Functional testing for sulfate resistance of concrete

Sulfate attack is a major durability challenge for concrete structures exposed to seawater or sulfate‑rich groundwater, leading to cracking, loss of integrity, and reduced service life. Despite more than a century of research, there is still no standardized, performance‑based test method that reliably characterizes sulfate resistance for modern concretes within exposure resistance classes (ERC).

Existing test methods largely rely on expansion alone and often fail to represent deterioration mechanisms, and the behavior of low‑carbon and blended cement systems. This limits their applicability for both design and standardization, particularly in the context of Eurocode 2 and the increasing use of alternative binders.

This project addresses these gaps by developing mechanism‑aware accelerated sulfate resistance tests that better reflect real exposure conditions. The work combines multi‑scale testing (concrete, cement paste) and multi‑parameter evaluation, including expansion, mass change, ultrasonic pulse velocity, and microstructural analyses (XRD, TGA, selected SEM). The approach decouples transport and chemical degradation mechanisms to improve interpretation and predict long‑term performance within shorter timeframes.

The project will benchmark the developed methods against established standards and translate the outcomes into practical guidelines for industry use. The results will support material selection, faster qualification of low‑carbon concretes, reduced testing time and costs, and increased durability of concrete infrastructure. The final outcomes will contribute to the implementation of ERC for sulfate resistance in Swedish standards and support sustainability goals in line with Agenda 2030.