Biochar-red clay composites for energy efficiency as eco-friendly building materials: Thermal and mechanical performance

• Published in: Journal of hazardous materials Vol. 373; pp. 844 - 855
• Main Authors: Yang, Sungwoong, Wi, Seunghwan, Lee, Jongki, Lee, Hwayoung, Kim, Sumin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.07.2019
• Subjects: Agricultural byproduct; Biochar; Building material; Red clay; Thermal property; Building material; Thermal property; Red clay; Agricultural byproduct; Biochar
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2019.03.079

•The binder of red clay & biochar were developed for building application with improved thermal and mechanical performance.•The thermal conductivity of the eco-friendly binder was reduced by up to 50%.•The compressive strength of red clay & biochar building material increased by up to 51%.•Temperature change value of specimen with 2.5 wt.% rice husk biochar decreased 40% compared to reference.•As a result of the comprehensive evaluation, speciment with 10 wt.% bamboo biochar showed the most efficient improvement. Biochar and red clay were used to develop eco-friendly building materials with improved thermal and mechanical performance. Rice husk, coconut shell, and bamboo were prepared by thermally decomposing as biochar. Thermal conductivity measurements, scanning electron microscopy imaging, compressive strength measurements, and an infrared heat transfer experiment were performed, and the results showed that the mixture of biochar tends to lower the thermal conductivity. The compressive strength of specimens mixed with rice husk decreased, but that of specimens mixed with coconut shell and bamboo tended to increase. The infrared heat transfer test showed that the thermal performance of the mixed rice husk specimens was significant, while the specimen mixed with coconut shell and bamboo showed thermal performance improvement. A comprehensive evaluation of the improvement in thermal performance and strength indicated that a 10 wt.% mixture of bamboo was the most effective. Therefore, it was possible to effectively determine the type and weight ratio of biochar to red clay binder an important step in the study of biochar and red clay building materials.