Historical timber buildings in Shanxi province, China, face significant restoration challenges due to natural degradation, extreme weather events, and restrictions on native timber harvesting, necessitating the use of alternative timber species for structural repairs. This study examines the material properties of four timber species – Chinese pine (Pinus tabuliformis Carrière), larch (Larix gmelinii var. principis-rupprechtii [Mayr] Pilger), Douglas fir (Pseudotsuga menziesii [Mirbel] Franco), and Mongolian Scots pine (Pinus sylvestris var. mongolica Litv.) – commonly used in the restoration of historical timber buildings in Shanxi. Given the structural diversity of these buildings, six loading modes were applied to assess the suitability of each species for different structural components: compression parallel to the grain, compression perpendicular to the grain in the radial direction, shear parallel to grain along the longitudinal-radial plane, shear parallel to grain along the longitudinal-tangential plane, four-point static bending, and tension. Douglas fir exhibited the highest compressive strength parallel to the grain, making it well-suited for load-bearing components, while Chinese pine demonstrated strong compressive strength perpendicular to the grain in the radial direction. Larch and Douglas fir excelled in shear resistance, and all four species exhibited high bending strengths, supporting their use in primary structural components. In contrast, Mongolian Scots pine exhibiting lower shear and bending strengths is more appropriate for non-load-bearing applications where structural demands are minimal. Positive correlations between strength, density, and dynamic modulus of elasticity suggest that density and ultrasonic testing can serve as effective non-destructive evaluation methods. These findings provide valuable insights into material selection for heritage timber restoration, promoting species-specific applications that enhance structural resilience while preserving traditional carpentry techniques.

The adaptive reuse of industrial heritage is increasingly recognized as an effective low-carbon strategy that reduces resource consumption, lowers embodied carbon emissions, and supports sustainable urban transitions. Developing appropriate reuse strategies, however, requires a robust understanding of heritage value. As material evidence of China’s modern industrialization, railway-associated industrial heritage possesses the characteristics of linear cultural heritage. Yet systematic and multi-scalar value assessments from a linear heritage perspective remain limited. Focusing on the Guanzhong Section of the Longhai Railway—one of the most representative industrial development axes in Northwest China—this study establishes a two-level value assessment framework and conducts a comprehensive evaluation of fourteen textile industrial heritage units. At the individual level, five dimensions—historical significance, architectural features, structural integrity, authenticity, and rarity—were assessed through field investigation, and type-specific weights were introduced to correct structural imbalances between quantity and value across building categories. At the unit level, the Analytic Hierarchy Process (AHP) was employed to determine the weights of spatial–functional integrity, process completeness, railway connectivity, industrial landscape characteristics, and the integrated individual-level value. The results show that factory workshops and warehouses consistently exhibit the highest value, whereas structures and residential buildings, despite their numerical dominance, contribute relatively little. Spatially, a clear west–east gradient emerges: high-value units cluster in Baoji and Xi’an, medium-value units in Xianyang, and low-value units mainly in Weinan and surrounding counties. The findings indicate that textile industrial heritage along the Guanzhong Section forms a railway-linked linear cultural heritage system rather than isolated sites. The proposed evaluation framework not only supports heritage identification and conservation planning but also provides a theoretical basis for promoting low-carbon adaptive reuse of existing industrial buildings.

Assessing decay-induced mechanical deterioration in hardwood components is essential for the conservation of northern Chinese timber heritage, where structural members such as the Dou and Gong have been exposed to complex environments for centuries. Within a unified experimental framework, this study systematically investigated the mechanical degradation behavior of two hardwood species commonly used in traditional timber buildings in northern China—elm (Ulmus pumila L.) and Chinese scholar tree (Styphnolobium japonicum (L.) Schott)—subjected to controlled brown-rot fungal decay (Gloeophyllum trabeum) over decay durations of 0–6 months. Four mechanical loading configurations were considered: tension, bending, compression parallel to grain and compression perpendicular to grain. Decay progression was quantitatively characterized using mass loss rate (MLR), ultrasonic elastic modulus loss rate (ELR) and strength loss ratio (SLR). The two hardwoods exhibited distinct material- and loading-dependent deterioration patterns. Elm showed faster and more variable degradation, with clearer time-dependent strength loss under tension and bending, whereas Chinese scholar tree displayed slower and more scattered strength deterioration. For both species, elastic modulus reduction generally preceded measurable mass loss, indicating that modulus-based indicators are more sensitive to decay progression under the tested conditions. Correlation analyses further indicate that ELR tends to show more stable and consistent associations with strength loss than MLR across most loading modes. Overall, the results suggest that elastic modulus–based ultrasonic indicators have potential advantages for characterizing mechanical deterioration under controlled decay conditions. However, the findings are limited to the tested materials, decay scenarios and loading configurations, and further validation on aged or naturally decayed components is required before in situ application to heritage structures can be established.