TITLE:
The Technique of the Tri-Layer Coating: An Effective Solution for the Protection of Earthen Constructions
AUTHORS:
Sinko Banakinao, Soviwadan Drovou, Komlan Lolo, Kodjo Attipou
KEYWORDS:
Tri-Layer, Tannin, Coating, Soil, Earthen Constructions
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.13 No.4,
December
21,
2023
ABSTRACT: The
problem with earth constructions is their low resistance to water. Step by
step, the water degrades the exterior facings of the structures and ends up
creating zones of weakness through the structures, making them collapse and
creating enormous socio-economic problems, especially in rural areas. The
solutions proposed to date, like the use of straw, cow dung, boiled skins,
banana leaves, tar, cement soil, have shown their limits. Generally, the poor
adhesion between the protected material and the protective layer means that the
latter always ends up peeling off. This work, which is inspired by the
traditional practice where plant tannins are used to brush the earthen walls to
waterproof them, proposes a tri-layer coating composed of soil, powder and hydrolysable
tannins extracted from the stem bark of Bridelia. This work focuses on the
geotechnical characterization of the soil, the extraction of hydrolysable
tannin, the manufacture of the micro-coating, the resistance tests carried out
on the micro-coating, the technique of implementation and the test of
evaluation of the performance of the tri-layer coating. The results obtained
show that not only does the tri-layer coating adhere perfectly to the layer to
protect, but it also waterproofs it and protects it against shocks.