Recent research highlights the pressing issue of waste slurry disposal, focusing on its environmental consequences and the need for innovative solutions. The study investigates the durability of solidified waste mud under the erosive effects of chloride salts and alternating dry-wet cycles, aiming to address these challenges.
Solidified mud, often used as filling material for construction projects, faces significant durability issues when subjected to varying environmental conditions. This research explores how the unconfined compressive strength and mass change rate of solidified mud are affected by sodium chloride solutions of different concentrations during dry-wet cycles, with findings aimed at enhancing the longevity and effectiveness of construction materials.
Conducted by researchers from multiple institutions including Songtao Zhang, Jianyong Pang, Jinsong Zhang, Changwei Zhou, and Yaxing Wang, this study was supported by the Anhui Provincial Higher Education Science Research Project. Published on May 20, 2025, it presents valuable insights for civil engineering applications.
The experimental investigations were conducted using waste materials sourced from Sichuan Renshou County and Tianjin, China. Tests involved exposing solidified mud samples to dry-wet cycles and sodium chloride solutions, mimicking natural conditions faced by construction materials.
A series of tests revealed alarming results: the unconfined compressive strength of solidified mud diminished significantly with increasing sodium chloride concentration. The most notable decline, reaching 52.89%, occurred under exposure to 40 g/L sodium chloride solution. Concurrently, the mass loss of specimens increased, indicative of micro-damage within the material.
"Under the same number of dry-wet cycles, the higher the concentration of sodium chloride solution, the more serious the micro-damage inside the sample," noted the authors of the article. This statement emphasizes the detrimental effects of chloride ion erosion on the structural integrity of solidified mud.
Prior studies on slurry curing methods have established foundational knowledge. Understanding how environmental conditions affect waste mud usage is of utmost importance, especially considering the global push for resource recycling and waste minimization.
The methodology involved rigorous testing of solidified mud specimens, each subjected to various sodium chloride concentrations and drying cycles. The goal was to simulate real-world conditions and assess the material's performance and durability adequately.
The results demonstrated consistent degradation of specimen strength and mass over repeated dry-wet cycles. The specimens showed significant surface damage, which worsened with higher sodium chloride concentrations. "The unconfined compressive strength of the cured mud specimens under erosion of water and different concentrations of sodium chloride solution decreased with the increase of the number of wet and dry cycles," the study notes.
These findings are particularly relevant for construction applications, where the integrity of solidified materials is critically important for projects exposed to saline environments.
Concluding their research, the authors noted, "The higher the concentration of NaCl solution, the more serious the damage on the surface of the specimen." This highlights the urgent need to develop enhanced solidification techniques to address erosive challenges posed by saline conditions.
Future studies should continue exploring advanced methods of improving the durability of solidified waste mud, potentially leading to more sustainable construction practices amid climate change and environmental degradation.