Papers by Keyword: Binder

Abstract: The effective recycling of industrial waste is a globally significant issue. In this study, a geopolymer binder was synthesized using an alkaline activator derived from brown coal gangue and blast furnace slag, along with silica fume as an industrial waste material. Also, the properties of these geopolymer binders are examined using them as a briquette binder. At temperatures above 700°C, roasted brown coal gangue is more active than the initial state. The optimum dosage of alkaline activator is 10M NaOH, silica fume/NaOH ratio of 3, specific gravity of 1.42, and the addition of binder of 6%. The main polymerization products of the alkali activated brown coal gangue geopolymer samples are N-A-S-H gel and amorphous aluminosilicate gel, while the main polymerization products of the alkali activated brown coal gangue -blast furnace slag geopolymer samples are N-A-S-H gel, C-(A)-S-H gel and amorphous aluminosilicate gel. Blast furnace slag is added during the preparation of briquette binder by brown coal gangue geopolymer, which increase the mechanical strength of the geopolymer binder and the optimum dosage is 30%. This study demonstrates a high-value and sustainable pathway for co-utilizing multiple industrial by-products.

Abstract: The WC-Co cemented carbide is one of the metal-matrix composites produced by sintering hard tungsten carbide (WC) with Co as metallic binder at high temperatures, and has excellent hardness and wear properties. In recent years, the high-entropy alloys (HEAs), which contain at least five elements with equiatomic or near-equiatomic ratio, have gained significant attention. The HEAs possess unique properties, which cannot be achieved by conventional alloying approaches based on only one alloying element, such as enhanced mechanical properties at high temperatures induced by severe lattice distortion effect and sluggish diffusion effect. In this study, HEAs were applied to alternative binders for the WC-Co cemented carbide as an attempt to seek enhanced mechanical properties. In the experiment, HEA powders such as the CrMnFeCoNi and CrFeCoNiMo HEAs were used as binder to fabricate WC-HEA cemented carbides by the multi-beam laser directed energy deposition (L-DED). WC-Co cemented carbide powder was also used for a comparative study. Through the comparative study, the role of elements in the initial binders are discussed. The multi-beam L-DED is one of the additive manufacturing (AM) processes. The WC-HEA cemented carbide powders were processed as single beads and square-shaped samples. Phase identification of the samples was performed by the X-ray diffraction (XRD). Microstructural observations were performed by a scanning electron microscope (SEM). The experimental results suggested the possibility for controlling hardness easily than the conventional processing routes by tailoring formed carbides through controlling laser processing conditions and alloying elements in initial binder materials.

Abstract: As the world shifts from a fossil-based to bio-based economy, energy production via the valorization of biomass residues is promising. However, raw biomass utilization for energy production proves to be challenging owing to their low bulk densities and hygroscopic nature. These problems are addressed through briquetting. This work focuses on the utilization of sugarcane bagasse (SCB) – an abundant agricultural residue in the Philippines – with lignin as a binder for solid fuel briquettes. The effects of SCB-to-lignin ratio and compaction pressure on the fuel characteristics and quality of the briquette were investigated. Briquetting experiments were carried out in a Carver press at a constant pressing temperature of 150°C and varying compaction pressures (CP = 5, 8 and 11 MPa) and binder content (BC = 4, 8 and 12%). Briquetting of SCB resulted in an increase in bulk density by 7 to 8 times (0.817 ± 0.006 - 0.974 ± 0.029 g/cm³) compared to loose SCB (0.110 ± 0.000 g/cm³). From ANOVA, it was found out that CP significantly affects bulk density (p < 0.05). The higher heating value (HHV) and compressive strength (CS) rose to as high as 19.7 ± 0.1 MJ/kg_db, and 113.14 ± 2.81 MPa, respectively. It was found out that BC significantly affects the HHV (p < 0.05) but has an insignificant effect on the CS (p > 0.05) while CP has insignificant effects on both HHV and CS (p > 0.05). Overall, SCB-lignin briquettes are able to overcome storage and handling challenges through improved bulk density, stacking capability of up to ~550,000 briquettes at the lowest achieved CS, retarded moisture uptake rate (0.0611 ± 0.0017 wt% per hr) and an equilibrium moisture content of 8.02 ± 0.15 wt%, making this fuel viable for domestic usage as determined by current briquetting standards.

