Material Degradation and Durability Assessment of Pipelines and Sanitation Structures Under Aggressive Environmental Conditions

Abstract

This study investigates the problem of accelerating material degradation and declining durability in pipelines and sanitation structures exposed to aggressive environmental conditions, where moisture intrusion, corrosive soils, chemical attack, salinity, microbial activity, and temperature fluctuation progressively weaken structural integrity and serviceability. The purpose of the study was to quantitatively assess how these environmental stressors influence degradation patterns and durability outcomes across selected infrastructure cases. A quantitative, cross-sectional, case-based research design was adopted, using structured questionnaire data collected from 186 valid respondents out of 214 distributed instruments, yielding an 86.9% valid response rate. The sample reflected clouded enterprise-style infrastructure case contexts through pipelines, sewer chambers, wastewater conduits, and sanitation tanks/manholes assessed by engineers, maintenance officers, utility managers, and sanitation specialists. The key variables were aggressive environmental conditions as the independent variable, material degradation indicators as the mediating variable, and durability and serviceability performance as the dependent variable. Data were analyzed using descriptive statistics, Pearson correlation, and multiple regression. The findings showed a high presence of aggressive exposure conditions with an aggregate mean of 4.18, led by moisture intrusion at 4.36, corrosive soil exposure at 4.27, and chemical attack at 4.21. Material degradation was also severe with an aggregate mean of 4.09, with corrosion intensity recording the highest mean of 4.33, followed by cracking severity at 4.17 and wall thinning at 4.09. Durability concern was substantial with an aggregate mean of 3.88, especially increased maintenance frequency at 4.12 and reduced expected service life at 4.07. Correlation analysis revealed a strong positive relationship between aggressive environmental conditions and material degradation (r = .742, p < .001), while degradation was strongly negatively related to durability performance (r = -.711, p < .001). Regression results further showed that environmental conditions explained 55.1% of degradation variance (R² = .551), and together with degradation explained 61.7% of durability loss (R² = .617). The study implies that durability management should shift toward risk-based, condition-focused, and exposure-sensitive maintenance planning for long-term infrastructure resilience.