S. Agaajani1, D. Waldmann2, and F. Scholzen2
1) ASARS Constructions
24-28, rue Goethe, L-1637 Luxembourg
2)  University of Luxembourg, FSTC
6, rue Richard Coudenhove-Kalergi, L-1359 Luxembourg

Keywords: Concrete, Dry-stacked masonry, Mortarless joints, Effective contact interface, Load percolation, Algorithm.

Abstract. In conventional masonry constructions, the mortar bed in the horizontal joint levels out the unevenness of masonry blocks and thus assures a uniform contact interface between the superposed block rows. In dry-stacked masonry systems, this stabilizing effect is not provided. In order to measure the effective remaining contact area in the horizontal joints for dry-stacked masonry elements, special measurement films were placed in the horizontal layers between dry-stacked blocks. Wall specimens were first subjected to different levels of axial compression and then unloaded and the films for numerical examination were removed. The mechano-numerical investigations show the relationship between the effective contact areas in a dry-stacked masonry wall and the applied load and demonstrate that the contact area at the joint interface is relatively low, even for rectified dry-stacked elements. Also, a new numerical technique for the determination of stress-percolation in drystacked load-bearing structures, based on geometrical properties of the dry-stacked elements is used in order to confirm the experimental observations.