Abrasion Loss Research Articles

Improved interfacial interactions of modified graphene oxide/natural rubber composites with the low heat build‐up and good mechanical property for the green tire application

AbstractWith the rapid development of transportation system, the safety, reliability, and durability of green tires play an important role in modern transportation. While for the material preparation, the poor dispersion ability of reinforced filler and the weak interfacial interactions with polymer matrix seriously restricted the further application in the green tire field. Meanwhile, avoiding the use of organic solvents is also an environmental issue that needs to be considered in the preparation process. Herein, water‐soluble 2‐mercapto‐1‐methylimidazole (MMI) functionalized graphene oxide (GO‐MMI) was obtained through a simple, green and one‐step hydrothermal method. Additionally, the modified graphene oxide/natural rubber composites (GO‐MMI/NR) with different GO‐MMI content were prepared by the latex coprecipitation approach. As a result, the modified GO‐MMI could be evenly dispersed in the NR matrix through the mechanical blending and the obtained GO‐MMI/NR composites possessed the good comprehensive properties after vulcanization. Specifically, the tensile strength (26.8 MPa), elongation at break (801%), low heat build‐up (6.2°C), Deutsches Institute for Normung (DIN) abrasion loss volume (71.31 mm3) and heat resistance index (162.1°C) were synchronic‐lifting when compared with the GO/NR composites. The results demonstrated that obtained GO‐MMI/NR composites owned the promising application for the industrial‐scale green tires.

Synthesis of alkali-activated mortar using phosphogypsum-neutralised bauxite residue

The present study was aimed at perspective utilisation of two wastes, bauxite residue (BR), an extremely alkaline material, and phosphogypsum (PG), a highly acidic substance, of entirely different natures. Development of alkali-activated mortar targeting pavement applications was explored. As BR and PG alone proved to be ineffectual in developing geopolymer/alkali-activated mortar because of undesirably low compressive strength, the challenge lies in synthesis of alkali-activated mortar with high strength using a combination of these wastes. PG proportions of 10, 20, 30, 40 and 50%; sodium hydroxide (NaOH) molarities of 8, 10, 12 and 14 M; and sodium silicate (Na2SiO3)/sodium hydroxide ratios of 0.5, 1.0, 1.5, 2.0 and 2.5 were chosen as variable parameters to develop the mortar. From the comprehensive experimental results, 30% PG, 12 M sodium hydroxide and sodium silicate/sodium hydroxide ratio of 1.5 were found as the optimum parameters for synthesising the mortar. It was demonstrated that the mortar made at a 70:30 combination of BR and PG had superior compressive strength of 31.24 MPa, minimum abrasion loss of 1.52 mm and water absorption of <7%, apart from constraining leaching of potentially toxic elements. On account of mechanical, durability and environmental performance, the present study recommends the aforementioned combination as ideally suitable material in pavement applications.

Utilization of plastic waste as replacement of natural aggregates in sustainable concrete: effects on mechanical and durability properties.

The study presents the mechanical and durability properties of concrete made up of recycled-waste-polyethylene (PE) and waste-polyethylene-terephthalate (PET)-based aggregate as replacement of natural fine and coarse aggregate, respectively. For this purpose, compressive strength, sorptivity, water permeability, aggressive exposure in acid, base, marine and wastewater, impact resistance, abrasion loss including surface and Cantabro, gas permeability, rapid chloride penetration test (RCPT), elevated temperature and leachability test of microplastic were performed. The experimental works were performed for different volumetric replacement (0-40%) of natural fine and coarse aggregates by PE and PET made aggregate respectively for different curing periods. The experimental results revealed that the sorptivity of PE-based concrete was lowest. Water permeability coefficient signified that with the increase of percentage of PET water permeability increased. In case of aggressive exposure test, the percentage of residual mass and residual strength for all replacement was decreased with the increase in exposure period. Further, impact resistance test result signified that energy absorption increased with the increase of PE and PET percentages. Cantabro and surface abrasion weight loss showed similar trend. Carbonation depth was increased with increasing percentages of PE and PET signified strength decreased with increase of percentages of PE and PET when subjected in CO2. RCPT test results demonstrated that with increase of PE and PET percentages chloride ion penetrability was reducing. It is observed that below 100°C temperature, compressive strength of all mix proportions was not affected with elevated temperature. Moreover, the PET-based concrete showed no presence of microplastic in case of leachability test.

