Calcium carbonate particle formation and distribution in mineralized spruce and beech wood

Abstract

Wood as a building material has many advantages. Yet, its susceptibility to fire and fungal decay is a recurring concern. Wood mineralization with calcium carbonate is an environmentally friendly treatment that increases fire resistance. While mineralization has been investigated, the growth and distribution of particles inside the wood matrix remain understudied. This work focuses on in-situ calcium carbonate particle formation and distribution within two anatomically distinct species, spruce and beech. The results show differences in distribution profile between longitudinal and radial directions for both species, with around 60% of the particles localized in the top 2 mm of 1 cm³ blocks. XRD and SEM analysis show that a combination of calcite and vaterite forms of calcium carbonate is mainly present in the lumen of the wood, as well as residual salts. The relative proportion between the polymorphic forms of these particles varies within the specimens and between species, attesting to a calcite-dominant mineralization process for beech specimens. Moreover, small flame test shows that both the flame height and burned area are reduced with mineralization. Calcium carbonate mineralization potentially improves wood fire resistance, and a better understanding of the mineralization process for different species could enable full exploitation of its properties.

The authors' abstract, as published at the source. Wood Material Science and Engineering, 2026 · DOI ↗