A review of the long-term effects of humidity on the mechanical properties of wood and wood-based products

Abstract

Wood is an indispensable building material for modern structures. As a kind of biological material, it is more likely than other materials to be affected by the environment. It has been shown that the effect of long-term exposure to humidity will accelerate the decrease in mechanical properties and long-term strength of wood and wood-based products. The most commonly used methods for studying the deterioration of the mechanical properties of wood and wood-based products under the action of long-term humidity exposure are artificially accelerated aging and outdoor exposure. Many scholars have studied various artificially accelerated aging tests, which can accelerate the aging of wood and wood-based products and save substantial time. However, the results of outdoor exposure tests can be better correlated with the aging of the materials in the actual environment. Scholars have established a relationship between artificially accelerated aging tests and the results of outdoor exposure tests and have studied the results of outdoor exposure tests under different climatic conditions. This paper not only reviews the artificially accelerated aging tests used for wood and wood-based products in the past twenty years, but also summarizes their characteristics and application scope. In addition, the relationship between the outdoor exposure tests and the artificially accelerated aging tests is reviewed. At the end of the paper, the challenges and prospects for the future works are put forward.