Effects of Air Void Content, Crumb Rubber, and Pozzolanic Fillers on OGFC Laboratory Performance

Open-graded friction course (OGFC) is recognized for its ability for rapid stormwater drainage and effective noise reduction. Yet, several state highway agencies have limited its use because of concerns about its durability. The objective of this study was to investigate the impacts of air void (AV) reduction, crumb rubber (CR), and pozzolanic fillers on OGFC durability. Six mixtures were fabricated in the laboratory and their performance was evaluated. A control mix, 9.5-NMAS mix, two mixes incorporating CR, and two mixes prepared with pozzolanic fillers (i.e., Portland cement and fly ash) were evaluated. The test factorial was designed so that each mix would be evaluated at three different stages (i.e., production, construction, and field performance). A suite of laboratory tests was conducted including draindown, prediction of compaction effort, Cantabro abrasion loss, Hamburg wheel-tracking, Texas overlay tester, modified Lottman test, and boiling test to evaluate production, compaction, and OGFC resistance to raveling, permanent deformation, cracking, and moisture damage. Results showed that the reduction in AV and the use of CR and pozzolanic fillers considerably enhanced OGFC durability while maintaining appropriate functional performance (i.e., permeability).

A comparative study for the main properties of silica and carbon black Filled bagasse-styrene butadiene rubber composites

A comparative study has been done to investigate the effect of carbon black (CB) and fumed silica (Si) on the physico-mechanical and thermal properties of Bagasse/styrene-butadiene rubber (B-SBR) composites. Based on the incorporation of 25 phr from natural ground bagasse powder (GBP) as a supplement reinforcing filler in styrene butadiene rubber (SBR) vulcanizates, two identical sets of formulations have been prepared using different concentrations (20, 40, 60 and 80 phr) of carbon black and silica as the main reinforcing fillers in SBR composites. The ground bagasse powder (GBP) employed in this work, has a selective grain size distribution ranging from about 20–180 μm. As well, 2.5 phr of maleic anhydride (MA) was incorporated to improve the interfacial adhesion between SBR and bagasse. The distinguishing effect of different fillers on the rheological properties was clearly established. Tensile strength, elongation at break, modulus at 100% elongation (M 100), hardness (Shore A), abrasion loss, degree of swelling, as well as, thermal gravimetric analysis (TGA) of the rubber vulcanizates were studied. The prepared samples were morphologically analysed by scanning electron microscopy (SEM). The tensile strength and M 100% values of carbon black-filled compounds were obviously higher than those of the silica filled ones. In addition, hardness, wear and swelling properties were improved more and more by increasing the filler content. Whereas, the Si filled B/SBR showed a decreasing trend in elongation at break values but with an evidently higher plateau than that of CB filled ones. Overall, the CB filled vulcanizates recorded dominant mechanical properties compared to the Si filled vucanizates. On the other hand, both fillers offered a noticeable improvement in thermal stability, but with a preference favored for the silica filled compounds. Furthermore, the findings for SEM were found to be in agreement with the observed mechanical properties. This study summarizes a detailed discussion of the emerging green technologies for tyre production and depicted comprehensive data from the available literature.

