Factors affecting productivity and functionality of precast concrete building construction

The purpose of this study is to bring out the factors affecting labour productivity, which can have a strong influence on both time and cost of construction of precast concrete buildings in the developing world countries such as India. This paper also provides a brief discussion on some parameters affecting the functionality of precast concrete buildings. For identifying the ‘wastes’ in the processes and quantifying the shortcomings in the productivity, work sampling was conducted in five precast concrete construction (PCC) projects in India. Freewheeling, on-site interviews were conducted at the projects to find out the factors affecting productivity. The frequency and severity of the various parameters affecting the functionality of precast concrete buildings were obtained through a questionnaire survey. The work sampling analysis found that about 46% were NVA (Non-value adding) and NVAR (Non-value adding but required) activities, which adversely affected the productivity and that the process ‘wastes’ identified at erection sites were more than those in the production yards. The questionnaire survey on functionality revealed that ‘non-conformance with tolerance limits for precast concrete elements’ has ‘high’ frequency of occurrence and ‘very high’ severity and a field study found that about 40% of the precast panels failed to comply with tolerance limits. The reasons for ‘wastes’ in different trades viz. concreting, shuttering, reinforcement and erection in Indian PCC projects were analyzed in this paper which could help in understanding the reasons behind the prevailing low productivity. More importantly, this study also explores the parameters affecting the functionality of precast concrete buildings. While the functionality issues identified may or may not be typical of the entire precasting industry, the wastage issues identified have been widely reported in literature as quite prevalent in the construction industry.