Mineralizace rostlého konstrukčního dřeva a její aplikace za účelem redukce vlhkostních objemových změn

Abstract

The submitted work is focused on modification of wooden properties by artificial mineralization. It contains design and experimental verification of analytical method complex for identification and characterization of mineralization component in the wood of various tree species, including application of standard methods used in the diagnosis of wooden structures. Electron microscopy SEM is recommended as an effective analytical tool for description of natural and artificial mineralization, allowing quality assessment of the nature of mineral particles deposition in the wood structure and also penetration depth of mineralization solution into the material. Application of thermal analysis methods was designed and confirmed for the quantification of mineral components in the treated wood, including the derivation of fundamental relation for quantitative description of the mineralization. Experiment, based on the evaluation of volume changes of the mineralized samples, was designed and performed to confirm binding of mineralization solution into wooden cell wall. Suitable mineralization substances were selected and tested so that their wooden application leads to a significant reduction of liquid water intake into pore system of the material and thus to reduce the moisture volume changes. The best results were achieved by using the preparation containing methyl-tripotassiumsilanol as an active ingredient, which has high potential for use in wooden materials. Experiment results demonstrated that increasing concentration of mineralization solution significantly reduces the intake of water into the treated wood. The new information was gained about the behavior of artificially mineralized wood during the exposition into different use classes. The obtained experimental data showed that the liquid water intake is limited for short term mineralized wood while nearly constant material hygroscopicity is maintained. In addition to the properties associated with the water intake, positive mineralization effect on wooden resistance against decaying fungi and mould was also demonstrated. Negative impact of the mineralization on wooden strength is further information. Long term exposure of wood in mineralization solution leads to a reduction in wooden compressive strength and a slight increase of its hygroscopicity. Set of gained knowledge contributes to understanding the processes associated with wooden mineralization and can be the basis for the creation of technological processes for mineralization of wooden structural elements and their distribution in building practice.