Analysis of dehydration in high-performance concrete at high temperature using neutron radiography

The aim of this study was to experimentally investigate the dehydration phenomenon of cement-based products in high-performance concrete exposed to high temperatures, using neutron imaging.Graywacke and limestone were employed as coarse aggregates in the high-strength concrete.The results revealed that when one side of a concrete block was heated, dehydration initiated at temperatures exceeding 100C during the early stages of heating.With prolonged heating, dehydration was observed to begin at temperatures below 100C.In limestone concrete, the region experiencing dehydration above 100C extended deeper into the sample compared to that in Graywacke concrete.These findings suggest that the dehydration of cement hydrates under high temperature conditions is influenced by the state of the interface between the coarse aggregate and the cement matrix.