Adaptation of rammed earth to modern construction systems: Comparative study of thermal behavior under summer conditions

Buildings should be understood as a process that consumes energy in all their phases (design, construction, use and end-of-life) and, more specifically, the building envelope is clearly involved in all of them. For this reason, the International Energy Agency defines in its latest publication the improvement of building envelopes as one of the key points to reduce the energy consumption in buildings. In the present study, two sustainable construction systems based on rammed earth walls are adapted to modern requirements to be thermally tested and compared against three Mediterranean conventional systems under summer conditions. The experimentation was done by performing several experiments in free floating and controlled temperature conditions at real scale in five cubicle-shape buildings with inner dimensions 2.4 × 2.4 × 2.4 m. The purpose of this study is to demonstrate that more sustainable construction systems can be used instead of conventional ones, with higher embodied energy, and achieve similar thermal response. Results show that the reduction of rammed earth wall thickness strongly penalizes its thermal behavior. However, similar thermal response than conventional systems is reached when 6 cm of wooden insulation panels are added in the outer face of the cubicle-shape building.The work is partially funded by the Spanish government (ULLE10-4E-1305 and ENE2015-64117-C5-1-R). The authors would like to thank the Catalan Government for the quality accreditation given to their research group GREA-UdL (2014 SGR 123) and the city hall of Puigverd de Lleida. This project has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under Grant agreement N° PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 657466 (INPATH-TES). Alvaro de Gracia would like to thank Ministerio de Economia y Competitividad de España for Grant Juan de la Cierva, FJCI-2014-19940