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1 – 10 of 590
Article
Publication date: 23 February 2018

Maxwell Fordjour Antwi-Afari, Heng Li, David John Edwards, Erika Anneli Pärn, De-Graft Owusu-Manu, Joonoh Seo and Arnold Yu Lok Wong

Work-related low back disorders (LBDs) are prevalent among rebar workers although their causes remain uncertain. The purpose of this study is to examine the self-reported…

Abstract

Purpose

Work-related low back disorders (LBDs) are prevalent among rebar workers although their causes remain uncertain. The purpose of this study is to examine the self-reported discomfort and spinal biomechanics (muscle activity and spinal kinematics) experienced by rebar workers.

Design/methodology/approach

In all, 20 healthy male participants performed simulated repetitive rebar lifting tasks with three different lifting weights, using either a stoop (n = 10) or a squat (n = 10) lifting posture, until subjective fatigue was reached. During these tasks, trunk muscle activity and spinal kinematics were recorded using surface electromyography and motion sensors, respectively.

Findings

A mixed-model, repeated measures analysis of variance revealed that an increase in lifting weight significantly increased lower back muscle activity at L3 level but decreased fatigue and time to fatigue (endurance time) (p < 0.05). Lifting postures had no significant effect on spinal biomechanics (p < 0.05). Test results revealed that lifting different weights causes disproportional loading upon muscles, which shortens the time to reach working endurance and increases the risk of developing LBDs among rebar workers.

Research limitations/implications

Future research is required to: broaden the research scope to include other trades; investigate the effects of using assistive lifting devices to reduce manual handling risks posed; and develop automated human condition-based solutions to monitor trunk muscle activity and spinal kinematics.

Originality/value

This study fulfils an identified need to study laboratory-based simulated task conducted to investigate the risk of developing LBDs among rebar workers primarily caused by repetitive rebar lifting.

Details

Construction Innovation, vol. 18 no. 2
Type: Research Article
ISSN: 1471-4175

Keywords

Article
Publication date: 6 January 2021

Cristina Toca Pérez and Dayana Bastos Costa

This paper proposes to apply the lean philosophy principle of minimizing or eliminating non-value adding activities combined with 4D building information modeling (BIM…

Abstract

Purpose

This paper proposes to apply the lean philosophy principle of minimizing or eliminating non-value adding activities combined with 4D building information modeling (BIM) simulations to reduce transportation waste in construction production processes.

Design/methodology/approach

This study adopts design science research (DSR) because of its prescriptive character to produce innovative constructions (artifacts) to solve real-world problems. The artifact proposed is a set of constructs for evaluating the utility of 4D BIM simulations for transportation waste reduction. The authors performed two learning cycles using empirical studies in projects A, B and C. The construction process of cast-in-place (CIP) reinforcement concrete (RC) was selected to demonstrate and evaluate 4D BIM's utility. The empirical studies focused on understanding the current transportation waste, collecting actual performance data during job site visits and demonstrating the usage of 4D BIM.

Findings

In the first cycle, 4D BIM successfully allowed users to understand the CIP-RC process's transportation activities, which were modeled. In the second cycle, 4D BIM enabled better decision-making processes concerning the definitions of strategies for placing reusable formworks for CIP concrete walls by planning transportation activities.

Practical implications

In Cycle 2, three different scenarios were simulated to identify the most suitable formwork assembly planning, and the results were compared to the real situations identified during the job site visits. The scenario chosen demonstrated that the 4D BIM simulation yielded an 18.75% cycle time reduction. In addition, the simulation contributed to a decrease in transportation waste that was previously identified.

Originality/value

The original contribution of this paper is the use of 4D BIM simulation for managing non-value adding activities to reduce transportation waste. The utility of 4D BIM for the reduction of those conflicts considered three constructs: (1) the capacity to improve transportation activity efficiency, (2) the capacity to improve construction production efficiency and (3) the capacity to reduce transportation waste consequences.

