A new PCM-TRC composite: A mechanical and physicochemical investigation

The present paper presents a multiscale and multiphysics study that focuses on the development of an innovative composite material, which combines a cementitious matrix modified by a phase-change material (PCM) with textile reinforcement (PCM-TRC). The development of this composite has been guided by the conjunction of several factors, among which it is appropriate to emphasise the lightweight of the composite due to the reduced covers in textile reinforced concrete (TRC) coupled to the high thermal inertia due to the addition of PCM microcapsules. This research focuses on the effect of PCM on the mechanical and physicochemical properties of TRC. Special emphasis is placed on providing the phenomenological explanation for the resulting mechanical behaviour of TRC according to the rate and state of the PCM. It has been found that the ductile mechanical behaviour of TRC composites is maintained in the presence of microencapsulated PCM; however, the mechanical performance of PCM-TRC decreases with the PCM rate. This is due to the disorder caused by PCM at the matrix and interface scales. Furthermore, it has been found that the PCM state (solid or liquid) can affect the mechanical performance of both the PCM-mortar matrix and PCM-TRC composite. This is due to PCM expansion during phase change from the solid to the liquid state, which can induce matrix microcracking.