Analysis and Measurement of Buildability Factors Influencing Rebar Installation Labor Productivity of In Situ Reinforced Concrete Walls

Abstract

Buildability is one of the most important factors influencing labor productivity. However, an extensive search of the literature revealed a dearth of research into its effects on labor productivity of in situ reinforced concrete construction, especially on the activity levels. Rebar installation is an integral, labor-intensive trade of this type of construction material. Its walls form major parts of reinforced concrete frames, which are typically associated with a higher unit rate cost compared with other structural elements, especially spread foundations and grade and one-way elevated slabs. Therefore, objective of this research is to investigate the effects and relative influence of the rebar diameter, quantity of reinforcement installed, wall thickness, plan geometry, and wall curvature intensity, on rebar installation labor productivity of walls. To achieve this objective, a sufficiently large volume of installation labor productivity data was collected and analyzed using the multiple categorical-regression method. The results obtained show a significant influence of factors investigated on the labor efficiency of the installation operation, which can be used to provide designers feedback on how well their designs consider the requirements of the buildability concept, and the tangible consequences of their decisions on labor productivity. In addition, a set of recommendations are presented, which on implementation, can improve the buildability level of this activity, hence translating into higher labor efficiency and lower labor cost. Moreover, the depicted patterns of factors explored may provide guidance to construction managers for effective activity planning and efficient labor utilization.