Utilizing pond ash as fine aggregates in sustainable green concrete pavement – A case study

According to a recent estimate, more than 75 major accidents related to coal ash ponds have been reported between 2010 and 2020 which have resulted not only in loss of life and property, but also in extensive pollution of land, water, and air around the accident sites. In order to promote mass consumption in lieu of disposal, this study was aimed at utilizing the unused coal ash as fine aggregates in concrete pavements. In this regard, a pilot study was undertaken at NTPC Mouda wherein M25 grade pavement quality concrete (PQC) was used for casting a 500 m stretch of road inside the power plant premises. The mix design was prepared at VNIT Nagpur utilizing coarse and fine pond ash from NTPC Mouda as fine aggregates. OPC 43 grade of cement along with locally procured crushed stone aggregates were used. A compatible hyper-plasticizer was also used to maintain the workability and rheology of the concrete. The concrete was laid manually and was observed to attain its final setting within 600 min. The segment was cured for 28-days and finally, cores were extracted to evaluate the in-situ compressive strength of PQC and ascertain its durability. A 28-day compressive strength of 29.3 MPa along with reduced chloride ion permeability and abrasion loss indicate that the suggested approach of utilizing pond ash as fine aggregates in concrete roads is a sustainable alternative to conventionally used mix designs. Hence, the said approach will be a “greener” approach towards PQC construction reducing the dependency on natural river sand. Owing to the abundance of coal ash available in ash dykes, it is also expected that the suggested approach will prove cost-effective in terms of unit cost of concrete production.

Improvement of mechanical and dynamic properties of high silica filled epoxide functionalized natural rubber

In this research, 3 different low degrees (4, 8, and 14 mol%) of epoxide functionalized natural rubber were prepared via chemical modification of natural rubber, which was then vulcanized. Each of them was mixed with silica (50 parts per hundred of rubber) without a silane coupling agent and investigated their properties. It was found that the tensile and tear properties, as well as abrasion resistance of the silica filled epoxide functionalized natural rubber vulcanizates were higher than the silica filled natural rubber vulcanizate. These properties improvements could be attributed to the interaction of the silanol groups of the silica with the epoxide groups of the modified rubber chains via chemical and physical interactions. This could be supported by the occurrence of tear parts from the morphology investigation of the tensile fractured surface of the modified rubber vulcanizates using a scanning electron microscope. The presence of silicon elements in the rubber matrix was evidenced by scanning electron microscopy and energy dispersive X-Ray spectrometer. Moreover, the silica filled epoxide functionalized natural rubber having 14 mol% epoxide content without a silane coupling agent exhibited low abrasion loss, low heat build-up and enhancement in loss tangent at 0 °C, hence improved wet skid resistance, compared to the silica filled natural rubber without a silane coupling agent. This work demonstrated that the prepared low degree of epoxide functionalized natural rubber could be potentially applied to the tire tread rubber application without the use of a silane coupling agent.

Statistical analysis of stone mastic asphalt containing steel fiber

The use of various fibers in asphalt mixes has been developed and applied to enhance pavement performance. The conventional asphalt mixture can be improved by including steel fibre as an additive in the asphalt mixture. However, the use of steel fibre in SMA mixtures was not widely studied. Consequently, the objective of this study was to evaluate the effect of steel fibre on the volumetric properties and characterize the performance of steel fibre in SMA mixture. Different steel fiber proportions of 0%, 0.3%, 0.5%, and 0.7% by the total weight of the mixture were used in this study. The test conducted includes the Marshall stability and Flow test, and the Resilient Modulus Test. Response Surface Methodology (RSM) from Design Expert Software was then performed to determine the most optimum properties from the experimental data. The test results revealed that adding steel fiber greatly improved the SMA mixture’s resistance to deformation while also increasing its stability, reducing the abrasion loss, and increasing the stiffness of the SMA mixture. Optimized performance was observed at 0.3% steel fiber content and 1598 MPa of resilient modulus. The relative error results show acceptable agreement between the prediction and the experiment which is considered tolerable and acceptable. This demonstrates that the software optimization of the specific SMA with steel fiber characteristics by the RSM technique has the desired precision for laboratory tests.

