Innovation: New seismic connection system for masonry blocks
Many earthquake regions worldwide are built-up with buildings of skeleton frame construction made of concrete or steel, the spaces of which are infilled with blocks. According to the manufacturer, an anchorage system was recently developed for the first time worldwide for protecting masonry blocks, made of various materials, from the forces exerted by seismic, thermal, and wind forces – a solution for which a world patent has already been applied.
A modular block of lightweight concrete with built-in anchorage components is fixed to anchor channels with a brick tie. For fixing to columns, an anchor channel is embedded in a modular joint of low compressive strength (marked in blue) – anchored to concrete columns and bolted onto steel columns. In an earthquake, this modular joint, owing to its low density, is designed to fail first, protecting in this way columns and shear walls from damage. This creates a connection that is capable of absorbing movements in all three directions and, in addition, is provided with pinning for anchoring in floor/ground slabs or beams/floors.
Before now no adequate solution available for seismic anchorage
Autoclaved aerated concrete (AAC/autoclaved cellular concrete) and/or CLC foam concrete is manufactured in more than 1000 plants worldwide, in which modular blocks and modular joints of these kinds can be manufactured at low investment with the mixed technology required. Precontech offers a complete, intercoordinated system consisting of formwork, side forms, and magnet and anchorage technology for combining modules in the plants’ existing horizontal production.
Every earthquake-prone country has different regulations for local tests and for the validity of patents for introducing these systems to the respective markets. Around 85 % of the construction volume consists of shear brick walls; the remaining 15 % is precast concrete, lightweight concrete, or fibrous concrete elements. The use of lightweight construction materials, due to their low weight and better insulation properties, is gaining increasing significance.
There exists a huge market potential for this development, since several hundred million square meters of bricks are processed worldwide, and until now no adequate solution for seismic anchorage has been offered. The connection system from Precontech prevents damage to masonry walls and shear walls under the action of seismic, thermal, and wind forces.
