International audienceThe Phase Change Materials (PCMs) are considered as an attractive way to reduce energy consumption thanks to their heat storage capacity. Their incorporation in the construction materials (gypsum, concrete) contribute to the reduction of the energy consumption of the building structures.Even though PCMs have shown their reliability from a thermal point of view, some drawbacks linked to their use were emphasized such as the loss of the compressive strength of the cementitious material with the addition of PCMs.This paper attempts to provide a possible explanation by the investigation of the hydration kinetic of PCM-mortars. The conventional semi-adiabatic Langavant test was adapted for this purpose. The results showed a lower heat released by the PCM-mortars compared to a control mortar as well as a delay in the hydration process with the addition of PCMs which may contribute to the loss of the compressive strength
