Emerald | Journal of Engineering, Design and Technology

COMPARING LEVELS OF USE OF PROJECT PLANS AND PERFORMANCE OF TRADITIONAL CONTRACT AND DESIGN-BUILD CONSTRUCTION PROJECTS IN NIGERIA

Godwin Iroroakpo IDORO — 2012-03-23 00:00:00.0

Abstract

Purpose - The prominent role of traditional contract and design-build methods in the procurement of projects and the importance of planning in the success of the projects prompt this study. The study evaluates the levels of use of project documents and their influence on the outcome of projects procured by the two methods. The purpose is to assist stakeholders in comparing the documents prepared and the performance of projects procured by traditional contract and design-build methods.Design/methodology/approach - The study adopted a questionnaire survey approach to achieve its purpose. A field survey of 84 projects made up of 42 traditional contract projects and 42 design-build projects selected by purposive sampling was conducted. Three categories of variables namely: procurement method, project planning and project outcome were used. Data were collected with the aid of structured questionnaires and analysed to derive and compare the levels of use of selected project plans, levels of project inception, design, tendering, construction and overall planning in projects procured by traditional contract and design-build methods using percentage, mean and t-test. Findings - The results reveal that the levels of project stage and overall planning in projects procured by the two methods investigated are the same. However, the levels of use of specific plans and project outcome in the two categories of projects are significantly different. The study considers the difference in the levels of use of project plans to be responsible for the lower delivery time and cost of projects procured by traditional contract method and higher quality standards in projects procured by design-build method.Research limitations/implications - The focus of planning in the study is the number of plans prepared. The quality of the plans in terms of the information contained and its accuracy are not covered in the study. However, the levels of use of the selected plans have revealed the plans that are not giving adequate priority when projects are procured by each of the two methods and their implications on project outcome.Practical implications - The study reveals that the existing levels of use of the selected plans have not achieved maximum performance of projects procured by the two methods. Increased planning of the delivery time of projects procured by design-build method and increased planning of quality standards of projects procured by traditional contract method are required to improve the outcome of construction project delivery in Nigeria. The study suggests that stakeholders should ensure that life-cycle chart and programme of work are duly prepared and used when projects are procured by design-build while structural drawings, bill of quantities, project specifications, quality management and buildability reports should be duly prepared and used when projects are procured by traditional contract.Originality/value - The study has revealed the level of efforts put into the planning of projects procured by traditional contract and design-build methods and their influence on the performance of the projects. The results will make project stakeholders to be aware of how to improve their efforts thereby improving the outcome of the projects.

Factors Influencing Power-Trowelling Productivity of Concrete Surface Floors

Abdulaziz M. Jarkas — 2012-03-23 00:00:00.0

Abstract

Purpose - The objective of the paper is to investigate the effects and relative influence of: a) surface floor area; b) number of trowelling machines used in the operation; c) machine floating ring diameter size; and d) operative employment mode, on power-trowelling productivity of concrete surface floors.Design/methodology/approach - To achieve this objective, a sufficiently large volume of productivity data was collected and analyzed using the categorical-regression method. As a result, the effects and relative influence of the factors investigated on trowelling productivity were determined and quantified.Findings - The findings show significant influence of the factors explored on the trowelling productivity of concrete surface floors, which substantiate the importance of the "economy of scale" concept and confirm the negative effect of "overcrowding". On the other hand, contrary to many previous productivity research findings, and anecdotal perceptions of industry practitioners, the results obtained provide little evidence to the positive impact of the subcontracting employment mode on the trowelling operation. Research limitations/implications - Further research into the influence of other factors which could not be determined by this study, i.e., quantifying the difference in trowelling productivity between the "walk-behind" and "ride-on" machine types, and the average change in the operation efficiency as a result of utilizing the 0.60 m "walk-behind" floating ring diameter size, in comparison with the 0.80, 1.00 and 1.20 m explored ring-size, is recommended. On the other hand, the results obtained suggest that for a specific surface floor area, there may be an optimum number of trowelling machines, which leads to optimum trowelling productivity. It is therefore recommended to determine this number in order to rationalize the use of such devices and optimize the efficiency of the operation.Practical implications - The findings of this research can provide estimators, planners and construction managers guidance for reasonable estimates, effective planning and efficient operative utilization. The results obtained may be further used to "benchmark" the efficiency of the operation, and "formalize" the specific productivity knowledge acquired. Originality/value - The outcomes of this study fill a gap in productivity knowledge of primary factors influencing an important surface floor finish technique, which is frequently encountered on concrete construction sites, especially parking structures, storages and industrial facilities.

