Additive manufacturing of self-compacting concrete through controlled heating

Abstract

Construction using concrete through additive manufacturing is gaining attention. This approach involves a layer-wise deposition of concrete. A layer of printed concrete needs to be ``strong" enough to sustain the weight of layers to be printed above. These layers may not bond well with each other, however. Self-compacting concrete (SCC) may lead to a better bonding, but it may not have sufficient strength. This paper presents a method to print SCC through controlled heating. Properties of printed concrete in fresh and hardened states are studied. Heating leads to a sharp rise in the strength of freshly-printed concrete layers, but a long duration of heating may lead to a reduction in strength of printed concrete after hardening particularly if water-to-cement ratio is small or if loads are applied parallel to the printed layers.