Dry Mixing Method Research Articles

The influence of Multi-Layer Plastic Packaging (MPP) on the high-temperature performance of asphalt binders and mixtures using wet and dry mixing methods

ABSTRACT High temperatures, combined with heavy traffic loads, increase the risk of permanent deformation and reduce the useful lifespan of pavements, leading to a greater need for maintenance and rehabilitation activities throughout the pavement's service life. This study aims to evaluate the effectiveness of recycled thermoplastic additives, specifically Multi-Layer Plastic Packaging (MPP) materials, in enhancing the high-temperature performance of asphalt mixtures. MPP materials, including types such as Polyester, Polyethylene, Nylon, and Metalized Polyester, were used for binder modification in asphalt mixtures. The modification was conducted using both wet and dry methods. The physical and rheological properties of the modified binders were assessed at high temperatures to determine their impact on stiffness and resistance to permanent deformation. The results indicate that MPP materials significantly improve the high-temperature performance of asphalt mixtures by enhancing binder stiffness and resistance to permanent deformation, with the wet method proving more effective than the dry method. These findings highlight the need for developing practical guidelines for incorporating MPP materials in asphalt production in the future and underscore the importance of comprehensive studies on maintenance, rehabilitation, and overall pavement lifecycle costs.

SIFAT MEKANIS KOMPOSIT MATRIKS ALUMINIUM BERPENGUAT ABU JERAMI DENGAN METODE METALURGI SERBUK

The powder metallurgy method is one method for making metal matrix composite products. This method provides researchers with material engineering.This study aims to determine how the effect of variations in mixing time and sintering holding time affects the hardness and compressive strength of composites made of aluminum powder and straw ash. The composition of this composite is 90%wt Aluminum and 10%wt straw ash. Preparation of specimens using powder metallurgy method. Mixing time variations were applied for 120, 150 and 180 minutes with the dry mixing method. Variation of sintering holding time was applied for 60, 120 and 180 minutes at 550°C.The mechanical test carried out are hardness test and compression test. The results showed that the optimum hardness value was found in the specimens with a mixing time of 150 minutes and sintering holding time of 180 minutes with an average hardness of 96 HRF. The optimum compressive strength is found in specimens with a mixing time of 150 minutes and sintering holding time of 120 minutes with an average compressive strength of 101.28 MPa. It can be concluded that mixing time and sintering holding time affect the hardness and compressive strength of the metal matrix composite.

Malleable, printable, bondable, and highly conductive MXene/liquid metal plasticine with improved wettability

Integration of functional fillers into liquid metals (LM) induces rheology modification, enabling the free-form shaping of LM at the micrometer scale. However, integrating non-chemically modified low-dimensional materials with LM to form stable and uniform dispersions remain a great challenge. Herein, we propose a solvent-assisted dispersion (SAD) method that utilizes the fragmentation and reintegration of LM in volatile solvents to engulf and disperse fillers. This method successfully integrates MXene uniformly into LM, achieving better internal connectivity than the conventional dry powder mixing (DPM) method. Consequently, the MXene/LM (MLM) coating exhibits high electromagnetic interference (EMI) shielding performance (105 dB at 20 μm, which is 1.6 times that of coatings prepared by DPM). Moreover, the rheological characteristic of MLM render it malleable and facilitates direct printing and adaptation to diverse structures. This study offers a convenient method for assembling LM with low-dimensional materials, paving the way for the development of multifunctional soft devices.

Microcrystalline Cellulose-A Green Alternative to Conventional Soil Stabilizers.