Aminosilane modified graphene oxide for reinforcing nitrile butadiene rubber: Experiments and molecular dynamic simulations

Graphene oxide (GO) was chemically modified by 3-aminopropyl)triethoxysilane. The modified GO (denoted as MGO) was used to reinforce nitrile butadiene rubber (NBR). The occurrence of the chemical modification was confirmed by various characterization techniques. NBR/GO (or MGO) composites were prepared by a mechanical blending process. Their mechanical and tribological properties of NBR-GO/MGO nanocomposites were investigated. The NBR/MGO composites exhibited superior performances compared to their NBR/GO counterparts over the GO (or MGO) range of 1–5 wt%. The tensile strength of the NBR/MGO (1phr) was increased by 43.7% and 30.3%, and the abrasion loss was decreased by 59.3% and 58.9% with regard to the NBR and NBR/GO composite, respectively. The morphologies of the fractured and worn surfaces of the composites were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy to reveal the reinforcement mechanisms of MGO. The pull-out behavior of the GO or MGO from the NBR matrix and the interlayer peel-off behavior of the GO or MGO were described by molecular dynamic simulations. The stress required to pull the MGO off the NBR matrix was 121.2% that for the GO, while that of the interlayer peel-off for the MGO was 36.7% that for the GO. This explains the fact that the MGO was able to be better dispersed in the NBR than the GO and consequently better reinforce the mechanical and tribological properties of the latter.

Suitability of gravel deposits in Kirkuk city for concrete & roads works

The aim of research to a study some Engineering properties, Mechanical abrasion (Loss Anglos) test and Californian bearing ratio (CBR), with some physical properties such as optimum water content and specific gravity tests for aggregate deposits in Kirkuk / Iraq . Six samples taken from (Chiman) and (Shurau) sits , three samples from each sit which represented (Bai Hassan Formation) from (Shurau) sit , and Quaternary deposits from (Chiman) sit to estimate its resistance to abrasion and friction of the outer surface for course aggregate to show the suitability of geotechnical qualification of road layers and concrete works. The physical geotechnical evaluation results grain size distribution for samples (1, 2, 3) are matching for class (A) with simple shift in fine sizes according designation[1], while the samples (4, 6) are matching with class (B), while sample (5) matching exactly class (A), through represented the result as a curves and matching with standard curves all samples gave well graded curves. A results of specific gravity (dry, wet) of coarse aggregate (gravel) for samples (1, 2, 3) reached at average (2.583, 2.6) respectively, while a results of samples (4, 5, 6) reached at average (2.607, 2.624), and results of specific gravity (dry, wet) of fine aggregate (sand) for samples (1, 2, 3) reached at average (2.56, 2.542) respectively, while a results of samples (4, 5, 6) reached at average (2.491, 2.511), all the results within of limits that allowable according on American designation[2] between (2.3 – 3.2) . The strength tests (California bearing ratio) shows suitability to qualification needs to road works for sub base layer , where the values are (36%), (35%) respectively. Durability geotechnical tests (loss Angeles) results shows the weight loss for samples (1,2,3) are (% 20.4 ,% 25 , % 22.7) respectively, while for samples (4, 5, 6) the result are (19.80%, 22.3%, 20.06%) respectively. The Soundness test results for coarse aggregate (gravel) are (1.236%) for sample (1) and (1.062%) for sample (4) ,while the Soundness test results for fine aggregate (sand) are (2.897%) for sample (1) and (2.717%) for sample (4), so all samples are suitable to use in roads & concrete works .

Effects of Asphalt Binder Additives and Industrial Fillers on the Mechanical and Functional Properties of Open Graded Friction Course

Open graded friction course (OGFC) is widely recognized for its environmental and safety benefits (e.g., water drainage and noise reduction). However, based on durability concerns, many states have limited the use of OGFC. The objective of this study was to evaluate the effectiveness of warm mix asphalt (WMA) additives, by-products (i.e., crumb rubber [CR]), and industrial fillers (i.e., Portland cement and fly ash) in enhancing the laboratory performance of OGFC mixes. To achieve this objective, a comprehensive experimental program was conducted to evaluate the performance of eight mixes at three distinct stages (i.e., production, construction, and service). A suite of laboratory tests was conducted including draindown, prediction of compaction energy, Cantabro abrasion loss, Hamburg wheel tracking, Texas overlay, modified Lottman, and boiling tests to evaluate production, compaction, and OGFC resistance to raveling, permanent deformation, cracking, and stripping damage. Results indicated that CR, Portland cement, and fly ash significantly enhanced OGFC durability while maintaining adequate functional performance. In addition, results also showed that the use of an organic WMA additive considerably reduced the production temperature and compaction effort required to place the mix at the desired density while showing a significant improvement in OGFC durability.

