Numerical modelling of the poto-poto by coupling of finite elements and boundary elements for acoustic characterization

Abstract

Sustainable development encourages the construction of buildings based from local raw materials because they are ecological, renewable, available, low energy consumption, less costly, low pollution, and therefore without risk to human health. The poto-poto is a widespread material, made of soil material and bamboo, two natural materials widely used in construction throughout the world and particularly in Central African countries, due to their affordable cost or the low technical requirements for their implementation. This material (poto-poto) although widely used, remains very insufficiently explored as well from the point of view of its mechanical characteristics as from the normative point of view necessary for its modernization. This is why, given the extent and large scale of its use, we considered it important to explore it by establishing its physical characteristics. In this paper, we have chosen to continue the characterization of poto-poto already started in the previous paper by also addressing its acoustic characteristics.Indeed, the effects of climate change are manifested by abnormal variations in temperature against seasons. Hence the urgency to master the physical properties in order to make the most of it both in terms of acoustic implementation and/or thermal insulation as regards its use as a green and modern construction material. In this work, we have, on the basis of the Biot model, carried out a 2D numerical modelling of a poto-poto wall by coupling finite elements method (FEM) and boundary elements method (BEM). The MATLAB software was used to obtain the sound absorption curves of our model. We then made several specimens of our eco-material (3 cm, 4 cm and 5 cm) dosed with 2%, 4% and 6% of bamboo fibers, on which Kundt tube measurements were performed to determine the experimental sound absorption curves. The comparison of these curves with those of the model showed acceptable standard deviations and above all allowed us to conclude that the poto-poto presents an acoustic absorption in the range of frequencies 500–1250 Hz and can thus be effectively used for the acoustic implementation of the walls and certain rooms of the buildings.