Nopal extract and aloe vera to improve structural concrete exposed to saline environments

The objective of this study was to examine the impact of Nopal (N) and Aloe Vera (AV) on the physical and mechanical properties of structural concrete in saline environments. Concrete with a compressive strength of 245 kg/cm² was used, adding N and AV extracted from natural plants in the study region. A total of 130 cylindrical specimens, 40 prismatic specimens, and 10 fresh mix samples were analyzed. Percentages of Nopal (2%, 6%, and 10%), Aloe Vera (0.5%, 1.5%, and 3%), and mixed (2%N + 0.5%AV, 6%N + 1.5%AV, 10%N + 3%AV) were added based on the weight of the cement. The control group contained no additives. The best results were obtained with the 2%N + 0.5%AV samples, with the highest compressive strength of 443.4 kg/cm² at 28 days and 445.4 kg/cm² at 56 days, a tensile strength of 41.4 kg/cm² at 28 days, a flexural strength of 66.4 kg/cm² at 56 days and 70.9 kg/cm² at 90 days of curing. The corrosion resistance decreased by a maximum of 0.22 mm/year. The physical and mechanical properties were optimized with the proportion of 2%N + 0.5%AV, indicating that the mixing matrix becomes more compact, and the carbonation rate is reduced, resulting in greater strength and durability.