A prediction method for abrasion loss rate of some Egyptian carbonate rocks due to cyclic salt crystallization weathering using physico-mechanical deterioration: insights from laboratory investigations

Salt crystallization is the most important weathering processes that causes problems for rocks used as building stones. Therefore, assessment of the physico-mechanical properties of stones against cyclic salt crystallization is a critical issue for rock engineering applications in salty environmental conditions especially prone to abrasion. This research aims at investigating the relationship between the degradation of various physico-mechanical properties including apparent porosity, point load index, unconfined compression strength and abrasion loss rate for rocks during salt weathering process. For showing rock weathering in the salt crystallization process, five kinds of carbonate rocks were sampled from different areas of Egypt and subject to cyclic salt crystallization, up to twenty cycles. The variation rates of their physico-mechanical characteristics and abrasion loss values were calculated after each five cycles of salt weathering. The results showed that the studied rocks are suitable for use as building and decorative stones in areas prone to crystallization of salts, but attention must be paid to rocks with high porosity and low strength characteristics such as El-Minia limestone specimens. It was also found that there are strong linear correlations between the physico-mechanical degradation parameters and the abrasion loss rate of the studied rock samples at the end of the twentieth cycle of salt weathering. These relationships may be used to estimate the abrasion loss rate of the studied rock types against the cyclic salt weathering conditions and hence to make a rapid evaluation of the stone durability.

Improved wear resistance of cemented carbide impact needle under high frequency micro-amplitude impact treated by high current pulsed electron beam

Assembly and packaging technology is one of the most critical factors that restrict the development of microelectromechanical systems (MEMS), including chips and other devices. Dispensing robot is a key high-end equipment in MEMS packaging. Its core component, WC-Co impact needle, is limited by fretting wear and deformation, leading to reduced service accuracy and life, which is the most important cause of failure. Impact fretting wear frequently occurs in micro-nano mechanical systems and has been widely studied. However, the combined high frequency (∼300 HZ) and micro impact amplitude (∼120 μm) wear behaviors such as WC-Co impact needle with ultrafine grain (∼100 nm) is rarely concerned. To further understand the influence of impact frequency and impact velocity on the wear rate of impact needle, dispensing experiments were designed and the wear mechanism was investigated. Results indicated that the impact velocity has more influence on the wear rate of impact needle than the impact frequency. In addition, a high-current pulsed electron beam (HCPEB) surface treatment method which can effectively increase the wear resistance of impact needle was proposed. After HCPEB treatment, the abrasion loss was reduced by 44% compared to the untreated one at the same impact frequency and different impact velocities, while the abrasion loss was reduced by 52% compared to the untreated one at the same impact velocity and different frequencies. These can be attributed to the fact that HCPEB treatment decreased the grain size of WC-Co cemented carbide impact needle and promoted WC phase transition, leading to an increase in microhardness.

Improving Dispersion of Carbon Nanotubes in Natural Rubber by Using Waterjet-Produced Rubber Powder as a Carrier.

Carbon nanotube (CNT), as reinforcing agents in natural rubber (NR), has gained a large amount of consideration due to their excellent properties. Uniform dispersion of CNT is the key to obtaining high-performance NR nanocomposites. In this contribution, a novel ultrasonic grinding dispersion method of CNT with waterjet-produced rubber powder (WPRP) as a carrier is proposed. Microscopic morphologies show that a Xanthium-like structure with WPRP as the core and CNTs as the spikes is formed, which significantly improves the dispersion of CNT in the NR matrix and simultaneously strengthens the bonding of the WPRP and NR matrix. With the increase in the WPRP loading, the Payne effect of CNT/WPRP/NR composites decreases, indicating the effectiveness of the dispersion method. The vulcanization MH and ML value and crosslinking density increase with the increase in the WPRP loading, whereas the scorch time and cure time exhibit a decreasing trend when the WPRP loading is less than 15 phr. It is found that the CNT/WPRP/NR composites filled with 5 phr WPRP have a 4% increase in 300% modulus, a 3% increase in tensile strength, while a 5% decrease in Akron abrasion loss, compared to CNT/NR composites.

