Mechanical behaviour of hybrid fibre reinforced cementitious composites exposed to high temperatures

Hybrid engineered cementitious composites (HECCs) combine the advantages of different fibres. However, based on current knowledge, the mechanical behaviours of HECC mixed with polyvinyl alcohol fibre (PVAF), steel fibre (SF) and basalt fibre (BF) exposed to high temperature still require study. The mechanical properties of HECCs can be obtained from tensile and compressive experiments. The mechanical properties of PVAF -ECC (mixed with only PVAF), BF-ECC (mixed with only BF), SF-ECC (mixed with only SF), HECC-PB (mixed with PVAF and BF) and HECC-PS (mixed with PVAF and SF) with additions of 65%, 70% or 78% fly ash (FA) at room temperature were investigated. The mechanical properties of the above five materials mixed with 70% FA were also investigated after high-temperature exposure. In these tests, the mixtures were heated to 200°C, 400°C or 600°C and then cooled to room temperature. According to the appearance change, strength change, mass loss, ductility loss and failure form of the specimens, HECC-PS was found to have the best tensile and compressive behaviours after high-temperature exposure. This material is thus suitable as a plastering layer on the surface on masonry structures to ensure the safety of masonry in high-temperature environments.