Biopolymers are polymers of natural origin and are environmentally friendly, carbon neutral and less energy-intense additives that can be used for various geotechnical applications. Biopolymers like xanthan gum, carrageenan, chitosan, agar, gellan gum and gelatin have shown potential for improving subgrade strength, erosion resistance, and as canal liners and in slope stabilization. But minimal research has been carried out on cellulose-based biopolymers, particularly microcrystalline cellulose (MCC), for their application in geotechnical and geo-environmental engineering. In this study, the effect of MCC on select geotechnical properties of kaolin, a weak, highly compressible clay soil, like its liquid and plastic limits, compaction behavior, deformation behavior, unconfined compression strength (UCS) and aging, was investigated. MCC was used in dosages of 0.5, 1.0, 1.5 and 2% of the dry weight of the soil, and the dry mixing method was adopted for sample preparation. The results show that the liquid limit increased marginally by 11% but the plasticity index was nearly 74% higher than that of untreated kaolin. MCC rendered the treated soil stiffer, which is reflected in the deformation modulus, which increased with both dosage and age of the treated sample. The UCS of kaolin increased with dosage and curing period. The maximum UCS was observed for a dosage of 2% MCC at a 90-day curing period. The increase in stiffness and strength of the treated kaolin with aging points out that MCC can be a potential soil stabilizer.

Karakterisasi Komposit Polimer dengan Matriks Polistirena dan Bahan Pengisi dari Berbagai Limbah Pabrik Kelapa Sawit

The first stage of this research was to make polystyrene grafted with maleic anhydride for making the couping agent with other filling compound. In the second stage, the polystyrene matrix grafted with maleic anhydride was combined with filler material derived from palm oil mill waste using the dry mixing method with an internal mixer. Among several variables tested, the optimum composition of the polymer composite was found to be Polystyrene grafted with maleic anhydride: sludge: boiler ash in a ratio of 60:25:15. This composition exhibited a Young's modulus of 856.752 MPa, a tensile strength of 6.057 MPa, and an elongation at break of 0.775%. Differential Scanning Calorimetry (DSC) testing revealed a glass transition temperature of 403.22°C, a crystallization temperature of 426.39°C, and a cross-linking indication temperature of 478.64°C. Scanning Electron Microscopy (SEM) tests showed an even distribution of the material. Fourier-transform infrared (FT-IR) spectroscopy indicated a decrease in absorption peaks at 3024.94 cm⁻¹ and 3025.15 cm⁻¹, while the polystyrene characteristics at the wave number 1600.57 cm⁻¹ appeared sharper. The sound absorption test results met the ISO 11654:1997 standard for the rating level of sound absorption coefficient in materials, achieving Class D and C sound absorption with an αₙₓ value ranging from 0.328 to 0.793.

Influence of Dry-Mixing and Solvent Casting Blending Techniques on the Mechanical and Biological Behavior of Novel Biocompatible Poly(ε-caprolactone)/Alumina-Toughened Zirconia Scaffolds Obtained by 3D Printing

This work focuses on the study and comparison of two mixing methods for the dispersion of Alumina-Toughened Zirconia (ATZ) within the polymer matrix of Poly(ε-caprolactone) (PCL). The dry-mixing method using solvent-free impact milling (M) and the solvent casting method with chloroform (SC) were investigated. Samples were produced by 3D printing, and specimens were printed at increasing ATZ loadings (namely, 10, 20, and 40 wt.%). The chemico-physical, mechanical, and cell interaction characteristics of the materials prepared with both mixing methods were studied. Solvent mixing allowed better dispersion of the ATZ in the polymer matrix with respect to dry mixing. In addition, dry mixing affected the molecular weight of the PCL/ATZ composites much more than the solvent casting method. For these reasons, materials obtained by solid mixing exhibited the worst mechanical performance with respect to those obtained by solvent casting, which showed increased Young’s moduli with increasing ATZ amounts. The in vitro biological response elicited in a mesenchymal stem cell model seemed to be influenced by the mixing method, with a preference for the composites obtained through solvent mixing and containing 20 or 40 wt.% of ATZ.

