Mineralogical analysis of portland cement pastes rehydrated

Hydrated products, such as (hydrated) cement pastes, decomposition through physicalchemical alterations when submitted to high temperatures. One of the main factors that lead to microstructural changes during calcination up to 800°C, is the dehydration phases of hydrated Portland cement. The present study sought to characterize crystalline phases occurring before and after calcination to the produced pastes using X-ray diffraction (XRD) analysis. Cement pastes were produced using Portland cement CP V-ARI RS, similar to type II (ASTM C150-07), with water/cement ratio 0.5. After a 28-day curing period, the pastes were calcinated at 800°C for 60 minutes with a 10°C / min heating rate. Afterwards, the newly produced hydraulic binder was cooled abruptly and reactivated through a rehydration process, and underwent analyses on the 7 and 28 day. During this study it was observed that the originally hydrated products can be rehydrated. © 2020 Widener University School of Civil Engineering. All rights reserved.