Comparative evaluation of different material options for moment-resisting framing systems in buildings

Load-bearing structural frames are among the highest contributors to the economic and environmental impacts of buildings. Hence, appraising various material configurations is important to understand their effects on environmental and cost performance. This paper provides a comparative evaluation of a mid-rise residential buildings’ moment-resisting framing system designed using five alternative material options. Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) are conducted to compare and benchmark the performance of each moment-resisting building frame configuration. Monte Carlo Simulation (MCS) is also performed to appraise inherent uncertainties to ensure that the results are reliably interpreted. It was discovered that, on average, options with steel-reinforced concrete (RC) had the highest environmental impacts across several life cycle impact assessment (LCIA) indicators except for ionising radiation potential and human toxicity potential (HTP). Glass Fibre-Reinforced Polymer and Ordinary Portland Concrete (GFRP-reinforced OPC-based concrete) were found to have the least environmental impact across almost all the LCIA indicators considered. It is worth noting that the environmental indicators with relatively high variations are the Land-Use Change, Water-Use Depletion and HTP. Based on the LCC analysis, the engineered timber was found to be the most expensive option among the materials considered. On average, it is 0.7% more expensive than the benchmark steel-reinforced concrete case. However, the range of costs can vary between −1.3% and +2% relative to the base case. On the contrary, the GFRP-reinforced OPC-based concrete option is found to be, on average, 0.2% lower than the steel RC option. Finally, the geopolymer-based systems are the most favourable when considering both the LCC and LCA.