Details

Engineering, Construction and Architectural Management, vol. 28 no. 8
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 20 June 2023

Tsu Yian Lee, Faridahanim Ahmad and Mohd Adib Sarijari

Activity sampling is a technique to monitor onsite labourers' time utilisation, which can provide helpful information for the management level to implement suitable labour…

Abstract

Purpose

Activity sampling is a technique to monitor onsite labourers' time utilisation, which can provide helpful information for the management level to implement suitable labour productivity improvement strategies continuously. However, there needs to be a review paper that compiles research on activity sampling studies to give readers a thorough grasp of the research trend. Hence, this paper aims to investigate the activity sampling techniques applied in earlier research from the angles of activity categories formation, data collection methods and data analysis.

Design/methodology/approach

The method used in this paper is a systematic review guided by the PRISMA framework. The search was conducted in Scopus and Web of Science. The inclusion and exclusion criteria were applied, selecting 70 articles published between 2011 and 2022 for data extraction and analysis. The analysis method involved a qualitative synthesis of the findings from the selected articles.

Findings

Activity sampling is broadly divided into four stages: targeting trade, determining activity categories, data collection and data analysis. This paper divides the activity categories into three levels and classifies the data collection methods into manual observation, sensor-based activity sampling and computer vision-based activity sampling. The previous studies applied activity sampling for two construction management purposes: labour productivity monitoring and ergonomic safety monitoring. This paper also further discusses the scientific research gaps and future research directions.

Originality/value

This review paper contributes to the body of knowledge in construction management by thoroughly understanding current state-of-the-art activity sampling techniques and research gaps.

Details

International Journal of Productivity and Performance Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1741-0401

Keywords

Article
Publication date: 22 January 2024

Md. Tareq Hossain Khondoker, Md. Mehrab Hossain and Ayan Saha

Due to its longer length compared to other construction materials and distinctive stacking patterns, obtaining construction steel bars in congested construction sites with limited…

Abstract

Purpose

Due to its longer length compared to other construction materials and distinctive stacking patterns, obtaining construction steel bars in congested construction sites with limited storage capacity becomes challenging. Lack of storage space in crowded places prompts the need for building steel bar storage choice optimization. Therefore, this study aims to optimize the construction steel bar procurement plan by providing when and how much rebar to order and how to stack different sizes of rebar considering limited storage capacity.

Design/methodology/approach

A novel approach has been presented in this paper by integrating 4D building information modelling (BIM) and mixed-integer linear programming (MILP). This technique uses BIM to retrieve material quantities, including rebar, during the design phase. Following that, activities are scheduled depending on the duration determined by crew productivity data and material quantity. Then, based on the prior price, the price of each unit of rebar is projected for the duration of construction using the exponential smoothing method. After that, the MILP approach is used to generate an optimal steel bar procurement plan for limited storage space following the scheduled rebar-related operations.

Findings

The developed strategy minimizes overall procurement costs and ensures the storage of rebar as per standard guidelines. An optimal rebar procurement and storage plan to construct a six-storied RC frame has been presented in this paper as a demonstrative example to show the effectiveness of the proposed method.

Originality/value

This work partially satisfies a long-sought research need for establishing a comprehensive construction steel bar procurement system, making it a very useful source of information for practitioners and researchers. The proposed method can be used to minimize a key performance limitation that the conventional rebar procurement practice for crowded building sites may experience.

Details

Construction Innovation , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1471-4175

Keywords

Article
Publication date: 16 January 2009

Gul Polat

The purpose of this paper is to assess the impacts of implementing different combinations of various organizational changes on the economics of rebar supply chains in the special…

Abstract

Purpose

The purpose of this paper is to assess the impacts of implementing different combinations of various organizational changes on the economics of rebar supply chains in the special conditions of a project environment, where on‐site fabrication of rebar is considered to be more economical than off‐site fabrication practice.

Design/methodology/approach

A range of recently published works (2005‐2006) seem to confirm that on‐site fabrication of rebar results in less cost to the contractor compared with off‐site fabrication in a special project environment. However, those analyses did not take into account two main cost components (i.e. storage cost and waiting cost) owing to the lack of such information, and they were based on a number of assumptions regarding current managerial capabilities, which may likely be enhanced through implementing various organizational changes. This study overcame these shortcomings of the recent studies through restoring the formerly developed simulation model to mimic the materials management system actually used by a contractor, and running this system by plugging in realistic input values associated with both those cost components and organizational changes.

