This research addresses the deterioration of concrete infrastructures, emphasizing the efficacy of Fiber-Reinforced Self-Compacting Concrete (FRSCC) in repair applications. The study investigates the bond strengths between new and existing concrete layers, employing both experimental and numerical methods to evaluate traditional and innovative testing approaches, including slant shear and push-out tests. Results demonstrate that FRSCC, enhanced with polypropylene fibers, significantly improves structural resilience and mechanical properties. The introduction of fuzzy logic models further refines the prediction of bond strengths, offering a robust framework for future concrete technology advancements.

This study embarks on a numerical exploration of Geogrid Reinforced Soil Walls (GRSW), employing finite difference analysis to compare two soil constitutive models, highlighting the efficacy of a refined strain-softening model. This innovative approach markedly improves the prediction of GRSW performance, particularly aligning the safety factor more closely with real-world observations. Notably, the strain-softening model demonstrates a superior ability over the perfectly plastic model by significantly reducing the mean overall error in predicting maximum geogrid strain overall from 51% to 30%, reflecting a significant 41% improvement in precision, thereby presenting a significant tool for enhancing geotechnical design practices. The research underlines the potential of this model to elevate the safety and reliability of GRSW constructions, contributing to elevated design standards within the field of geotechnical engineering.

The current paper deals with the numerical investigation of a unique designed pre-stressed reinforced concrete railway sleeper for the design speed of 300 km/h, as well as an axle load of 180 kN. The authors applied different methodologies in their research: traditional hand-made calculations and two types of finite element software. The latter were AxisVM and ABAQUS, respectively. During the calculations, the prestressing loss was not considered. The results from the three methods were compared with each other. The hand-made calculations and the finite element modeling executed by AxisVM software are adequate for determining the mechanical inner forces of the sleeper; however, ABAQUS is appropriate for consideration of enhanced and sophisticated material models, as well as the stress-state of the elements, i.e., concrete, pre-stressed tendons, etc. The authors certified the applicability of these methodologies for performing the dimensioning and design of reinforced concrete railway sleepers with pre-stressing technology. The research team would like to continue their research in an improved manner, taking into consideration real laboratory tests and validating the results from FE modeling, special material models that allow calculation of crackings and their effects in the concrete, and so that the real pattern of the crackings can be measured by GOM Digital Image Correlation (DIC) technology, etc.