Performance assessment of LC3 concrete structures considering life-cycle cost and environmental impacts

Developing green materials for infrastructure construction is of vital importance for sustainable development. Limestone calcined clay cement (LC3) is an appropriate alternative for the reduction of CO2 emissions and resource consumption in the cement industry. Recycled concrete aggregate (RCA), seawater and sea sand are potentially advantageous from a sustainability perspective, especially in coastal regions. Fiber-reinforced polymer (FRP) bars with excellent corrosion resistance are ideal alternative materials for steel bars in a corrosive environment. In this paper, a new type of green concrete structure incorporating LC3, seawater, sea sand, RCA, and FRP bars was investigated, and the performance was assessed to verify the considerable sustainable advantages while considering life cycle cost and environmental impacts. The results showed that the proposed LC3 concrete exhibited lower environmental impacts: compared with traditional concrete, and the CO2 and energy consumption of LC3 concrete were reduced by 32%-41.7% and 23.3%-28%, respectively. Although the initial cost was higher for LC3 and CFRP bars, this disadvantage could be offset by their longer service life and lower maintenance costs during their life cycle. Compared with traditional RC structures, the total cost, CO2 and energy consumption in the life cycle were reduced by 39%, 30.5%-65.4%, and 18.5%-58.9% for the LC3 concrete structure, respectively. In contrast to the life cycle cost, the LC3 replacement ratio had a negative effect on the environmental indices for the LC3 concrete and structure. Considering the promising advantages in economy and environmental impact, the proposed LC3 concrete and structure provides an effective approach for the sustainable development of the construction industry.