WOMEN-OWNED CONSTRUCTION ENTERPRISES: A SOUTH AFRICAN ASSESSMENT

Theo C. Haupt, Ferdinand Fester — 2012-03-23 00:00:00.0

Abstract

Purpose - This paper reports on the findings of a needs assessment study of South African Women-Owned Enterprises in construction. The study was done in preparation for the rolling out of an empowerment initiative country-wide in South Africa, building on the lessons learnt and recommendations from the current and previous studies.Design/methodology/approach - An extensive review of relevant literature was used to develop a survey instrument and guide the stakeholder workshops to establish the needs of women-owned contractors in South Africa. Findings - The study found that fair procurement processes, women friendly construction sites, a construction bank and relevant career-aligned training with mentoring were enablers to transform existing enterprises to multi-skilled independent entities able to participate in the mainstream construction sector and register in the higher grades of the CIDB Register of Contractors. Research limitations/implications - Findings are based on views from respondents in South Africa registered in grades 1 through 5 on the CIDB Register of Contractors with legitimate e-mail addresses.Practical implications - The professionally facilitated workshops and broad-based stakeholder involvement in the project enhanced the validity of the study and the success of a development agenda if adopted for implementation.Originality/value - The value of the paper lies in the roadmap for development for similar initiatives.

Major Challenges in Managing Multiple Project Environments (MPE) in Australia's Construction Industry

Noor Ismah Hashim, Nicholas Chileshe — 2012-03-23 00:00:00.0

Abstract

Purpose - This paper aims at exploring the major challenges to managing multiple project environments in Australia. Design/methodology/approach - The views from Australian project management practitioners drawn from various industrial sectors were collected via an emailed questionnaire survey. The respondents were asked to rate a total of 22 challenges that affect the management of multiple project environments as identified from the literature review. The results of the questionnaire were analysed using ranking analysis.Findings - The findings show that "commitment and responsibility", "leading projects", "planning", and "conflict and communication" are perceived as the four challenges of most importance. Furthermore, the 22 challenges could be classified into eleven sub groupings as follows: 1 – project management processes, 2 – competencies of project managers, 3 –project assignments, 4 – human resource allocation, 5 – resource availability, 6 – organisational culture, 7 – problem solving, 8 – competition among projects, 9 – information sharing, 10 – management of a single project, 11 – project location. Research limitations/implications - The study forms the basis for further research; replication of this study to other parts of the industries and world about how identification of major challenges in managing multiple projects could be used as a basis for developing appropriate strategies aimed at improving the competencies of project managers.Practical implications - Based on the findings, the project management practitioners could develop a better understanding of the challenges needed to be overcome in order to perform effectively. Furthermore, the identification of these challenges could form the basis for the development of guidelines and provision of useful information for development of strategies aimed at improving the effectiveness and efficiency of project managers operating within the multiple projects environments in AustraliaOriginality/value - Major challenges to improving the effectiveness and efficiency of project managers in managing multiple project environments in Australia are indentified and analysed in this study.

