The effect of growth conditions in specific areas of Croatia and the Czech Republic on the physical and mechanical properties of black alder wood (Alnus glutinosa Gaertn.)

In this paper, static bending (modulus of rupture, MOR, and modulus of elasticity, MOE) and compression strength parallel to grain (σcǀǀ) of black alder wood (Alnus glutinosa Gaertn.) were investigated. For experimental testing, we used black alder wood from two different areas: Crni Jarci, Croatia, and Malá Bystřice, Czech Republic. Experimental tests were carried out according to the Czech national standards: ČSN 49 0115 and ČSN 49 0116 for static bending and ČSN 49 0110 for compression strength. The samples from Malá Bystřice showed lower values of MOR (~14%), MOE (~30%), and σcǀǀ (~4%), when compared to the samples from Crni Jarci. The relationship between density and strength was investigated. The difference between the studied groups at the 0.05 significance level was confirmed. The average linear correlation was found between density and the observed mechanical properties (for σcǀǀ). The average density was 549 kg m–3 for samples from Crni Jarci and 469 kg m–3 for samples from Malá Bystřice. The results were compared with values indicated in similar studies.