An Integrated Approach to Using Sheep Wool as a Fibrous Material for Enhancing Strength and Transport Properties of Concrete Composites

Abstract

An important goal to achieve sustainable development is to use raw materials that are easily recyclable and renewable, locally available, and eco-friendly. Sheep wool, composed of 60% animal protein fibers, 10% fat, 15% moisture, 10% sheep sweat, and 5% contaminants on average, is an easily recyclable, easily renewable, and environmentally friendly source of raw material. In this study, slump testing, compressive and flexural strengths, ultrasonic pulse velocity, sorptivity, and chloride penetration tests were investigated to assess the influence of wool fibers on the strength and transport properties of concrete composites. Ordinary Portland cement was used to make five concrete mixes incorporating conventional wool fibers (WFs) ranging from 0.5 to 2.5% and a length of 70 mm. The wool fibers were modified (MWFs) via a pre-treatment technique, resulting in five different concrete compositions with the same fiber content. The addition of WF and MWF to fresh concrete mixes resulted in a decrease in slump values. The compressive strength of concrete was reduced when wool fibers were added to the mix. The MWF mixes, however, achieved compressive strength values of more than 30 MPa after a 90-day curing period. Furthermore, by including both WF and MWF, the flexural strength was higher than that of plain concrete. In addition, adding fibers with volume fractions of up to 2% reduced the concrete composite’s sorptivity rate and chloride penetration depths for both WF and MWF content mixes. Consequently, biomass waste like sheep wool could be recycled and returned to the field following the circular economy and waste valorization principles.

A Comprehensive Review of Types, Properties, Treatment Methods and Application of Plant Fibers in Construction and Building Materials

“…[38,56,57]-have multiple benefits, such as; low costs and abundant availability. Alyousef et al [58] reported the same for sheep wool fiber when used as dispersed reinforcement in a cementitious concrete composite to enhance the mechanical properties of said concrete composite. The incorporation of low-density (1.2-1.6 g/cm 3 ) plant fibers produces lighter composites compared to synthetic fibers.…”

Mechanical and radar absorption properties of sheep wool/epoxy composites

“…Natural fiber composites are widely used in many fields due to their superior mechanical properties. The use of waste and natural fibers is extremely important in terms of environmental sustainability and cost (Alyousef et al, 2022a(Alyousef et al, , 2022b. Recently, there has been a significant increase in the amount of studies in this field (Fiore et al, 2020).…”

“…They concluded that acoustic properties of the produced materials depend on their structure and parameters. In the search of cheap and ecofriendly materials in the building industry, researchers were also produced sheep wool fiber reinforced concrete composite materials and, investigated their structural and mechanical properties (Alyousef et al, 2020;Alyousef et al, 2022aAlyousef et al, , 2022bFantilli and J o zwiak-Nied zwiedzka, 2020;Fiore et al, 2020;J o zwiak-Nied zwiedzka and Fantilli, 2020).…”

Comparative cracking resistance‐cost study for the hot mix asphalt (HMA) mixtures made of natural and recycled asphaltic materials

“…Such products can be used in the construction of pavements and overlays or concrete structures. For example, natural, synthetic, and industrial fibers such as steel fibers, 1–5 jute and kenaf fiber, 6–8 rice fiber, 9 glass fiber, 10–12 basalt fiber, 13 wool of animals, 14,15 and Forta aramid fibers 16–20 have been employed in previous works in the mix design of concrete materials. Review of literature also reveals that other industrial waste materials such as recycled stone and metal aggregates, rubber powders and granules, shredded PET, furnace slag aggregates, and powders are possible candidate materials to be utilized in the mix design of asphalt or concrete materials 21–29 …”