The long-term durability and structural integrity of modern buildings, which are inherently reliant on reinforced concrete, are governed by the rate of corrosion of embedded steel reinforcement. Corrosion kinetics, therefore, is not merely an academic exercise, but rather a critical foundation for predicting and extending a structure’s life span, mitigating safety risks, and ensuring the sustainability of the built environment against a host of environmental and chemical degradation factors. The present study conducts a comparative analysis of the short-term corrosion initiation behavior of steel reinforcement embedded in three distinct types of geopolymer binders, a cementitious paste, and a cementitious composite with natural aggregates. Electrochemical techniques, such as Open Circuit Potential (OCP) and linear polarization tests were used to characterize the behavior of the steel reinforcement embedded in the 4 types of samples. Additionally, these samples containing the reinforcement were further characterized using advanced microstructural techniques, specifically porosimetry, Nuclear Magnetic Resonance (NMR), and Scanning Electron Microscopy (SEM).

This study aims to investigate the application of nuclear magnetic resonance (NMR) to characterize mortars containing recycled rubber waste as an eco-innovative material for sustainable construction. The primary objective was to analyze the way rubber granules influence hydration kinetics, microstructural development and pore structure. The innovative mortar formulations incorporated rubber granules, casein, natural hydraulic lime (NHL), and latex. NMR analysis revealed distinct T₂ relaxation time distributions correlated with different pore sizes and water states: shorter T₂ values demonstrate strongly bound water in small pores, while longer T₂ values are associated with loosely bound or free water in larger pores. The formulation with 3.5% NHL and 5% rubber granules exhibited optimal microstructural characteristics. These results reveal that NMR is a valuable, non-destructive tool for monitoring cementitious material evolution and supporting the use of tire-derived waste in eco-innovative mortar designs.

The European Union’s transition to climate neutrality by 2050 requires measurable reductions in energy consumption and greenhouse gas emissions, especially in territories characterized by geographical constraints, such as mountainous regions. The study analyzes how European funding guidelines are translated into concrete technical interventions for public buildings in mountainous areas of Romania, using a representative case study from Rodna, Bistrița-Năsăud County. The methodology is based on the national energy performance calculation framework (Mc 001/2022), harmonized with Directive 2010/31/EU and aligned with the EN ISO 52016-1 framework, while maintaining compatibility with the quasi-steady-state methodology implemented in MC 001/2022, and includes the assessment of compliance with the “Do No Significant Harm” (DNSH) principle also. The integrated energy rehabilitation of the analyzed building led to reductions in final energy consumption of 30–45%, primary energy consumption of 40–45%, and operational CO₂ emissions of 45–50%. The integration of renewable energy sources increased their share to approximately 35% of the building’s energy mix. The estimated annual reduction of 40–45 tons of CO₂ highlights the direct climate impact of investments financed from European funds. The results confirm that European funding instruments function not only as financial mechanisms, but also as governance instruments capable of steering the transition towards a low-emission construction sector in vulnerable mountain regions.

Sustainable investments in construction are essential for the development of communities and for reducing environmental impacts. This study analyzes two scenarios: rehabilitation of an existing building and construction of a new NZEB-compliant building, based on a life cycle cost–benefit analysis. The results show that both scenarios generate negative Net Present Values (NPVs) due to the social nature of the project, but the new NZEB building presents superior performance (NPV: USD –2.61 million vs. USD –3.05 million for rehabilitation) and lower operational costs (USD 1.49 million vs. USD 1.92 million over 30 years). Key financial indicators (IRR, CBR), sensitivity analysis, and discount rate variation support the conclusion that the NZEB scenario ensures greater economic resilience. This study highlights the relevance of extended LCCBA in guiding sustainable investment decisions in social infrastructure.