Alternated desorption-absorption accelerated aging of Salix psammophila sand barrier

Abstract

Salix psammophila has been extensively used as a sand barrier material in many desertification control applications. Thus, understanding its degradation processes with long-term environmental moisture changes is essential. In this paper, via alternated desorption-absorption treatment of the S. psammophila sand barrier, damage of differing degrees occurred, and moisture variation was simulated. Through FTIR, X-ray diffraction, SEM, and other characterization methods, changes in macroscopic morphology and physical-mechanical properties of S. psammophila sand barrier were tracked, evaluated, and compared, and the causes were analyzed. The results showed that the alternated desorption-absorption accelerated aging treatment weakened the physical-mechanical properties of the S. psammophila sand barrier. The microscopic manifestation was the decrease in space between the tracheids, which caused the formation of cracks on the macroscopic level. Carbohydrates (cellulose, hemicellulose, and lignin) degraded, which reduced the crystallinity of cellulose, and cracks appeared on the surface of the S. psammophila sand barrier. As the aging degree increased, the number of cracks increased, and the cracks continued to extend to both ends. Therefore, the degradation of the S. psammophila sand barrier was mainly caused by shrinkage cracking in the alternated desorption-absorption aging process, which reduced the ability of the S. psammophila sand barrier to resist lodging damage.