Fibers were extracted from the pseudostem of the plantain of the variety Hartón, belonging to the order Zingiberales, family Musaceae, genus Musa, species Musa paradisiaca. The fibers were exposed to alkaline treatment to improve their physicomechanical properties for use as reinforcement in green composites. $NaOH$ solutions of 4 %, 5 %, and 6 % by weight were prepared. The fibers were immersed for 2 h in each solution. Fibers were washed with acetic acid to remove $NaOH$ residues and dried at room temperature. Weight loss and lignin, cellulose, and hemicellulose content were evaluated. FTIR, tensile, and elongation tests were performed. SEM images and EDS mapping allowed to conclude the phenomena that occurred in the treatments. The untreated fibers obtained a tensile strength of 37.23 MPa, in contrast to 104.26 MPa obtained by the fibers treated with 5 % NaOH solution. It was concluded that the partial elimination of impurities and waxes improved the mechanical behavior of the fibers by 180 %. Regarding elongation, the fibers treated with 4 % NaOH solution obtained the best result with 3.7 %. It was determined that the partial elimination of lignin favors elongation by 48 %. Excessive hemicellulose removal was found to cause fibril separation and detachment. Considerable contraction of vascular bundles occurred. Roughness in the fibers surface topography were improved.

Given the importance of wood as a building material for hundreds of years, it is often necessary to increase the resilience of existing wood elements. Due to their notable adaptability and high mechanical capacities, materials composed of polymers that have been reinforced with fibers represent a good alternative to traditional reinforcement systems. This study looks at the compressive behavior of prismatic wild pinewood test pieces confined with three types of fabric—one of carbon fiber reinforced polymer (CFRP) and two of basalt fiber reinforced polymer (BFRP) featuring two very different grammages. The reinforced pieces attain at least 96% greater resistance than the unreinforced pieces (FC300), reaching as much as 133% more resistance in the case of the pieces reinforced with FB600; however, the ductility of the reinforced pieces is much lower than that of the unreinforced, by approximately one-sixth and one-quarter, respectively. The study also allowed us to conclude that there is no relationship between the mechanical capacity of the reinforcement and the ultimate strength of the test piece tested, but there is a strong relationship between the rigidity of the reinforcement and modulus of elasticity and the ultimate strain of the reinforced pieces.

The aim of this study is to investigate the corrosion behavior of steel reinforcement embedded in mortar specimens in which both the aggregate and cement are partially replaced by ladle furnace slag (LFS) and different percentages of chloride ions by weight of cement are introduced into the mix at the time of kneading. The corrosion behavior was studied by using electrochemical techniques in order to evaluate the corrosion rate and the symptoms produced in steels of specimens with and without slag LFS. From the analysis of the results, it is concluded that the use of LFS in a partial replacement of aggregate and cement in mortar specimens does not compromise the behavior of the mortar with regard to corrosion of the steel reinforcement; consequently, partial replacement by LFS is fully feasible from this standpoint.

Reinforced concrete is the most widely used material in the construction of building structures, being noted for its versatility and low cost. However, the durability of reinforced concrete structures can be compromised by the corrosion of steel re-bars, especially in the presence of chlorides. To address this challenge and promote sustainability, the use of corrosion inhibitors has been researched as a way to extend the lifespan of structures. This study assessed the effectiveness of using a commercial corrosion inhibitor on steel re-bars embedded in types of concrete with different chloride percentages, using electrochemical methods to measure the corrosion rate and potential. The results indicate that, in the absence of corrosion inhibitors, corrosion rates become unacceptable with chloride percentages equal to or higher than 0.8% by weight of cement. The application of inhibitors significantly reduced the corrosion rate, particularly at chloride percentages of 0.8% and 1.2%, maintaining the re-bars in a passive state or at moderate levels of corrosion. However, for chloride percentages higher than 1.6%, high levels of corrosion were observed, even in the presence of inhibitors. The findings suggest that the use of inhibitors can be an effective strategy in preventing corrosion in reinforced concrete structures, contributing to their structural integrity and long-term sustainability.

This study experimentally investigated the mechanical properties of cement mortars that were reinforced with polypropylene (PP) fibers after being exposed to high temperatures and cooled under different regimes. PP fibers were added in amounts of 2, 3 and 4 kg/m³, the residual strengths of the mortars exposed to various temperatures up to 500 °C and cooled under different regimes were determined. It was found that the addition of PP fiber at the level of 2 kg/m³ improves the residual flexural and compressive strengths up to 300 °C. The residual flexural strength was approximately 75%, which is 15% higher than that observed in the simple mortar, and the same happens with the residual compressive strength which was approximately 85%, which is 17% higher than that observed in the simple mortar, regardless of the types of cooling used on the specimens. It was determined by means of a statistical analysis that there are no significant differences in the mechanical properties of the mortar according to the cooling regimes used, after having been exposed to high temperatures. The correlation of the residual flexural and compressive strengths was achieved with a coefficient of determination, R² = 0.82, and the relationships between the variables were considered acceptable regardless of the types of cooling used.