Studies have shown that the proper selection of core materials in sandwich structures improves the overall structural performance in terms of bending stiffness and strength. The core materials used in such systems, such as foam, corrugated, and honeycomb, are frequently applied in aerospace engineering. However, they are a costly option for civil engineering applications. This paper investigates the bending performance of the proposed GFRP softwood sandwich beams assembled using pultruded GFRP with adhesive connection methods for potential applications in prefabricated building construction. The ultimate load capacity, load–deflection responses, failure modes, bending stiffness, load–axial-strain behaviour, and degree of composite action were experimentally evaluated. The effects of varying shear-span-to-depth ratios a/d between 2 and 6.5, as well as different timber fibre directions of the softwood core, on the overall structural performance were clarified. The results showed that changing the timber fibres’ orientation from vertical to longitudinal shifted the failure mode from a brittle to progressive process. Moreover, the adhesive bonding was able to provide full composite action until the failure occurred. Finally, numerical modelling was developed to understand failure loads, deformation, failure modes, and strain responses, and to evaluate bending stiffness and composite action. The results showed satisfactory agreement with the experiments.

BISCO plaster (BRP) is an environmentally friendly material with high mechanical properties and is considered a great elective to conventional materials such as gypsum and cement. Our investigation seeks to examine BISCO plaster (BRP) and a mixture of resin and hardener in three proportions (30%, 45%, and 60%) to achieve our ultimate goal, which is to preserve the environment and achieve the vision of the Kingdom of Saudi Arabia 2030 to reach zero carbon emissions by 2060? Emissions tests were performed, and although the CO₂ level was zero, they emitted SO₂ sulfur dioxide and NO₂ nitrogen dioxide, and 60% was the lowest emission rate. We also used ANSYS 2023 R1 software to compare them with their mechanical properties resulting from tensile and compression testing. In this study, we looked closely at the mechanical characteristics of different materials designed for wall coverings, with particular emphasis on their environmental sustainability. We carried out experiments to gauge the tensile and compressive stress on samples with varying mixing ratios. Our main objective was on crucial mechanical properties such as the modulus of elasticity, ultimate tensile strength, yield strength, yield strain, modulus of resilience, and ductility. Through meticulous scrutiny, we determined that the amalgamation of these mechanical attributes at the 30% mixing ratio provides an optimal combination for attaining structural integrity, adaptability, and resilience in wall coverings. Significantly, this ratio also underscores a commitment to environmentally conscious material selection. Our study offers important new insights into the selection of wall covering materials by providing a detailed understanding of their mechanical behavior under various stress conditions. It aligns with the increasing significance of environmental responsibility in contemporary design and construction. By emphasizing the 30% mixing ratio, our findings establish a foundation for informed decision making, promoting the utilization of sustainable materials that achieve a balance between strength, flexibility, and longevity. This ensures optimal performance in practical applications while simultaneously minimizing the environmental impact.

Epoxy adhesives possess excellent mechanical properties, durability, and stability in harsh environments, making them suitable for producing engineering materials. This study selects four commercially available epoxy adhesives in Saudi Arabia: Epotec YD 128; Sikadur^®-52 LP; Sikadur^®-31 CF; and Sikadur^®-42 MP Slow. Firstly, a comparison of their storage, application, and service temperatures was made, detailing the hazard identification and prevention measures established in accordance with the Occupational Safety and Health Administration (OSHA) guidelines. Subsequently, test samples of the four adhesives were produced, and tensile, compressive, and shear tests were conducted to compare their fundamental mechanical properties. Finally, a gas analyzer assessed the major harmful gases emitted by these epoxy adhesives 120 min after mixing the epoxy resins and curing agents. The results show that Sika 42 exhibits the highest tensile and compressive strengths among other types of adhesives, reaching 75.7 MPa and 133.8 MPa, respectively. It also has the longest pot life of 48 min at elevated temperatures (40 °C), making it suitable for the climatic conditions in Saudi Arabia. However, as a three-component adhesive, its application is complex and associated with the most identified hazards. Sika 31 presents a tensile modulus of up to 10.4 GPa, at least 3.8 times higher than the other adhesives, making it practical for controlling tensile deformation. Additionally, its ultimate shear strain reaches 10.7%, at least 6.6 times higher than the other samples, highlighting its suitability for constructing ductile bonds. After mixing of epoxy resins with curing agents, the presence of NO₂ and SO₂ were detected. However, no harmful gases were detected after 120 min, possibly due to the complete curing of the adhesives.