Key Engineering Materials Vol. 1046

Abstract: Recent studies have aimed to develop sustainable bio-based fire-resistant building materials to replace the conventional building materials. Traditional fire retardants such as halogenated compounds rely on toxic chemicals that pose environmental and health risks. Mycelium-Based Composites (MBCs), produced from fungal mycelia cultured from agricultural byproducts, offer a promising eco-friendly alternative with inherent fire-retardant properties. Addressing fire safety in buildings is vital for enhancing resilience, reducing casualties and economic losses, and aligning buildings with development goals. MBCs contribute to circular economies by repurposing waste and making it key to climate-adaptive construction. This study provides a review of MBCs' fire-retardant properties from various studies. The high char formation of MBCs (up to 48% at 600°C) at low heating rates (as low as 33 kW/m²), delayed ignition, and minimal smoke production outperformed those of their synthetic counterparts. This study identifies key research gaps and provides actionable solutions, such as tripartite studies, to disentangle mycelium, substrate, and additive effects.

Abstract: The present study evaluated the mechanical behavior of adobe when incorporating crushed barley straw as a natural stabilizer. Specimens were prepared with three different stabilizer proportions: 0, 1, and 2%. These were used to compare their compressive and flexural strength. The results showed an average 10% increase in compressive strength and a 43% increase in flexural strength in adobes incorporating 2% stabilizer compared to the control units. This increase demonstrates the potential of crushed barley straw to improve the load-bearing capacity and ductility of adobe, thus contributing to the creation of sustainable material for construction in rural areas.

Abstract: This study investigates the comparative flexural performance of concrete reinforced with three distinct types of natural fibers: abaca, banana, and ramie. Concrete specimens were prepared with varying fiber contents (0%, 0.25%, 0.50%, 0.75%, and 1.00%) for each fiber type, and their slump and flexural strength were evaluated. The slump test results revealed a consistent reduction in the workability of concrete as the fiber content increased, indicating the need for optimizing the fiber content to balance the enhanced mechanical properties with the workability requirements. The flexural strength test results showed that the incorporation of abaca and banana fibers at an optimal content of 0.5% significantly improved the flexural strength of the concrete, with increases of 59% and 50%, respectively, compared to the control mix without fibers. The ramie fiber-reinforced concrete exhibited a relatively lower enhancement in flexural strength compared to the abaca and banana fiber-reinforced mixes, though its performance remained comparable to the control. Further analysis using ANOVA confirmed the statistical significance of the fiber content on the flexural strength for abaca and banana fibers, underscoring their efficacy in enhancing the concrete's load-bearing capacity.

Abstract: The article addresses the challenges and methodologies for enhancing the properties of asphalt concrete utilized in the Republic of Armenia. Environmental factors, including abrupt temperature fluctuations, precipitation, and black ice, coupled with the escalating load on road surfaces, necessitate the development of high-performance asphalt concrete. To this end, both local mineral resources and various industrial waste materials have been investigated for their potential to augment the properties of bitumen. It has been determined that the most effective additive-modifiers are synthesized from waste materials, specifically aluminum palmitate and aluminum oleate. These additives enhance bitumen properties and are likely to fortify the chemisorption bonds at the interface between bitumen and the mineral phase. The study further examined the variation in bitumen properties based on the type and quantity of synthesized additive-modifiers incorporated. Results indicate that the most substantial improvement in modified bitumen is achieved at a concentration of 3 mass percent of the additives relative to the weight of the bitumen.

Abstract: The occurrence of the super typhoon Pablo, along with frequent earthquakes, and flash floods, served as a pivotal phenomenon towards the call for enhancing disaster response and mitigation strategies in Davao Oriental. This study aimed to design disaster-resilient housing in Davao Oriental using Botong bamboo (Dendrocalamus latiflorus)- a locally accessible material that diminishes construction costs without compromising its physical and mechanical attributes. To do so, the soil properties-with a bearing capacity of 677 kPa-was obtained using the Meyerhof’s bearing capacity theory with the mechanical properties of bamboo provided from related literature and the design loads (i.e. dead, live, seismic, wind) were approximated and applied onto the structure model. By simulating the proposed design model into the Finite Element Analysis (FEA) via STAAD in adherence to NSCP 2015 and AISC-LRFD specifications, force reactions were generated in the structural members; 87.46 kN for the columns, 26.23 kN for the roof truss, 9.22 kN for the slab truss, 2.87 kN for the purlins, and 32.68 kN for the bracings. Architectural and structural plans were provided applying the validated findings. It was proven that Botong bamboo is indeed a promising material for constructing disaster-resilient housing. This study is an attempt to attain the following Sustainable Development Goals (SDGs): SDG9: the need for resilient structure and innovation, and SDG 11: making human settlements inclusive, safe, resilient, and sustainable.

Abstract: This study was prepared on the bending and buckling analyses of the 2D honeycomb structure beam with a pocket section on it. In the study, two different materials,PLA and ABS, were selected to be examined for the beam. The aim of the study was to determine the buckling modes and critical buckling loads of lattice beams using numerical methods. Besides, bending analyses were conducted. As a result of bending analyses, the displacement (u_y), equivalent von Mises stress (σ_von), shear stress (τ_xy) and normal stress (σ_yy) behaviours for two different materials were obtained. It was determined that the ABS material deformed more than the PLA material beam. In this direction, important findings were obtained for understanding the bending and buckling behavior of lattice beams.