Findings

The paper reveals that while fabricating rebar off site is more economical than fabricating it on site when the storage and waiting costs were taken into account in the current state of the construction industry, and the lowest total cost of rebar can be achieved by implementing organizational changes in the on‐site fabrication practice.

Originality/value

This paper is a very useful source of information for practitioners and researchers because it indicates that off‐site fabrication practice is only beneficial to builders if they have the ability to exploit it, and if the cultural and business environment enables that exploitation.

Details

Construction Innovation, vol. 9 no. 1
Type: Research Article
ISSN: 1471-4175

Keywords

Article
Publication date: 11 November 2013

Long D. Nguyen and Hung T. Nguyen

The purpose of this paper is to examine the relationship between building floor and labor productivity of the structural work including formwork installation and rebar

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Abstract

Purpose

The purpose of this paper is to examine the relationship between building floor and labor productivity of the structural work including formwork installation and rebar fabrication/installation.

Design/methodology/approach

The case study methodology and learning curve theory are adopted for the paper. Records from the structural work of a 20-storey apartment building were analyzed to calculate floor-based labor productivities.

Findings

Labor productivity of the formwork activity increased more than twice in the first five floors. If the first cycle (floor 2) is omitted, the straight-line learning curve model shows a learning rate of 83.5 percent. Labor productivity of the rebar activity tended to increase in the first 15 floors. If the first two cycles are omitted, the straight-line learning curve model indicates a learning rate of 83.6 percent.

Research limitations/implications

Future research is needed to examine and quantify factors that affect the level of learning in high-rise building construction. The relationship between building floor and labor productivity should be further investigated for other construction activities.

Practical implications

Practitioners should consider the relationship between building floor and labor productivity and learning effects when planning manpower and construction duration for individual activities and for a building.

Originality/value

The paper substantiates the hypothesis that labor productivity does not reach 100 percent of the normal level at the very first floors while they do not support the hypothesis that labor productivity does not reach 100 percent at the top floors.

Details

Engineering, Construction and Architectural Management, vol. 20 no. 6
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 10 April 2007

M. de Magistris, M. Morozov, G. Rubinacci, A. Tamburrino and S. Ventre

The paper aims to apply an innovative inversion method to the problem of imaging (location, direction and size) of concrete rebars by means of eddy current measurements.

Abstract

Purpose

The paper aims to apply an innovative inversion method to the problem of imaging (location, direction and size) of concrete rebars by means of eddy current measurements.

Design/methodology/approach

An accurate numerical model of the probe‐rebar interaction, including eddy currents and skin effect, is considered. The inverse problem is approached with a very efficient inversion procedure previously introduced in a different context.

Findings

A critical analysis of the issues to be considered for the quantitative imaging of rebars is given, and the possibility of relevant simplifications in the numerical model outlined, allowing the development of an accurate and computationally efficient method.

Originality/value

The proposed formulation is applied for the first time to the problem of rebars imaging. Experimental tests have been carried out to validate the numerical model and its underlying hypothesis.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 26 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 27 July 2018

Nivin M. Ahmed, Mostafa G. Mohamed, Reham H. Tammam and Mohamed R. Mabrouk

This study aims to apply novel anticorrosive pigments containing silica fume-phosphates (Si-Ph), which were prepared using core-shell technique by covering 80-90 per cent silica…

Abstract

Purpose

This study aims to apply novel anticorrosive pigments containing silica fume-phosphates (Si-Ph), which were prepared using core-shell technique by covering 80-90 per cent silica fume (core) with 10-20 per cent phosphates (shell) previously, to play dual functions simultaneously as anticorrosive pigments in coating formulations and as an anticorrosive admixture in concrete even if it is not present in the concrete itself. Two comparisons were held out to show the results of coatings on rebars containing core-shell pigments in concrete, and concrete admixtured with silica fume can perform a dual function as anticorrosive pigment and concrete admixture. The evaluation of corrosion protection efficiency of coatings containing core-shell pigments and those containing phosphates was performed.

