This study aims to investigate the service performances of a new full-section asphalt concrete waterproof sealing structure (FSACWSS) for the high-speed railway subgrade through…
Abstract
Purpose
This study aims to investigate the service performances of a new full-section asphalt concrete waterproof sealing structure (FSACWSS) for the high-speed railway subgrade through on-site tracking, monitoring and post-construction investigation.
Design/methodology/approach
Based on the working state of the waterproof sealing structure, the main functional characteristics were analyzed, and a kind of roller-compacted high elastic modulus asphalt concrete (HEMAC) was designed and evaluated by several groups of laboratory tests. It is applied to an engineering test section, and the long-term performance monitoring and subgrade dynamic performance testing system were installed to track and monitor working performances of the test section and the adjacent contrast section with fiber-reinforced concrete.
Findings
Results show that both the dynamic performance of the track structure and the subgrade in the test section meet the requirements of the specification limits. The water content in the subgrade of the test section is maintained at 8–18%, which is less affected by the weather. However, the water content in the subgrade bed of the contrast section is 10–35%, which fluctuates significantly with the weather. The heat absorption effect of asphalt concrete in the test section makes the temperature of the subgrade at the shoulder larger than that in the contrastive section. The monitoring value of the subgrade vertical deformation in the test section is slightly larger than that in the contrastive section, but all of them meet the limit requirements. The asphalt concrete in the test section is in good contact with the base, and there are no diseases such as looseness or spalling. Only a number of cracks are found at the joints of the base plates. However, there are more longitudinal and lateral cracks in the contrastive section, which seriously affects the waterproof and sealing effects. Besides, the asphalt concrete is easier to repair, featuring good maintainability.
Originality/value
This research can provide a basis for popularization and application of the asphalt concrete waterproof sealing structure in high-speed railways.
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Ganesh Prabhu Ganapathy, Theodore C. Haupt and Pandimani
Cracking, deformation and rutting are the most prevalent types of pavement distress, and these deformations and flow characteristics greatly distress the pavement features while…
Abstract
Purpose
Cracking, deformation and rutting are the most prevalent types of pavement distress, and these deformations and flow characteristics greatly distress the pavement features while also limiting its use. In India, on the other hand, more than 300 million scrap tyres are generated each year, and their disposal has become a severe environmental issue. Furthermore, the scrap generated by the used tyre must be disposed of properly. Hence, this study presents the experimental investigations of bitumen incorporating with Crumb rubber as main additive along with SBS polymer, to enhance the engineering property.
Design/methodology/approach
Crumb rubber (CR) was used as an additive along with styrene–butadiene–styrene (SBS) polymer to enrich the engineering qualities of the bitumen to reduce the disposal problem of scrap tyres and reduce the risk of environmental pollution. Because SBS polymer is expensive, response surface methodology modelling's central composite design (CCD) was used to optimise the number of tests. CCD modelling's input factors (process variables) were the inclusion rates of SBS and CR, which ranged from 2% to 5% and 4% to 10%, respectively, by total weight. Furthermore, the influence of SBS polymer and CR on the characteristics of modified bitumen was prioritised.
Findings
The addition of SBS and CR enhanced the bitumen's penetration resistance at service temperatures. Furthermore, increasing the SBS and CR concentration affected the flow characteristics of the modified bitumen and enhanced its viscosity. The addition of SBS and CR as bitumen modifiers increased penetration resistance by 24.06%. The Dynamic Shear Rheometer test demonstrated that the complex modulus of virgin bitumen increases with increasing SBS and CR content, which is consistent with the shifting softening point trend. The dosing rate of up to 3.5% SBS and 11% CR considerably contributed to the creation of polymer link networks, which increased the complex modulus of the bitumen by 16.5%. The CCD model's analysis of variance and Pareto bar chart demonstrated that the dose of CR is significant in improving the engineering features of the virgin bitumen rather than the SBS.
Originality/value
The utilisation of CR as a bitumen modifier may solve the problem of waste tyre disposal while also lowering the risk of environmental damage. Furthermore, because the presence of CR increased the engineering properties, particularly the complex modulus of virgin bitumen, the use of CR in combination with SBS polymer can be an efficient and cost-effective strategy to improving bitumen qualities.