Alternative Fillers in Asphalt Concrete Mixtures: Laboratory Investigation and Machine Learning Modeling towards Mechanical Performance Prediction.

In recent years, due to the reduction in available natural resources, the attention of many researchers has been focused on the reuse of recycled materials and industrial waste in common engineering applications. This paper discusses the feasibility of using seven different materials as alternative fillers instead of ordinary Portland cement (OPC) in road pavement base layers: namely rice husk ash (RHA), brick dust (BD), marble dust (MD), stone dust (SD), fly ash (FA), limestone dust (LD), and silica fume (SF). To exclusively evaluate the effect that selected fillers had on the mechanical performance of asphalt mixtures, we carried out Marshall, indirect tensile strength, moisture susceptibility, and Cantabro abrasion loss tests on specimens in which only the filler type and its percentage varied while keeping constant all the remaining design parameters. Experimental findings showed that all mixtures, except those prepared with 4% RHA or MD, met the requirements of Indian standards with respect to air voids, Marshall stability and quotient. LD and SF mixtures provided slightly better mechanical strength and durability than OPC ones, proving they can be successfully recycled as filler in asphalt mixtures. Furthermore, a Machine Learning methodology based on laboratory results was developed. A decision tree Categorical Boosting approach allowed the main mechanical properties of the investigated mixtures to be predicted on the basis of the main compositional variables, with a mean Pearson correlation and a mean coefficient of determination equal to 0.9724 and 0.9374, respectively.

Utilization of Bitumen Modified with Pet Bottles as an Alternative Binder for the Production of Paving Blocks

This study considers the utilization of bitumen modified with molten polyethylene terephthalate (PET) waste bottles as an alternative binder in paving blocks. PET waste was used at 2, 4, 6, 8, and 10% to modify bitumen in the production of paving blocks. Compressive strength test and skid resistance test were conducted on the paving block samples to evaluate their mechanical strength properties, while water absorption and the Cantabro abrasion tests were carried out to ascertain the durability of the paving block samples. The PET-modified bitumen paving blocks (PMBPB) have enhanced compressive strength and skid resistance compared to unmodified bitumen paving blocks. Also, a significant reduction in water absorption rate of up to 56% was achieved in PET-modified bitumen paving blocks (PMBPB) compared to the unmodified sample. The abrasion loss in the PMBCB samples was the least compared to that in normal cement paving blocks and unmodified bitumen paving blocks. The maximum compressive strength and least water absorption for the PET-modified bitumen concrete paving blocks were obtained at a 10% PET replacement level. It can be concluded that enhanced compressive strength and durability in cement paving blocks and unmodified bitumen paving blocks could be achieved with the use of PET modified bitumen in concrete paving block production, and this will also encourage PET waste recycling and contribute meaningfully to sustainability in concrete paving block production. Doi: 10.28991/CEJ-2023-09-01-08 Full Text: PDF

Effect of magnetic field intensity on the microstructure and abrasion resistance of magnetic electrodeposited Ni–Co–SiC thin films