Ni-rich LiNi0.905Co0.043Al0.052O2 cathode material for high-energy density Li-ion cells: Tuning lithium content, structural evolution, and full-cell performance

Ni-rich LiNi0.905Co0.043Al0.052O2 oxides with the Li excess (x) up to 7 mol.% used in the synthesis are prepared by a facile dry-mixing method. It is shown that the Li/Ni mixing level and crystallite size are dependent on the Li amount, while Al from the precursor acts as a scavenger of the excessive Li. Operando X-ray diffraction (XRD) studies enable explaining differences in the structural evolution of materials exhibiting high and low Li/Ni mixing, especially in the H2↔H3 transition region. Soft X-ray absorption spectroscopy (XAS) studies show differences in the charge state evolution of the surface and bulk Ni. The optimized oxide with the Li excess x = 2 mol.% delivers excellent electrochemical performance, with an initial discharge capacity of 205.5 mAh g−1 at 0.1C, and 91.4 % capacity retention after 100 cycles at 1C. The unmodified in any other way cathode material allows achieving the discharge capacity of 178.5 mAh g−1 at the high rate of 5C, and works well in the full-cells.

Wet combustion synthesis of new thermochemical energy-storage materials based on carbide slag/magnesium oxide using citric acid

In this study, industrial solid waste carbide slag (as the calcium source) is modified using the critic acid (as the fuel) combustion mixing method to prepare a new type of magnesium oxide–doped energy-storage material. The experimental results show that the prepared H2O-CM-100 material doped with magnesium oxide exhibits good energy-storage performance and cycling stability during calcium cycling. After 20 energy-storage cycles, the energy-storage density and effective conversion rate remained stable at 1800 kJ/kg and 0.57, respectively. These values exceed the reported energy-storage densities and effective conversion rates of carbide slag energy-storage materials modified using the dry physical mixing method employed in previous studies. In addition, the carbonation kinetics results indicate that the doping of magnesium oxide effectively improves the carbonation reaction rate of carbide slag materials in the carbide slag cycle. In summary, magnesium oxide doping can not only improve the sintering of calcium oxide particles in carbide slag materials but also effectively enhance the energy-storage performance and carbonation reaction rate of carbide slag during carbide slag cycles. Thus, this study proposes a novel method for the efficient resource utilization of carbide slag and development of energy-storage materials.

Enhancing interface adhesion between waterjet‐produced rubber powders and natural rubber by wet‐mixing method

AbstractThe addition of rubber powder (RP) to natural rubber (NR) matrix using the dry mixing method leads to uneven distribution and poor interface bonding while the wet mixing method is not feasible due to the hydrophobic nature of the RP surface. To address this issue, we developed a method for producing RP with weakened hydrophobicity on the surface by high‐pressure waterjet and successfully achieved even distribution of the waterjet‐produced rubber powders (WPRPs) in NR and strong interface adhesion between WPRPs and NR by the wet mixing method. The properties of NR/WPRP composites were tested and characterized carefully. When adding 6 phr of 140‐mesh WPRPs in the NR matrix, the tensile strength and elongation at break of the NR/WPRP composites were 30.2 MPa and 627.2%, respectively, which were 4% and 7% higher than NR without WPRPs. Moreover, the anti‐abrasion property of the NR/WPRP composite was also strengthened by the addition of WPRPs. Our findings demonstrate that recycling waste rubber through a reasonable recycling method can not only reduce material waste and alleviate environmental pollution but also enhance the performance of the raw rubber, which offers significant economic benefits.

A Self-Disperse Copper-Based Catalyst Synthesized via a Dry Mixing Method for Acetylene Hydrochlorination

Traditional methods for synthesizing single-site catalysts are typically complicated and require special chemicals due to their tendency to agglomerate. In this study, we present a self-disperse copper-based catalyst synthesized via a dry mixing method for acetylene hydrochlorination. During the reaction, the copper precursor compounds, i.e., CuBr, and CuI, were converted to CuCl. Subsequently, the formed CuCl crystals underwent a significant structural transformation, leading to the formation of small clusters and Cu single sites. The catalytic activity of 5% CuCl + C prepared through the dry mixing method decreased from 93.7% to 92.9% after 100 h of reaction under the condition of GHSV (C2H2) = 60 mL·h−1·g−1. A comparison of the 5% CuCl + C with the 5% CuCl/C obtained by the impregnation method reveals that the catalytic stability of the former was higher than the one prepared by the conventional impregnation method. The exceptional catalytic performance can be attributed to the reaction-induced active sites being highly dispersed and the porous structure of activated carbon being maximally preserved, which was confirmed by HAADF-STEM, BET, TPR, and TG. The reaction-induced dispersion of CuCl on carbon provides a new strategy for preparing single-site catalysts for acetylene hydrochlorination.

