Embodied Energy Assessment of Onsite Construction Processes of Concreting Work: Models and Validation

The built environment life cycle consists of manufacturing of materials, onsite construction, operation, periodical maintenance, repair, and the end-of-service life phases. Among these phases, the onsite construction-related impacts are often ignored or underestimated due to challenges in gathering reliable field data from construction sites or poor documentation of site data. Given the fact that many developing countries are expected to witness major construction and infrastructure development initiatives in the coming decades, the assessment of sustainability metrics such as the embodied energy and embodied carbon of onsite construction processes assumes significance. Further, the onsite construction phase-related impacts are expected to be significant at the aggregate (national) level considering all development projects in a given time period. When the energy efficiency of the operational phase reaches a threshold limit as in the case of low-energy or low-carbon buildings, the next focus of improvement is the construction phase consisting of materials and onsite construction processes. This chapter presents a framework for assessing the energy use of onsite construction processes along with the identification of several technological and operational parameters. A set of regression models are presented to assess the electricity and fuel use for concreting construction processes using field data gathered from four major high-rise building construction projects in India. The application and validation of the proposed models are demonstrated using data gathered from two additional case studies in the Indian context. The methodology and the models presented in this chapter are useful for construction planners to assess the sustainability metrics along with the project performance metrics, thereby facilitating the integration of sustainability metrics in project planning.