitate this 12*