Impact of Superabsorbent Polymer on Shrinkage and Compressive Strength of Mortar and Concrete

This article aims to study the effects of mixtures with superabsorbent polymers (SAPs) when using different mixing methods. The mixing methods used in this study are the dry mixing method and wet mixing method. Autogenous shrinkage, total shrinkage, drying shrinkage, compressive strength, and curing sensitivity index values are investigated. The results show that mixtures with SAPs have reduced autogenous shrinkage and total shrinkage. Shrinkage is more effectively reduced by the dry SAP mixing method than the wet SAP mixing method. The compressive strength derived by the dry SAP mixing method is higher than that derived by the wet SAP mixing method.

Towards a high-performance asphalt concrete for extreme climatic conditions using asphaltenes and polyethylene terephthalate fibres

Asphalt pavement experiences various deteriorations in different weather conditions due to the viscoelastic nature of asphalt binder. This study aims to develop a high-performance asphalt concrete (HPAC) for extreme temperature conditions by incorporating waste polyethylene terephthalate (PET) fibres and asphaltenes, a by-product from Alberta oil sands. First, performance of asphalt binder modified with asphaltenes is evaluated according to the Superpave performance grading (PG) system. Next, to improve low-temperature properties, HPAC mixtures modified with PET fibre at percentages of 0.05–0.30% are tested for compactibility to reflect field construction considerations. Then, performance tests including dynamic modulus; indirect tensile strength test at low temperatures; and Hamburg wheel-track at high temperature are conducted for an effective evaluation of the unmodified and modified mixtures that are prepared using a combination of the dry and wet mix methods. Results of binder PG tests reveal that with 12% asphaltenes, the modified binder is suitable for HPAC applications. The mixes with and without PET fibres exhibit similar compactibility and meet air void requirements of a maximum 6%, and incorporating PET fibres increases stiffness by up to 3.3%. Compared with the unmodified mixes, an optimum dosage of 0.15% PET fibre increases fracture energy by up to 27% at −10 °C and enhances tensile strength by up to 18% at 0 °C. The mixture with the optimum dosage also exhibits excellent rut resistance at 60 °C showing no signs of moisture damage sensitivity. As a result, it boasts a remarkable rutting resistance index that is five times higher than that of the control unmodified mix.

Tribological and thermal characteristics of copper-free brake friction composites

Abstract The effects of zinc, steel, aluminum, and brass materials that can be used instead of copper in brake friction composites on braking performance were investigated in this study. The specimens containing three different ratios of metallic shavings were produced by the dry mixing method. In terms of comparison, a total of 16 specimens were examined by producing the specimen containing copper at the same rates and the specimen containing no metallic chip. The weight loss, specific wear rate, and friction coefficient of the specimens were determined by the brake test results. The hardness and density tests were carried out. Thermal conductivity tests of the specimens were carried out to determine the thermal characteristic of copper. Among the metallic chips used, aluminum and steel wool were found to be good alternatives to copper.

Lab-scale environmental impact measurement of polymer-modified asphalt concrete mixtures production

