Thermal and mechanical behavior of straw-based construction: A review

Ghadie Tlaiji (1) , Salah Ouldboukhitine (1) , Fabienne Pennec (1) , Pascal Henry Biwole (2, 1)

1 IP - Institut Pascal
2 PERSEE - Centre Procédés, Énergies Renouvelables, Systèmes Énergétiques

Bio-based materials such as straw are becoming a promising alternative to improve the building energy performance and to reduce its carbon footprint. When compared to common building construction materials, bio-based materials control the temperature and the relative humidity variation to ameliorate the indoor comfort with a low embodied energy and CO2 emission. This paper presents a comprehensive review of the thermal and mechanical properties of straw-based materials and buildings. The objective is to synthesis the work that has been carried out by the research community and to compare the results. The paper first introduces straw bale as a construction material from a historical viewpoint and in the context of the current building sector. The second part focuses on the available chemical and microstructural data of the straw fiber. The third part refers to the thermophysical and mechanical properties of the bales. The fourth part reviews the numerical and experimental studies done at the wall scale. The fifth part describes straw bale construction methods considering the regulation, structure requirements, and life cycle assessment data. Last, a critical analysis of the currently available data on straw as a building material is carried out and pending research issues are discussed. It was found that, despite abundant literature on structural and thermal properties of straw bale constructions, there is still a lack of some information. At a fiber scale, more research should be done to compare straw fibers to other natural and synthetic fibers. At a bale scale, further pH-related research is needed because it affects the material's interior conditions and durability. In addition, a thermal conductivity model for straw should be developed. On a bigger scale, the hygrothermal characteristics of various types of walls must be measured and computed experimentally and theoretically under various exterior and internal situations. More research is needed to improve the sound resistance of the straw wall by adding new layers capable of absorbing acoustic waves. Studies on the energy behavior, cost analysis, and how interior air moisture is self-regulated in straw buildings are needed at the building size. Therefore, a lack of consistent data among the different studies was noted depending on the straw characteristics.

Mots clés: Straw bale construction Bio-based material Thermal behavior Mechanical properties Life cycle assessment

Domaines: Sciences de l'ingénieur [physics]

Ghadie Tlaiji, Salah Ouldboukhitine, Fabienne Pennec, Pascal Henry Biwole. Thermal and mechanical behavior of straw-based construction: A review. Construction and Building Materials, 2022, 316, pp.125915. ⟨10.1016/j.conbuildmat.2021.125915⟩. ⟨hal-03514128⟩