As the world´s largest producer of bricks, Wienerberger has addressed this challenge by engaging in international research projects on the design and construction of brickwork structures in seismically threatened zones. After many years of research, Wienerberger developed a solution for earthquake-prone areas.
The PHM or Perforated Handmade Brick is a special type of brick, whose properties make it particularly well-suited for earthquake-prone areas. The main objective of this product is to protect people´s lives and buildings during seismic activities. Facing brick masonry may be reinforced to introduce a more tensile and flexural strength, to provide better seismic protection. The PHM brick has a dramatically increased ductility and energy dissipation capacity compared with conventional bricks.
Normally, the flexural strength is limited by the bond strength between the masonry units and the mortar. The compressive strength of conventional bricks is adequate for normal circumstances, and they can be installed in the form of unreinforced cavity walls in two masonry leaves. To withstand wind loads, wall ties between the facing brick facade and the backing structure are needed. This method can be applied in non-seismic or moderate seismic zones.
In pronounced seismic regions, there is a need for facing bricks with enhanced ductility through reinforcement. Building codes also propose a minimum amount of reinforcement in these areas. In the case of an earthquake, energy can be dissipated by the reinforcement, which ensures a safe and stable wall. With this construction method, the reinforcement is located in the bed joint, often in the form of prefabricated “ladders”. The three large perforations in the PHM brick also allow vertical reinforcement. The increased energy dissipation capacity, ductility and reinforcement of PHM brick makes it an ideal choice for a façade that withstands the potential impact of seismic activities in earthquake-threatened areas.