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Article
Publication date: 7 February 2022

Muralidhar Vaman Kamath, Shrilaxmi Prashanth, Mithesh Kumar and Adithya Tantri

The compressive strength of concrete depends on many interdependent parameters; its exact prediction is not that simple because of complex processes involved in strength…

Abstract

Purpose

The compressive strength of concrete depends on many interdependent parameters; its exact prediction is not that simple because of complex processes involved in strength development. This study aims to predict the compressive strength of normal concrete and high-performance concrete using four datasets.

Design/methodology/approach

In this paper, five established individual Machine Learning (ML) regression models have been compared: Decision Regression Tree, Random Forest Regression, Lasso Regression, Ridge Regression and Multiple-Linear regression. Four datasets were studied, two of which are previous research datasets, and two datasets are from the sophisticated lab using five established individual ML regression models.

Findings

The five statistical indicators like coefficient of determination (R2), mean absolute error, root mean squared error, Nash–Sutcliffe efficiency and mean absolute percentage error have been used to compare the performance of the models. The models are further compared using statistical indicators with previous studies. Lastly, to understand the variable effect of the predictor, the sensitivity and parametric analysis were carried out to find the performance of the variable.

Originality/value

The findings of this paper will allow readers to understand the factors involved in identifying the machine learning models and concrete datasets. In so doing, we hope that this research advances the toolset needed to predict compressive strength.

Details

Journal of Engineering, Design and Technology , vol. 22 no. 2
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 24 May 2023

Vijaya Prasad Burle, Tattukolla Kiran, N. Anand, Diana Andrushia and Khalifa Al-Jabri

The construction industries at present are focusing on designing sustainable concrete with less carbon footprint. Considering this aspect, a Fibre-Reinforced Geopolymer Concrete…

Abstract

Purpose

The construction industries at present are focusing on designing sustainable concrete with less carbon footprint. Considering this aspect, a Fibre-Reinforced Geopolymer Concrete (FGC) was developed with 8 and 10 molarities (M). At elevated temperatures, concrete experiences deterioration of its mechanical properties which is in some cases associated with spalling, leading to the building collapse.

Design/methodology/approach

In this study, six geopolymer-based mix proportions are prepared with crimped steel fibre (SF), polypropylene fibre (PF), basalt fibre (BF), a hybrid mixture consisting of (SF + PF), a hybrid mixture with (SF + BF), and a reference specimen (without fibres). After temperature exposure, ultrasonic pulse velocity, physical characteristics of damaged concrete, loss of compressive strength (CS), split tensile strength (TS), and flexural strength (FS) of concrete are assessed. A polynomial relationship is developed between residual strength properties of concrete, and it showed a good agreement.

Findings

The test results concluded that concrete with BF showed a lower loss in CS after 925 °C (i.e. 60 min of heating) temperature exposure. In the case of TS, and FS, the concrete with SF had lesser loss in strength. After 986 °C and 1029 °C exposure, concrete with the hybrid combination (SF + BF) showed lower strength deterioration in CS, TS, and FS as compared to concrete with PF and SF + PF. The rate of reduction in strength is similar to that of GC-BF in CS, GC-SF in TS and FS.

Originality/value

Performance evaluation under fire exposure is necessary for FGC. In this study, we provided the mechanical behaviour and physical properties of SF, PF, and BF-based geopolymer concrete exposed to high temperatures, which were evaluated according to ISO standards. In addition, micro-structural behaviour and linear polynomials are observed.

