Effect of sorption capacity on thermo-mechanical properties of unfired clay bricks

International audienc

Dynamic thermal performance of three types of unfired earth bricks

International audienceThe present work aims at studying the thermophysical properties of three types of unfired earth bricks through experimental investigation, and their dynamic thermal performance (thermal capacity, decrement factor and thermal lag) as a function of wall thickness. The objective is to determine the ideal thickness of a raw earth wall, built by these bricks, to achieve the optimum values of thermal inertia. These bricks were industrially produced by the Briqueteries du Nord, which is a factory located in the north of France. The process used was the extrusion. The main difference between the three types of bricks is the origin of the soils, which were extracted from various quarries. They were characterised to determine their physical, chemical and geotechnical properties, and to identify their impact on development and production of unfired earth bricks. This work has identified the optimum thickness of the wall built by these unfired earth bricks. (It was 0.3 m for two types of bricks and for the other one was 0.4 m.) This thickness ensures the greatest heat capacity and a thermal lag between 10 and 12 hours, while taking into account the quantity of bricks necessary for the construction of such a wall and the habitable area

Thermal performance of unfired clay bricks used in construction in the north of France: Case study

The objective of this study is to demonstrate and to study the sustainability and the qualities of the earthen construction in real conditions. A demonstrative building was designed and built with unfired clay bricks, were industrially produced by the factory “Briqueteries du Nord” (BdN). This industrial plant is located in the north of France. This project aims to create conditions for the development of earthen construction techniques in the north of France. Moreover, it aims to prove the benefits of this material on the sanitary quality of the building. This article is composed of three parts. Firstly, the identification of raw materials was performed in order to study the mains properties of these building materials. The second part of this work presented an experimental study conducted to investigate the dynamic thermal performance of unfired clay bricks. To complete the tests already carried out in laboratory, an experimental investigation was carried out in situ on a demonstrative building. The hygrothermal performance of building is monitored for two consecutive years. The first analysis of the obtained data proved clearly that the earthen wall reduces the fluctuations of the outside temperature