Acta Scientiarum Polonorum

The paper deals with the issue of safety and durability of the buildings built in large panel building system
in the 1960–1990. During this period, at the various stages of the investment process, there were many
irregularities, which could have resulted in a reduction in the quality of the performance of buildings and
caused of a number of different defects among others in the area of structural joints between precast. The
article indicates the possibility of using numerical modelling to evaluate the work of joints, in which, for
example, there is a heterogeneity of the structure of the filling material (so-called cancers). Horizontal joints
of the ceiling and internal supporting wall made in the central system Wk-70; were chosen for the analyses.
The paper presents the results of variant computer simulations of the so-called work reference joints and
joints containing variable share, distribution and shape of defects. The results of calculations can constitute
the basis for determining the directions of diagnostic works of large panel buildings, assessment the technical
condition of the structure and eventual the decision to repair or strengthen them.