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Sai Ma, Qinghong Xie, Jiaxin Wang and Jingjing Dong
Customer referral programs (CRPs) are popular; however, they often generate low referral rates. The authors propose that certain CRP referral tasks may hinder consumers’ referral…
Abstract
Purpose
Customer referral programs (CRPs) are popular; however, they often generate low referral rates. The authors propose that certain CRP referral tasks may hinder consumers’ referral likelihood. This study aims to explore the effects of referral tasks (communication content and approach) on customers’ referral likelihood on social platforms and the role of self-construal.
Design/methodology/approach
This study establishes a theoretical model based on online social platforms and conducts three scenario-based experiments. The authors obtain data from consumers on Sojump platform and test the hypotheses using analysis of variance (ANOVA) analysis and mediation analysis in SPSS. The valid sample sizes for these three experiments are 288, 203 and 214, respectively.
Findings
Three experimental studies indicate that communication content and approach have a significant effect on referral likelihood. Furthermore, the effect of communication content on referral likelihood depends on the communication approach. Self-construal plays a moderating role in the effect of communication content and approach on perceived social costs.
Originality/value
CRPs typically involve tasks and rewards; consumers are asked to complete a referral task and then receive a reward. Both tasks and rewards can affect an individual’s willingness to participate; however, existing studies on CRP focus primarily on the reward component. To the best of the authors’ knowledge, this is the first study to systematically investigate the role of referral tasks (communication content and approach) in CRPs. The authors extend the related research by examining the impact of referral tasks on consumers’ willingness to recommend. In addition, this study introduces self-construal into CRPs research.
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Merve Albayrak and Cemil Ceylan
The aim of this research is to combine and synthesize the findings of previous studies search for the effects of eWom on purchase intention by meta-analysis.
Abstract
Purpose
The aim of this research is to combine and synthesize the findings of previous studies search for the effects of eWom on purchase intention by meta-analysis.
Design/methodology/approach
The paper shows a meta-analysis process step by step. Within the scope of certain criteria, the studies in the Google Scholar and ITÜ library databases were eliminated and the results of the remaining 19 studies were analyzed in CMA (Comprehensive Meta-Analysis) program.
Findings
By conducting a meta-analysis of the research question, a common effect size was obtained from 19 studies. In addition, the effect size of 21 eWom (electronic word of mouth communication) factor on purchasing intention related to the 21 hypotheses defined in the study was obtained by means of meta-analysis separately.
Originality/value
With the increasing number of Internet users, the desire to share their comments and ideas on the Internet, and the increasing importance of electronic word of mouth communication in our lives, people's decisions have started to be affected by this situation. One of the decision-making movements is the purchase intention. Therefore, it is expected to see more researches on meta-analysis for the effect of eWom on purchase intention in the following years.
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Chunjiang Yang, Qinhai Ma and Ling Hu
The purpose of this paper is first, to overview the current research situation on job embeddedness (JE), including the theoretical underpinning of JE, the definition and…
Abstract
Purpose
The purpose of this paper is first, to overview the current research situation on job embeddedness (JE), including the theoretical underpinning of JE, the definition and dimensions of JE, its comparisons with similar constructs, and its global and composite measure; second, to intergrate the unfolding model, JE and image theory to better understand voluntary turnover – and indicate future research directions.
Design/methodology/approach
An extensive literature search covering several separate electronic databases, including ScienceDirect, EBSCO, Kluwer and Emerald, was conducted. Most of the articles can be acquired online from The University of California Riverside. The validity and reliability are compared between global and composite scales. The authors summarized and categorized the findings of current research.
Findings
JE can be differentiated from those similar constructs and measures already in the literature. Almost all of the studies on JE have found that it predicted voluntary turnover better than job attitudes and perceived ease of movement from traditional models of turnover. Along with extended research on it, JE was disaggregated into two major sub‐dimensions, namely, on‐the‐job and off‐the‐job embeddedness, and it has been extended to occupational and career level.
Research limitations/implications
In this paper, the authors use qualitative methods to evaluate the current studies on JE, only. Meta‐analysis, as a reviewing method, should be used in future research on clarifying the relationships between JE and other constructs in organizational behavior.
Originality/value
This research reviews almost all of the studies on JE from 2001 to 2009 and organizes and categorizes them into three kinds: cause, consequence and theoretical extension. The authors also summarize its relationships with other constructs (e.g. turnover, turnover intention, organizational commitment, organizational citizenship behavior) in various settings. Finally, based on discussion, the authors indicate future research directions.