Finding sustainable alternatives to conventional concrete is crucial for mitigating the remarkable contribution of the construction sector to global resource consumption and carbon dioxide emissions. Based on limestone calcined clay cement (LC3), recycled coarse aggregate (RCA), seawater, and sea sand, a type of low-carbon concrete was developed recently. To further verify the environmentally friendly advantage of the new concrete (i.e., LC3 concrete), a comprehensive life cycle assessment (LCA) and cost analysis were conducted in this study, considering sustainability and uncertainty. Focusing on the "cradle-to-gate" scope, an integrated LCA model was proposed, and the life cycle sustainable cost (LCSC) was evaluated for LC3 concrete through the monetization of the environmental impacts (i.e., global warming potential, abiotic depletion potential-fossil fuels, acidification potential, eutrophication potential, and photochemical ozone creation potential). In addition, to reflect the variability and uncertainty associated with activities in the whole life cycle, a probabilistic assessment of LCA and cost is conducted combined with the Monte Carlo simulation (MCS). The deterministic results show that the environmental cost of LC3 concrete accounts for 21%-24 % of the corresponding LCSC, and the LCSC of LC3 concrete was reduced by 14%-29 % compared to conventional concrete, indicating a significant sustainable advantage. Probabilistic analysis results indicate that the environmental impacts, economic benefits and sustainability of LC3 concrete are superior to those of conventional concrete with a probability of 80%-100 %. Overall, LC3 concrete demonstrates significant potential to reduce environmental impacts and economic burdens, providing a promising path for sustainable development in construction materials.