Adobe bricks reinforced with paper & pulp wastes improving thermal and mechanical properties

Abstract

Soil-based building material has been used since ancient times but lately it has been mainly considered for restoration purposes of traditional architecture instead of an eco-friendly construction material for new buildings. However, the promotion of a more sustainable architecture has recently led to look towards adobe or rammed earth, among others. Because of the high impact of concrete and the fired clay brick industry, mainly due to the use of clinker and the firing process, respectively, adobe may highly reduce the ecological footprint of conventional construction and building materials. In addition, the use of fibers for adobe reinforcement has been also highlighted as a key factor for improving adobe performance. Obviously, when residues successfully replace such fibers the ecological footprint may be reduced even more. Thus, this research focuses on the assessment of adobe reinforced with paper and pulp industry residues (PPR) with the aim of demonstrating the feasibility of this construction material. Several series have been made by varying the replacement percentage up to 20% and technological properties and toxicity have been assessed. It is concluded that compressive strength may be improved up to 190% while thermal conductivity is reduced approx. 30% for 12.5% of PPR replacement. Besides, adobe meets standards related to water resistance and toxicity values.