Thermal and mechanical properties of a sustainable bio-flax fiber based light-weight aggregate concrete

A novel lightweight aggregate concrete (LWAC) or lightweight concrete (LWC) is developed using the expanded perlite powder (EPP) and light-weight expanded clay aggregate (LECA) as a replacement for conventional fine and coarse aggregates respectively. Furthermore, the natural plant-based flax fiber in treated form was added to the LWC mix at three different volume fractions. The mechanical and thermal characterization of lightweight concrete was done using the compressive strength test, split tensile test, modulus of rupture, thermal conductivity and thermal resistance test. Moreover, the micro-structural and durability properties were obtained using scanning electron microscope/ energy dispersive X-ray spectrum analysis, rapid chloride penetration test, sorptivity and water absorption test. Test results reveal that the addition of 2.0% flax fiber resulted in improved mechanical, thermal and durability properties when compared to the LWC with no fibers. Moreover, the micro-structural analysis using SEM revealed the formation of Ettringite which is responsible for the strength development in the LWAC mix.