Reinforced brick floors at the German Empire 1892-1925

Dissertation at the chair for Construction History and Structural Preservation, by Michael Fischer 2003 - 2009

Awarded best dissertation in 2009 at the BTU Cottbus
Awarded "Max-Grünebaum-Preis" 2010

At the beginning of the twentieth century, reinforced brick floors influenced high-rise construction as they were very frequently used because of their cost-effectiveness, variety and simplicity of erection. They prevailed for many years over the contemporaneously developed reinforced concrete slabs and gained worldwide importance especially in connection with frame structures. Despite the importance of reinforced brick floors, their history and the contemporary methods of design remain mostly unknown. This has significant impacts on how historic reinforced brick floor structures are treated nowadays. Current structural evaluations are marked by unclear boundary conditions. As an alternative, load tests of the floor slabs are performed or they are strengthened. Both methods are expensive but the lack of knowledge often results in an even more costly replacement of the floors. This dissertation examines the historical and structural development of reinforced brick floors. For the first time a comprehensive development history is presented, documented and evaluated.Volume 1 of the dissertation begins with a chapter on the genealogy of hollow floor slab structures which seeks to place the development of the reinforced brick floor in a historical and technological context. A chronology of the reinforced brick floor in the German Empire shows the initial development, propagation and differentiation as well as its decreasing use and associated stagnation of new developments. Based on the common properties of the floor systems, a typology is developed which allows the classification of reinforced brick floors into different types as well as the characterization of the various floor systems. This is followed by a discussion of the construction materials used in the erection of reinforced brick floors, the associated building certification and the historic design methods. A compilation of the original design methods and rules serves to assess the design concepts of reinforced brick floors at that time. Since it is common nowadays to use the method for structural evaluations of these historic floor systems based on building codes used at the time of construction, some proposals are made for correcting the design parameters. Finally, the first volume of this work concludes with a description of the possible effects of the discoveries made on the loading capacity of historic reinforced brick floor structures.A catalogue of numerous historic reinforced brick floor systems is presented in volume 2. All relevant systems described in historic technical literature – independent of whether patents or utility models exist, or of their practical application – are documented and graphically represented at the same scale. The second volume is completed by a comprehensive treatise of every step required in the erection of every floor system listed.A representative selection of historic decrees and ordinances as well as numerous illustrations serving to elucidate volumes 1 and 2 are presented in volume 3.

Doctoral thesis committee
Prof. Dr.-Ing. Werner Lorenz,
Prof. Berthold Burkhardt,
Prof. Karen Eisenloffel, M.Sc.

Disputation
03.07.2008

Link to the publication
http://opus.kobv.de/btu/volltexte/2009/781