Work

Effect of recycled waste cardboard chips on the physico-thermal-hygric properties of hemp-lime biocomposites

Year: 2026

Type: article

Abstract: ABSTRACT Buildings are major contributors to global energy consumption and environmental impacts, highlighting the critical need for sustainable and energy-efficient insulation materials. Biocomposites incorporating recycled cardboard have emerged as promising solutions for such applications; however, their production methods are often labor-intensive, energy-demanding, and time-consuming. To address these limitations, the present study explores the feasibility of using recycled waste cardboard chips (RWCC) as a partial or complete replacement for conventional hemp shives in hemp-lime biocomposites. A simplified, low-energy, and rapid processing methodology was developed in which untreated RWCC, cut directly from post-consumer cardboard, were incorporated into hemp-lime matrices without any pre-treatment. The RWCC were mixed using a rapid blending procedure and lightly compacted, thereby eliminating the need for grinding, crushing, soaking, defibrating, extended compaction, or thermal curing. Substitution ratios ranging from 0 to 100 wt% were investigated to assess physical, thermal, and hygric properties. The resulting biocomposites exhibited low densities (514–682 kg/m 3 ) and high porosities (68.7–75.5 %), leading to low thermal conductivity (0.0775–0.0919 W/(m⸱K)), high heat capacity (972–1036 J/(kg⸱K)), low thermal diffusivity (1.25–1.51 × 10 −7 m 2 /s), and low thermal effusivity (200–248 J/(m 2 ⸱K⸱s 1/2 )), thereby enhancing both insulation performance and thermal inertia. Adequate vapor permeability (1.24–2.12 × 10 −11 kg/(m⸱s⸱Pa)) and moisture buffer capacity (0.66–1.59 g/(m 2 ⸱%RH)) were also observed, supporting healthy indoor environments. Overall, the results demonstrate the feasibility of valorizing untreated RWCC in hemp-lime matrices, achieving properties comparable to those of established bio-based insulation materials while significantly reducing processing intensity.

Source: Results in Engineering

DOI: 10.1016/j.rineng.2026.109773

Authors: Akli Younsi, Armelle Nouviaire, Rafik Belarbi

Institutions: Centre National de la Recherche Scientifique, Laboratoire des Sciences de l'Ingénieur pour l'Environnement, La Rochelle Université, Canadian University of Dubai

Language: English

Topic: Hygrothermal properties of building materials

Subfield: Building and Construction

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Affordable and clean energy, Climate action

Open Access status: gold

Estimated APC paid: $1,940