Details

Journal of Structural Fire Engineering, vol. 15 no. 1
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 4 December 2023

Bahareh Nikmehr, Bidur Kafle and Riyadh Al-Ameri

Concrete, the second most used material in the world, surpassed only by water, relies on a vast amount of cement. The process of cement production emits substantial amounts of…

Abstract

Purpose

Concrete, the second most used material in the world, surpassed only by water, relies on a vast amount of cement. The process of cement production emits substantial amounts of carbon dioxide (CO2). Consequently, it is crucial to search for cement alternatives. Geopolymer concrete (GC) uses industrial by-product material instead of traditional cement, which not only reduces CO2 emissions but also enhances concrete durability. On the other hand, the disposal of concrete waste in the landfills represents a significant environmental challenge, emphasising the urgent need for sustainable solutions. This study aimed to investigate waste concrete's best form and rate as the alternative aggregates in self-compacting and ambient-cured GC to preserve natural resources, reduce construction and demolition waste and decrease pertinent CO2 emissions. The binding material employed in this research encompasses fly ash, slag, micro fly ash and anhydrous sodium metasilicate as an alkali activator. It also introduces the best treatment method to improve the recycled concrete aggregate (RCA) quality.

Design/methodology/approach

A total of25%, 50% and 100% of coarse aggregates are replaced with RCAs to cast self-compacting geopolymer concrete (SCGC) and assess the impact of RCA on the fresh, hardened and water absorption properties of the ambient-cured GC. Geopolymer slurry was used for coating RCAs and the authors examined the effect of one-day and seven-day cured coated RCA. The mechanical properties (compressive strength, splitting tensile strength and modulus of elasticity), rheological properties (slump flow, T500 and J-ring) and total water absorption of RCA-based SCGC were studied. The microstructural and chemical compositions of the concrete mixes were studied by the methods of energy dispersive X-Ray and scanning electron microscopy.

Findings

It is evident from the test observations that 100% replacement of natural aggregate with coated RCA using geopolymer slurry containing fly ash, slag, micro fly ash and anhydrous sodium metasilicate cured for one day before mixing enhances the concrete's quality and complies with the flowability requirements. Assessment is based on the fresh and hardened properties of the SCGC with various RCA contents and coating periods. The fresh properties of the mix with a seven-day curing time for coated RCA did not meet the requirements for self-compacting concrete, while this mix demonstrated better compressive strength (31.61 MPa) and modulus of elasticity (15.39 GPa) compared to 29.36 MPa and 9.8 GPa, respectively, for the mix with one-day cured coated RCA. However, incorporating one-day-cured coated RCA in SCGC demonstrated better splitting tensile strength (2.32 MPa) and water absorption (15.16%).

Research limitations/implications

A potential limitation of this study on SCGC with coated RCAs is the focus on the short-term behaviour of this concrete. This limited time frame may not meet the long-term requirements for ensuring the sustained durability of the structures throughout their service life.

Originality/value

This paper highlights the treatment technique of coating RCA with geopolymer slurry for casting SCGC.

Details

Smart and Sustainable Built Environment, vol. 13 no. 2
Type: Research Article
ISSN: 2046-6099

Keywords

Open Access
Article
Publication date: 19 March 2024

Feng Chen, Zhongjin Wang, Dong Zhang and Shuai Zeng

Explore the development trend of chemically-improved soil in railway engineering.

Abstract

Purpose

Explore the development trend of chemically-improved soil in railway engineering.

Design/methodology/approach

In this paper, the technical standards home and abroad were analyzed. Laboratory test, field test and monitoring were carried out.

Findings

The performance design system of the chemically-improved soil should be established.

Originality/value

On the basis of the performance design, the test methods and standards for various properties of chemically-improved soil should be established to evaluate the improvement effect and control the engineering quality.

Details

Railway Sciences, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2755-0907

Keywords

Content available
Book part
Publication date: 7 March 2024

Mudit Kumar Singh

Abstract

Details

Social Capital
Type: Book
ISBN: 978-1-83797-587-7

Book part
Publication date: 20 March 2024

Satlaj Dighe, John M. LaVelle, Paidamoyo Chikate, Meral Acikgoz, Padmavati Kannan, Doris Espelien and Trupti Sarode

Although educators would likely agree that values and ethics are important in all disciplines, they have particular importance for practice-oriented fields. These applied…

Abstract

Although educators would likely agree that values and ethics are important in all disciplines, they have particular importance for practice-oriented fields. These applied professionals need to solve complex social problems that require the application of ethical standards and value perspectives. While the importance of value-engaged practice is known to the applied field, there is little research and conversation about how values can be integrated into teaching. This chapter synthesizes values-education approaches in various practice-based disciplines such as public administration (PA), program evaluation, social work, and public health. This chapter draws from empirical and theoretical works as well as the authors' experiences developing, participating in, and conducting values-based research on professionals and professional education.

Article
Publication date: 19 October 2023

Maaike Muntinga, Elena Bendien, Tineke Abma and Barbara Groot

Researchers who work in partnership with older adults in participatory studies often experience various advantages, but also complex ethical questions or even encounter obstacles…

Abstract

Purpose

Researchers who work in partnership with older adults in participatory studies often experience various advantages, but also complex ethical questions or even encounter obstacles during the research process. This paper aims to provide insights into the value of an intersectional lens in participatory research to understand how power plays out within a mixed research team of academic and community co-researchers.

Design/methodology/approach

Four academic researchers reflected in a case-study approach in a dialogical way on two critical case examples with the most learning potential by written dialogical and via face-to-face meetings in duos or trios. This study used an intersectionality-informed analysis.

Findings

This study shows that the intersectional lens helped the authors to understand the interactions of key players in the study and their different social locations. Intersections of age, gender, ethnicity/class and professional status stood out as categories in conflict. In hindsight, forms of privilege and oppression became more apparent. The authors also understood that they reproduced traditional power dynamics within the group of co-researchers and between academic and community co-researchers that did not match their mission for horizontal relations. This study showed that academics, although they wanted to work toward social inclusion and equality, were bystanders and people who reproduced power relations at several crucial moments. This was disempowering for certain older individuals and social groups and marginalized their voices and interests.

Originality/value

Till now, not many scholars wrote in-depth about race- and age-related tensions in partnerships in participatory action research or related approaches, especially not about tensions in research with older people.

Details

Quality in Ageing and Older Adults, vol. 25 no. 1
Type: Research Article
ISSN: 1471-7794

Keywords

Article
Publication date: 11 December 2023

Boyu Lin, Woojin Lee and Yunseon Choe

Local events play a significant role in rebuilding relationships and increasing engagement with local communities in the postpandemic. This study aims to investigate how potential…

Abstract

Purpose

Local events play a significant role in rebuilding relationships and increasing engagement with local communities in the postpandemic. This study aims to investigate how potential attendees’ usage of local event hashtags facilitates social media engagement, further enhancing their intentions to attend local events.

Design/methodology/approach

This study adopted an exploratory sequential mixed approach. The qualitative phase used 12 semistructured in-depth interviews to explore motivations for hashtag usage and developed instruments to measure hashtag usage and social media engagement. The quantitative phase examined the relationship among motivations and behaviors of hashtag usage, social media engagement and behavioral intention through 522 online surveys.

Findings

Qualitatively, four themes manifest in hashtag users’ motivations in the context of local events: self-promoting, searching, summarizing and conforming. The quantitative findings show that these motivations influence active and passive hashtag usage differently, leading to different types of social media engagement (i.e. persistent, customized and triggered engagement). All social media engagements can significantly enhance the intention to attend local events.

Originality/value

This study divides active and passive hashtag users, conceptualizes social media engagement through hashtag usage under the affordance approach and develops instruments for these concepts. It emphasizes the importance of hashtag usage that drives social media engagement and provides insights for local event planners.

