Influence of Chopped Sisal Fiber (CSF) on Properties of Pure Gypsum with Various Water-Gypsum Ratios

The current study investigates the impact of employing one of the natural fibres (Sisal Fibre (SF)) on pure gypsum characteristics (specifically compressive strength and density). The research plan consists of using six mixes of pure gypsum; these mixes are divided into two groups according to the (water/pure gypsum) ratios (0.55 & 0.65). Each group was divided into three subgroups according to volume fraction (Vf) of chopped sisal fibre (CSF) 0.0%, 0.2% and 0.4%. Three cubic (50 x 50 x 50) mm samples were performed for each mix. It was found that, the addition of chopped sisal fibre to the pure gypsum mixes increases the compressive strength for both (W/PG) ratios, and the percentage of this increase is enlarged with increasing (W/PG) ratio. Additionally¸ the compressive strength decreases for all (Vf) of CSF whenˑthe (W/PG) ratio is increased¸ and this percentage of deterioration decreases as increases volume fraction (Vf) of chopped sisal fibre (CSF). However¸ it was also shown that adding CSF to pure gypsum mixtures results in a modest loss in density for both (W/PG) ratios¸ with the proportion of this drop decreasing as the (W/PG) ratio decreases. Additionally¸ the density deteriorates for all (Vf) of CSF when the (W / PG) ratio is increased¸ and this percentage of deterioration is marginally increased as increases volume fraction (Vf) of chopped sisal fibre (CSF).