Papers by Keyword: Mechanical

Abstract: The construction industry remains a major contributor to global CO₂ emissions, primarily due to its high consumption of non-renewable mineral resources and energy-intensive materials. In response to the growing need for sustainable alternatives, this study focuses on valorizing lignocellulosic biomass waste specifically Solid Olive Waste (SOW), a byproduct of olive oil production abundant in Mediterranean countries as a partial replacement for mineral aggregates in concrete. The main objective is to develop and evaluate an Innovative Solid Olive Waste Composite (ISOWC) as an eco-friendly material suitable for construction sector. The incorporation of SOW was optimized using the Talbot–Fuller–Thompson (T-F-T) semi-empirical method, which enabled the determination of ideal incorporation rates (10%, 20%, and 30% by aggregate volume) based on maximum packing density. Composite formulations were developed using the volumetric mix design method, incorporating both raw and water-saturated SOW. Comparative tests demonstrated that saturated SOW significantly improved the composite’s compressive strength and thermal conductivity, particularly as the SOW content increased. To further assess performance, a sensitivity analysis was conducted on ISOWC with 30% saturated SOW at varying cement dosages (200–350 kg/m³). The formulation with 200 kg/m³ cement achieved a compressive strength of approximately 6 MPa and thermal conductivity of 0.72 W/mK, meeting the criteria for insulating applications such as blocks and cladding panels. These results highlight the promising potential of ISOWC and support further investigation into the use of Solid Olive Waste as a full replacement for gravel in the development of eco-efficient, sand-based concretes.

Abstract: This work presents interesting results on the manufacturing and mechanical response of new mixtures for geopolymeric mortars using soils collected from sites near the Khapia hill located in the Puno region (Peru). Four types of soils were collected and used as binder raw material within a geopolymeric mortar mixture with a binder: sand ratio of 1:3. In parallel and for comparative purposes, the mechanical response of conventional Portland cement mortars was manufactured and evaluated, with a binder: fine sand volumetric ratio also of 1:3. To obtain the geopolymeric mortars, the sodium hydroxide solution with a molarity of 12 was considered as the liquid phase. While for the conventional Portland cement mortar, water was used. For all cases, the liquid phase: binder ratio was 0.6. The mechanical results were variable, with maximum average mechanical strength values between 30.1 and 45.4 MPa for geopolymeric mortars and 37.4 MPa for conventional mortars. On the other hand, Young's modulus values were found between 5.9 and 10.4 GPa for geopolymeric mortars and 8.8 GPa for conventional mortars. Regarding the porosity estimated from real and apparent densities, values between 27.2 and 28.3 % were found for geopolymeric mortars and 30.2 % for conventional mortars. The microstructure found for both types of mortars studied was very similar, all mortars consisted of two well-identified phases, a continuous and homogeneous phase of binder (geopolymeric or Portland cement) that surrounded another dispersed phase of aggregate particles (fine sand).

Abstract: This research explores the development of advanced materials known as natural fiber reinforced polymer (FRP) composites with the aim of enhancing overall quality of life. Hybrid fibers derived from durian/luffa fibers were integrated into Polyethylene (PE) matrices to fabricate hybrid natural fiber PE composites. The study involves a comprehensive examination of these composites through tensile testing, scanning electron microscopy (SEM), and Fourier-Transform Infrared (FTIR) analysis. Results indicate that the tensile strength of the durian/luffa PE (DLPE) composite surpasses that of neat PE laminates, highlighting its superior stress tolerance. Overall, the composites exhibit specific tensile strength and modulus, contributing to the creation of lightweight materials compared to neat PE. SEM analysis indicates satisfactory fiber-to-matrix bonding with room for improvement, as observed gaps between fibers and matrix are present. FTIR analysis uncovers constituents in the chemical composition of durian and luffa fibers. The inclusion of natural fibers as an alternative to synthetic counterparts aligns with Sustainable Development Goals (SDG) standards. This research underscores the feasibility and benefits of fiber hybridization, emphasizing improved mechanical strength, environmental sustainability, and cost efficiency.

