posted on 2020-07-08, 16:06authored byHuizhang Guo, Merve Özparpucu, Elisabeth Windeisen-Holzhauser, Christian M. Schlepütz, Elia Quadranti, Sabyasachi Gaan, Christopher Dreimol, Ingo Burgert
A more extensive use of wood can
reduce the environmental and climatic
impacts of the building industry. However, flammability limits the
application of wood in multistory and high rise timber buildings.
Struvite mineralization has been shown to be a green solution for
fire-resistant timber, but the influence of struvite minerals on the
mechanical and gluing properties of wood as well as the combustion
behavior have not been studied yet. In this work, we investigate the
mechanical properties of mineralized wood by compression, bending,
and tension tests as well as gluing properties by tensile shear tests.
Evolved gas analysis using GC/MS system is applied to determine the
thermal decomposition behavior of the mineralized wood, and Double
shot analysis reveals volatile components of mineralized wood during
the thermal decomposition process. The results show that the struvite
mineralization treatment is a bulk modification technique that improves
the fire resistance of wood. The mineralization can significantly
influence the thermal decomposition behavior of wood, which results
in an enhanced char formation. This char layer is a fire barrier that
slows down the heat and oxygen penetration. The heat penetration rate
of wood panels fabricated with mineralized wood is 0.6 mm/min during
the cone calorimeter test, which is half of that of the wood panels
fabricated with native wood. Transverse strength and stiffness under
compression were improved, whereas mechanical loading in the longitudinal
direction revealed similar or decreased strength and stiffness. The
mineralization had a minor impact on the gluing properties of solid
wood. Wood mineralization by struvite may enable the more extensive
use of wood in the construction sector as a substitute for less eco-friendly
building materials.