An integrated design method for functional cementitious composites (FCC)

Abstract

The disease of the operating tunnel lining has seriously threatened traffic safety and needs to be cured urgently. Engineered Cementitious Composite (ECC), due to its excellent deformation ability and high damage tolerance, has the potential to retrofit the linings, but the quite high cost of raw material, mainly involving PVA fiber, has limited the broader application of ECC in the civil infrastructure. This paper proposed a practical design method of integrating four parts: engineering requirements, economical cost, matrix design and environmental assessment. A novel type of cementitious composites with low water absorption, moderate flexibility and light-weigh, named functional cementitious composite (FCC), was exploited to handle the common diseases of tunnel lining economically and environmentally. The results indicated that the cost-effective fiber is available to prepare the FCC, which shows great performance of cost-saving and functional properties. Besides, the functional characteristics, including low water sorptivity, light density and moderate flexibility, were optimized by response surface methodology (RSM) and subsequently the optimized results were proven by the test results. Finally, the environmental assessment emphasized an excellent material greenness of FCC with reduction of 26.9% embodied energy consumption and 26.2% carbon equivalent emission compared to the ECC (M45).