Analysis of the response of flax concrete submitted to intense hygrothermal solicitations

Abstract

Flax concrete, an alternative material to hemp concrete, has been studied several times because of its interesting hygrothermal and acoustic performances. However, the durability of this material is questionable and there is a lack of knowledge about it. This paper aims to study the evolution of the compressive strength of flax concrete after accelerated ageing. Two different ageing protocols were carried out: immersion-drying (ageing 1) and immersion-freezing-drying (ageing 2). The results show that the compressive strength is initially affected by the length of the flax shive. The reference concrete has a higher strength with larger flax shive, while the impact of ageing is greater compared to concrete with medium flax shive. After intensive hygrothermal solicitations, the compressive strengths decreased, the reduction is higher for ageing 2 compared to ageing 1, which is explained by the thermal solicitation in addition to the hygric solicitation