Reduction of the Cement Content in Selective Cement-Activation (2023-12)¶

This work systematically investigates possibilities for the reduction of the cement content in Particle bed 3D Printing by Selective Cement Activation. To do so, the amount of cement is decreased (i) by increasing the aggregate content or (ii) by substitution with quartz flour of similar particle size to the cement. Both variants were then produced with constant water content and constant w/c ratio of 0.5, i.e. decreasing water content with decreasing cement content. To characterize the effect of the cement reduction, the compressive strength, as well as the dimensional accuracy are analyzed. It is shown that at constant w/c-ratio the compressive strength decreases with decreasing cement content compared to the reference mix, while the dimensional accuracy is increasing. For a constant water content during printing, the compressive strength of cement-reduced specimens is similar or only slightly lower compared to the reference. The dimensional accuracy, however, is decreasing.