*2.2. Fibre Preparation*

Natural jute fibres (Sunrise Agriculture, Ajmer, Rajasthan, India) were used for this study. The fibres were initially of variable length, as shown in Figure 1 prior to processing. Clumps of fibres were gently brushed and then hand cut to approximately 6 mm. The length of fibres (*n* = 20) averaged 5.88 mm ± 1.60. A scanning electron microscope (SEM; SNE-4500M Plus Tabletop, SEC, Suwon-si, Korea) was used in this study to measure the diameter of the fibres following the production of the biocemented sand columns.

**Figure 1.** Jute fibres (not to scale).

Prior to use, the jute fibres were washed thoroughly using a sieve and deionised water, followed by autoclaving at 121 ◦C for 20 min. The fibres were then oven dried at 50 ◦C. Autoclaving was not considered to have an adverse effect on the fibres given its short duration. Lignocellulosic fibres have been observed to thermally degrade through dehydration, depolymerisation and oxidation when heated [19], dependent upon temperature and duration of heat exposure. Van de Velde and Baetens [26] reported that after exposing flax fibres to 120 ◦C for up to 2 h no significant decrease in tensile strength was observed.
