The incorporation of sustainable construction is essential for minimizing the environmental footprint of cementitious composites. This research examines the mechanical behavior and microstructural features of alternative mortars in which pumice acts as a partial cement replacement. By applying the Taguchi methodology, nine mortar mix variations were assessed at different pumice replacement rates (15%, 25%, and 50%), and their mechanical strength was compared against a control mixture without substitution. Additionally, an X-ray diffraction (XRD) analysis identified the mineral components in the pumice to evaluate their performance and durability. Based on a statistical variance analysis (ANOVA), mortars with up to 25% substitution are suggested as they attain mechanical strength values comparable to those of a control mixture. This study contributes to the advancement of environmentally sustainable construction materials and provides valuable insights into the viability of using pumice in sustainable infrastructure developments.

Constructed wetlands (CWs), increasingly adopted as nature-based solutions (NBS) for wastewater treatment, require a rigorous assessment of the durability and structural performance of the materials used in their supporting systems. In contrast to the extensive literature addressing hydraulic efficiency and contaminant removal, the structural behavior of CWs has been scarcely examined, with existing studies offering only general references to reinforced concrete and masonry and lacking explicit design criteria or deterioration analyses. This study integrates evidence from real-world CW installations with a systematic review of 31 studies on the degradation of cementitious materials in analogous environmental conditions, following PRISMA 2020 guidelines, with inclusion criteria based on quantified wastewater-related exposure conditions (e.g., chemical aggressiveness, persistent saturation, and biogenic activity). Results indicate that reinforced concrete, despite its structural capacity, is susceptible to biogenic corrosion, accelerated carbonation, and sulfate–chloride attack under conditions of persistent moisture, with reported degradation rates in analogous wastewater infrastructures on the order of millimeters per year for concrete loss and tens of micrometers per year for reinforcement corrosion. Masonry structures, similarly, exhibit performance constraints when exposed to mechanical overloads and repeated wetting–drying cycles. In contrast, emerging alternatives—such as nanomodified matrices and concretes incorporating supplementary cementitious additives—demonstrate potential to enhance durability while contributing to a reduced carbon footprint, without compromising mechanical strength. These findings reinforce the need for explicit structural design criteria tailored to CW applications to improve sustainability, durability, and long-term performance.

This study investigates alkali-activated recycled pumice as a sustainable cement replacement for hydraulic concrete used in rigid pavements. Cement was replaced at 15%, 25%, and 50% by mass and activated using NaOH solutions at 1 N, 0.5 N, and 0.25 N, resulting in nine mixture variants. Mechanical performance was assessed through compressive strength at 7, 14, and 28 days, and flexural strength at 28 days. Durability was evaluated via natural carbonation depth at 210 and 1090 days. X-ray diffraction (XRD) identified aluminosilicate phases in the pumice, supporting its alkali-reactive potential. Mixtures with 15% pumice replacement achieved compressive strengths up to 20.99 MPa, comparable to the control mix (20.45 MPa), whereas 25% and 50% replacements produced moderate strength reductions. Flexural strength in 15% mixtures (7.38–7.44 MPa) was also comparable to the control (7.30 MPa), while higher replacement levels reduced flexural performance. Carbonation resistance improved for mixtures with an optimized alkaline-to-pumice ratio (APR, defined as NaOH concentration relative to pumice content) between 0.0167 and 0.02, indicating more balanced activation and reduced CO₂ ingress. Overall, alkali-activated recycled pumice enables partial cement replacement while maintaining mechanical performance and carbonation resistance at 15% substitution, supporting circular economy strategies and lowering the carbon footprint of rigid pavement concrete.

This study integrated multivariate statistical analysis and machine learning to characterize fruit quality variability and prediction of soluble solids content across nine passion fruit production sites in Veracruz, Mexico. A total of 143 valid observations were analyzed, including fruit weight, pulp weight, fruit height, fruit diameter, rind thickness, number of seeds, peel color, location (site code), and soluble solids (°Brix). Fruit weight ranged from 40.7 to 204.5 g, pulp weight from 8.3 to 115 g, and site-level mean soluble solids ranged from 10.31 to 23.39 °Brix. Canonical Variate Analysis (CVA) showed that the first two canonical axes accounted for 75.97% of the total discriminant variation among production sites (CV1 = 45.42%; CV2 = 30.55%). CV1 was primarily associated with soluble solids content, whereas CV2 was associated with fruit dimensions. Under nested leave-one-site-out cross-validation, Random Forest achieved the highest performance among the evaluated machine-learning models (R² = −0.408; RMSE = 6.051 °Brix), but did not outperform the training-mean baseline (R² = −0.190; RMSE = 5.562 °Brix). Permutation importance identified fruit weight and diameter as the most influential predictors in the fitted Random Forest model, although their predictive contributions were insufficient for reliable generalization to previously unseen production sites. These findings provide insights into fruit quality variability across nine passion fruit production sites in Veracruz, Mexico, during the 2025 sampling period, while highlighting the complementary value of multivariate analysis and machine learning for characterizing fruit traits and evaluating predictive performance across locations.