This study aims to evaluate and compare the environmental impact of producing numerous polymer-modified asphalt concrete mixture types for road structures at the laboratory scale measured by air quality monitoring devices in a designed isolated area. Several mixture combinations were examined in this study, namely between the production of the standard hot mix at 160oC (case 1) and polymer-modified warm mix asphalt with 5% and 6% polymer dosages at 130oC (case 2 and case 3), as well as the production of hot mix asphalt using polymer modification by wet mix - known as polymer modified binder/PMB at 180oC (case 4) and dry mix methods using 5% and 6% polymer dosages at 160oC (case 5 and case 6), with each case represented by five samples fabrication. Case 4 yields the highest carbon dioxide, the volatile organic compound (VOC), formaldehyde (HCHO), and particulate matter (PM10 and PM1) by a total of 8195ppm, 10.12ppm, 6.5ppm, 1643 µg/m3, and 838 µg/m3, respectively, except PM2.5, where the outcome of case 3 is 1.2% higher than case 4. Meanwhile, the lowest emissions are recorded for case 2 and case 5, with the ratio to case 4 ranging from 43.5% to 96.5%. The heating phase generally gives the highest contribution to the total result, with the proportion ranging from 43.5% for carbon dioxide to above 90% for particulate matter. To sum up, producing hot mix asphalt with PMB and the mixer blending stage generates the highest emission.

Understanding the Role of Lithium Borate as the Surface Coating on High Voltage Single Crystal LiNi0.5Mn1.5O4

AbstractThe high‐voltage spinel lithium nickel manganese oxide (LNMO) with an operating voltage of 4.8 V is a promising cathode material for next‐generation lithium‐ion batteries (LIBs). However, LNMO/graphite (LNMO/Gr) full cells suffer capacity fading, which limits their practical applications. In this study, lithium metaborate (LBO) is applied on the LNMO surface to improve the full cell performance via a dry mixing method. The LBO‐coated LNMO delivers much better cycling stability than the uncoated LNMO in full cells with a practical 3 mAh cm−2 areal capacity. Different characterizations are performed to understand the coating effect to track the boron and its impact on the cathode, electrolyte, and anode. The LBO‐coated LNMO owns a 5 nm cathode electrolyte interphase (CEI) with mitigated phase change after long‐term cycling. The uncoated LNMO has negligible CEI with obvious phase change. However, no boron can be detected on the surface of the coated sample. Electrolyte and anode analyses indicate that the coating acts as an additive reservoir, gradually dissolves into the electrolyte, and generates BF4− species. As a result, Nickel/Manganese (Ni/Mn) dissolution from LNMO and the extensive generation of solid electrolyte interphase (SEI) on the anode side is mitigated, thus improving the full‐cell cycling stability to a great extent.

Analisis Indeks Workabilitas pada Campuran Asphalt Concrete dengan Asbuton B 50/30

The majority of road construction in Indonesia uses flexible pavement, namely Asphalt Concrete (AC). Therefore, to meet the need for asphalt, Asbuton was carried out. This research aims to determine the effect of Asbuton content, mixing temperature, and compaction temperature on the workability index value. Therefore, research was carried out regarding the workability of the AC-WC mixture with Asbuton B 50/30
 The preparation of test objects was carried out using the dry mixing method. The Asbuton content used was 10% and 15% and the mixing temperature was varied, namely 160⁰ C, 170⁰ C, 180⁰ C 190⁰ C, and 200⁰ C and the compaction temperature was 110⁰ C, 120⁰ C, 130⁰ C, 140⁰ C, and 150⁰ C at the level optimum asphalt. Then, the data obtained is processed using a statistical approach.
 The research results showed that the AC-WC mixture with 10% Asbuton content and varying mixing and compaction temperatures had a workability index value from 2.9890 to 5.7737. Meanwhile, the AC-WC mixture with 15% Asbuton content and varying mixing and compaction temperatures has a workability index value ranging from 3.3252 to 6.9845. This shows that variations in Asbuton content, mixing temperature and compaction temperature influence the workability index value of the AC-WC mixture.

