Paving blocks might encounter diverse environmental conditions during their lifespan. The durability of paving blocks is determined by their capacity to endure various exposure conditions. Synthetic fibers have been used in mortar and concrete to improve their properties. This research investigates the influence of including banana fiber (BF) on the physical and mechanical characteristics of mortar. Five different mortar mixes were developed, with varying amounts of BF ranging from 0 to 2% by volume. Testing included ultrasonic pulse velocity, compressive strength, flexural strength, total water absorption, and sorptivity. Specimens were cured for up to 90 days. The results indicate that using 0.5% BF resulted in an improvement in compressive and flexural strength compared to the control mix. There was an increase in total water absorption and the water absorption coefficient in the presence of fibers. There appeared to be good correlations between the compressive strength and the other properties examined.

Portland cement production is energy- and carbon-intensive. Substituting part of the clinker with natural pozzolans is a promising route to lower-impact mortars. This work evaluates mortar where Portland cement is partially replaced by a German natural pozzolan (12–56% by mass). Compressive and flexural strengths were measured at 7, 28, and 90 d. Water-accessible porosity (28 d) and 24 h water absorption were also determined. Strength development and water transport were interpreted using (i) a three-parameter strength–age model and (ii) a capillary–diffusive model. The results showed delayed reactivity typical of pozzolanic materials. At 90 d, 12% replacement slightly exceeded the control by 3.38% and 1.4% in compressive and flexural strengths respectively. Higher replacement levels caused a drop in strength at 90 d (18.3% at 36% and 42.5% at 56% in compression; 25.3% and 31.0% in flexure). Porosity and absorption increased with replacement, consistent with the mechanical trends. The compressive and flexural strengths were strongly correlated. Life cycle analysis showed a significant reduction in embodied carbon, reaching approximately 52% at 56% replacement. Overall, moderate replacement (12–21%) provides the best balance between performance and carbon reduction.

Conventional valorization of blast furnace slag commonly involves granulation, fine grinding, mechanical activation, or chemical activation, which increase energy demand and processing complexity. This study investigated a minimally processed blast furnace slag (MP-BFS), defined here as the fraction passing 64 µm obtained by sieving a 0–8 mm industrial material without grinding, additional granulation, thermal treatment, or chemical activation. MP-BFS replaced 10–50% of the cement by mass to reduce clinker in industrial mortars formulated at a constant flow spread of 23–24 cm and tested from 8 h to 90 d. Bulk density, water-accessible porosity, total and capillary water absorption, and compressive and flexural strengths were evaluated. Replacing 10% of the cement with slag improved compressive strength from the earliest test age and increased the 28-day compressive and flexural strengths by 5.1% and 9.5%, respectively, relative to the control mortar; this response coincided with a reduction in measured porosity from 8.95% to 8.01%. This improvement is consistent with a physical filling effect and improved particle packing, although these mechanisms were not directly verified by microstructural analyses. At higher replacement levels, water-accessible porosity increased, reaching 24.45% at 50% slag replacement, alongside greater water ingress and delayed strength development. Exploratory empirical regression analyses described associations among slag content, porosity, water transfer, and compressive strength within the investigated formulations. A simplified screening-level constituent-production-and-transport comparison per cubic meter, based on generic ICE factors and an assumed 50 km transport distance, estimated a maximum embodied carbon reduction of 44% at 50% replacement. Curing energy, use, carbonation, maintenance, and end-of-life stages were excluded. Overall, 10% MP-BFS replacement provided the most favorable performance–carbon content balance, whereas 30–50% achieved larger carbon reductions but showed early-age strength losses that limit their suitability for rapid-demolding applications under the investigated conditions.

Purpose: This work aims to improve the performance of cement-based materials for paving block applications by evaluating the influence of banana fibers (Ba-F) on the mechanical and physical properties of cement paste, addressing the demand for sustainable, low-cost alternatives to synthetic fibers. Design/methodology/approach: Five cement paste mixes containing 0%, 0.5%, 1%, 1.5% and 2% Ba-F by volume were prepared and tested over a 90-day curing period. Physical properties (density, ultrasonic pulse velocity (UPV), total water absorption, sorptivity) and mechanical properties (compressive and flexural strength) were evaluated according to ASTM standards. Capillary-diffusive and hyperbolic models were applied to predict moisture transport and compressive strength development. Findings: A 0.5% Ba-F addition improved compressive and flexural strengths by 3.6 and 8.6%, respectively, compared to the control, with minimal impact on density. Higher Ba-F dosages (>0.5%) reduced strength and UPV while increasing water absorption and sorptivity. Strong correlations (R2 ≥ 0.9) were observed between compressive strength, ultrasonic pulse velocity and flexural strength. However, negative correlation was noticed between compressive strength and water absorption. Originality/value: This study provides paste-scale evidence on banana-fiber reinforcement by combining (1) UPV-based nondestructive assessment, (2) absorption/sorptivity characterization interpreted through a capillary–diffusive model (yielding transport parameters) and (3) strength development captured by a hyperbolic model, enabling identification of an optimum fiber dosage for paving-block-oriented applications.