Incorporating Reinforcement into Digital Concrete Construction (2018-07)¶

Digital construction (DC) or 3d-concrete-printing is causing a paradigm shift in construction processes towards complete automation, enabling faster, productive and cost-efficient construction of complex structures. DC is also facilitating and inspiring creativity in structural design. However, the stumbling block on the way to wide-spread application of DC is the implementation of reinforcement, for which no complete solutions are available yet. This article gives a brief overview of various approaches for integrating reinforcement in digitally produced concrete structures. In addition, experimental investigations, following two approaches viz. a) use of short fibers pre-mixed in printable concrete and b) 3d-printing of steel reinforcement will be delineated. Experimental investigations on 3d-printed (gasmetal arc welding based) steel reinforcement showed that its tensile strength, strain capacity as well as bond to concrete are comparable to those of conventional steel rebar. The 3d-printed strain-hardening cement-based composite (PSHCC – printable SHCC) exhibited remarkable performance in terms of tensile strength and strain capacity too, thanks to addition of high-strength polyethylene (PE) fibers. The mechanical properties of PSHCC were found to be comparable to those of casted SHCC.