Rice is the staple food in Madagascar. The rind of this rice is, therefore, a waste present in large quantities on the island. Some of these bark is used by brickmakers to bake clay bricks. A minimal amount of the ash produced by these burned bark is used to produce soap. The rest is released into the environment as agricultural waste. Our work aims to find another way of recycling this ash, which is mainly located on the large island. The studies carried out in this article have been directed towards mixing these ashes with cement dedicated to the construction of buildings. The idea is not new but provides a local solution to a specific problem in the country. The advantage of such an approach is twofold : it reduces the cost of construction but also enables the recovery of the agricultural waste produced in Malagasy state.