Effect of Seawater with Average Salinity on the Moisture Content, Ash Content and Tensile Strength of Some Coniferous Wood

Abstract

In this paper, the differences in mechanical strength tested during the static tensile and compression test of Scots pine (Pinus sylvestris L.), European larch (Larix decidua) and Norway spruce (Picea abies) wood exposed to continuous soaking in water with a salinity of 7‰ were determined. The value of salinity corresponded to the average salinity on the Polish Baltic coast. This paper also aimed to examine the content of mineral compounds absorbed during four cycles of two weeks each. The essence of the statistical research was to identify the effect of the mineral range compounds and salts depending on the mechanical strength of the wood. Based on the results of the experiments, it can be concluded that the medium used has a specific effect on the wood species’ structure. The effects of soaking on the wood parameters depend obviously on the type of wood. A tensile strength test of pine, as well as the tensile strength other species, was enhanced by incubating it in seawater. A native sample’s initial mean tensile strength was 82.5 MPa, which increased to 94.8 MPa in the last cycle. It was found that the larch wood had the lowest tensile strength difference (9 MPa) of the woods studied in the current study. Four to six weeks of soaking was necessary to notice an increase in tensile strength.

The Effects of Seawater Treatment on Selected Coniferous Wood Types

“…The volume of the liquid that was absorbed during immersion was estimated based on the mass of the sample. Studies were developed based on a previous analysis that was already published in the literature [16]. The moisture before the strength test was always 12% [24] for comparison purposes.…”

“…This can affect the moisture content (MC) and the growth of NaCl crystals in wood and its impact on the mechanical properties. However, the material strength tests were aimed at maintaining the same moisture content concerning the standard [24], while the issue of NaCl absorption was demonstrated in the ash measurement tests, to be more widely dissected in the authors' previous article [16]. The weighted vessels were dried in a dryer at 103 • C during this study.…”

“…The crucible content was compared with the raw material's weight before the ash was obtained. The results of this research were based on previous analyses of wood that had been soaked in NaCl, and we compared and described the results from the table with those found in the literature [16]; the preparation of the tested samples and methodology were also described. According to the methodology, approximately two hours later, the samples' ash content was measured after preparation.…”

“…A summary of the average effect of the number of soaking cycles used on the compressive strength values for all species is presented in Table 7. Additional mechanical tests were conducted in a previous analysis that has been published by the authors in the literature [16]. Studies were developed and the results of the strength test were taken into account.…”

“…According to the authors of [15], one of the largest drawbacks of wood as a raw material, used in a wide variety of industries, is its susceptibility to the environmental and weather conditions in which the wood grows. Moreover, it is affected by the environment and climate of the site where it is used [16]. As a result of their action, the physical and strength properties deteriorate, so that the durability of an object composed of unprotected wood is also reduced.…”