Behavior of Chinese Dahurian Larch Wood after High-Temperature Exposure: Degradation of Mechanical Properties and Damage Constitutive Model

Abstract EN

Wood has been extensively used in Chinese ancient buildings, and it is important to clearly understand the mechanical properties of wood after exposure to elevated temperatures.

In this paper, three kinds of tests with 102 clear wood specimens fabricated with Chinese Dahurian larch for each kind of test were conducted.

The residual compressive strength, tensile strength, and shear strength parallel to grain of specimens after exposure to different temperatures (100°C, 150°C, 200°C, and 250°C) with various exposure times (15 min, 30 min, and 45 min) and different cooling methods (natural cooling and water cooling) were obtained.

Results indicate that exposure to elevated temperatures causes great degradation of compressive strength, tensile strength, and shear strength parallel to grain.

When the exposure temperatures exceed 200°C, the relative compressive strength, tensile strength, and shear strength parallel to grain decrease greatly with the increase of exposure time.

The residual compressive strength, tensile strength, and shear strength of specimens after water cooling are lower than that after natural cooling.

Exposure temperatures also have a great impact on the weight loss and color change of wood.

Based on the test data, degradation models for the residual compressive strength, tensile strength, and shear strength of wood were developed.

Furthermore, the damage constitutive model of compressive (CDMC) and tensile (CDMT) parallel to grain was established and validated reasonably by tests.