Life Cycle Assessment of Off-Site Construction Using Ultra-High-Performance Concrete

Abstract

This study aims to evaluate the environmental impacts of off-site construction using ultra-high-performance concrete (UHPC) and different curing methods. Life cycle assessment (LCA) is implemented to evaluate the environmental impacts of the proposed UHPC and the traditional concrete (TC) under different curing conditions from cradle to gate. Unlike the previous studies that considered the function unit of concrete as 1 m3, this study investigates the concrete elements with the same load capacity. Comparison is made between off-site water bath heating curing (HC) ultra-high-performance concrete (UHPC), on-site UHPC, off-site HC traditional concrete (TC), on-site TC, and off-site CO2 curing TC. The LCA results show that UHPC is generally better than TC in terms of environmental impacts. Using off-site CO2 curing further improves its environmental benefits. The off-site HC UHPC shows higher productivity and higher environmental impacts compared to the on-site construction method. However, when the design load capacity of the concrete increases, the difference between off-site construction using 50 °C HC UHPC and on-site curing (20 °C HC UHPC) decreases.