Earthquake mortar for lightweight-concrete masonry structures
Walls are intrinsic parts of building structures. For buildings in regions threatened by earthquakes, installation of shear walls is mandatory – in Germany, even a legal requirement. However, under cyclic and dynamic shear loading, the bond becomes a problem for masonry walls. The relevant failure zone here lies between the mortar joint and the tile/ brick.
A research project conducted by the Weimar Institute of Applied Construction Research (IAB) has developed high-performance, fabric-reinforced mortar for masonry in regions subjected to earthquakes. The additives added to the mortar formulation enhance the bond at the interface of block and mortar. The project revealed significant increase of shear strength under dynamic actions by inclusion of glass fiber mesh in the mortar layer.
A series of experimental investigations determined the effect of the additives and the glass fiber mesh in the mortar. Further large-scale tests with experimental walls confirmed these research results and determined the absorbed shear forces and crack propagation during failure of the walls. All tests showed that the mortar system with integrated glass fiber mesh that had been developed absorbs significantly greater shear forces than conventional mortar. A follow-up project being planned is oriented toward development of a new mortar system for upgrading masonry consisting of lightweight concrete blocks.
