M.Sc. Johannes Mahner investigated the “Test and efficiency of various surface retarders for roadway coverings of washed concrete”.
Surface retarders, which prevent the near-surface cement paste from setting and hardening, have a considerable influence on the quality of the surface. The prerequisite for the development of improved retarders is a reproducible test procedure. One focus of this procedure must be the transferability of the test results to practice (establishment of the test surface and a brushing off procedure in step with actual practice). The development and use of a turnable formwork and a brushing off device with adjustable, constant contact pressure are the actual results of this master thesis. A test procedure attuned to these auxiliaries made it possible to test the various retarders (sugar, citric acid and phosphoric acid) in a reproducible way as regards their efficiency. With the results of this master thesis a practically oriented test method for the efficiency of surface retarders for washed concrete is now available.
The members of the jury, Prof. Dr.-Ing. Horst-Michael Ludwig, Chair of Building Materials and Director of the F. A. Finger Institute for Building Materials Science, Dipl.-Ing. Heiko Theuerkauf, Managing Director of dornburger zement as well as Dipl.-Ing. Dennys Dressel, acknowledged the high practical orientation of the Master theses. With this award the dornburger zement company presents prizes to exceptional theses, the results of which can be used directly in the building materials industry. The company honours the outstanding performances of graduates to underline the value of student research for the economy.
For more than ten years dornburger zement has cooperated closely with the Weimar Bauhaus University in the field of building materials research and science. This includes the dornburger zement award as well as the support of the annual summer festival.