Durability of sandwich beams with textile reinforced cementitious composite faces Matthias De Munck a,⇑ , Tine Tysmans a , Michael El Kadi a , Jan Wastiels a , Jolien Vervloet a , Panagiotis Kapsalis a , Olivier Remy b a Department Mechanics of Materials and Constructions, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium b CRH Structural Concrete Belgium nv, Marnixdreef 5, 2500 Lier, Belgium highlights  Temperature shocks induce microcracks with a lowered initial stiffness as result.  Heat-rain cycles lead to a continued hydration and to premature failure of the fibrous reinforcement.  The presence of the core has a positive influence on the residual behaviour of aged sandwich beams. article info Article history: Received 13 May 2019 Received in revised form 7 August 2019 Accepted 29 August 2019 Keywords: Accelerated ageing Digital Image Correlation (DIC) Environmental loading Four-point bending tests Sandwich plates Textile Reinforced Concrete (TRC) Uniaxial tensile tests abstract Using large lightweight insulating sandwich panels with cement composite faces offers great possibilities for the renovation of existing dwellings. To guarantee the structural performance of these lightweight panels, it is necessary to quantify the impact of varying weathering conditions in the long term. Therefore, this study investigates sandwich beams with textile reinforced cementitious composite faces subjected to heat-rain, heat-cold and/or freeze-thaw cycles to simulate the different weathering condi- tions. To separate the degradation effects at the sandwich element level from the degradation mechanism related to the face material level, also textile reinforced cementitious composite plates were subjected to identical environmental loading. The observations at the material level did not match the observations at the element level. While the structural performance of the textile reinforced cementitious composite plates was strongly affected by the durability cycles, the sandwich panels showed a non-degraded mechanical response after environmental loading. Ó 2019 Published by Elsevier Ltd. 1. Introduction The reduction of the large energy consumption of the building industry is one of the main targets in the race against global warm- ing. A considerable part of the consumed energy in construction is used for the heating of buildings. Therefore, national and interna- tional standards put focus on the energy efficiency of the future and existing building stock. These standards create a strong need for highly energy efficient building solutions, both for new build- ings and for the retrofitting of existing dwellings. Even more for renovation purposes, solutions are searched to facilitate the instal- lation measures and to reduce the total installation time. As such, the inconvenience for the current residents is limited to the minimum. To address this need, insulating sandwich panels offer great possibilities. By placing large prefabricated lightweight cladding panels in front of existing walls, the total renovation time can be reduced to a couple of days. The production of lightweight sand- wich panels for construction purposes can be achieved by using textile reinforced cementitious composites (TRC) as face material. The use of TRC as face material for insulating sandwich panels has been reported by different research teams. The mechanical behaviour of sandwich panels with TRC faces is widely experimen- tally characterised, both in bending [1–3] and in buckling [4]. Parameters as the span [5,6] and the use of connectors [7–9] are looked at as well. This conducted research proves the potential of using sandwich panels with TRC faces as façade/cladding panels. During their service life, sandwich panels and thus the TRC faces experience changing climatic conditions: varying temperatures, rain, freeze, heat, etc. These environmental loadings can cause https://doi.org/10.1016/j.conbuildmat.2019.116832 0950-0618/Ó 2019 Published by Elsevier Ltd. ⇑ Corresponding author. E-mail address: Matthias.De.Munck@vub.be (M. De Munck). Construction and Building Materials 229 (2019) 116832 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat