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Article
Publication date: 18 October 2021

Haitao Zhang, Junfeng Sun and Mingyang Gong

The purpose of this study is to compare and analyze the anti-aging durability of asphalt and asphalt mixture under the conditions of inherent and improved performance. The…

Abstract

Purpose

The purpose of this study is to compare and analyze the anti-aging durability of asphalt and asphalt mixture under the conditions of inherent and improved performance. The research contents include: the mechanical properties (dynamic stability, bending strain, freeze-thaw splitting tensile strength ratio (TSR)) of different modified asphalt mixtures were tested by using the best modified asphalt.

Design/methodology/approach

The anti-aging durability of different modified asphalt was analyzed by using the results of macro tests such as penetration and softening point as evaluation indexes. Meanwhile, the change of the asphalt colloid instability index (Ic) in the aging process was used as the evaluation index to verify the results of the macroscopic test, and the best modified asphalt was obtained. On this basis, the composition of different modified asphalt mixtures was designed by using the best modified asphalt. Meanwhile, water stability was used as evaluation indexes to study the anti-aging durability of different modified asphalt mixtures.

Findings

The results show that styrene-butadiene-styrene (SBS) modified asphalt has better aging resistance. Due to the special storage time, the performance of rubber asphalt is also the best. Meanwhile, in terms of modified asphalt mixture, its high temperature performance and durability of anti-aging is as follows: 4% SBS /16% rubber modified asphalt mixture (IV) > 4% SBS modified asphalt mixture (II) > asphalt mixture (90#) (I) > 16% rubber modified asphalt mixture (III). The low temperature performance and durability of anti-aging is as follows: Ⅱ > IV > Ⅰ > Ⅲ. The water stability performance and durability of anti-aging is as follows: IV > Ⅲ > Ⅱ > Ⅰ.

Originality/value

The research results have important theoretical and guiding significance for exploring the change of intrinsic properties and improved properties of asphalt and asphalt mixture in the aging process and revealing the anti-aging mechanism of different modified asphalt mixtures.

Details

Multidiscipline Modeling in Materials and Structures, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1573-6105

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Book part
Publication date: 17 March 2017

Eunice Y. Rhee, Jade Y. Lo, Mark T. Kennedy and Peer C. Fiss

Drawing on the notion of imprinting, we develop a framework for understanding category emergence and durability by suggesting that the durability of a category reflects…

Abstract

Drawing on the notion of imprinting, we develop a framework for understanding category emergence and durability by suggesting that the durability of a category reflects its emergence conditions. We propose four ideal-typical mechanisms – consensus, proof, fiat, and truce – that arise from differences in the degree of agreement and the centralization of the authority regarding category definitions. Our framework not only relates category durability to emergence but also highlights the role of category promoters and constituencies in an ongoing process of category maintenance. We discuss implications for understanding the dynamics of the categorization process in various social and product market contexts.

Details

From Categories to Categorization: Studies in Sociology, Organizations and Strategy at the Crossroads
Type: Book
ISBN: 978-1-78714-238-1

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Article
Publication date: 7 March 2008

Wei Hai‐jun

The purpose of this paper is to discuss a method that can evaluate the friction durability of automatic transmission fluid.

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Abstract

Purpose

The purpose of this paper is to discuss a method that can evaluate the friction durability of automatic transmission fluid.

Design/methodology/approach

A small clutch was used to test the friction durability. The method adopts a similar sequence to that of SAE No. 2. Three commercial oils were studied. One of them meets the specification of the GM's DEXRONIIE and the others meet the DEXRONIII.

Findings

The results showed that two commercial oils have different friction durability. Two further samples were blended in the lab and friction durability was researched by this method.

Originality/value

The results showed that the samples have a good durability. The research indicates that the method is quite capable of distinguishing between some samples. The results also indicate the difference between the DEXRON specifications at friction durability.

Details

Industrial Lubrication and Tribology, vol. 60 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 August 2005

Yajun Ma, Wancheng Zhao, Shenghua Li, Yuansheng Jin, Yucong Wang and Tung C. Simon

Improved fuel economy, lower emission and longer durability are the major developing trends of engine oils. Aims to describe further research on the friction coefficient…

Abstract

Purpose

Improved fuel economy, lower emission and longer durability are the major developing trends of engine oils. Aims to describe further research on the friction coefficient of engine oils.

Design/methodology/approach

The lubricating durability D was defined based on definition of three characteristic points Pd, PS, Pi and three key time lengths Td, Ts, Ti. Two kinds of engine oils, respectively, belonging to GF‐2 and GF‐3 categories, were selected as samples to compare their lubricating durability.

Findings

Test results indicate the GF‐3 oil has much better lubricating durability than GF‐2 oil. With investigation of the topography and chemical composition changes of wear tracks along with the tribotests' time extending, the meanings of three characteristic points were discussed. Analysis indicates much better tribofilm, formed by the synergistic effect of Ca‐containing detergent with MoDTC/ZDTP in GF‐3 oil, is the major factor resulting in GF‐3 oil's longer lubricating durability.

Originality/value

Provides further research on lubricating durability, which is important for engine oil change and maintenance, as well as decreased cost and pollution to the environment, and improved energy conservation.

Details

Industrial Lubrication and Tribology, vol. 57 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 3 June 2020

Poonam Shekhawat, Gunwant Sharma and Rao Martand Singh

The purpose of this study is to investigate the effect of various heat conditions on the durability of eggshell powder (ESP)–flyash (FA) geopolymer subjected to…

Abstract

Purpose

The purpose of this study is to investigate the effect of various heat conditions on the durability of eggshell powder (ESP)–flyash (FA) geopolymer subjected to wetting–drying cycles.

Design/methodology/approach

In this study, two waste materials, ESP and FA, which are destined for landfills, were used as precursors to produce geopolymers in a sustainable manner. The mixture of Na2SiO3 and NaOH was used as a liquid alkaline activator in geopolymerization. The ESP and FA content were varied as 30, 50 and 70% and Na2SiO3/NaOH ratios were varied as 0.5, 1 and 2. Geopolymer samples were cured at three heat conditions: 25°C (ambient temperature), 50°C and 80°C for seven days prior to durability tests.

Findings

The results of this study revealed that the strength loss of the geopolymer decreases with an increase in curing temperature up to 50°C and then increases for higher temperature up to 80°C. Further, the strength loss of the geopolymer decreases with an increase in FA replacement and Na2SiO3/NaOH ratio. Geopolymer composites exhibited early strength development because of the inclusion of calcium-rich ESP. The weight loss of the ESP–FA geopolymer follows a similar pattern of strength loss. Geopolymer samples previously cured at optimum heat condition of 50°C for seven days exhibited higher durability.

Originality/value

The inclusion of calcium-rich ESP in FA-based geopolymer is novel research. As ESP–FA geopolymer composites show higher mechanical strength and higher durability compared to Indian standards, the potential use of this geopolymer can be in road subbases/subgrades.

Details

Journal of Engineering, Design and Technology , vol. 18 no. 6
Type: Research Article
ISSN: 1726-0531

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Article
Publication date: 11 February 2019

Salvinder Singh and Shahrum Abdullah

The purpose of this paper is to present the durability analysis in predicting the reliability life cycle for an automobile crankshaft under random stress load using the…

Abstract

Purpose

The purpose of this paper is to present the durability analysis in predicting the reliability life cycle for an automobile crankshaft under random stress load using the stochastic process. Due to the limitations associated with the actual loading history obtained from the experimental analysis or due to the sensitivity of the strain gauge, the fatigue reliability life cycle assessment has lower accuracy and efficiency for fatigue life prediction.

Design/methodology/approach

The proposed Markov process embeds the actual maximum and minimum stresses by a continuous updating process for stress load history data. This is to reduce the large credible intervals and missing loading points used for fatigue life prediction. With the reduction and missing loading intervals, the accuracy of fatigue life prediction for the crankshaft was validated using the statistical correlation properties.

Findings

It was observed that fatigue reliability corresponded well by reporting the accuracy of 95–98 per cent with a mean squared error of 1.5–3 per cent for durability and mean cycle to failure. Hence, the proposed fatigue reliability assessment provides an accurate, efficient, fast and cost-effective durability analysis in contrast to costly and lengthy experimental techniques.

Research limitations/implications

An important implication of this study is durability-based life cycle assessment by developing the reliability and hazard rate index under random stress loading using the stochastic technique in modeling for improving the sensitivity of the strain gauge.