Abstract: Polyvinyl alcohol (PVA) is a non-toxic, thermoplastic polymer that is completely biodegradable. So it is based on many composite materials for biomedical applications. In this study, various specimens were prepared by solvent casting method and then tested by tensile, FTIR, contact angle, SEM, antibacterial and cytotoxicity test. The results obtained showed the tensile strength decreased with the addition of PEG and then tended to improve after the addition of collagen and nano-titanium oxide. The wettability test shows the prepared specimens changed from hydrophobic to hydrophilic properties. The biological properties explained that the prepared composite had a better antibacterial effect and none of the samples had a toxic effect.

Abstract: To study the influence of cement-sand ratio, fly ash content, steel slag content, and fiber content on the performance of iron tailings premixed dry mixed mortar based on Box-Behnken, the regression model of compressive strength and fiexural strength and the above four factors was established, and the optimized mix ratio parameters were obtained. The results showed that the significance of the effect on compressive strength is ranked as follows: cement-sand ratio is greater than fly ash content than steel slag powder content than fiber content, and the significance of the effect on flexural strength is ranked as follows: cement-sand ratio is greater than fiber content than steel slag powder content than fly ash content.

Abstract: The increase in copper productivity in Zambia has resulted in the expansion of disposal areas occupied by mineral wastes and tailings. This not only consumes land but also, due to insufficient management, poses negative environmental impacts and health risks to people. Therefore, efficient and sustainable approaches for the proper management of these waste materials must be developed. In this study, the potential utilization of copper mine tailings was assessed. After analyzing the physical and chemical properties of copper mine tailings from Kitwe Tailings Dam (TD25), hollow concrete block specimens were prepared. Copper mine tailings were used as a partial replacement for cement in the mix design, with replacement ratios as follows: 0% for CBCMT O% (control specimen), 10% for CBCMT1O%, 20% for CBCMT2O%, 30% for CBCMT3O%, 40% for CBCMT4O%, and 50% for CBCMT5O%, all aimed at achieving a target strength of 5 MPa. Specimen compressive strength was evaluated, and it was found that CBCMT1O% and CBCMT2O% achieved the target compressive strength at 28 days of age. Water absorption rates and resistance to acid attack were also assessed. Findings revealed that all specimens outperformed the control specimen in terms of these properties. Furthermore, the environmental feasibility of the hollow concrete blocks specimens was examined, and the results showed limited leaching of heavy metals from the specimens, with concentrations within permissible thresholds. Additionally, a statistical analysis was conducted to study the influence cell shape has on the specimens’ compressive strength. Aimed at identifying the optimal specimen type for achieving compressive strength at an early age, results indicated that cell shape had a significant impact on the 28-day age of hollow concrete blocks. The study proposes a novel copper mine tailings (waste) management approach, by utilizing the potential it has to replace cement in the production of hollow concrete blocks, evident from the observed enhancement of the mechanical and durability properties.

Abstract: This research paper presents the findings of an experimental study conducted to investigate the influence of varying sizes and percentages of steel and nylon fibers on the mechanical and durability properties of concrete. The objective of this study was to explore the potential enhancements in concrete performance through fiber reinforcement, considering the two distinct fiber types - steel and nylon. A comprehensive testing program was devised, encompassing a wide range of fiber combinations to assess their individual and combined effects on concrete properties. The concrete specimens were prepared by incorporating different sizes (length and diameter) and proportions (percentage by volume) of steel and nylon fibers into the concrete mix. Mechanical properties, including compressive strength, tensile strength, and flexural strength, were evaluated to determine the impact of fiber reinforcement on the concrete's load-bearing capacity and resistance to cracking. Additionally, the durability properties, chloride ion penetration, and abrasion resistance, were assessed to understand the potential improvement in the concrete's long-term performance under adverse environmental conditions. The experimental results revealed significant variations in the mechanical and durability properties of the fiber-reinforced concrete compared to the conventional concrete mix. Steel fibers demonstrated superior performance in enhancing the concrete's load-carrying capacity and ductility, especially at higher percentages. On the other hand, nylon fibers exhibited exceptional resistance to and abrasion, contributing to improved durability. Notably, the steel and nylon fibers exhibited synergistic effects, leading to a balanced enhancement of mechanical and durability properties. In conclusion, this study provides valuable insights into the benefits of incorporating steel and nylon fibers in concrete, offering an effective means of optimizing the material's overall performance for diverse engineering applications. The results from this research can serve as a basis for developing more resilient and sustainable concrete structures, which can withstand harsh environmental conditions and contribute to the advancement of construction practices. Further exploration into the long-term behavior and cost-effectiveness of fiber-reinforced concrete is recommended for a comprehensive understanding of its feasibility in practical engineering applications.

