scholarly journals The Effects of Buildability Factors on Rebar Fixing Labour Productivity of Beamless Slabs

2010 ◽  
Vol 10 (1-2) ◽  
pp. 16-35
Author(s):  
Abdulaziz M Jarkas
Keyword(s):  
Significant Influence ◽  
Construction Material ◽  
Labour Productivity ◽  
Regression Method ◽  
Activity Levels ◽  
Construction Sites ◽  
Slab Geometry ◽  
Factors Affecting ◽  
Productivity Data

 Buildability is an important factor affecting labour productivity. Nevertheless, a thorough search of the literature revealed a dearth of research into its effects on in situ reinforced concrete construction, especially at the activity levels. Since rebar fixing is an integral trade of this type of construction material, and beamless slabs are amongst the major encountered activities on construction sites, the objective of this research is to explore the buildability factors affecting its rebar fixing efficiency. To achieve this objective, a large volume of fixing productivity data was collected and analysed using the categorical interaction - regression method. As a result, the main and interaction effects of rebar diameter; reinforcement quantity; slab geometry; and reinforcement layer location are determined. The findings show a significant influence of these factors on the fixing operation, which can be used to provide designers and construction managers with feedback on how well the design of this activity considers the requirements of buildability, and the tangible consequences of designers‟ decisions on labour productivity

THE IMPACTS OF BUILDABILITY FACTORS ON FORMWORK LABOUR PRODUCTIVITY OF COLUMNS

2010 ◽  
Vol 16 (4) ◽  
pp. 471-483 ◽  
Author(s):  
Abdulaziz M. Jarkas
Keyword(s):  
Reinforced Concrete ◽  
Labour Productivity ◽  
Unit Cost ◽  
Regression Method ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Productivity Data ◽  
Effective Activity ◽  
Concrete Elements

The impacts of buildability on formwork labour productivity of major in situ reinforced concrete elements such as, foundations, walls, columns, beams and slabs, are yet to be determined and quantified. The labour unit cost of columns formwork, in comparison with other constituents of the reinforced concrete frame, is constantly higher due to the forming complexity of these elements, especially non‐rectangular shapes, and the small output achieved in the operation. Therefore, the objective of this research is to investigate the impacts of buildability factors on columns formwork labour productivity. To achieve this objective, a large volume of productivity data was collected and analyzed using the categorical‐regression method. As a result, the impacts of the grid patterns, variability of column sizes, repetition, total and aver‐age shutter size, and geometry of columns are quantified. Apart from the variability of column sizes, the findings show significant effects of these factors on labour productivity, which can be used to provide designers feedback on how well their designs consider the requirements of buildability principles, and the consequences of their decisions on labour efficiency. Moreover, the depicted patterns of results may provide guidance to construction managers for effective activity planning and efficient labour utilization. Santrauka Statybos veiksniu itaka gelžbetoniniu konstrukciju, kaip antai pamatu, sienu, kolonu, siju ir perdangos plokščiu, klojiniu, irengimo darbo našumui turi būti nustatyta ir kiekybiškai ivertinta. Vienetines darbo sanaudos kolonos klojiniams irengti, palyginti su kitomis gelžbetoninio remo dalimis, yra didesnes, nes sudetinga suformuoti elementus, ypač kai kolonos yra ne stačiakampio formos. Todel šio tyrimo tikslas – nustatyti statybos veiksniu itaka kolonu klojiniu irengimui. Siekiant šio tikslo buvo surinkta daug duomenu apie darbo našuma ir šie duomenys buvo ištirti naudojant kategoriju‐regresijos metoda. Buvo ivertinti šie veiksniai: ašiu tinklas, kolonu dydžio ivairove, kartojimasis, bendrasis ir vidutinis užrakto dydis, geometrija. Neivertinus kolonu dydžio ivairoves, gauti rezultatai rodo didžiuli šiu veiksniu poveiki darbo našumui. Naudojantis šia informacija galima ivertinti, ar projektuotojas atsižvelge i statybos principus ir priimtu sprendimu itaka darbo našumui. Be to, rezultatai gal suteikti papildomos informacijos darbu vadovui, kaip efektyviau panaudoti darbo jega.

scholarly journals Identification and analysis of factors affecting labour productivity in Iraq

2018 ◽  
Vol 162 ◽  
pp. 02032 ◽  
Author(s):  
Tareq Khaleel ◽  
Yasser Nassar
Keyword(s):  
Labor Productivity ◽  
Construction Projects ◽  
Arab World ◽  
Labour Productivity ◽  
Relative Importance ◽  
Construction Sites ◽  
Factors Affecting ◽  
Importance Index ◽  
Leadership Motivation ◽  
Major Factors

