Technology, exploitation and consumption of natural resources of traditional brick productions in Madagascar

The history of brick manufacturing in Madagascar dates back to the early 1800 s when European colonisers imparted to the local population the basic knowledge for firing clayey sediment to obtain a more durable construction material. The evaluation of the entire production cycle accounting for the involved natural resources such as raw materials, fuels and derived bricks, represents the aim of this research started in 2015 and focused on both rural and urban contexts. Clayey raw materials from lateritic soils widely occur in central Madagascar whereas, in southern coastal sites, carbonate-bearing clays definitely prevail since their composition are influenced by the reef. Bricks are prepared on site with no additional manipulation of the base clay and, depending on the climatic conditions, the bricks are dried and fired from one week up to ten days. Furnaces are powered by rice husk in south-western part of the island whereas in central Madagascar the use of peat and wood was also recorded. The calorific performances of these common fuels allow achieving temperatures of 800–900 °C; however, the huge loss of heat due to the poor quality of the furnaces determine low equivalent firing temperatures (EFT) that negatively affect the quality of the bricks. The above described ceramic process has remained unchanged for more than 200 years and even if new social and economic opportunities arose, this unvirtuous system slowly (but inexorably) contributed to the impoverishment of important energy sources and, above all, of natural resources