Design/methodology/approach

Simple chemical techniques were used to prepare core-shell pigments, and their characterization was carried out in a previous work. These pigments were incorporated in solvent-based paint formulations based on epoxy resin. Different electrochemical techniques such as open-circuit potential and electrochemical impedance spectroscopy were used to evaluate the anticorrosive efficiency of the new pigments.

Findings

The electrochemical measurements showed that concrete containing coated rebars with core-shell pigments exhibited almost similar results to that of concrete admixtured with silica fume. Also, the anticorrosive performance of coatings containing Si-Ph pigments offered protection efficiency almost similar to that of phosphates, proving that these new pigments can perform both roles as anticorrosive pigment and concrete admixture.

Originality/value

Although the new Si-Ph pigments contain more than 80 per cent waste material, its performance can be compared to original phosphate pigments in the reinforced concrete.

Details

Pigment & Resin Technology, vol. 47 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 17 February 2012

Albert P.C. Chan, Michael C.H. Yam, Joanne W.Y. Chung and Wen Yi

Heat stress, having caused preventable and lamentable deaths, is hazardous to construction workers in the hot and humid summers of Hong Kong. The purpose of this paper is to…

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Abstract

Purpose

Heat stress, having caused preventable and lamentable deaths, is hazardous to construction workers in the hot and humid summers of Hong Kong. The purpose of this paper is to develop a heat stress model, based on the Wet Bulb Globe Temperature (WBGT) index.

Design/methodology/approach

Field studies were conducted during the summer time in Hong Kong (July to September 2010). Based upon 281 sets of synchronized meteorological and physiological data collected from construction workers in four different construction sites between July and September 2010, physiological, work‐related, environmental and personal parameters were measured to construct and verify the heat stress model.

Findings

It is found that drinking habit, age and work duration are the top three significant predictors to determine construction workers' physiological responses. Other predictors include percentage of body fat, resting heart rate, air pollution index, WBGT, smoking habit, energy consumption, and respiratory exchange rate. The accuracy of the model is verified against data which have not been used in developing the model. The accuracy of the heat stress model is found to be statistically acceptable (Mean Absolute Percentage Error=5.6 percent, Theil's U inequality coefficients=0.003).

Practical implications

Based on these findings, appropriate work‐rest pattern can be designed to safeguard the well being of workers when working in a hot and humid environment.

Originality/value

The model reported in this paper provides a more scientific and reliable prediction of the reality which may benefit the industry to produce solid guidelines for working in hot weather.

Details

Journal of Facilities Management, vol. 10 no. 1
Type: Research Article
ISSN: 1472-5967

Keywords

Article
Publication date: 24 November 2022

Nihar Gonsalves, Omobolanle Ruth Ogunseiju and Abiola Abosede Akanmu

Recognizing construction workers' activities is critical for on-site performance and safety management. Thus, this study presents the potential of automatically recognizing…

Abstract

Purpose

Recognizing construction workers' activities is critical for on-site performance and safety management. Thus, this study presents the potential of automatically recognizing construction workers' actions from activations of the erector spinae muscles.

Design/methodology/approach

A lab study was conducted wherein the participants (n = 10) performed rebar task, which involved placing and tying subtasks, with and without a wearable robot (exoskeleton). Trunk muscle activations for both conditions were trained with nine well-established supervised machine learning algorithms. Hold-out validation was carried out, and the performance of the models was evaluated using accuracy, precision, recall and F1 score.

Findings

Results indicate that classification models performed well for both experimental conditions with support vector machine, achieving the highest accuracy of 83.8% for the “exoskeleton” condition and 74.1% for the “without exoskeleton” condition.

Research limitations/implications

The study paves the way for the development of smart wearable robotic technology which can augment itself based on the tasks performed by the construction workers.

Originality/value

This study contributes to the research on construction workers' action recognition using trunk muscle activity. Most of the human actions are largely performed with hands, and the advancements in ergonomic research have provided evidence for relationship between trunk muscles and the movements of hands. This relationship has not been explored for action recognition of construction workers, which is a gap in literature that this study attempts to address.

Details

Smart and Sustainable Built Environment, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2046-6099

Keywords

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