CIC.R.3DP-Crete: Chloride-induced corrosion resistance of reinforced 3D-printed concrete

The construction industry is facing problems due to its low productivity and the increasing shortage of skilled labor. It is thus essential to introduce automation and digital technologies in construction processes.

The 3D-printed concrete (3DPC) technology is one of the digital construction technologies, seeing remarkable progress over the recent years. However, the durability performance of 3DPC has received less attention.

The incorporation of reinforcement in 3DPC is essential for structural applications for load-carrying capacity, ductility, and robustness.

The chloride-induced corrosion of reinforcement is one of the main durability problems, causing numerous casualties and substantial economic losses.

However, the durability performance of 3DPC with respect to chloride-induced reinforcement corrosion has not been fully understood.

This project aims to fully understand chloride transport properties, and corrosion mechanisms in 3DPC, and to develop corrosion protection techniques for 3DPC made with different printing materials (i.e., normal strength concrete and ultra-high performance concrete) and incorporating different types of reinforcements (i.e., steel bars and/or steel fibers).

The chloride transport properties will be studied by exposing specimens to chloride environments through a wetting-drying process and determining chloride contents, including free, total, and bound chlorides, chloride diffusion coefficient, and chloride binding capacity.

Corrosion specimens exposed to various chloride environments will be investigated by corrosion potential and corrosion current density measurements.

Finally, the currently available corrosion protection methods developed for cast concrete will be investigated for 3DPC.

The findings will be used to develop design recommendations to enhance the corrosion free life of reinforced 3DPC structures. The outcome of this project will boost the safety, durability, and service life of reinforced 3DPC structures.