PSI - Issue 81

Dmytro Y. Kysliuk et al. / Procedia Structural Integrity 81 (2026) 430–433

431

(2018); Polasik et al. (2025)). Therefore, experimental studies on softwood species modified with epoxy resin via autoclave impregnation under axial compression along the grain with short-term loading are particularly relevant. The purpose of the work is to study the mechanical characteristics of solid larch, pine, and spruce wood modified with epoxy resin by autoclave impregnation. 2. Methods of experimental research Prismatic specimens measuring 30 × 30 × 120 mm with a moisture content of 12% were manufactured at a woodworking facility without any visible defects (DSTU 4922:2008; DSTU EN 518 – 2003).

a

c

b

Fig. 1. Samples of unmodified wood: (a) pine; (b) larch; (c) spruce.

In this study, a two-component epoxy resin was used for wood modification. The treated specimens were softwood species, namely pine, larch, and spruce. Impregnation was carried out in an autoclave at a pressure of 2 atm for one hour. After autoclaving, the samples were dried in a drying chamber at 50 °C for two hour s until the resin was fully cured.

b

a

с

Fig. 2. Wood prisms modified with epoxy resin by autoclave impregnation: (a) pine; (b) larch; (c) spruce.

The scope of the experimental research is presented in Table 1.

Table 1. The scope of the experimental research

Wood species Cross-sectional dimensions, mm

Processing moisture content, %

Impregnation fluid Modification method Number of specimens

Pine

12 12 12

epoxy resin epoxy resin epoxy resin

autoclave autoclave autoclave

5 5 5

30х30х120 30х30х120 30х30х120

Larch Spruce

The determination of compressive strength along the grain for both modified and unmodified specimens was carried out using a STM-100 servo-hydraulic press under a single short-term loading mode (DSTU 3129:2015; Yasniy et al. (2022)).