Practical implications

The durability analysis is one of the fundamental attributes for the safe operation of any component, especially in the automotive industry. Focusing on safety, structural health monitoring aims at the quantification of the probability of failure under mixed mode loading. In practice, diverse types of protective barriers are placed as safeguards from the hazard posed by the system operation.

Social implications

Durability analysis has the ability to deal with the longevity and dependability of parts, products and systems in any industry. More poignantly, it is about controlling risk whereby engineering incorporates a wide variety of analytical techniques designed to help engineers understand the failure modes and patterns of these parts, products and systems. This would enable the automotive industry to improve design and increase the life cycle with the durability assessment field focussing on product reliability and sustainability assurance.

Originality/value

The accuracy of the simulated fatigue life was statistically correlated with a 95 per cent boundary condition towards the actual fatigue through the validation process using finite element analysis. Furthermore, the embedded Markov process has high accuracy in generating synthetic load history for the fatigue life cycle assessment. More importantly, the fatigue reliability life cycle assessment can be performed with high accuracy and efficiency in assessing the integrity of the component regarding structural integrity.

Details

International Journal of Structural Integrity, vol. 10 no. 4
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 8 August 2016

Xiaoli Kong, Bo Zhou, Jixiao Wang and Wenping Li

The purpose of this paper is to study the engineering application of diamond like carbon (DLC) coatings on the surfaces of piston pins and bucket tappets for a 2.0 L…

Abstract

Purpose

The purpose of this paper is to study the engineering application of diamond like carbon (DLC) coatings on the surfaces of piston pins and bucket tappets for a 2.0 L supercharged gasoline engine. The friction loss and durability of DLC-coated components were investigated.

Design/methodology/approach

The tribological characteristics were examined under oil-lubricated conditions in a CETR UMT reciprocating tribometer. In a motored engine test rig, friction loss torque test was performed to estimate the improvement in fuel economy. Fired engine durability bench tests of typical duration of 450 h were completed to access the durability and wear resistance of DLC coating. Before and after durability tests, coated and uncoated components were measured on the sliding surface by a profilometer technique.

Findings

Friction and wear test results show that DLC coating has low friction coefficient and reduces the wear rates by almost ten times compared to those of uncoated surfaces. Friction loss measurements indicate that DLC-coated tappets can reduce valve train friction loss by 29 per cent, and DLC-coated piston pins can reduce piston group friction by 11 per cent. Based on fired engine durability bench tests, it is evidenced that none of the coated tappets and pins show any noticeable peeling or delamination. Wear profiles analysis results indicate that DLC-coated engine components give rise to a substantial reduction in wear.

Originality/value

DLC coating applied onto the working surface of piston pin and bucket tappet can effectively reduce the friction loss of gasoline engine. DLC coating exhibits sufficient durability and improves friction and wear performance.

Details

Industrial Lubrication and Tribology, vol. 68 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 3 May 2017

Visar Hoxha, Tore Haugen and Svein Bjorberg

The purpose of this paper is to develop the empirically tested framework about the knowledge and perception about sustainability of building materials in Prishtina, Kosovo…

Abstract

Purpose

The purpose of this paper is to develop the empirically tested framework about the knowledge and perception about sustainability of building materials in Prishtina, Kosovo from the perspective of users, construction industry and facility managers.

Design/methodology/approach

A survey of representative sections of the population was designed and carried out in the capital city of Kosovo to determine the knowledge and perception of the population about the sustainability of building materials and to determine the main criteria of selection of sustainable building materials. The study may be used as guidelines for sustainable real estate developers in Prishtina during the materials selection process. Qualitative interviews were conducted with architects, consulting engineering companies, construction companies and facility managers from the region of Prishtina with open-ended questions also being used.

Findings

Results of quantitative research find that embodied energy, durability and low energy consumption are used as key criteria that influence the materials selection process on the part of users. The results of the cross-case analysis of qualitative measure the perceptions of construction industry and facility managers, according to which durability to a large degree is the main criterion for selection of sustainable building materials followed by embodied energy and low energy consumption.

Research limitations/implications

The study of measurement of level of knowledge and perception about sustainability of building materials in Kosovo focuses only on one pilot city; hence, further research is needed throughout Kosovo to validate the empirically tested tool within other geographical settings in Kosovo.