Abstract: In the 18th century, hydraulic-based binders gradually supplanted air-hardening binders, and by the early 20th century, these were eventually replaced by cement. The distinction between binders categorized as natural and other hydraulic binders, such as natural cement and conventional cement, is that the former is characterized by raw materials with a naturally favorable mineralogical composition. This study examined the experimental possibilities of natural hydraulic binder production with marl resources commonly found in Turkey. Two raw materials quarried from Mersin (M) and Adana (A) were selected. These raw materials were calcined at temperatures of 750-850-950-1050 °C. The X-ray diffraction (XRD) analysis indicates that while the binders produced with M-coded raw materials contain varying amounts of the hydraulic phases larnite (C₂S and C₃S), the A-coded binders exhibit an absence of these critical hydraulic phases, which are essential for strength development in hydraulic binder paste. The increase in the strength of A-coded binders is thought to be due to the formation of calcium silicate hydrate (C-S-H) phases, which result from the reaction between water, clay minerals (SiO₂, Al₂O₃, and Fe₂O₃), and hydrated lime (portlandite, Ca (OH)₂).

Abstract: This study explores the synthesis and application of bio-based polyurethane (bio-PU) as a sustainable alternative to synthetic polyurethane (PU) in rubber polyurethane flooring. Bio-PU was synthesized by converting epoxidized palm oil (EPO) to bio-polyols using polysorbate20 at a ratio of 3:1, which was then reacted with polymeric methylene diphenyl diisocyanate (pMDI) to produce bio-PU. The bio-PU was blended with commercial PU and rubber granulate in concentrations of 10%, 20%, and 30%, with the aim of developing eco-friendly flooring materials. Key properties, including hydroxyl value, chemical functional groups (via FT-IR), force reduction, vertical deformation, tensile strength, elongation at break, and UV weathering resistance, were evaluated. The results demonstrated that rubber polyurethane flooring containing 30% bio-PU exhibited comparable or superior mechanical properties to flooring made with synthetic PU, meeting industry standards for force reduction, vertical deformation, and UV resistance. This study concludes that bio-based PU can serve as a viable alternative for the base layer of synthetic flooring, offering both environmental benefits and reliable performance.

Abstract: Pervious concrete is considered an advanced pavement material in terms of environmental benefits resulting from its basic feature - high water permeability. While natural aggregate is a standard component for permeable concrete production, the paper presents the potential of air-cooled blast furnace slag aggregate. The aggregate is specific for its open internal structure and at the same time high hardness and strength, which was assumed to be advantageous for this type of concrete. As permeable concrete is characterized by a specific structure and low amount of binder, it needs for optimization of kind and composition of aggregate, as well as the quantity and quality of the binder. In the experiment, following variables of composition were applied: a ratio of binder to aggregate b/a (0.28 and 0.36), a ratio of fine to coarse aggregate f/c (0.1, 0.2 and 0.3), and a set of blended cements. Experimental results point to the specific benefit of slag aggregate for permeable concrete production. The values of total porosity (30-38%) and permeability (4.6-17.5 mm/s) are higher than those recommended by most publications, as well as than those of concretes with natural aggregates. The compressive strength runs from 7.5 MPa to 15.0 MPa depending on the variables, while the effect of fine aggregate portion on both compressive strength and hydraulic conductivity is found to be much greater than that of the amount of binder. An important aspect is that, due to the nature of the aggregate, sufficient permeability is maintained even with higher proportion of fines. The range and variance values of the individual properties indicate that a change in the quality of the binder causes less variation in the results than a change in the composition of the mixtures.

