ORIGINAL ARTICLE Behaviour of clay bricks from small-scale production units after high temperature exposure J. C. Bidoung . P. Pliya . P. Meukam . A. Noumowe ´ . T. Beda Received: 6 January 2016 / Accepted: 26 February 2016 Ó RILEM 2016 Abstract The mechanical and thermal behaviour of traditional clay bricks were investigated after one hour exposure at three different temperatures (200, 400, 600 °C). Specimens collected from small-scale pro- duction units in Cameroon were used. It has been shown that the mechanical behaviour of traditional clay bricks after exposure depends on their quality of firing, which is most of the time affected by the limits of the traditional technologies used for their produc- tion. Among the samples collected, bricks of good quality and low quality of firing were identified. Bricks of good quality of firing have shown a progressive decay of mechanical strength from 200 °C after an increase from the room temperature to 200 °C. Those of low quality have shown an increase in mechanical strength from 400 °C after a stability observed between the room temperature and 400 °C. Both bricks have shown a phenomenon of embrittlement with the increase of the exposure temperature, which was much accentuated in the case of less fired bricks. Thermal conductivity of both bricks has shown a quasi-stability with exposure temperature due to their high porosity from the beginning. Keywords Temperature Á Mechanical strength Á Thermal conductivity Á Physicochemical properties Á Traditional clay bricks 1 Introduction Fired clay bricks are one of the oldest building materials [1, 2]. They are estimated to have been used since the year 5000 to 4000 BC [3, 4] and are classified in the group of traditional ceramics. Despite their age, they continue to be in high demand and are ranked among the most important building materials because of their many advantages such as: aesthetics, strength, durability, low cost and insulation performance [3, 5]. Nowadays, the production of fired clay bricks is practiced worldwide, from small-scale to industrial- scale. Whatever the method of production, fired clay bricks have been used and are still used in housing projects. The products obtained from the small-scale production sector are used for social housing in developing countries. It is useful, not only to master the strength and durability of such products, but also be able to predict their behaviour in extreme condi- tions such as fire exposures. Furthermore, the similar- ity of those products with traditional bricks also opens the possibility to contribute to the study of the J. C. Bidoung (&) Á P. Meukam Á T. Beda Ecole Nationale Supe ´rieure Polytechnique, Universite ´ de Yaounde ´ I, BP: 8390 Yaounde ´, Cameroun e-mail: bidoung@yahoo.com P. Pliya Á A. Noumowe ´ Laboratoire de Me ´canique et Mate ´riaux du Ge ´nie Civil, Universite ´ de Cergy-Pontoise, 5 Mail Gay Lussac, Neuville sur Oise 95031, France Materials and Structures DOI 10.1617/s11527-016-0838-0