The poultry industry, highly prevalent worldwide, generates approximately 7.7 106 metric tons of chicken feathers (CFs), which become a major environmental challenge due to their disposal when considered waste or due to their energy transformation consumption when considered by-products. CFs are mainly composed of keratin (approximately 90%), which is one of the most important biopolymers whose inherent characteristics make CFs suitable as biopolymer fibers (BPFs). This paper first assesses the morphological and chemical characteristics of these BPFs, through scanning electron microscopy and energy dispersive X-ray spectroscopy, and then evaluates the waste valorization of these BPFs as a sustainable alternative for fiber-reinforcement of earthen mixes intended for earthen construction, such as adobe masonry, rammed earth, and earthen plasters. In particular, four earthen mixes with increasing doses of BPFs (i.e., 0%, 0.25%, 0.5%, and 1% of BPFs by weight of soil) were developed to evaluate the impact of BPF-reinforcement on the capillary, mechanical, impact, and abrasion performance of these earthen mixes. The addition of BPFs did not significantly affect the mechanical performance of earthen mixes, and their incorporation had a statistically significant positive effect on the impact performance and abrasion resistance of earthen mixes as the BPF dose increased. On the other hand, the addition of BPFs increased the capillary water absorption rate, possibly due to a detected increment in porosity, which might reduce the durability of water-exposed BPF-reinforced earthen mixes, but a statistically significant increment only occurred when the highest BPF dose was used (1%).
Bibliographical noteFunding Information:
The authors want to thank the financial support provided by Pontificia Universidad Cat?lica de Chile grants PIA-3581-050-81 and Proyecto de investigaci?n interdisciplina II190041. The authors are grateful for the assistance of Matias Gutierrez, Ren? Santelices, and the technical staff at the laboratory of teaching and research of the School of Civil Construction, where most of this research was conducted. Finally, the authors would like to acknowledge Proyecto Fondequip EQM150101 that provided the experimental infrastructure where SEM and EDS analyses were performed.
Author Contributions: Conceptualization, G.A.-L., Ú.R., C.S., R.A. and F.B.; Data curation, H.G.-C., G.A.-L. and S.K.; Formal analysis, H.G.-C., G.A.-L., C.B.-G., Ú.R., R.A. and F.B; Funding acquisition, G.A.-L. and F.B.; Investigation, G.A.-L., S.K., Ú.R., C.S., R.A. and F.B.; Methodology, G.A.-L., C.B.-G., C.S., and R.A.; Project administration, G.A.-L. and C.B.-G.; Supervision, G.A.-L. and F.B.; Writing—original draft, G.A.-L., and Ú.R.; and Writing—review and editing, H.G.-C., S.K., C.B.-G., S.C., R.A. and F.B. All authors have read and agree to the published version of the manuscript Funding: The authors want to thank the financial support provided by Pontificia Universidad Católica de Chile grants PIA-3581-050-81 and Proyecto de investigación interdisciplina II190041.
© 2020 by the authors.
- Abrasion resistance
- Biopolymer fiber
- Fiber-reinforced earthen mixes
- Impact strength
- Waste chicken feathers