Abstract: Pigment printing requires binder to assist adherence of pigment particles on the textile surface. The binders used industrially are synthetic types that need relatively high curing temperature (higher than 110°C), consequently, bringing about harmful environmental pollution if a proper pollution control and treatment are not taken into account. Nowadays, changes in world environmental protection scheme have been encouraging a development of sustainable textile products aiming to reduce an adverse environmental impact arising from textile production. At present, both textile manufacturers and users have increasingly seen eye to eye on using natural alternatives in substitute of the synthetic chemicals. In this research, natural rubber latex, an abundantly available natural material, was utilized as a binder to replace the commercial synthetic binder for textile pigment printing. The study was performed on the knit fabrics of cotton (single jersey and rib knits) and nylon (interlock knit). It was observed from the results that natural rubber latex added to the print paste (recipes R50, R70 and R90) exhibited a superior thickening effect (increasing viscosity) to the print paste with improved color strength and color fastness to washing obtained on the prints to those containing the synthetic binder (T^®). Moreover, natural rubber latex could well also act as a binder for pigment printing by rendering adhesion of pigment onto cotton and nylon fabrics even under room-temperature drying condition (recipe NR90-2). It was not necessary to dry and cure the print at high temperature when natural rubber latex was employed. Hence, energy-and cost-saving pigment printing process could be established with this sustainable natural material.

Abstract: The effect of artificial sand on the amount of core gas emission was examined. Mass loss by thermal decomposition of the binder was evaluated when resin-coated sand (RCS) with various amounts of artificial sand was exposed to high temperature. Compared to natural sand, the mass loss and temperature variation of artificial sand was reduced. It was confirmed that this is because the contact area between the two particles is reduced when the binder bridge is created between the foundry sands. Therefore, the surface morphology of the artificial sand has ragged surface, so that the heat conduction area is decreased.

Abstract: Fracture resistance curves (R-curves) have served as a robust tool in characterizing the entire fracture process of engineering materials. However, obtaining such curves for asphalt concrete (AC) mixtures is cumbersome due to the non-linear inelastic behavior of the mixtures. In this research, a single-specimen technique is developed based on the unloading compliance method which is used for metals. AC mixtures with limestone aggregate and PG58-22 binder were prepared. Beam specimens were fabricated and single-edge notched beam (SE(B)) fracture testing was conducted at low temperatures. A loading-partial unloading regime was used in the experiments and crack growth increments were captured by digital images throughout the tests. Using a multi-variable regression analysis, modified compliance equations were obtained for AC and R-curves of the mixtures could be constructed. It was revealed that the R-curve developed by ASTM E1820 compliance method could potentially overestimate the resistance of the mixtures against low-temperature fracture. The constructed R-curve exhibits a lower semi-vertical region addressing lower resistance of the mixture in the crack blunting phase. Also, the post-peak phase of the fracture shows a significantly lower slope in the constructed R-curve which denotes lower resistance of the mixture against unstable crack propagation.

Abstract: In this research, asphalt concrete (AC) mixtures modified by polymerized Sulfur were prepared. PG58-22 bitumen was used as the base binder for the mixtures along with crushed siliceous aggregate. The base binder was replaced by 20%, 30%, and 50% ratios with polymerized Sulfur in the modified mixtures while the reference mix was fabricated with 0% binder replacement. Single edge notched-beam fracture tests (SE(B)) were carried out in a temperature range of 0 °C to-20 °C on the AC beam specimens. Load-displacement curves were obtained from the experiments and the fracture energy of the mixtures could be determined. It was revealed that modifying the mixtures with polymerized Sulfur could improve the load bearing of the beam specimens as higher peak load values were recorded at fracture. However, fracture failure of the AC beams occurred at lower values of displacement addressing further embrittlement of the mixtures due to replacement of the base binder. Higher contents of polymerized Sulfur in the mixtures resulted in higher magnitudes of fracture energy as a general trend in this research addressing an improved resistance to low-temperature cracking.