CORROSION ANALYSIS OF GTA WELDED METAL MATRIX COMPOSITES

Palaniswamy Venugopal, Natarajan Murugan — 2012-03-23 00:00:00.0

Abstract

Purpose - The SiC reinforced Al composite is perhaps the most successful class of MMCs produced to date. They have found widespread application for aerospace, energy, and military purposes, as well as in other industries – for example, they have been used in electronic packaging, aerospace structures, aircraft and internal combustion engine components, and a variety of recreational products. In all these applications, welding plays a vital role. Little attention has been paid to SiC reinforced aluminum matrix composites joined by GTA welding. Design/methodology/approach - This paper involves production and welding of metal matrix composites. The welded composites have been treated at elevated and cryogenic temperatures for experimental studies. Pitting corrosion analysis of welded plates was carried out as per Box Benkehn Design. Findings - From the results, it should be noted that maximum pitting resistance was observed with MMCs containing 10% SiC treated at cryogenic temperature. Corrosion resistance of welded composites treated at elevated temperature was found to be higher than that of as-welded and at cryogenic temperature treated composites. The pitting potential increases with increase in % SiC to certain level and decreases with further increase in % SiC. Corrosion potential of composites treated at elevated temperature is high compared to other composites. Maximum pitting resistance is observed when the welding current was kept at 175 amps for 10% addition of SiC in LM25 matrix treated at cryogenic temperature.Originality/value - The paper outlines the manufacturing method for producing MMCs, GTA welding of MMCs and pitting corrosion analysis of welded MMCs. The results obtained may be helpful for the automobile and aerospace industries.

ANALYSIS OF METALLURGICAL AND MECHANICAL PROPERTIES OF LASER WELDED SUPER AUSTENITIC STAINLESS STEEL

SATHIYA PAULRAJ, M.Y ABDUL JALEEL, B Shanmugarajan — 2012-03-23 00:00:00.0

Abstract

Purpose - Laser welding under high power, high degree of automation and high production rate is extremely advantageous in automotive application. Super austenitic stainless steel is the preferable material for high corrosion resistance requirements. These steels are relatively cheaper than austenitic stainless steel and it is expensive than nickel base super alloys for such applications. The main purpose of this paper is to present the investigations of the microstructure and mechanical properties of super austenitic stainless steel butt joints made by 3.5 kW cooled slab CO2 laser welding using different shielding gases like argon, nitrogen and helium.Design/methodology/approach - The tensile and impact tests were performed and the fractured surfaces were analyzed by scanning electron microscope. The hardness across the joint zone was measured. The X-ray diffraction technique was used to analyze the phase composition. The microstructure of the laser welds were analyzed through optical microscopy.Findings - The tensile sample fractures indicate that the specimen fails in a ductile manner under the action of tensile loading. The impact fracture surfaces of the different shielding gas laser welded joints show mixed mode fractures, that is, ductile and cleavage fractures. The hardness values of the Helium shielded laser joints in the weld metal regions are much higher than the others.Research limitations/implications - There is no limitation, except for the availability of the high beam power laser welding machine. Practical implications - The implication is limited to the laser welding shop hazard during the experiment. Originality/value - The research work is original.

Buckling Analysis of Thin Rectangular Plates with Cutouts subjected to Partial Edge Compression using FEM

Sandeep Singh, Kamlesh Vasudeo Kulkarni, Ramesh Pandey, Harpreet Singh — 2012-03-23 00:00:00.0

Abstract

Purpose - This paper presents elastic buckling behaviour of simply supported and clamped thin rectangular isotropic plates having central circular cutouts subjected to uniaxial partial edge compression. Analysis is carried out for four different kinds of partial edge compression and it is extended to study the effect of aspect ratio of plate on buckling load. Design/methodology/approach - A finite element method technique is used in current work to solve buckling problem of plate using eight node quadrilateral element and plate kinematics based on first order shear deformation theory. Results obtained from finite element analysis are first validated for isotropic square plates without cutouts subjected to uniaxial partial edge compression with earlier published literature. Findings - From current work, it is concluded that buckling strength square plates is highly influenced by partial edge compression as compared to plate subjected to uniform edge compression, but with increase in aspect ratio influence of partial edge compression on plate buckling load decreases. Originality/value - This paper usefully shows that, how partial edge compression of plates effects the buckling strength of plate having circular cutouts. Generally, simply supported plates subjected uniaxial partial edge compression of Type-I and Type – III are found stronger than plates subjected to partial edge compression Type-II and Type – IV respectively.