A novel test protocol for assessing accelerated salt weathering effects on construction materials and natural rocks

Salt weathering poses significant challenges to the durability and integrity of construction materials across various engineering applications. This study introduces a novel accelerated salt weathering protocol designed for standardised laboratory testing, aimed at evaluating the effects of salt crystallisation on natural rocks and construction materials. The protocol was validated using three distinct materials: Flysch rocks, Vosges sandstone, and high-performance concrete. The core protocol features continuous partial immersion of cylindrical-shaped samples in a 3 molal sodium sulphate solution at 32 °C. At the same time, room temperature is maintained at 20 °C, providing well-defined boundary conditions for easy reproducibility and potential numerical modelling. Non-destructive monitoring techniques, including time-lapse photography coupled with Digital Image Correlation (DIC) and acoustic emission (AE) analysis, were integrated into the core protocol. In addition, post-mortem X-ray tomography and optical microscopy were used to characterise salt-induced crack patterns further. The Flysch rock samples exhibited significant external deterioration, with DIC analysis highlighting the influence of material heterogeneity in damage susceptibility. AE analysis captured internal damage progression and identified the onset of salt-induced deterioration in the Vosges sandstone samples, which displayed consistent responses to the weathering test protocol. The concrete samples, pre-cracked by mechanical loading to mimic on-site coastal erosion conditions, exhibited salt-induced crack propagation and development of new salt-induced cracks when tested under the weathering protocol. These findings demonstrate the protocol’s effectiveness in evaluating salt-induced damage in construction materials, providing a reproducible framework that can be readily implemented in diverse testing environments to enhance durability assessment in engineering applications. • A novel accelerated salt weathering protocol is introduced for standardized laboratory testing. • The protocol features continuous partial immersion in a sodium sulphate solution under controlled temperature conditions. • Non-destructive monitoring techniques track real-time damage evolution and post-mortem analysis reveals salt-induced crack patterns. • The protocol successfully evaluates salt-induced damage in Flysch rock, Vosges sandstone, and high-performance concrete. • The study provides a reproducible framework to improve durability assessments in construction materials.