Properties of concrete incorporating treated prickly pear fibers
The integration of natural fibers into building materials is key to enhancing sustainability within the construction industry. However, vegetable fibers are known to undergo mechanical degradation over time when embedded in the alkaline environment of cementitious matrices. This study investigates the incorporation of prickly pear fibers into concrete, evaluating the efficacy of three surface treatments (epoxy, lime, and bitumen) over a curing period extending from 3 to 180 days. Results indicate that while untreated fibers reduce compressive strength, the applied treatments significantly mitigate this loss. Notably, epoxy-treated fiber concrete exhibited only an 11% decrease in compressive strength at 28 days compared to ordinary concrete, eventually achieving a strength 53% higher than that of untreated fiber concrete by 180 days. At the optimal dosage of 15 kg/m3, epoxy treatment enhanced 28-day flexural strength by 333%, while lime treatment yielded a 229% increase. Furthermore, whereas untreated fibers exhibited mechanical degradation after 28 days, treated fibers demonstrated sustained strength gains up to 180 days. Additionally, a fiber dosage of 40 kg/m3 substantially improved thermal performance, reducing conductivity by 40−45% and increasing specific heat capacity by 22−24%. These findings highlight the potential of treated prickly pear fibers as a viable, sustainable reinforcement for high-performance construction applications.