Summer Scholarship: Properties of cement mortar incorporating cotton fibres
Abstract
Textile waste is a growing global issue with no effective methods of disposal currently
available. In Australia, 85% of new clothing purchased annually ends up in landfill, which
represents a waste of water and energy to produce these textiles. Escalating this issue, is the
synthetic composition of these textile materials which represent 60% of current clothing
textiles globally. To minimise the environmental impacts and relieve waste management from
existing facilities, the concept of utilising recycled cotton fibres as reinforcement in cement
mortar has been proposed. While most engineering practices typically use synthetic fibre
reinforcement to obtain specific mechanical improvements, the processing and development of
these fibres is unsustainable and environmentally damaging.
Recent studies have found effective uses for natural fibre reinforcement in cement-based
products. Results demonstrated comparable mechanical improvements, while minimising
environmental impacts and costs to manufacture. In this study, cotton bed sheets obtained from
a textile-waste recycling facility were repurposed to a fibrous state to assess the physical,
mechanical, and microstructural interaction with a cement-mortar. A total of 7 different mix
designs were prepared with various quantities and lengths of cotton fibres, to evaluate the
influence of fibre content and fibre length on cement composites.
To observe the physical properties, flow table tests were performed for each mix to determine
the workability of fresh mix. It was observed that the increase in fibre content decreased the
workability, and superplasticiser had minimal effect on higher quantities of fibres. Hardened
properties were measured using compressive and flexural tests at 7, 28 and 56 day curing ages.
The compressive strength for samples with increasing cotton fibre content demonstrated a
decrease in compressive properties. However, flexural properties indicated a significant
improvement in flexural toughness, and confirmed that the presence of cotton fibres was
influencing a fibre bridging mechanism. This was supported through microstructural imaging,
which indicated a strong correlation between fibre dispersion and the cohesion with cement
bonding.
Cotton fibres display promising flexural improvements in cement composites, however
additional research should focus on the chemical pre-treatment of fibres, to enhance the
dispersion and bonding between cement particles.
Files in this item
This item appears in the following categories
- 2022 Final Reports
CRDC Final Reports submitted in 2022