The Evaluation Effect of Copper Fibre Diameter on Enhancing Compressive Strength of Pure Gypsum

The sustainability and impact of copper fibres on pure gypsum is the primary purpose of this study to inves - tigate a combination of two kinds of copper fibres obtained from environmental waste (damaged electrical wires). The copper fibres are dividings into a fixed length of 10 mm, but with two different diameters: the first is 0.83 mm and the second is 0.63 mm, where the ratio of width to height (L/D) is 12 and 15.9, respectively, with a volume ratio V f = 0.4%, the ratios 0.5 and 0.6 represent the water to gypsum ratio (W/G ) individually. Each W/G ratio has two types of mixtures which organize according to diameter. The first considers a refer - ence mixture without copper fibres (CF), and the other is a copper fibres mixture. This work found that the compressive strength increased from adding the copper fibres to a mixture of pure gypsum. Furthermore, this increase is apparent in pure gypsum compressive strength when raising the aspect ratio because of reducing the copper fibres’ diameters. In another way, increasing ratio of W/G in the case of existing copper fibres or none may reduce a compressive strength of mixtures. Therefore, when the ratio of W/G drops, the significance of copper fibres may become more apparent.