{ "background": "The durability of conventional concrete in acidic environments is a significant concern for infrastructure in regions affected by industrial or volcanic pollution. Alkali-activated materials, particularly those derived from volcanic ash, offer a promising sustainable alternative, but their long-term performance under acid rain exposure requires rigorous assessment.", "purpose and objectives": "This article presents a novel, standardised methodology for evaluating the acid rain resistance of alkali-activated concrete formulated with volcanic ash from Mount Nyiragongo. The objective is to establish a predictive framework for material degradation to inform durable infrastructure design in Goma and similar volcanic regions.", "methodology": "The proposed method involves accelerated laboratory testing using a cyclic immersion regime in a synthetic acid rain solution (pH 3.5, simulating sulphate and nitrate deposition). Specimens are characterised pre- and post-exposure via mass change, compressive strength, ultrasonic pulse velocity, and microstructural analysis (XRD, SEM-EDS). Degradation kinetics are modelled using a non-linear regression: $\\Delta Mt = \\beta0 + \\beta1 \\ln(t) + \\epsilont$, where $\\Delta Mt$ is mass loss, $t$ is exposure time, and $\\epsilont$ represents heteroskedastic errors corrected with robust standard errors.", "findings": "As this is a methodology article, no empirical results from applying the protocol are presented. However, the proposed analytical framework is designed to quantify degradation rates, with an expected outcome being the determination of a threshold mass loss (e.g., >5%) correlating with a significant reduction in mechanical performance, estimated with 95% confidence intervals.", "conclusion": "The developed methodology provides a comprehensive and replicable protocol for assessing the acid durability of volcanic ash-based alkali-activated concretes, filling a critical gap in material standardisation for aggressive environmental conditions.", "recommendations": "It is recommended that this methodology be adopted for qualifying local volcanic ashes for construction use in Central and East Africa. Further validation through long-term field exposure studies at