Effect of printed parameters on the mechanical performance of printed concrete

Abstract

Three-dimensional concrete printing is a new method of construction that has been gaining the interest of many researchers around the world due to its various advantages over the conventional method of casting concrete into formwork. However, this innovative construction method faces many obstacles since there are many interconnected criteria to which the cementitious material to be used for three-dimensional concrete printing should conform including extrudability, flowability, buildability, and inter-layer adhesiveness. Hence, the aim of this research is to study the effect of two printing parameters which are the workability and the interlayer adhesiveness on the mechanical strength of printed elements. Three mixes were used for printing beams with a workability that was varied between the three mixes by varying the percentage of super-plasticizer. Plus, for each mix beams with three different time intervals were printed (1-minute, 30-minute, and 60-minute time intervals) along with control non-printed beams. Results showed that the mix with the highest workability had the highest compressive strength for a time interval of one minute and that the compressive strength of the beams decreased as the time intervals between layers increased. Nevertheless, the decrease in the strength of beams as the time interval between layers increased was not the same for the three mixes, it depends on the workability of the mix. Keywords