Determination of the Bond Strength of Wood Veneer and Geopolymer Matrix by Means of a Pull-Out Test

Abstract

The bonding strength of wood veneer (Picea abies) attached between a geopolymer matrixes were investigated by means of a pull-out test. Effects of pre-treatment of wood on the bonding strength were applied whereas a strong influence of pre-treatment on bonding strength could be observed. The treatment of wood veneer showed that using wet veneer (~90% moisture content) leads to the best results compared to untreated dry (~12% moisture content) veneer. Furthermore, the effects of sodium hydroxide extraction and sodium silicate treatment were examined. The lignin UV absorbance values in treated wood, obtained by scanning ultraviolet microspectrophotometry (UMSP), do not show any significant changes in absorbance which mean that there were no complex changes in phenolic wood components, including modification of the lignin side chains. It can be said that the alkaline environment needed for geopolymer was not the main problem that limits wood (Picea abies)-geopolymer compatibility.