研究目的

在后疫情时期, 本地活动在重建关系和增加与当地社区的参与方面发挥着重要作用。本研究调查了潜在参与者对当地活动话题标签的使用如何促进社交媒体的参与, 进一步增强了他们参加当地活动的意愿。

研究方法

本研究采用了一种探索性的顺序混合方法。定性阶段采用了12次半结构化的深度访谈, 以探讨话题标签使用的动机, 并开发了用于测量话题标签使用和社交媒体参与的量表。定量阶段通过522份在线调查研究了动机与话题标签使用、社交媒体参与和行为意向之间的关系。

研究发现

在定性研究中, 话题标签用户的动机在当地活动背景下表现为四个主题:自我推广、搜索、总结和顺应。定量研究结果显示, 这些动机以不同方式影响主动和被动话题标签使用, 从而导致不同类型的社交媒体参与(即持续型、定制型和触发型参与)。所有社交媒体参与都能显著增强参加当地活动的意愿。

研究创新

本研究区分了主动和被动话题标签用户, 通过能力方法构想了话题标签使用下的社交媒体参与, 并为这些概念开发了测量工具。本研究强调了推动社交媒体参与的话题标签使用的重要性, 并为当地活动策划者提供了见解。

Article
Publication date: 13 April 2023

Sebastian Schneck and Julia Hautz

This study aims to explain the cognitive bias of overconfidence and portray the different ways in which overconfident top managers may affect firm outcomes. This paper outlines…

Abstract

Purpose

This study aims to explain the cognitive bias of overconfidence and portray the different ways in which overconfident top managers may affect firm outcomes. This paper outlines their opportunities and risks and how these managers are surrounded by contextual factors.

Design/methodology/approach

This study draws on a systematic overview of the current literature on senior executives' overconfidence and empirical studies investigating its impact on strategic outcomes.

Findings

This study identifies the opportunities and risks of overconfident top managers in firms and considers the contextual factors that influence firm outcomes. The results provide three important managerial implications for interactions with overly confident top managers.

Practical implications

These findings help us understand top managers' overconfidence. Organizations receive guidance on how to constrain inappropriately confident top managers who are detrimental to their businesses.

Originality/value

This study contributes to a better understanding of overconfidence among top managers, illustrates associated opportunities and risks and provides recommendations for controlling and dealing with top managers characterized by this cognitive bias.

Details

Journal of Business Strategy, vol. 45 no. 2
Type: Research Article
ISSN: 0275-6668

Keywords

Article
Publication date: 29 March 2024

Chowdhury Jony Moin, Mohammad Iqbal, A.B.M. Abdul Malek, Mohammad Muhshin Aziz Khan and Rezwanul Haque

This research aims to investigate how manufacturing flexibility can address the challenges of an ever-changing and unpredictable business environment in Bangladesh’s…

Abstract

Purpose

This research aims to investigate how manufacturing flexibility can address the challenges of an ever-changing and unpredictable business environment in Bangladesh’s labor-intensive ready-made garment (RMG) industry, which is underserved and situated in a developing country.

Design/methodology/approach

Using Partial Least Square Structural Equation Modeling, this study empirically evaluated the relationships between manufacturing flexibility, environmental uncertainty and firm performance. The analysis utilized 320 survey responses from potential RMG experts, representing 95 organizations.

Findings

The study achieved a decision-making model for implementing manufacturing flexibility in the RMG industry of Bangladesh with acceptable model fit criterion. The research pinpointed that workforce flexibility plays the maximum mediating among different types of manufacturing in coping with demand and supply uncertainty in the RMG sector.

Research limitations/implications

The study made valuable contributions to theoretical and practical knowledge in the context of manufacturing flexibility in Bangladesh’s RMG and other underserved labor-intensive sectors in developing economies. It suggests that managers should shift from defensive and risky business strategies to more aggressive and proactive approaches by utilizing workforce flexibility resources adaptively to enhance manufacturing capabilities and align with dynamic market demand. Additionally, the study offers recommendations for future research to build upon its findings.

Originality/value

This study is unique in its approach because it presents a decision model for implementing manufacturing flexibility in a labor-intensive industry in a developing economy, specifically the RMG industry in Bangladesh, whereas previous research has primarily focused on high-tech industries in developed economies.

Details

Journal of Manufacturing Technology Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1741-038X

Keywords

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