Productivity is a very important element in the estimation process in construction management. The objective of this research is to identify and analyze the factors which affect labor productivity in construction projects. In this research, 42 effective factors were collected from site survey, interview with engineers and experts, and previous research in the Arab world. These factors are grouped into Nine categories “Workforce, Leadership, Motivation, Supervisors, Safety, Project, Time, Material, and External”. A survey questionnaire of 70 respondents was distributed among different experts. A statistical analysis was done using SPSS and EXCEL packages. The Relative Importance Index was used to find out the most significant factors affecting the labor productivity in construction sites. The results accomplished from the survey revealed that the major factors negatively affect the labor productivity (ranked from the worst factor with Relative Importance Index values, respectively) namely, Availability Material (88.571%), Climate status “Weather” (88%), Religious occasions (86.29%), Number of working groups (86%), Ganger experience (85.714%), Workforce surveillance (84.857%), Ganger Age (84%), working at height (82%), Drawings and specifications alteration during execution (81.69%), and Sequence of floor (80.571%). Based upon these findings, this can help the construction professionals to improve the productivity and project performance in Iraq.

scholarly journals An Assessment of Labour Productivity Influencing Factors in the Construction Industry: A Case study of Zaria, Nigeria

2021 ◽  
Vol 2 (02) ◽  
pp. 26-37
Author(s):  
T. Adagba ◽  
J.O Ati ◽  
A.I Makarfi
Keyword(s):  
Labour Force ◽  
Labour Productivity ◽  
Research Area ◽  
Research Approach ◽  
Construction Sites ◽  
Site Factors ◽  
Factors Affecting ◽  
High Severity ◽  
Human Labour ◽  
Site Managers

In this research, factors affecting construction labour productivity in Zaria, Kaduna state was assessed. The research seeks to identify the factors affecting labour productivity in the research area. It is believed that this information will aid site managers and the construction professionals on decisions to take in-order to limit these controlling factors thereby leading to an improved level of efficiency in labour force, increase product labour productivity and reduce cost and time over runs on construction projects. The research adopted a quantitative research approach with the use of questionnaires as an instrument for data collection from site managers at construction sites in Zaria. Sixty-seven questionnaires were administered on construction sites within Zaria and Forty-one were returned giving a sixty-one percent response. The Questionnaire sought to assess the perception of site managers on factors affecting construction labour productivity. Data was analysed using descriptive statistics analysis to obtain frequencies, mean and Relative Importance Index (RII). RII was used to rank the factors. Thirty-Nine out of the Forty-One factors researched indicated high severity with the RII ranging between 0.60 RII < 0.80. The research revealed that external forces tend to affect construction labour productivity more than Site factors and Human Labour Factors. This can be attributed to the fact that site factors and Human Labour factors can be controlled by the site engineers while the external factors cannot be really controlled by the site engineers. The survey also revealed that Rain, Conflict with project stakeholders, Skill of labour, and Financial Crisis had a very high severity in affecting construction labour productivity on the construction sites in Zaria, Kaduna State.

Buildability factors affecting formwork labour productivity of building floors

2010 ◽  
Vol 37 (10) ◽  
pp. 1383-1394 ◽  
Author(s):  
Abdulaziz M. Jarkas
Keyword(s):  
Labour Productivity ◽  
Area Ratio ◽  
Design Stage ◽  
Curved Beams ◽  
Building Projects ◽  
Factors Affecting ◽  
Floor Area ◽  
Floor Area Ratio ◽  
Effective Activity

Several factors affect labour productivity, but buildability is one of the most important. A thorough investigation of the literature, however, revealed a dearth of research into the effect of buildability on labour productivity of in situ reinforced concrete construction. Therefore, this research focuses on quantifying the effects and relative influence of the variability of beam sizes, repetition of floor layout, floor area, average slab panel area, intersection of beams, beam–floor area ratio, and percentage of curved beams and nonrectangular slab panels on formwork labour productivity of building floors. Apart from the variability of beam sizes, buildability factors investigated are found to have significant effects on formwork labour productivity, confirming the importance of applying the concepts of rationalization, standardization, and repetition to the design stage of building projects. The findings can be used to provide designers with feedback on how well their designs consider the requirements of buildability principles and the consequences of their decisions on the labour efficiency of the formwork operation. On the other hand, the depicted patterns of results may further provide guidance to construction managers for effective activity planning and efficient labour utilization.

