Q&A: Structural Engineering of LOPO Ventilated Facade System
1. Whether terracotta ventilated facade system can adopt sealed system (namely use sealant for sealed treatment)?
In many of China’s Terracotta Panel curtain wall projects, in order to avoid misalignment of the curtain wall’s horizontal seams and vertical seams, many construction parties use sealant treatment. But looking from the terracotta panel’s hanging system, an open system is recommended, which can effectively take away the moisture from the curtain wall back, and prolong the life of the building structure itself;
The sealed system itself needs sealant joint treatment, and looking from the terracotta panel’s hanging structure, each piece of the terracotta panel curtain wall is a movable unit, and its mobility may easily cause cracking of the sealant joint, which cannot realize the sealing effect; and the material properties of the terracotta panel itself also determine that the sealant will cause pollution to the terracotta panel.
As for the open terracotta ventilated facade system, its vertical seams normally use elastic metal lines of rubber strips for waterproof sealing, which at the same time has the effect of preventing the terracotta panels from lateral sliding, that’s preventing collision between terracotta panels due to their lateral sliding.
2. Whether there is any limit of terracotta panel curtain wall division?
The division of terracotta panel curtain wall is always a great difficulty to the designers. Many designers like to pursue chunks of terracotta panels, especially due to the cost factor or personal preferences, many designers blindly pursue large-sized design, and even require the size to be consistent with the stone plate’s size.
However, considering the strength and the impact resistance of terracotta panel, the terracotta panel will have better safety performance and also better reflect the terracotta panel curtain wall’s advantages, if divided with the size specification controlled with 500*1200mm, and designed with panels in proportion close to 1:3.
3. Whether terracotta ventilated facade system is suitable for super high rising buildings?
At present in China there is no unified standard of construction methods of the terracotta ventilated facade system, and it cannot clearly define the usage of terracotta ventilated facade system; but from the test of the terracotta ventilated facade system’s resistance performance to wind pressure and deformation and its anti-seismic performance, as long as the standard dry hanging system of the terracotta ventilated facade system is used(continuous transverse keel hanging system), and under the condition that is can pass the structural calculation, there is no problem to apply terracotta panels in high-rise buildings.
4. Whether the terracotta panel curtain wall’s installation system can adopt discontinuous transverse beam hanging system, to save installation cost?
In China, for cost consideration, many enterprises develop discontinuous transverse beam hanging system, the so-called short cantilever hanging system or point hanging system. But in a high-rise building project, it is suggested, by adding transverse connection between the stand columns(adding transverse beam connection between the stand columns), to make the transverse keel only with linking function in the structural system, without bearing the main force, and to enable the curtain wall’s keel to form a complete structural system. This can avoid a single stand column to produce axial eccentric tension, and to change the direction of horizontal seismic force.