Influence of nanosized magnesia on the hydration of borehole-sealing cements prepared using different methods

Gas drainage is an effective technology for gas control in coal mines. A high borehole-sealing quality is the fundamental precondition for efficient gas drainage. The expansibilities of cement pastes used in borehole-sealing processes are critical for the borehole-sealing effect. Nanosized magnesia expansive agents are used to improve the expansibilities of cement pastes and improve the borehole-sealing effect. Nuclear magnetic resonance spectrometry and scanning electron microscopy were adopted to study the effects of nanosized magnesia on the hydration of borehole-sealing cements used with different preparation methods. The results showed that an increase in the mass fraction of the nanosized magnesia promoted cement hydration, and the mass fraction was positively correlated with the promotion effect. The use of different preparation methods did not change the water-phase distribution in the cement. When using the wet-mixing preparation method, nanosized magnesia promoted the induction, acceleration, and deceleration periods of hydration; when using the dry-mixing preparation method, the nanosized magnesia promoted the induction period of cement hydration, and the promotion effect was less obvious than that seen when using the wet-mixing method. When using the wet-mixing preparation method, the nanosized magnesia was uniformly dispersed, thus enlarging the surface area of the reaction, which provided more nucleation sites for the hydration products of the cement and therefore accelerated the hydration reaction. When using the dry-mixing preparation method, the nanosized magnesia powders were dispersed nonuniformly and aggregated. Under these conditions, only a few nanosized magnesia particles on the surfaces of the aggregated clusters took part in hydration, so only a small number of nucleation sites were provided for the hydration products of cement. This led to inconsistent hydration of cement pastes prepared using the dry-mixing method. The surface porosity of the cement prepared with the wet-mixing preparation method first decreased and then increased with increases in the mass fraction of the nanosized magnesia. The cement surface exhibited compact hydration products and few pores, and the surface was relatively smooth. In comparison, the surface porosity of the cement prepared using the dry-mixing method fluctuated with increasing mass fraction of the nanosized magnesia, resulting in a rough cement surface and microfractures on some surfaces. The two preparation methods both reduced the surface porosity of the cement. The wet-mixing preparation was more effective and consistent in improving the compactness of the cement than the dry-mixing preparation. These results provide important guidance on the addition of nanosized magnesia in borehole-sealing engineering and the selection of cement preparation methods, and they also lay a solid foundation for realizing safe and efficient gas drainage.

Development of the Ni-Rich Li1+XNi0.905Co0.043Al0.052O2 High-Energy-Density Cathode Materials for Li-Ion Cells: Operando XRD Studies, Surface Modification, and Electrochemical Properties

With an increasing pressure to address major energy and environmental issues associated with consumption of the fossil fuels, the public is more and more aware of the need for electrification of the transportation sector. However, the rapid development of electric vehicles (EV) industry has put forward much higher and strict requirements for the energy storage density and safety of the applied batteries. Obviously, the accessible to the driving range per charge, depend on the characteristics of the EV batteries, which in turn depend mainly on the reversible capacity of the cathode and anode materials. To meet the demand of more than 500 kilometers driving range, development of high-energy-density cathode materials is required. Currently, the Ni-rich layered oxides (LiNiO2-type) are considered as primary candidates for a significant boosting of the properties, due to the very high reversible discharge capacity (>200 mAh g-1), high operating voltage (~3.7 V vs. Li/Li+), and relatively low costs. Nevertheless, such oxides still suffer from severe issues, such as surface sensitivity, poor structure with Li/Ni mixing effect, and insufficient thermal stability, which hinder their practical application. In particular, presence of LiOH/Li2CO3 lithium residuals in the active material, which originate from the synthesis process, has deleterious effect on the rate performance and may affect cycling stability of the cells.In this work, a simple vibratory dry mixing method was adopted to synthesize high-Ni-content Li1+xNi0.905Co0.043Al0.052O2 (NCA90) cathode materials with varying lithium excess used during the preparation route. The Ni-rich [Ni0.905Co0.043Al0.052](OH)2 precursor was used in the synthesis. The obtained samples maintained the desired ball-like morphology of the precursor, as well as layered R-3m crystal structure. To quantify the lattice volume changes during charge and discharge, operando XRD experiments were also conducted. A custom-made cell, having a Be window was used for the measurements. Two cycles were measured, with the first one up to 4.3 V, and the second up to 4.5 V. The registered charge/discharge curves, obtained using the operando cell, were nearly the same as those obtained using the normal 2032 coin-type half cells. Analysis of the XRD operando data showed that the a lattice parameter decreases monotonically as the charging proceeds, whereas the c parameter initially increases, and then begins to contract, for voltages higher than ca. 4.0 V. Above ca. 4.2 V, the c parameter abruptly decreases, which can be related to the so called H2 → H3 phase transition. It is worth noting that this transition is responsible for the capacity fading. During charge and discharge, the observed behavior of the 003 reflection was reversible, but showing small changes in the recorded intensity and position of the peak. Overall, the generated profiles of the structural changes of the Ni90 cathode materials are almost symmetrical, with only small asymmetric behavior, especially visible during the first cycle. The results indicate that the operando XRD tests are important for realizing the real-time monitoring and provide on-site information of the structural evolution and phase transitions occurring for the cathode materials. Also, the electrochemical performance of the NCA90 cathodes was characterized using 2032 coin-type half cells with a Li metal anode and 1 M LiPF6 in EC:DEC 1:1 vol. ratio electrolyte. The cycling tests were performed between 2.7 V and 4.3-4.5 V at different current densities. One of the best performing Li1.05Ni0.905Co0.043Al0.052O2 cathode delivered an initial discharge capacity of 234.5 mAh g-1 at 0.05 C, with a capacity retention of 70.7% after 100 cycles. Finally, an attempt was done to introduce surface coating of the obtained cathode materials, in order to enhance the capacity retention.