The purpose of this work is intended to fabricate Ni–Co–SiC thin films on the surface of carbon steel bearing by magnetic electrodeposition (MED) technique. The surface morphology and composition of Ni–Co–SiC thin films were investigated by scanning electron microscope (SEM), energy disperse spectroscopy (EDS), and X-ray diffraction (XRD). The microhardness and frictional coefficient were detected by utilizing microhardness tester and ball-on-desk wear tester. The surface protrusion of Ni–Co–SiC thin films presented first descent and then ascent with the increasing magnetic field intensity. The surface morphology of Ni–Co–SiC thin films obtained at magnetic field intensity of 0.8 T presented more flat and dense than those deposited at magnetic field intensity of 0.4 and 1.2 T. Meanwhile, the highest microhardness of 987.5 Hv and lowest frictional coefficient of 0.75 were also emerged in the Ni–Co–SiC thin films fabricated at magnetic field intensity of 0.8 T. In addition, XRD results indicated the Ni–Co–SiC thin films manufactured at magnetic field intensity of 0.8 T possessed smallest Ni–Co grain size of 15.6 nm. The abrasion loss of M2 thin film was 17.3 mg, while the M1 film processed the largest abrasion loss of 31.5 mg. In addition, the average frictional coefficients of M1, M2 and M3 thin films were 1.04, 0.75 and 0.85, respectively.

Influence of Weather Conditions and Mechanical Reclamation on Molding Sand with Alkali-Phenolic Binder for Manganese Cast Steel

The article presents the results of research on the properties of molding sands in Alphaset technology (alkaline-phenolic). These sands are often used in steel foundries, producing large castings. However, knowledge about them, and especially about the changeability of their properties with the change of environmental conditions (seasons), is still insufficient. Various compositions of molding sand were analyzed based on fresh chromite sand and reclaimed sand. A binder and hardener in various mass ratios were used to prepare the mass. The research methodology included, among others, tests of tensile and bending strength, permeability, abrasion, gas emissivity, and ignition losses. These tests were carried out for summer and winter conditions. The results showed the optimal proportions of resin and hardener, showed the influence of ambient temperature on the properties of the molding sand, and the possible ratio of reclaimed sand in relation to fresh sand. However, you should always remember to verify them under the conditions of a specific foundry.

Optimising filler dosage to balance rolling resistance and grip properties tyre tread compound

Silica is a reinforcing filler which is known for its ability to improve wet/snow grip and rolling resistance in tyres. However, incorporating Silica in high quantities impairs other significant features like physical properties and processing behaviour of the compounds. In this study, the focus was on balancing rolling resistance and grip properties while attempting to nullify the negative effects of Silica, by arriving at an optimum ratio of combination of Carbon Black and Silica. Three different compounds were prepared – COMP_1 had CB:Silica in 2:1 ratio, whereas COMP_2 and COMP_3 had CB:Silica in the ratios 1:1 and 1:2 respectively. The impact of their dosage on various properties were investigated. Taking into consideration abrasion loss and grip properties, 1:1 ratio was deemed to possess the optimized ratio.

Natural Rubber Composites Reinforced with Green Silica from Rice Husk: Effect of Filler Loading on Mechanical Properties

Natural rubber (NR) composites filled with silica are typically used for tire tread applications owing to their low energy consumption and low rolling resistance. Tire tread properties vary broadly depending on the compound formulation and curing conditions. Silica loading is recognized as a critical factor influencing the mechanical properties of the composites. In this work, we aim to investigate the effect of silica loading (10–50 phr) on the mechanical properties of NR composites. Silica was prepared from rice husk waste via chemical treatment and subsequent calcination at 600 °C. Prior to the compound mixing process, silica was modified by a silane coupling agent to improve compatibility with the NR matrix. The NR compounds reinforced with silane-modified silica from rice husk were prepared using a two-roll mill machine. The scorch and cure times increased as the silica loading increased. The mechanical properties of the NR composites, including tensile strength, elongation at break, modulus, hardness, and abrasion loss, were examined as a function of silica loading. Tensile strength increased and reached the maximum value at 20 phr but decreased at high loading owing to the agglomeration of silica in the NR matrix. With increasing silica loading, hardness and modulus increased, whereas elongation at break and abrasion resistance decreased slightly. These results indicate that NR composites filled with silica are stiffer and harder at a higher silica loading due to the strong interaction between silica and the NR matrix, inhibiting the segmental mobility of rubber chains. We anticipate that the compound formulation presented in this work could potentially be adapted to tire tread applications.