I-Corps: Sustainable Infrastructure Rehabilitation

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

The alarming condition of civil infrastructures in the US has been well documented. It has also been documented that about 50% of current repairs in the field fail, requiring costly re-repairs. Beyond economics, repeated repairs pose a high cost to the environment and to transportation mobility. Repair failure can be traced to the brittleness of repair mortars and their tendency to delaminate from the substrate. In this project, the team proposes a ductile fiber reinforced cement based composite that suppresses brittle fracture and delamination, and that can undergo self-healing, when damaged. This material, once applied, can permanently protects the original infrastructure and extend its service life. By introducing an engineered cementitious composite (ECC) material into the civil infrastructure industry, the tam expects broad impacts on a number of fronts. These include lowering lifecycle costs of infrastructure maintenance, enhancing user mobility on transportation infrastructure, and reducing environmental costs and impacts caused by the construction and repeated repairs of civil infrastructure. The proposed team has developed ECCs with different functionalities, including lightweight, low stiffness, and self-healing ECC. Lightweight ECC has a density about 40% that of normal concrete. This translates directly to a reduced pavement slab weight by the same percentage, transport cost from precast yard to construction site, and hoisting machine capacity requirement during installation. Recently, a low E-stiffness ECC was developed using recycled tire-rubber in place of rigid aggregates in ECC. This material stiffness reduction translates into a slab stiffness reduction by the same percentage. Self-healing translates into a unique zero-maintenance feature for next-generation pavement slabs.