New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full field soft X-ray imaging in the water window is providing new insight into the cement hydration process on the nano scale. Hard X-ray microtomography results on ice inside cement paste and cracking caused by the alkali-silica reaction (ASR) enables 3dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is being explored