Initial state of excavated soil and rock (ESR) to influence the stabilisation with cement

This paper investigates the initial state of excavated soil and rock (ESR). These initial states include dry density, organic content, water content (Wc), cement content (Cc), liquid index (LI), dry or wet mixing method. Three ESRs collected from tunnelling projects and kaolin were used in this study to compare. The specimens (i.e., 50 mm in diameter and 100 mm in height) were prepared in the laboratory and cured at 7 and 14 days, and then assessed by the unconfined compressive strength (UCS) test. The analysis shows that the ratio of Wc/Cc is the primary factor to obtain different UCS for high LI ESR and a simple equation is proposed for quick prediction. For ESR with a more general LI, predictive equations are also proposed in terms of artificial neural network (ANN) and genetic programming (GP) for 7-days curing time. The results indicate that the both ANN models with Bayesian Regularization (BR) algorithm outperform ANN with Levenberg-Marquardt (LM) and GP model are accurate to predict UCS of mixtures.

Pengaruh Karet Remah Terhadap Stabilitas Campuran Beraspal Laston AC-WC Menggunakan Metode Dry Mix

Roads must have the appropriate mix of thickness and design to protect the subgrade from damage and to accommodate the load pressure on the road. The purpose of this research is to investigate the effects of adding crumb rubber to the hot asphalt mixture of the Laston AC-WC type. The research was conducted in two stages, involving the creation of test specimens. In the first stage, the bitumen content of the specimens included 5%, 5.5%, 6%, 6.5%, and 7%. In the second stage, In the second stage, crumb rubber was added to the mixture at percentages: 0%, 5%, 10%, 15%, and 20%. The crumb rubber was mixed using the dry mix method. Several parameters were considered based on the results of the Marshall Test, in accordance with the General Highways specifications (VFA, VIM, VMA, Stability, Meltability and MQ). characteristics analysis aims to determine the impact of crumb rubber content on the elasticity, durability, and other properties of the asphalt mixture. Of all the variations of the hot mix asphalt type Laston AC-WC mixed with crumb rubber; the optimum level of crumb rubber mixture was obtained at 5% for the hot mix asphalt type Laston AC-WC. From the research results, when 5% crumb rubber was added to the asphalt mixture, the following values were obtained: 856.1 kg stability, 3.07 mm flow and 290.40 kg/mm MQ. In contrast, the stability value of hot asphalt concrete asphalt concrete type AC-WC with 5% asphalt has 813.7 kg stability, 3.03 mm flow and 268.30 kg/mm MQ.