Analysis of factors affecting re-bar steel fabrication works and methodologies to optimize the process : a case study for the major construction projects in Sri Lanka

Abstract

Reinforcement (rebar) steelwork plays a major role in the construction industry, especially in high-rise buildings. It is the most valued work item in a high-rise building, accounting for around 12%-15% of the total construction cost. Re-bar work is also one of the most challenging construction activities, which needs skilled labour, competent officers, effective use of cutting and bending machines and effective use of handing machinery. If the fabrication process can be optimized, a considerable construction cost of a project can be saved. With the continuous price increase in steel, it is essential to use effective systems to reduce the cost in order to be competitive in the construction industry. New technologies have been implemented in developed countries to optimize this process, but conventional methods are still used in developing countries like Sri Lanka. Therefore, there is a very good opportunity here to study and analyze the effectiveness of this process and to identify the areas that need to be improved. This paper describes the identification of the factors affecting the production cost and analyses the effects of machines used, transport and handling costs, labour costs and staff costs. This also describes the analysis of the wastage factors in different types of projects using the data collected from completed projects where conventional fabrication methods were used. The factors that have a significant impact on the fabrication cost are identified in the analysis. This study adopted a quantitative approach to collecting data from completed construction projects, using Descriptive, Correlation, and Regression Analysis techniques to analyze the collected data. The theoretical cost of Rebar fabrication in a Centralized Automated Bar Bending Yard was compared with the values obtained from the descriptive analysis to check its financial feasibility. The results of these analyses revealed that the re-bar steel fabrication process in the local construction industry had gained average efficiency in re-bar fabrication works, and the cost of production is marginally acceptable. Further, the cost of cutting and bending machinery and the labour cost had a direct inverse relationship with the production volumes of machinery. The comparison between the average industrial cost of fabrication and the theoretical fabrication cost in the Centralized Automated Bar Bending yard revealed that it is not financially feasible during the economic downturn. However, there is an opportunity for it once the economy of the country becomes normal.