Concrete has a significant impact on the environment and efforts are being made to replace it with more environmentally friendly alternatives. One possibility is to replace all or part of the conventional components (i.e., cement, water, sand and gravel) with recyclable solutions. Several studies have already demonstrated the mechanical and ecological suitability of the new eco-concretes, but the safety of structures built with them is not considered in the literature, which indicates a lack of knowledge. The purpose of this study is to evaluate the fire safety of reinforced concrete beams built with eco-friendly concretes and compare them to conventional concretes. The analysis was performed numerically and solved with Abaqus software using the finite element method, assuming the thermal parameters previously proposed in the literature through experimental investigations. The thermal field generated in beams with eco-concrete is a maximum of 50% lower compared to conventional concrete and the temperatures of the reinforcement are reduced by a maximum of 260%. There is an interesting perspective for the use of these materials in terms of fire safety criteria.

This study investigates the thermal performance of 23 different mortar types, each containing different mixes, properties, and additives. A comprehensive literature review was conducted to collect experimental data on the thermal properties of these mortars, which were then used in a numerical analysis through thermal finite element modeling. The results showed that all mortar types contributed to reducing the internal temperature of structural steel and reinforced concrete elements, with performance primarily influenced by key factors such as the mortar’s thermal conductivity, specific heat capacity, thermal diffusivity, and coating thickness. In particular, the mortar with glass fiber reinforced polymer (GFRP) as a slag substitute and the mortar with expanded perlite replacing sand showed the highest thermal protection and achieved a temperature reduction on the order of 100%. In contrast, mortars containing 30% vermiculite or 15% light expanded polyvinyl chloride (PVC) as a sand substitute showed the lowest thermal performance.

Ribbed slabs are a solution for increasing the bending capacity while reducing the total concrete consumption and the dead weight compared to conventional reinforced concrete slabs. The EN 1992-1.2 standard contains a tabulated method (TM) for the fire design of these structures, which suggests combinations of cross-sectional dimensions and concrete cover thickness to determine the fire resistance. Using a finite element (FE) model solved with Abaqus software, a transient thermal analysis of these slabs was performed, correlating the results with the standardized TM. Cross-sections with different concrete widths and concrete covers were numerically tested to define a new TM based on the same criteria proposed by the EN. To validate the FE models, the results were compared with the experimental data of two full-scale specimens of ribbed slabs. It was found that the current TM is not consistent in all cases, and the concrete cover needs to be improved by between 20 and 50%. A fire design of ribbed slabs based on EN 1992-1.2 shows that the reinforcement is heated beyond its critical temperature, but the flange thickness can be reduced. A new tabular procedure is proposed based on the critical temperature of the reinforcement, the concrete cross-section, and the thermal insulation criteria.

Building structures are vulnerable to fire, requiring design strategies that address temperature-induced mechanical degradation. This study evaluates the thermal performance of 23 mortar formulations with different compositions and additives, using experimentally derived thermal properties collected from the literature and implemented in a thermal finite element model. All mortars reduced the internal temperature of structural steel and reinforced concrete members, with effectiveness governed by coating thickness and intrinsic thermal properties. The best performance was achieved by mortars incorporating glass fiber reinforced polymer (GFRP) as a slag substitute and expanded perlite as a sand replacement, reaching temperature reductions on the order of 100%, whereas mixtures with 30% vermiculite or 15% light expanded polyvinyl chloride (PVC) as sand substitutes exhibited the lowest thermal efficiency.