Comparison of physical and mechanical properties of cementitious mortars reinforced with natural and synthetic fibres prior and after wet/dry cycles
In this research, the physical and mechanical properties of cement-based mortars reinforced with hemp, flax and polypropylene fibres, exposed to accelerated aging of wet/dry cycles, were studied and compared with their initial properties, prior aging. The mortar mixture was made with Portland cement as a binder, cement/sand/water ratio of 1:1:0.4 by weight and with sand of particle size between 0.4-0.8mm. As fibre reinforcement short hemp, flax and polypropylene fibres with dosage of 1,0 vol% (volume ratio) within the matrix was used.
The results show that both the density and compressive strength of all composites increased after accelerated aging. The highest density increase was observed by hemp fibre mortars (up to 11.6%) whereas the highest increase in compression strength exhibited flax fibre reinforced mortars (up to 57.97%). When exposed to accelerated aging of wet/dry cycles, all mortars loss their initial flexural strength, however the lowest loss was observed by natural fibre reinforced mortars. Generally, the addition of fibre reinforcement significantly increases the energy consumption capacity under flexure of plain mortars (in case of hemp fibres even by 348%). However, under accelerated aging all composites exhibit a significant loss in their energy consumption capacity under flexure.