Three-dimensional printing with cement-based materials is a promising manufacturing technique for civil engineering applications that already allows for the design and the construction of complex and highly customized structures using a layer-by-layer deposition approach. The extrusion mechanism is one of the most expensive parts of the 3D printer. Also, for low-scale 3D printers, based on the shape of the extruder and the geometry limitation of the mixing blade, the 3D mixture is often limited to a narrow range of materials due to the risk of layer splitting or blockage. Therefore, there is a need to develop affordable and feasible alternatives to the current design–fabrication–application approach of 3D printers. In this paper, various newly designed mixtures of fiber-reinforced mortars that can be 3D printed using only a commercially available screw pump are analyzed based on their fresh properties and mechanical characteristics. The results, in terms of extrudability, buildability, flowability, and flexural and compressive strengths, highlight the potential of using this technology for constructing complex structures with high strength and durability. Also, the reduced facility requirements of this approach enable 3D printing to be made more available for civil engineering applications. With further innovations to come in the future, this method and these mixtures can be extended for the sustainable and economically feasible printing of single-family housing units.

Building integrated photovoltaics (BIPVs) are modern photovoltaic (PV) modules which are integrated into the building’s envelope. Usually, these devices replace the conventional roofing system, but they may be also integrated into the facade. The modules integration has a significant advantage in limiting the overall cost of the construction. Furthermore, building integrated photovoltaics, in comparison to non-integrated ones, don’t require stand-alone systems or allocation of land. This paper presents the state-of-the-art review regarding the existing BIPVs technologies. Also, in the second part of the paper, future research directions are discussed.

This study investigates the aerodynamic behavior of roof structures under wind-induced forces, focusing on buildings equipped with photovoltaic panels. Experimental data were obtained through wind tunnel testing of three 1:100 scale models, each representing a distinct roof geometry: gabled, hipped, and multi-pitched. Measurements of dynamic pressure and pressure coefficients were conducted for various wind incidence angles, ranging from 0° to ±150°. The results highlight the impact of roof geometry and PV panel placement on the pressure distribution, with notable variations due to flow separation and vortex formation around the panels. Gabled roofs exhibited pronounced pressure gradients, while hipped roofs showed more uniform distributions. Multi-pitched roofs demonstrated the most complex aerodynamic behavior due to their variable slopes. These findings enhance the understanding of wind-structure interactions for buildings with roof photovoltaic panels, contributing to the development of more resilient and energy-efficient structures. The research supports sustainable construction practices by improving wind load predictions and informing design decisions that promote the safe integration of renewable energy systems into the built environment.

This study focuses on implementing two distinct recycling methods, the reclaimed asphalt pavement and the reclaimed concrete material, on classical road pavements, by totally replacing the surface or base courses with ones made with recovered materials. The majority of the road networks in the eastern European countries were built between 1950 and 1980 and are, nowadays, aged and degraded. Within this frame, the cold in-place recycling methods were developed, which can be applied to both asphalt and concrete pavements. During the cold in-place recycling process, the reclaimed asphalt or concrete materials do not leave the construction site at all, but they are processed on the spot and reused immediately. Thus, the material is granulated to the desired depth, mixed with the binding agent and water and then repaved and compacted in a new layer. One of the most significant benefits of the cold in-place recycling process is that the material is simultaneously recycled and mixed with the binding agent, enabling the road pavement to be strengthened without the need to import expensive virgin aggregates. This work describes the manufacturing technology and the equipment train used to cold recycle aged and deteriorated asphalt and concrete pavements.

3D printing with cement-based materials is a promising manufacturing technique for civil engineering applications that already allows for the design and the construction of complex and highly customized structures using a layer-by-layer deposition approach. Usually, in this type of additive manufacturing, a mixture of cement, water, aggregate and additives is extruded through a specific print head and deposited in successive layers to form the desired shape. The extrusion mechanism is one of the most expensive parts of the 3D printer. Also, for low scale 3D printers, based on the shape of the extruder and the geometry limitation of the mixing blade, the 3D mixture is often limited to a narrow range of materials due to the risk of layer splitting or blockage. Therefore, there is a need to develop affordable and feasible alternatives to the current design-fabrication-application approach of 3D printers. In this paper, various new designed mixtures of fiber reinforced mortars that can be 3D printed using only a commercially available screw pump are analyzed based on their fresh properties and mechanical characteristics. The reduced facility requirements in this approach allow 3D-printing to be more available for civil engineering applications. With further innovation in the future, this method and mixtures can be extended for sustainable and economically feasible printing of single-family housing units.

This study presents an experimental investigation on the electrical performance, durability, and sustainability of different types of photovoltaic panels subjected to controlled climatic conditions and simulated solar radiation. Four photovoltaic technologies were analyzed, including monocrystalline, polycrystalline, and two semi-flexible panels, to evaluate their behavior under thermal stress. The experimental methodology consisted of repeated freeze–thaw cycles conducted in a double climatic chamber, with temperatures varying between −18 °C and +5 °C. Each panel was subjected to up to 500 cycles designed to reproduce repeated freeze–thaw environmental conditions representative of moderate cold-climate operation. At predefined intervals, the electrical characteristics of the panels were assessed using a solar radiation simulator based on high-pressure mercury vapor lamps, ensuring controlled and repeatable irradiation conditions. The results indicate that all tested panels exhibited relatively stable open-circuit voltage and output current values throughout the investigated thermal cycling interval, with only minor fluctuations observed during the experimental measurements. No visible macroscopic structural degradation and no major variations in the monitored electrical parameters were identified during the investigated testing conditions. Semi-flexible panels demonstrated comparable behavior to rigid panels, highlighting their potential for applications requiring mechanical adaptability. From a sustainability perspective, the observed durability and performance stability contribute to extending the operational lifetime of photovoltaic systems, reducing maintenance needs and material replacement rates. The findings provide comparative experimental observations regarding the evolution of selected electrical parameters under repeated moderate freeze–thaw exposure conditions.