Factors Affecting the Use and Consequences of Management Accounting Practices in A Transitional Economy: The Case of Vietnam

2016 ◽  
pp. 54-73 ◽  
Author(s):  
Anh Doan Ngoc Phi
Keyword(s):  
Significant Influence ◽  
Quantitative Data ◽  
Structural Equation ◽  
Qualitative Data ◽  
Management Accounting ◽  
Transitional Economy ◽  
Equation Modeling ◽  
Enterprise Performance ◽  
Factors Affecting

This study seeks to help fill an important gap in the literature by investigating factors that have facilitated the use of management accounting practices (MAPs) in Vietnam - a transitional economy. Data were collected from 220 medium-to-large enterprises. Follow-up interviews were conducted with 20 accounting heads/vice heads to obtain further information and clarification. The quantitative data collected was analyzed using both descriptive and inferential statistics (including t-tests and structural equation modeling), while the qualitative data was used to shed further light on the various relationships described by the quantitative analysis. This paper reveals that both decentralization and competition have a positive, significant influence on the use of new MAPs except for the old ones. Consequently, the use of MAPs has a positive, significant influence on enterprise performance.

scholarly journals The Impact of Post-Manufacture Treatments on the Surface Characteristics Important for Finishing of OSB and Particleboard

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 975
Author(s):  
Antonio Copak ◽  
Vlatka Jirouš-Rajković ◽  
Nikola Španić ◽  
Josip Miklečić
Keyword(s):  
Water Vapour ◽  
Oriented Strand Board ◽  
Construction Material ◽  
Surface Characteristics ◽  
Surface Treatments ◽  
Factors Affecting ◽  
Treatment Conditions ◽  
Water Vapour Absorption ◽  
The Impact

Oriented strand board (OSB) is a commonly used structural wood-based panel for walls and roof siding, but recently the industry has become interested in OSB as a substrate for indoor and outdoor furniture. Particleboard is mainly used in furniture productions and has become popular as a construction material due to its numerous usage possibilities and inexpensive cost. Moisture is one of the most important factors affecting wood-based panel performance and the post-treatment conditions affected their affinity to water. When OSB and particleboard are used as substrates for coatings, their surface characteristics play an important role in determining the quality of the final product. Furthermore, roughness can significantly affect the interfacial phenomena such as adsorption, wetting, and adhesion which may have an impact on the coating performance. In this research particleboard and OSB panels were sanded, re-pressed and IR heated and the influence of surface treatments on hardness, roughness, wetting, water, and water vapour absorption was studied. Results showed that sanding improved the wetting of particleboard and OSB with water. Moreover, studied surface treatments increased water absorption and water penetration depth of OSB panels, and re-pressing had a positive effect on reducing the water vapour absorption of particleboard and OSB panels.

Fabrication of monodisperse polypyrrole/SBA-15 composite for the selective removal of Cr(Ⅵ) from aqueous solutions

2021 ◽  
Author(s):  
Liang Wang ◽  
Peng Gao ◽  
Mengxin Liu ◽  
Ziqing Huang ◽  
Shixia Lan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Adsorption Process ◽  
In Situ Polymerization ◽  
Selective Removal ◽  
Factors Affecting

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...

Factors affecting safety performance on construction sites

1999 ◽  
Vol 17 (5) ◽  
pp. 309-315 ◽  
Author(s):  
Edwin Sawacha ◽  
Shamil Naoum ◽  
Daniel Fong
Keyword(s):  
Safety Performance ◽  
Construction Sites ◽  
Factors Affecting

Analysis of TBM Tunnel Behavior in Jointed Rock Mass

2011 ◽  
Vol 90-93 ◽  
pp. 2033-2036 ◽  
Author(s):  
Jin Shan Sun ◽  
Hong Jun Guo ◽  
Wen Bo Lu ◽  
Qing Hui Jiang
Keyword(s):  
Rock Mass ◽  
Numerical Models ◽  
Jointed Rock ◽  
In Situ Stress ◽  
Jointed Rock Mass ◽  
Joint Orientation ◽  
Joint Spacing ◽  
Factors Affecting ◽  
Dip Angle

The factors affecting the TBM tunnel behavior in jointed rock mass is investigated. In the numerical models the concrete segment lining of TBM tunnel is concerned, which is simulated as a tube neglecting the segment joint. And the TBM tunnel construction process is simulate considering the excavation and installing of the segment linings. Some cases are analyzed with different joint orientation, joint spacing, joint strength and tunnel depth. The results show that the shape and areas of loosing zones of the tunnel are influenced by the parameters of joint sets and in-situ stress significantly, such as dip angle, spacing, strength, and the in-situ stress statement. And the stress and deformation of the tunnel lining are influenced by the parameters of joint sets and in-situ stress, too.

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