Abstract: In order to enhance diverse composites and foster sustainable development, it is essential to use strategic measures. Microcrystalline cellulose (MCC) has the desirable characteristics of being both renewable and biodegradable. The characteristics above provide MCC with a favorable option for enhancing the structural integrity of composite materials. This study examines the literature on using MCC as a composite reinforcement to identify its primary characteristics. This evaluation explores the properties and potential future advancements of the naturally derived materials under investigation. This work comprehensively reviews scientific publications to guide future research efforts. Based on empirical investigations, using MCC as a composite reinforcement has enhanced various mechanical and tribological characteristics. This study provides a comprehensive reference for implementing sustainable MCC as a composite reinforcement.

Abstract: Ceramic Metallic Alloys of TiC/Ni, Comprising Titanium Carbide with Nickel Contents of 5%, 15%, 30%, and 50%, were Fabricated through Solid-Phase Sintering at 1400°C with a 2-hour Holding Time and a Pressure of 50MPa. This Study Explores the Impact of Nickel Content on the Mechanical and Structural Properties. The Solidification Mechanism between TiC and Ni is Governed by Carbon Diffusion through TiC Particles, Affecting the Morphology of TiC and Carbon Particles in Ni Samples. The Reaction Behavior within the TiC/Ni Alloys was Analyzed, and Microstructural and Mechanical Characteristics were Examined to Evaluate the Influence of Varying Nickel Contents. Results indicate that in all samples, the TiC matrix exhibited a solid solution of the FCC phase. The reaction mechanism of Ti-C-Ni reveals the evolution of solid phase formation with increasing nickel content. As nickel content increases, the mass and size of nickel particles grow, leading to a more uniform and homogeneous structure. At a nickel content of 15%, the samples displayed a bending strength of 1200 ± 50 N, a microhardness of 800 ± 20 (HV _0.1), and a density of 5.6 ± 0.2.

Abstract: Environmental issues over the eventual fate of post-consumer polymers can be dealt with in two separate ways which is recycling or using biodegradable polymers. However, it is evident that recycling polymers from post-consumer polymers can decrease the mechanical properties over time. Hence, to strengthen the recycled polymers, integrating fibers, such as luffa, into the High-Density Polyethylene (HDPE) matrix, was carried out to produce a fiber reinforced recycled polymer (FRrP) composite. The tensile testing of the FRrP composite shows that the 10% fiber volume fraction (FVF) composite exhibits a higher tensile strength of 3.9% than the neat recycled HDPE (RHDPE). In terms of Young’s Modulus, the 5% FVF of FRrP is shown to have a higher value than the neat RHDPE by 54%. The low density of luffa fibers also contributes to the composites lightweight character. The impact testing shows that the FRrP enhances the impact properties when compared to the neat RHDPE. The peak load, perforation energy, and the total energy absorbed by the FRrP indicate an increasing trend when luffa, of up to 15% FVF, is added as the reinforcement. Thus, the addition of luffa as reinforcement in RHDPE shows significant potential as a high-performance, sustainable, and environmentally friendly material, such as automotive parts and protective gear.