Characterization of the Coffee Husk: A Potential Alternative for Sustainable Construction

Agro-industrial wastes are a potential alternative for sustainable construction because they provide a renewable source, reducing raw materials consumption, emissions, and waste production. In the Colombian coffee sector, a big waste amount of husk is developed in its production, which is obtained from the pulping of coffee, being this husk an excellent source of cellulose and lignin, in a natural way. This experimental research aims to characterize the coffee husk as a potential alternative for sustainable construction in dividing walls. The methodology was developed in three steps, concerns from the obtention of the coffee husk in Ocaña Norte de Santander in Colombia to the physical and chemical characterization properties of this material considering the NTC-2441 Colombian Technical Standard. The results showed that the coffee husk presents a humidity of 13.3% with an average particle size of 611.93 μm. Also, the particle size of the coffee husk is related to the threshing process, where the by-product base coffee waste is obtained. In addition, the visualization of internal micro-cracks, carbon, and oxygen composition was possible with the presence of natural fibers using the Scanning Electron Microscopy technique. Finally, the coffee husk exposes in its chemical composition the presence of carbon and lignin, showing a structure with cracks of excellent resistance without the evidence of the samples fracture, which allows concluding that the coffee husk can be a potential and new alternative for sustainable construction for diving walls and another kind of applications in non-structural masonry in civil engineering, taking into account that in Colombia this bio-material has been little used in the mixture for obtaining products with good physical and mechanical performance.