Originality/value

This survey represents the first quantification of knowledge and perception regarding the sustainability of building materials among users, construction sector and facility managers.

Details

Facilities, vol. 35 no. 7/8
Type: Research Article
ISSN: 0263-2772

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Article
Publication date: 12 November 2019

Wu Huijun, Zhan Diao and Kaizuo Fan

The purpose of this paper is to focus on the durability of underwater non-dispersible concrete in seawater environment.

Abstract

Purpose

The purpose of this paper is to focus on the durability of underwater non-dispersible concrete in seawater environment.

Design/methodology/approach

In this paper, ten groups of underwater non-dispersible concrete mixtures were designed, and the anti-dispersibility and fluidity of the mixtures were tested.

Findings

The durability test analysis shows that different pouring methods have different effects on the durability of concrete. The durability of concrete poured on land is better than that poured in water. Different mineral admixtures have different effects on the durability of concrete: the frost resistance of the underwater non-dispersible concrete specimens with silica fume is the best; the impermeability and chloride ion permeability of the non-dispersible underwater concrete specimens with waterproofing agent are the best; and the alternation of wetting and drying has adverse effects on the durability indexes of the non-dispersible underwater concrete.

Originality/value

The durability of underwater non-dispersible concrete is tested and the results can be used for reference in engineering practice.

Details

International Journal of Structural Integrity, vol. 11 no. 3
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 22 June 2012

Kamil Janeczek, Tomasz Serzysko, Małgorzata Jakubowska, Grażyna Kozioł and Anna Młożniak

The purpose of this paper is to investigate the durability of radio‐frequency identification (RFID) chips assembled on flexible substrates (paper and foil), with materials…

Abstract

Purpose

The purpose of this paper is to investigate the durability of radio‐frequency identification (RFID) chips assembled on flexible substrates (paper and foil), with materials evaluated with regard to mechanical stresses and dependence on the applied substrate, antenna materials, chip pad printing and chip encapsulation.

Design/methodology/approach

RFID chips were assembled to antennas screen printed on flexible substrates. Shear and bending tests were conducted in order to evaluate the mechanical durability of the chip joints depending on the materials used for mounting the RFID chip structures. X‐ray inspection and cross sectioning were performed to verify the quality of the assembly process. The microstructure and the resistance of the materials used for chip pads were investigated with the aim of determining the conductivity mechanism in the printed layers.

Findings

Addition of carbon nanotubes to the conductive adhesive (CA) provided a higher shear force for the assembled RFID chips, compared to the unmodified conductive adhesive or a polymer paste with silver flakes. However, this additive resulted in an increase in the material's resistance. It was found that the RFID substrate material had a significant influence on the shear force of mounted chips, contrary to the materials used for printing antennas. The lower shear force for chips assembled on antennas printed on paper rather than on foil was probably connected with its higher absorption of solvent from the pastes. Increasing the curing temperature and time resulted in an additional increase in the shear force for chips assembled to antennas printed on foil. A reverse dependence was observed for chips mounted on the antennas made on paper. An improvement in the durability of the RFID chip structures was achieved by chip encapsulation. Bending tests showed that a low‐melting adhesive was the best candidate for encapsulation, as it provided flexibility of the assembled structure.

Research limitations/implications

Further studies are necessary to investigate the mechanical durability of RFID chips assembled with a conductive adhesive, with different addition levels and types of carbon nanotubes.

Practical implications

The results revealed that the best candidate for providing the highest RFID chip durability related to mechanical stresses was the low‐melting adhesive. It can be recommended for practical use, as it simplified the assembly process and reduced the curing step in the encapsulation of the RFID devices. From the results of shear testing, conductive adhesives with carbon nanotubes can be used in RFID chip assembly because of their ability to increase the shear force of joints created between the antenna and the chip.

Originality/value

In this paper, the influence of the materials used for antenna, chip pads, encapsulation and the curing conditions on the mechanical durability (shear and bending) of RFID chips was analyzed. Commercial and elaborated materials were compared. Some new materials containing a conductive adhesive and carbon nanotubes were proposed and tested in RFID chip assembly to antennas printed on flexible substrates (paper and foil).

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